/* Language-independent node constructors for parse phase of GNU compiler. Copyright (C) 1987, 1988, 1992, 1993, 1994 Free Software Foundation, Inc. This file is part of GNU CC. GNU CC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU CC; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ /* This file contains the low level primitives for operating on tree nodes, including allocation, list operations, interning of identifiers, construction of data type nodes and statement nodes, and construction of type conversion nodes. It also contains tables index by tree code that describe how to take apart nodes of that code. It is intended to be language-independent, but occasionally calls language-dependent routines defined (for C) in typecheck.c. The low-level allocation routines oballoc and permalloc are used also for allocating many other kinds of objects by all passes of the compiler. */ #include #include "config.h" #include "flags.h" #include "tree.h" #include "function.h" #include "obstack.h" #ifdef __STDC__ #include #else #include #endif #include #define obstack_chunk_alloc xmalloc #define obstack_chunk_free free /* Tree nodes of permanent duration are allocated in this obstack. They are the identifier nodes, and everything outside of the bodies and parameters of function definitions. */ struct obstack permanent_obstack; /* The initial RTL, and all ..._TYPE nodes, in a function are allocated in this obstack. Usually they are freed at the end of the function, but if the function is inline they are saved. For top-level functions, this is maybepermanent_obstack. Separate obstacks are made for nested functions. */ struct obstack *function_maybepermanent_obstack; /* This is the function_maybepermanent_obstack for top-level functions. */ struct obstack maybepermanent_obstack; /* The contents of the current function definition are allocated in this obstack, and all are freed at the end of the function. For top-level functions, this is temporary_obstack. Separate obstacks are made for nested functions. */ struct obstack *function_obstack; /* This is used for reading initializers of global variables. */ struct obstack temporary_obstack; /* The tree nodes of an expression are allocated in this obstack, and all are freed at the end of the expression. */ struct obstack momentary_obstack; /* The tree nodes of a declarator are allocated in this obstack, and all are freed when the declarator has been parsed. */ static struct obstack temp_decl_obstack; /* This points at either permanent_obstack or the current function_maybepermanent_obstack. */ struct obstack *saveable_obstack; /* This is same as saveable_obstack during parse and expansion phase; it points to the current function's obstack during optimization. This is the obstack to be used for creating rtl objects. */ struct obstack *rtl_obstack; /* This points at either permanent_obstack or the current function_obstack. */ struct obstack *current_obstack; /* This points at either permanent_obstack or the current function_obstack or momentary_obstack. */ struct obstack *expression_obstack; /* Stack of obstack selections for push_obstacks and pop_obstacks. */ struct obstack_stack { struct obstack_stack *next; struct obstack *current; struct obstack *saveable; struct obstack *expression; struct obstack *rtl; }; struct obstack_stack *obstack_stack; /* Obstack for allocating struct obstack_stack entries. */ static struct obstack obstack_stack_obstack; /* Addresses of first objects in some obstacks. This is for freeing their entire contents. */ char *maybepermanent_firstobj; char *temporary_firstobj; char *momentary_firstobj; char *temp_decl_firstobj; /* This is used to preserve objects (mainly array initializers) that need to live until the end of the current function, but no further. */ char *momentary_function_firstobj; /* Nonzero means all ..._TYPE nodes should be allocated permanently. */ int all_types_permanent; /* Stack of places to restore the momentary obstack back to. */ struct momentary_level { /* Pointer back to previous such level. */ struct momentary_level *prev; /* First object allocated within this level. */ char *base; /* Value of expression_obstack saved at entry to this level. */ struct obstack *obstack; }; struct momentary_level *momentary_stack; /* Table indexed by tree code giving a string containing a character classifying the tree code. Possibilities are t, d, s, c, r, <, 1, 2 and e. See tree.def for details. */ #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE, char *standard_tree_code_type[] = { #include "tree.def" }; #undef DEFTREECODE /* Table indexed by tree code giving number of expression operands beyond the fixed part of the node structure. Not used for types or decls. */ #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH, int standard_tree_code_length[] = { #include "tree.def" }; #undef DEFTREECODE /* Names of tree components. Used for printing out the tree and error messages. */ #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME, char *standard_tree_code_name[] = { #include "tree.def" }; #undef DEFTREECODE /* Table indexed by tree code giving a string containing a character classifying the tree code. Possibilities are t, d, s, c, r, e, <, 1 and 2. See tree.def for details. */ char **tree_code_type; /* Table indexed by tree code giving number of expression operands beyond the fixed part of the node structure. Not used for types or decls. */ int *tree_code_length; /* Table indexed by tree code giving name of tree code, as a string. */ char **tree_code_name; /* Statistics-gathering stuff. */ typedef enum { d_kind, t_kind, b_kind, s_kind, r_kind, e_kind, c_kind, id_kind, op_id_kind, perm_list_kind, temp_list_kind, vec_kind, x_kind, lang_decl, lang_type, all_kinds } tree_node_kind; int tree_node_counts[(int)all_kinds]; int tree_node_sizes[(int)all_kinds]; int id_string_size = 0; char *tree_node_kind_names[] = { "decls", "types", "blocks", "stmts", "refs", "exprs", "constants", "identifiers", "op_identifiers", "perm_tree_lists", "temp_tree_lists", "vecs", "random kinds", "lang_decl kinds", "lang_type kinds" }; /* Hash table for uniquizing IDENTIFIER_NODEs by name. */ #define MAX_HASH_TABLE 1009 static tree hash_table[MAX_HASH_TABLE]; /* id hash buckets */ /* 0 while creating built-in identifiers. */ static int do_identifier_warnings; /* Unique id for next decl created. */ static int next_decl_uid; /* Unique id for next type created. */ static int next_type_uid = 1; /* Here is how primitive or already-canonicalized types' hash codes are made. */ #define TYPE_HASH(TYPE) ((HOST_WIDE_INT) (TYPE) & 0777777) extern char *mode_name[]; void gcc_obstack_init (); static tree stabilize_reference_1 (); /* Init the principal obstacks. */ void init_obstacks () { gcc_obstack_init (&obstack_stack_obstack); gcc_obstack_init (&permanent_obstack); gcc_obstack_init (&temporary_obstack); temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0); gcc_obstack_init (&momentary_obstack); momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0); momentary_function_firstobj = momentary_firstobj; gcc_obstack_init (&maybepermanent_obstack); maybepermanent_firstobj = (char *) obstack_alloc (&maybepermanent_obstack, 0); gcc_obstack_init (&temp_decl_obstack); temp_decl_firstobj = (char *) obstack_alloc (&temp_decl_obstack, 0); function_obstack = &temporary_obstack; function_maybepermanent_obstack = &maybepermanent_obstack; current_obstack = &permanent_obstack; expression_obstack = &permanent_obstack; rtl_obstack = saveable_obstack = &permanent_obstack; /* Init the hash table of identifiers. */ bzero ((char *) hash_table, sizeof hash_table); } void gcc_obstack_init (obstack) struct obstack *obstack; { /* Let particular systems override the size of a chunk. */ #ifndef OBSTACK_CHUNK_SIZE #define OBSTACK_CHUNK_SIZE 0 #endif /* Let them override the alloc and free routines too. */ #ifndef OBSTACK_CHUNK_ALLOC #define OBSTACK_CHUNK_ALLOC xmalloc #endif #ifndef OBSTACK_CHUNK_FREE #define OBSTACK_CHUNK_FREE free #endif _obstack_begin (obstack, OBSTACK_CHUNK_SIZE, 0, (void *(*) ()) OBSTACK_CHUNK_ALLOC, (void (*) ()) OBSTACK_CHUNK_FREE); } /* Save all variables describing the current status into the structure *P. This is used before starting a nested function. */ void save_tree_status (p) struct function *p; { p->all_types_permanent = all_types_permanent; p->momentary_stack = momentary_stack; p->maybepermanent_firstobj = maybepermanent_firstobj; p->momentary_firstobj = momentary_firstobj; p->momentary_function_firstobj = momentary_function_firstobj; p->function_obstack = function_obstack; p->function_maybepermanent_obstack = function_maybepermanent_obstack; p->current_obstack = current_obstack; p->expression_obstack = expression_obstack; p->saveable_obstack = saveable_obstack; p->rtl_obstack = rtl_obstack; /* Objects that need to be saved in this function can be in the nonsaved obstack of the enclosing function since they can't possibly be needed once it has returned. */ function_maybepermanent_obstack = function_obstack; function_obstack = (struct obstack *) xmalloc (sizeof (struct obstack)); gcc_obstack_init (function_obstack); current_obstack = &permanent_obstack; expression_obstack = &permanent_obstack; rtl_obstack = saveable_obstack = &permanent_obstack; momentary_firstobj = (char *) obstack_finish (&momentary_obstack); momentary_function_firstobj = momentary_firstobj; maybepermanent_firstobj = (char *) obstack_finish (function_maybepermanent_obstack); } /* Restore all variables describing the current status from the structure *P. This is used after a nested function. */ void restore_tree_status (p) struct function *p; { all_types_permanent = p->all_types_permanent; momentary_stack = p->momentary_stack; obstack_free (&momentary_obstack, momentary_function_firstobj); /* Free saveable storage used by the function just compiled and not saved. CAUTION: This is in function_obstack of the containing function. So we must be sure that we never allocate from that obstack during the compilation of a nested function if we expect it to survive past the nested function's end. */ obstack_free (function_maybepermanent_obstack, maybepermanent_firstobj); obstack_free (function_obstack, 0); free (function_obstack); momentary_firstobj = p->momentary_firstobj; momentary_function_firstobj = p->momentary_function_firstobj; maybepermanent_firstobj = p->maybepermanent_firstobj; function_obstack = p->function_obstack; function_maybepermanent_obstack = p->function_maybepermanent_obstack; current_obstack = p->current_obstack; expression_obstack = p->expression_obstack; saveable_obstack = p->saveable_obstack; rtl_obstack = p->rtl_obstack; } /* Start allocating on the temporary (per function) obstack. This is done in start_function before parsing the function body, and before each initialization at top level, and to go back to temporary allocation after doing permanent_allocation. */ void temporary_allocation () { /* Note that function_obstack at top level points to temporary_obstack. But within a nested function context, it is a separate obstack. */ current_obstack = function_obstack; expression_obstack = function_obstack; rtl_obstack = saveable_obstack = function_maybepermanent_obstack; momentary_stack = 0; } /* Start allocating on the permanent obstack but don't free the temporary data. After calling this, call `permanent_allocation' to fully resume permanent allocation status. */ void end_temporary_allocation () { current_obstack = &permanent_obstack; expression_obstack = &permanent_obstack; rtl_obstack = saveable_obstack = &permanent_obstack; } /* Resume allocating on the temporary obstack, undoing effects of `end_temporary_allocation'. */ void resume_temporary_allocation () { current_obstack = function_obstack; expression_obstack = function_obstack; rtl_obstack = saveable_obstack = function_maybepermanent_obstack; } /* While doing temporary allocation, switch to allocating in such a way as to save all nodes if the function is inlined. Call resume_temporary_allocation to go back to ordinary temporary allocation. */ void saveable_allocation () { /* Note that function_obstack at top level points to temporary_obstack. But within a nested function context, it is a separate obstack. */ expression_obstack = current_obstack = saveable_obstack; } /* Switch to current obstack CURRENT and maybepermanent obstack SAVEABLE, recording the previously current obstacks on a stack. This does not free any storage in any obstack. */ void push_obstacks (current, saveable) struct obstack *current, *saveable; { struct obstack_stack *p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack, (sizeof (struct obstack_stack))); p->current = current_obstack; p->saveable = saveable_obstack; p->expression = expression_obstack; p->rtl = rtl_obstack; p->next = obstack_stack; obstack_stack = p; current_obstack = current; expression_obstack = current; rtl_obstack = saveable_obstack = saveable; } /* Save the current set of obstacks, but don't change them. */ void push_obstacks_nochange () { struct obstack_stack *p = (struct obstack_stack *) obstack_alloc (&obstack_stack_obstack, (sizeof (struct obstack_stack))); p->current = current_obstack; p->saveable = saveable_obstack; p->expression = expression_obstack; p->rtl = rtl_obstack; p->next = obstack_stack; obstack_stack = p; } /* Pop the obstack selection stack. */ void pop_obstacks () { struct obstack_stack *p = obstack_stack; obstack_stack = p->next; current_obstack = p->current; saveable_obstack = p->saveable; expression_obstack = p->expression; rtl_obstack = p->rtl; obstack_free (&obstack_stack_obstack, p); } /* Nonzero if temporary allocation is currently in effect. Zero if currently doing permanent allocation. */ int allocation_temporary_p () { return current_obstack != &permanent_obstack; } /* Go back to allocating on the permanent obstack and free everything in the temporary obstack. FUNCTION_END is true only if we have just finished compiling a function. In that case, we also free preserved initial values on the momentary obstack. */ void permanent_allocation (function_end) int function_end; { /* Free up previous temporary obstack data */ obstack_free (&temporary_obstack, temporary_firstobj); if (function_end) obstack_free (&momentary_obstack, momentary_function_firstobj); else obstack_free (&momentary_obstack, momentary_firstobj); obstack_free (&maybepermanent_obstack, maybepermanent_firstobj); obstack_free (&temp_decl_obstack, temp_decl_firstobj); current_obstack = &permanent_obstack; expression_obstack = &permanent_obstack; rtl_obstack = saveable_obstack = &permanent_obstack; } /* Save permanently everything on the maybepermanent_obstack. */ void preserve_data () { maybepermanent_firstobj = (char *) obstack_alloc (function_maybepermanent_obstack, 0); } void preserve_initializer () { struct momentary_level *tem; char *old_momentary; temporary_firstobj = (char *) obstack_alloc (&temporary_obstack, 0); maybepermanent_firstobj = (char *) obstack_alloc (function_maybepermanent_obstack, 0); old_momentary = momentary_firstobj; momentary_firstobj = (char *) obstack_alloc (&momentary_obstack, 0); if (momentary_firstobj != old_momentary) for (tem = momentary_stack; tem; tem = tem->prev) tem->base = momentary_firstobj; } /* Start allocating new rtl in current_obstack. Use resume_temporary_allocation to go back to allocating rtl in saveable_obstack. */ void rtl_in_current_obstack () { rtl_obstack = current_obstack; } /* Start allocating rtl from saveable_obstack. Intended to be used after a call to push_obstacks_nochange. */ void rtl_in_saveable_obstack () { rtl_obstack = saveable_obstack; } /* Allocate SIZE bytes in the current obstack and return a pointer to them. In practice the current obstack is always the temporary one. */ char * oballoc (size) int size; { return (char *) obstack_alloc (current_obstack, size); } /* Free the object PTR in the current obstack as well as everything allocated since PTR. In practice the current obstack is always the temporary one. */ void obfree (ptr) char *ptr; { obstack_free (current_obstack, ptr); } /* Allocate SIZE bytes in the permanent obstack and return a pointer to them. */ char * permalloc (size) int size; { return (char *) obstack_alloc (&permanent_obstack, size); } /* Allocate NELEM items of SIZE bytes in the permanent obstack and return a pointer to them. The storage is cleared before returning the value. */ char * perm_calloc (nelem, size) int nelem; long size; { char *rval = (char *) obstack_alloc (&permanent_obstack, nelem * size); bzero (rval, nelem * size); return rval; } /* Allocate SIZE bytes in the saveable obstack and return a pointer to them. */ char * savealloc (size) int size; { return (char *) obstack_alloc (saveable_obstack, size); } /* Print out which obstack an object is in. */ void print_obstack_name (object, file, prefix) char *object; FILE *file; char *prefix; { struct obstack *obstack = NULL; char *obstack_name = NULL; struct function *p; for (p = outer_function_chain; p; p = p->next) { if (_obstack_allocated_p (p->function_obstack, object)) { obstack = p->function_obstack; obstack_name = "containing function obstack"; } if (_obstack_allocated_p (p->function_maybepermanent_obstack, object)) { obstack = p->function_maybepermanent_obstack; obstack_name = "containing function maybepermanent obstack"; } } if (_obstack_allocated_p (&obstack_stack_obstack, object)) { obstack = &obstack_stack_obstack; obstack_name = "obstack_stack_obstack"; } else if (_obstack_allocated_p (function_obstack, object)) { obstack = function_obstack; obstack_name = "function obstack"; } else if (_obstack_allocated_p (&permanent_obstack, object)) { obstack = &permanent_obstack; obstack_name = "permanent_obstack"; } else if (_obstack_allocated_p (&momentary_obstack, object)) { obstack = &momentary_obstack; obstack_name = "momentary_obstack"; } else if (_obstack_allocated_p (function_maybepermanent_obstack, object)) { obstack = function_maybepermanent_obstack; obstack_name = "function maybepermanent obstack"; } else if (_obstack_allocated_p (&temp_decl_obstack, object)) { obstack = &temp_decl_obstack; obstack_name = "temp_decl_obstack"; } /* Check to see if the object is in the free area of the obstack. */ if (obstack != NULL) { if (object >= obstack->next_free && object < obstack->chunk_limit) fprintf (file, "%s in free portion of obstack %s", prefix, obstack_name); else fprintf (file, "%s allocated from %s", prefix, obstack_name); } else fprintf (file, "%s not allocated from any obstack", prefix); } void debug_obstack (object) char *object; { print_obstack_name (object, stderr, "object"); fprintf (stderr, ".\n"); } /* Return 1 if OBJ is in the permanent obstack. This is slow, and should be used only for debugging. Use TREE_PERMANENT for other purposes. */ int object_permanent_p (obj) tree obj; { return _obstack_allocated_p (&permanent_obstack, obj); } /* Start a level of momentary allocation. In C, each compound statement has its own level and that level is freed at the end of each statement. All expression nodes are allocated in the momentary allocation level. */ void push_momentary () { struct momentary_level *tem = (struct momentary_level *) obstack_alloc (&momentary_obstack, sizeof (struct momentary_level)); tem->prev = momentary_stack; tem->base = (char *) obstack_base (&momentary_obstack); tem->obstack = expression_obstack; momentary_stack = tem; expression_obstack = &momentary_obstack; } /* Free all the storage in the current momentary-allocation level. In C, this happens at the end of each statement. */ void clear_momentary () { obstack_free (&momentary_obstack, momentary_stack->base); } /* Discard a level of momentary allocation. In C, this happens at the end of each compound statement. Restore the status of expression node allocation that was in effect before this level was created. */ void pop_momentary () { struct momentary_level *tem = momentary_stack; momentary_stack = tem->prev; expression_obstack = tem->obstack; /* We can't free TEM from the momentary_obstack, because there might be objects above it which have been saved. We can free back to the stack of the level we are popping off though. */ obstack_free (&momentary_obstack, tem->base); } /* Pop back to the previous level of momentary allocation, but don't free any momentary data just yet. */ void pop_momentary_nofree () { struct momentary_level *tem = momentary_stack; momentary_stack = tem->prev; expression_obstack = tem->obstack; } /* Call when starting to parse a declaration: make expressions in the declaration last the length of the function. Returns an argument that should be passed to resume_momentary later. */ int suspend_momentary () { register int tem = expression_obstack == &momentary_obstack; expression_obstack = saveable_obstack; return tem; } /* Call when finished parsing a declaration: restore the treatment of node-allocation that was in effect before the suspension. YES should be the value previously returned by suspend_momentary. */ void resume_momentary (yes) int yes; { if (yes) expression_obstack = &momentary_obstack; } /* Init the tables indexed by tree code. Note that languages can add to these tables to define their own codes. */ void init_tree_codes () { tree_code_type = (char **) xmalloc (sizeof (standard_tree_code_type)); tree_code_length = (int *) xmalloc (sizeof (standard_tree_code_length)); tree_code_name = (char **) xmalloc (sizeof (standard_tree_code_name)); bcopy ((char *) standard_tree_code_type, (char *) tree_code_type, sizeof (standard_tree_code_type)); bcopy ((char *) standard_tree_code_length, (char *) tree_code_length, sizeof (standard_tree_code_length)); bcopy ((char *) standard_tree_code_name, (char *) tree_code_name, sizeof (standard_tree_code_name)); } /* Return a newly allocated node of code CODE. Initialize the node's unique id and its TREE_PERMANENT flag. For decl and type nodes, some other fields are initialized. The rest of the node is initialized to zero. Achoo! I got a code in the node. */ tree make_node (code) enum tree_code code; { register tree t; register int type = TREE_CODE_CLASS (code); register int length; register struct obstack *obstack = current_obstack; register int i; register tree_node_kind kind; switch (type) { case 'd': /* A decl node */ #ifdef GATHER_STATISTICS kind = d_kind; #endif length = sizeof (struct tree_decl); /* All decls in an inline function need to be saved. */ if (obstack != &permanent_obstack) obstack = saveable_obstack; /* PARM_DECLs go on the context of the parent. If this is a nested function, then we must allocate the PARM_DECL on the parent's obstack, so that they will live to the end of the parent's closing brace. This is neccesary in case we try to inline the function into its parent. PARM_DECLs of top-level functions do not have this problem. However, we allocate them where we put the FUNCTION_DECL for languauges such as Ada that need to consult some flags in the PARM_DECLs of the function when calling it. See comment in restore_tree_status for why we can't put this in function_obstack. */ if (code == PARM_DECL && obstack != &permanent_obstack) { tree context = 0; if (current_function_decl) context = decl_function_context (current_function_decl); if (context) obstack = find_function_data (context)->function_maybepermanent_obstack; } break; case 't': /* a type node */ #ifdef GATHER_STATISTICS kind = t_kind; #endif length = sizeof (struct tree_type); /* All data types are put where we can preserve them if nec. */ if (obstack != &permanent_obstack) obstack = all_types_permanent ? &permanent_obstack : saveable_obstack; break; case 'b': /* a lexical block */ #ifdef GATHER_STATISTICS kind = b_kind; #endif length = sizeof (struct tree_block); /* All BLOCK nodes are put where we can preserve them if nec. */ if (obstack != &permanent_obstack) obstack = saveable_obstack; break; case 's': /* an expression with side effects */ #ifdef GATHER_STATISTICS kind = s_kind; goto usual_kind; #endif case 'r': /* a reference */ #ifdef GATHER_STATISTICS kind = r_kind; goto usual_kind; #endif case 'e': /* an expression */ case '<': /* a comparison expression */ case '1': /* a unary arithmetic expression */ case '2': /* a binary arithmetic expression */ #ifdef GATHER_STATISTICS kind = e_kind; usual_kind: #endif obstack = expression_obstack; /* All BIND_EXPR nodes are put where we can preserve them if nec. */ if (code == BIND_EXPR && obstack != &permanent_obstack) obstack = saveable_obstack; length = sizeof (struct tree_exp) + (tree_code_length[(int) code] - 1) * sizeof (char *); break; case 'c': /* a constant */ #ifdef GATHER_STATISTICS kind = c_kind; #endif obstack = expression_obstack; /* We can't use tree_code_length for INTEGER_CST, since the number of words is machine-dependent due to varying length of HOST_WIDE_INT, which might be wider than a pointer (e.g., long long). Similarly for REAL_CST, since the number of words is machine-dependent due to varying size and alignment of `double'. */ if (code == INTEGER_CST) length = sizeof (struct tree_int_cst); else if (code == REAL_CST) length = sizeof (struct tree_real_cst); else length = sizeof (struct tree_common) + tree_code_length[(int) code] * sizeof (char *); break; case 'x': /* something random, like an identifier. */ #ifdef GATHER_STATISTICS if (code == IDENTIFIER_NODE) kind = id_kind; else if (code == OP_IDENTIFIER) kind = op_id_kind; else if (code == TREE_VEC) kind = vec_kind; else kind = x_kind; #endif length = sizeof (struct tree_common) + tree_code_length[(int) code] * sizeof (char *); /* Identifier nodes are always permanent since they are unique in a compiler run. */ if (code == IDENTIFIER_NODE) obstack = &permanent_obstack; break; default: abort (); } t = (tree) obstack_alloc (obstack, length); #ifdef GATHER_STATISTICS tree_node_counts[(int)kind]++; tree_node_sizes[(int)kind] += length; #endif /* Clear a word at a time. */ for (i = (length / sizeof (int)) - 1; i >= 0; i--) ((int *) t)[i] = 0; /* Clear any extra bytes. */ for (i = length / sizeof (int) * sizeof (int); i < length; i++) ((char *) t)[i] = 0; TREE_SET_CODE (t, code); if (obstack == &permanent_obstack) TREE_PERMANENT (t) = 1; switch (type) { case 's': TREE_SIDE_EFFECTS (t) = 1; TREE_TYPE (t) = void_type_node; break; case 'd': if (code != FUNCTION_DECL) DECL_ALIGN (t) = 1; DECL_IN_SYSTEM_HEADER (t) = in_system_header && (obstack == &permanent_obstack); DECL_SOURCE_LINE (t) = lineno; DECL_SOURCE_FILE (t) = (input_filename) ? input_filename : ""; DECL_UID (t) = next_decl_uid++; break; case 't': TYPE_UID (t) = next_type_uid++; TYPE_ALIGN (t) = 1; TYPE_MAIN_VARIANT (t) = t; TYPE_OBSTACK (t) = obstack; TYPE_ATTRIBUTES (t) = NULL_TREE; #ifdef SET_DEFAULT_TYPE_ATTRIBUTES SET_DEFAULT_TYPE_ATTRIBUTES (t); #endif break; case 'c': TREE_CONSTANT (t) = 1; break; } return t; } /* Return a new node with the same contents as NODE except that its TREE_CHAIN is zero and it has a fresh uid. */ tree copy_node (node) tree node; { register tree t; register enum tree_code code = TREE_CODE (node); register int length; register int i; switch (TREE_CODE_CLASS (code)) { case 'd': /* A decl node */ length = sizeof (struct tree_decl); break; case 't': /* a type node */ length = sizeof (struct tree_type); break; case 'b': /* a lexical block node */ length = sizeof (struct tree_block); break; case 'r': /* a reference */ case 'e': /* an expression */ case 's': /* an expression with side effects */ case '<': /* a comparison expression */ case '1': /* a unary arithmetic expression */ case '2': /* a binary arithmetic expression */ length = sizeof (struct tree_exp) + (tree_code_length[(int) code] - 1) * sizeof (char *); break; case 'c': /* a constant */ /* We can't use tree_code_length for INTEGER_CST, since the number of words is machine-dependent due to varying length of HOST_WIDE_INT, which might be wider than a pointer (e.g., long long). Similarly for REAL_CST, since the number of words is machine-dependent due to varying size and alignment of `double'. */ if (code == INTEGER_CST) { length = sizeof (struct tree_int_cst); break; } else if (code == REAL_CST) { length = sizeof (struct tree_real_cst); break; } case 'x': /* something random, like an identifier. */ length = sizeof (struct tree_common) + tree_code_length[(int) code] * sizeof (char *); if (code == TREE_VEC) length += (TREE_VEC_LENGTH (node) - 1) * sizeof (char *); } t = (tree) obstack_alloc (current_obstack, length); for (i = (length / sizeof (int)) - 1; i >= 0; i--) ((int *) t)[i] = ((int *) node)[i]; /* Clear any extra bytes. */ for (i = length / sizeof (int) * sizeof (int); i < length; i++) ((char *) t)[i] = ((char *) node)[i]; TREE_CHAIN (t) = 0; if (TREE_CODE_CLASS (code) == 'd') DECL_UID (t) = next_decl_uid++; else if (TREE_CODE_CLASS (code) == 't') { TYPE_UID (t) = next_type_uid++; TYPE_OBSTACK (t) = current_obstack; } TREE_PERMANENT (t) = (current_obstack == &permanent_obstack); return t; } /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field. For example, this can copy a list made of TREE_LIST nodes. */ tree copy_list (list) tree list; { tree head; register tree prev, next; if (list == 0) return 0; head = prev = copy_node (list); next = TREE_CHAIN (list); while (next) { TREE_CHAIN (prev) = copy_node (next); prev = TREE_CHAIN (prev); next = TREE_CHAIN (next); } return head; } #define HASHBITS 30 /* Return an IDENTIFIER_NODE whose name is TEXT (a null-terminated string). If an identifier with that name has previously been referred to, the same node is returned this time. */ tree get_identifier (text) register char *text; { register int hi; register int i; register tree idp; register int len, hash_len; /* Compute length of text in len. */ for (len = 0; text[len]; len++); /* Decide how much of that length to hash on */ hash_len = len; if (warn_id_clash && len > id_clash_len) hash_len = id_clash_len; /* Compute hash code */ hi = hash_len * 613 + (unsigned)text[0]; for (i = 1; i < hash_len; i += 2) hi = ((hi * 613) + (unsigned)(text[i])); hi &= (1 << HASHBITS) - 1; hi %= MAX_HASH_TABLE; /* Search table for identifier */ for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp)) if (IDENTIFIER_LENGTH (idp) == len && IDENTIFIER_POINTER (idp)[0] == text[0] && !bcmp (IDENTIFIER_POINTER (idp), text, len)) return idp; /* <-- return if found */ /* Not found; optionally warn about a similar identifier */ if (warn_id_clash && do_identifier_warnings && len >= id_clash_len) for (idp = hash_table[hi]; idp; idp = TREE_CHAIN (idp)) if (!strncmp (IDENTIFIER_POINTER (idp), text, id_clash_len)) { warning ("`%s' and `%s' identical in first %d characters", IDENTIFIER_POINTER (idp), text, id_clash_len); break; } if (tree_code_length[(int) IDENTIFIER_NODE] < 0) abort (); /* set_identifier_size hasn't been called. */ /* Not found, create one, add to chain */ idp = make_node (IDENTIFIER_NODE); IDENTIFIER_LENGTH (idp) = len; #ifdef GATHER_STATISTICS id_string_size += len; #endif IDENTIFIER_POINTER (idp) = obstack_copy0 (&permanent_obstack, text, len); TREE_CHAIN (idp) = hash_table[hi]; hash_table[hi] = idp; return idp; /* <-- return if created */ } /* Enable warnings on similar identifiers (if requested). Done after the built-in identifiers are created. */ void start_identifier_warnings () { do_identifier_warnings = 1; } /* Record the size of an identifier node for the language in use. SIZE is the total size in bytes. This is called by the language-specific files. This must be called before allocating any identifiers. */ void set_identifier_size (size) int size; { tree_code_length[(int) IDENTIFIER_NODE] = (size - sizeof (struct tree_common)) / sizeof (tree); } /* Return a newly constructed INTEGER_CST node whose constant value is specified by the two ints LOW and HI. The TREE_TYPE is set to `int'. This function should be used via the `build_int_2' macro. */ tree build_int_2_wide (low, hi) HOST_WIDE_INT low, hi; { register tree t = make_node (INTEGER_CST); TREE_INT_CST_LOW (t) = low; TREE_INT_CST_HIGH (t) = hi; TREE_TYPE (t) = integer_type_node; return t; } /* Return a new REAL_CST node whose type is TYPE and value is D. */ tree build_real (type, d) tree type; REAL_VALUE_TYPE d; { tree v; int overflow = 0; /* Check for valid float value for this type on this target machine; if not, can print error message and store a valid value in D. */ #ifdef CHECK_FLOAT_VALUE CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow); #endif v = make_node (REAL_CST); TREE_TYPE (v) = type; TREE_REAL_CST (v) = d; TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow; return v; } /* Return a new REAL_CST node whose type is TYPE and whose value is the integer value of the INTEGER_CST node I. */ #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC) REAL_VALUE_TYPE real_value_from_int_cst (i) tree i; { REAL_VALUE_TYPE d; REAL_VALUE_TYPE e; /* Some 386 compilers mishandle unsigned int to float conversions, so introduce a temporary variable E to avoid those bugs. */ #ifdef REAL_ARITHMETIC if (! TREE_UNSIGNED (TREE_TYPE (i))) REAL_VALUE_FROM_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i)); else REAL_VALUE_FROM_UNSIGNED_INT (d, TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i)); #else /* not REAL_ARITHMETIC */ if (TREE_INT_CST_HIGH (i) < 0 && ! TREE_UNSIGNED (TREE_TYPE (i))) { d = (double) (~ TREE_INT_CST_HIGH (i)); e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); d *= e; e = (double) (unsigned HOST_WIDE_INT) (~ TREE_INT_CST_LOW (i)); d += e; d = (- d - 1.0); } else { d = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_HIGH (i); e = ((double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) * (double) ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2))); d *= e; e = (double) (unsigned HOST_WIDE_INT) TREE_INT_CST_LOW (i); d += e; } #endif /* not REAL_ARITHMETIC */ return d; } /* This function can't be implemented if we can't do arithmetic on the float representation. */ tree build_real_from_int_cst (type, i) tree type; tree i; { tree v; int overflow = TREE_OVERFLOW (i); REAL_VALUE_TYPE d; jmp_buf float_error; v = make_node (REAL_CST); TREE_TYPE (v) = type; if (setjmp (float_error)) { d = dconst0; overflow = 1; goto got_it; } set_float_handler (float_error); d = REAL_VALUE_TRUNCATE (TYPE_MODE (type), real_value_from_int_cst (i)); /* Check for valid float value for this type on this target machine. */ got_it: set_float_handler (NULL_PTR); #ifdef CHECK_FLOAT_VALUE CHECK_FLOAT_VALUE (TYPE_MODE (type), d, overflow); #endif TREE_REAL_CST (v) = d; TREE_OVERFLOW (v) = TREE_CONSTANT_OVERFLOW (v) = overflow; return v; } #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */ /* Return a newly constructed STRING_CST node whose value is the LEN characters at STR. The TREE_TYPE is not initialized. */ tree build_string (len, str) int len; char *str; { /* Put the string in saveable_obstack since it will be placed in the RTL for an "asm" statement and will also be kept around a while if deferring constant output in varasm.c. */ register tree s = make_node (STRING_CST); TREE_STRING_LENGTH (s) = len; TREE_STRING_POINTER (s) = obstack_copy0 (saveable_obstack, str, len); return s; } /* Return a newly constructed COMPLEX_CST node whose value is specified by the real and imaginary parts REAL and IMAG. Both REAL and IMAG should be constant nodes. The TREE_TYPE is not initialized. */ tree build_complex (real, imag) tree real, imag; { register tree t = make_node (COMPLEX_CST); TREE_REALPART (t) = real; TREE_IMAGPART (t) = imag; TREE_TYPE (t) = build_complex_type (TREE_TYPE (real)); TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag); TREE_CONSTANT_OVERFLOW (t) = TREE_CONSTANT_OVERFLOW (real) | TREE_CONSTANT_OVERFLOW (imag); return t; } /* Build a newly constructed TREE_VEC node of length LEN. */ tree make_tree_vec (len) int len; { register tree t; register int length = (len-1) * sizeof (tree) + sizeof (struct tree_vec); register struct obstack *obstack = current_obstack; register int i; #ifdef GATHER_STATISTICS tree_node_counts[(int)vec_kind]++; tree_node_sizes[(int)vec_kind] += length; #endif t = (tree) obstack_alloc (obstack, length); for (i = (length / sizeof (int)) - 1; i >= 0; i--) ((int *) t)[i] = 0; TREE_SET_CODE (t, TREE_VEC); TREE_VEC_LENGTH (t) = len; if (obstack == &permanent_obstack) TREE_PERMANENT (t) = 1; return t; } /* Return 1 if EXPR is the integer constant zero. */ int integer_zerop (expr) tree expr; { STRIP_NOPS (expr); return (TREE_CODE (expr) == INTEGER_CST && TREE_INT_CST_LOW (expr) == 0 && TREE_INT_CST_HIGH (expr) == 0); } /* Return 1 if EXPR is the integer constant one. */ int integer_onep (expr) tree expr; { STRIP_NOPS (expr); return (TREE_CODE (expr) == INTEGER_CST && TREE_INT_CST_LOW (expr) == 1 && TREE_INT_CST_HIGH (expr) == 0); } /* Return 1 if EXPR is an integer containing all 1's in as much precision as it contains. */ int integer_all_onesp (expr) tree expr; { register int prec; register int uns; STRIP_NOPS (expr); if (TREE_CODE (expr) != INTEGER_CST) return 0; uns = TREE_UNSIGNED (TREE_TYPE (expr)); if (!uns) return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == -1; prec = TYPE_PRECISION (TREE_TYPE (expr)); if (prec >= HOST_BITS_PER_WIDE_INT) { int high_value, shift_amount; shift_amount = prec - HOST_BITS_PER_WIDE_INT; if (shift_amount > HOST_BITS_PER_WIDE_INT) /* Can not handle precisions greater than twice the host int size. */ abort (); else if (shift_amount == HOST_BITS_PER_WIDE_INT) /* Shifting by the host word size is undefined according to the ANSI standard, so we must handle this as a special case. */ high_value = -1; else high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1; return TREE_INT_CST_LOW (expr) == -1 && TREE_INT_CST_HIGH (expr) == high_value; } else return TREE_INT_CST_LOW (expr) == ((HOST_WIDE_INT) 1 << prec) - 1; } /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only one bit on). */ int integer_pow2p (expr) tree expr; { HOST_WIDE_INT high, low; STRIP_NOPS (expr); if (TREE_CODE (expr) != INTEGER_CST) return 0; high = TREE_INT_CST_HIGH (expr); low = TREE_INT_CST_LOW (expr); if (high == 0 && low == 0) return 0; return ((high == 0 && (low & (low - 1)) == 0) || (low == 0 && (high & (high - 1)) == 0)); } /* Return 1 if EXPR is the real constant zero. */ int real_zerop (expr) tree expr; { STRIP_NOPS (expr); return (TREE_CODE (expr) == REAL_CST && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0)); } /* Return 1 if EXPR is the real constant one. */ int real_onep (expr) tree expr; { STRIP_NOPS (expr); return (TREE_CODE (expr) == REAL_CST && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1)); } /* Return 1 if EXPR is the real constant two. */ int real_twop (expr) tree expr; { STRIP_NOPS (expr); return (TREE_CODE (expr) == REAL_CST && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2)); } /* Nonzero if EXP is a constant or a cast of a constant. */ int really_constant_p (exp) tree exp; { /* This is not quite the same as STRIP_NOPS. It does more. */ while (TREE_CODE (exp) == NOP_EXPR || TREE_CODE (exp) == CONVERT_EXPR || TREE_CODE (exp) == NON_LVALUE_EXPR) exp = TREE_OPERAND (exp, 0); return TREE_CONSTANT (exp); } /* Return first list element whose TREE_VALUE is ELEM. Return 0 if ELEM is not it LIST. */ tree value_member (elem, list) tree elem, list; { while (list) { if (elem == TREE_VALUE (list)) return list; list = TREE_CHAIN (list); } return NULL_TREE; } /* Return first list element whose TREE_PURPOSE is ELEM. Return 0 if ELEM is not it LIST. */ tree purpose_member (elem, list) tree elem, list; { while (list) { if (elem == TREE_PURPOSE (list)) return list; list = TREE_CHAIN (list); } return NULL_TREE; } /* Return first list element whose BINFO_TYPE is ELEM. Return 0 if ELEM is not it LIST. */ tree binfo_member (elem, list) tree elem, list; { while (list) { if (elem == BINFO_TYPE (list)) return list; list = TREE_CHAIN (list); } return NULL_TREE; } /* Return nonzero if ELEM is part of the chain CHAIN. */ int chain_member (elem, chain) tree elem, chain; { while (chain) { if (elem == chain) return 1; chain = TREE_CHAIN (chain); } return 0; } /* Return the length of a chain of nodes chained through TREE_CHAIN. We expect a null pointer to mark the end of the chain. This is the Lisp primitive `length'. */ int list_length (t) tree t; { register tree tail; register int len = 0; for (tail = t; tail; tail = TREE_CHAIN (tail)) len++; return len; } /* Concatenate two chains of nodes (chained through TREE_CHAIN) by modifying the last node in chain 1 to point to chain 2. This is the Lisp primitive `nconc'. */ tree chainon (op1, op2) tree op1, op2; { if (op1) { register tree t1; register tree t2; for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1)) ; TREE_CHAIN (t1) = op2; for (t2 = op2; t2; t2 = TREE_CHAIN (t2)) if (t2 == t1) abort (); /* Circularity created. */ return op1; } else return op2; } /* Return the last node in a chain of nodes (chained through TREE_CHAIN). */ tree tree_last (chain) register tree chain; { register tree next; if (chain) while (next = TREE_CHAIN (chain)) chain = next; return chain; } /* Reverse the order of elements in the chain T, and return the new head of the chain (old last element). */ tree nreverse (t) tree t; { register tree prev = 0, decl, next; for (decl = t; decl; decl = next) { next = TREE_CHAIN (decl); TREE_CHAIN (decl) = prev; prev = decl; } return prev; } /* Given a chain CHAIN of tree nodes, construct and return a list of those nodes. */ tree listify (chain) tree chain; { tree result = NULL_TREE; tree in_tail = chain; tree out_tail = NULL_TREE; while (in_tail) { tree next = tree_cons (NULL_TREE, in_tail, NULL_TREE); if (out_tail) TREE_CHAIN (out_tail) = next; else result = next; out_tail = next; in_tail = TREE_CHAIN (in_tail); } return result; } /* Return a newly created TREE_LIST node whose purpose and value fields are PARM and VALUE. */ tree build_tree_list (parm, value) tree parm, value; { register tree t = make_node (TREE_LIST); TREE_PURPOSE (t) = parm; TREE_VALUE (t) = value; return t; } /* Similar, but build on the temp_decl_obstack. */ tree build_decl_list (parm, value) tree parm, value; { register tree node; register struct obstack *ambient_obstack = current_obstack; current_obstack = &temp_decl_obstack; node = build_tree_list (parm, value); current_obstack = ambient_obstack; return node; } /* Return a newly created TREE_LIST node whose purpose and value fields are PARM and VALUE and whose TREE_CHAIN is CHAIN. */ tree tree_cons (purpose, value, chain) tree purpose, value, chain; { #if 0 register tree node = make_node (TREE_LIST); #else register int i; register tree node = (tree) obstack_alloc (current_obstack, sizeof (struct tree_list)); #ifdef GATHER_STATISTICS tree_node_counts[(int)x_kind]++; tree_node_sizes[(int)x_kind] += sizeof (struct tree_list); #endif for (i = (sizeof (struct tree_common) / sizeof (int)) - 1; i >= 0; i--) ((int *) node)[i] = 0; TREE_SET_CODE (node, TREE_LIST); if (current_obstack == &permanent_obstack) TREE_PERMANENT (node) = 1; #endif TREE_CHAIN (node) = chain; TREE_PURPOSE (node) = purpose; TREE_VALUE (node) = value; return node; } /* Similar, but build on the temp_decl_obstack. */ tree decl_tree_cons (purpose, value, chain) tree purpose, value, chain; { register tree node; register struct obstack *ambient_obstack = current_obstack; current_obstack = &temp_decl_obstack; node = tree_cons (purpose, value, chain); current_obstack = ambient_obstack; return node; } /* Same as `tree_cons' but make a permanent object. */ tree perm_tree_cons (purpose, value, chain) tree purpose, value, chain; { register tree node; register struct obstack *ambient_obstack = current_obstack; current_obstack = &permanent_obstack; node = tree_cons (purpose, value, chain); current_obstack = ambient_obstack; return node; } /* Same as `tree_cons', but make this node temporary, regardless. */ tree temp_tree_cons (purpose, value, chain) tree purpose, value, chain; { register tree node; register struct obstack *ambient_obstack = current_obstack; current_obstack = &temporary_obstack; node = tree_cons (purpose, value, chain); current_obstack = ambient_obstack; return node; } /* Same as `tree_cons', but save this node if the function's RTL is saved. */ tree saveable_tree_cons (purpose, value, chain) tree purpose, value, chain; { register tree node; register struct obstack *ambient_obstack = current_obstack; current_obstack = saveable_obstack; node = tree_cons (purpose, value, chain); current_obstack = ambient_obstack; return node; } /* Return the size nominally occupied by an object of type TYPE when it resides in memory. The value is measured in units of bytes, and its data type is that normally used for type sizes (which is the first type created by make_signed_type or make_unsigned_type). */ tree size_in_bytes (type) tree type; { tree t; if (type == error_mark_node) return integer_zero_node; type = TYPE_MAIN_VARIANT (type); if (TYPE_SIZE (type) == 0) { incomplete_type_error (NULL_TREE, type); return integer_zero_node; } t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), size_int (BITS_PER_UNIT)); if (TREE_CODE (t) == INTEGER_CST) force_fit_type (t, 0); return t; } /* Return the size of TYPE (in bytes) as an integer, or return -1 if the size can vary. */ int int_size_in_bytes (type) tree type; { unsigned int size; if (type == error_mark_node) return 0; type = TYPE_MAIN_VARIANT (type); if (TYPE_SIZE (type) == 0) return -1; if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) return -1; if (TREE_INT_CST_HIGH (TYPE_SIZE (type)) != 0) { tree t = size_binop (CEIL_DIV_EXPR, TYPE_SIZE (type), size_int (BITS_PER_UNIT)); return TREE_INT_CST_LOW (t); } size = TREE_INT_CST_LOW (TYPE_SIZE (type)); return (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT; } /* Return, as a tree node, the number of elements for TYPE (which is an ARRAY_TYPE) minus one. This counts only elements of the top array. */ tree array_type_nelts (type) tree type; { tree index_type = TYPE_DOMAIN (type); return (integer_zerop (TYPE_MIN_VALUE (index_type)) ? TYPE_MAX_VALUE (index_type) : fold (build (MINUS_EXPR, TREE_TYPE (TYPE_MAX_VALUE (index_type)), TYPE_MAX_VALUE (index_type), TYPE_MIN_VALUE (index_type)))); } /* Return nonzero if arg is static -- a reference to an object in static storage. This is not the same as the C meaning of `static'. */ int staticp (arg) tree arg; { switch (TREE_CODE (arg)) { case FUNCTION_DECL: /* Nested functions aren't static. Since taking their address involves a trampoline. */ if (decl_function_context (arg) != 0) return 0; /* ... fall through ... */ case VAR_DECL: return TREE_STATIC (arg) || DECL_EXTERNAL (arg); case CONSTRUCTOR: return TREE_STATIC (arg); case STRING_CST: return 1; case COMPONENT_REF: case BIT_FIELD_REF: return staticp (TREE_OPERAND (arg, 0)); case INDIRECT_REF: return TREE_CONSTANT (TREE_OPERAND (arg, 0)); case ARRAY_REF: if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST) return staticp (TREE_OPERAND (arg, 0)); } return 0; } /* Wrap a SAVE_EXPR around EXPR, if appropriate. Do this to any expression which may be used in more than one place, but must be evaluated only once. Normally, expand_expr would reevaluate the expression each time. Calling save_expr produces something that is evaluated and recorded the first time expand_expr is called on it. Subsequent calls to expand_expr just reuse the recorded value. The call to expand_expr that generates code that actually computes the value is the first call *at compile time*. Subsequent calls *at compile time* generate code to use the saved value. This produces correct result provided that *at run time* control always flows through the insns made by the first expand_expr before reaching the other places where the save_expr was evaluated. You, the caller of save_expr, must make sure this is so. Constants, and certain read-only nodes, are returned with no SAVE_EXPR because that is safe. Expressions containing placeholders are not touched; see tree.def for an explanation of what these are used for. */ tree save_expr (expr) tree expr; { register tree t = fold (expr); /* We don't care about whether this can be used as an lvalue in this context. */ while (TREE_CODE (t) == NON_LVALUE_EXPR) t = TREE_OPERAND (t, 0); /* If the tree evaluates to a constant, then we don't want to hide that fact (i.e. this allows further folding, and direct checks for constants). However, a read-only object that has side effects cannot be bypassed. Since it is no problem to reevaluate literals, we just return the literal node. */ if (TREE_CONSTANT (t) || (TREE_READONLY (t) && ! TREE_SIDE_EFFECTS (t)) || TREE_CODE (t) == SAVE_EXPR) return t; /* If T contains a PLACEHOLDER_EXPR, we must evaluate it each time, since it means that the size or offset of some field of an object depends on the value within another field. Note that it must not be the case that T contains both a PLACEHOLDER_EXPR and some variable since it would then need to be both evaluated once and evaluated more than once. Front-ends must assure this case cannot happen by surrounding any such subexpressions in their own SAVE_EXPR and forcing evaluation at the proper time. */ if (contains_placeholder_p (t)) return t; t = build (SAVE_EXPR, TREE_TYPE (expr), t, current_function_decl, NULL_TREE); /* This expression might be placed ahead of a jump to ensure that the value was computed on both sides of the jump. So make sure it isn't eliminated as dead. */ TREE_SIDE_EFFECTS (t) = 1; return t; } /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size or offset that depends on a field within a record. Note that we only allow such expressions within simple arithmetic or a COND_EXPR. */ int contains_placeholder_p (exp) tree exp; { register enum tree_code code = TREE_CODE (exp); tree inner; /* If we have a WITH_RECORD_EXPR, it "cancels" any PLACEHOLDER_EXPR in it since it is supplying a value for it. */ if (code == WITH_RECORD_EXPR) return 0; switch (TREE_CODE_CLASS (code)) { case 'r': for (inner = TREE_OPERAND (exp, 0); TREE_CODE_CLASS (TREE_CODE (inner)) == 'r'; inner = TREE_OPERAND (inner, 0)) ; return TREE_CODE (inner) == PLACEHOLDER_EXPR; case '1': case '2': case '<': case 'e': switch (tree_code_length[(int) code]) { case 1: return contains_placeholder_p (TREE_OPERAND (exp, 0)); case 2: return (code != RTL_EXPR && code != CONSTRUCTOR && ! (code == SAVE_EXPR && SAVE_EXPR_RTL (exp) != 0) && code != WITH_RECORD_EXPR && (contains_placeholder_p (TREE_OPERAND (exp, 0)) || contains_placeholder_p (TREE_OPERAND (exp, 1)))); case 3: return (code == COND_EXPR && (contains_placeholder_p (TREE_OPERAND (exp, 0)) || contains_placeholder_p (TREE_OPERAND (exp, 1)) || contains_placeholder_p (TREE_OPERAND (exp, 2)))); } } return 0; } /* Given a tree EXP, a FIELD_DECL F, and a replacement value R, return a tree with all occurrences of references to F in a PLACEHOLDER_EXPR replaced by R. Note that we assume here that EXP contains only arithmetic expressions. */ tree substitute_in_expr (exp, f, r) tree exp; tree f; tree r; { enum tree_code code = TREE_CODE (exp); tree inner; switch (TREE_CODE_CLASS (code)) { case 'c': case 'd': return exp; case 'x': if (code == PLACEHOLDER_EXPR) return exp; break; case '1': case '2': case '<': case 'e': switch (tree_code_length[(int) code]) { case 1: return fold (build1 (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r))); case 2: /* An RTL_EXPR cannot contain a PLACEHOLDER_EXPR; a CONSTRUCTOR could, but we don't support it. */ if (code == RTL_EXPR) return exp; else if (code == CONSTRUCTOR) abort (); return fold (build (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r), substitute_in_expr (TREE_OPERAND (exp, 1), f, r))); case 3: /* It cannot be that anything inside a SAVE_EXPR contains a PLACEHOLDER_EXPR. */ if (code == SAVE_EXPR) return exp; if (code != COND_EXPR) abort (); return fold (build (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r), substitute_in_expr (TREE_OPERAND (exp, 1), f, r), substitute_in_expr (TREE_OPERAND (exp, 2), f, r))); } break; case 'r': switch (code) { case COMPONENT_REF: /* If this expression is getting a value from a PLACEHOLDER_EXPR and it is the right field, replace it with R. */ for (inner = TREE_OPERAND (exp, 0); TREE_CODE_CLASS (TREE_CODE (inner)) == 'r'; inner = TREE_OPERAND (inner, 0)) ; if (TREE_CODE (inner) == PLACEHOLDER_EXPR && TREE_OPERAND (exp, 1) == f) return r; return fold (build (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r), TREE_OPERAND (exp, 1))); case BIT_FIELD_REF: return fold (build (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r), substitute_in_expr (TREE_OPERAND (exp, 1), f, r), substitute_in_expr (TREE_OPERAND (exp, 2), f, r))); case INDIRECT_REF: case BUFFER_REF: return fold (build1 (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r))); case OFFSET_REF: return fold (build (code, TREE_TYPE (exp), substitute_in_expr (TREE_OPERAND (exp, 0), f, r), substitute_in_expr (TREE_OPERAND (exp, 1), f, r))); } } /* If it wasn't one of the cases we handle, give up. */ abort (); } /* Given a type T, a FIELD_DECL F, and a replacement value R, return a new type with all size expressions that contain F updated by replacing F with R. */ tree substitute_in_type (t, f, r) tree t, f, r; { switch (TREE_CODE (t)) { case POINTER_TYPE: case VOID_TYPE: return t; case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: case CHAR_TYPE: if ((TREE_CODE (TYPE_MIN_VALUE (t)) != INTEGER_CST && contains_placeholder_p (TYPE_MIN_VALUE (t))) || (TREE_CODE (TYPE_MAX_VALUE (t)) != INTEGER_CST && contains_placeholder_p (TYPE_MAX_VALUE (t)))) return build_range_type (t, substitute_in_expr (TYPE_MIN_VALUE (t), f, r), substitute_in_expr (TYPE_MAX_VALUE (t), f, r)); return t; case REAL_TYPE: if ((TYPE_MIN_VALUE (t) != 0 && TREE_CODE (TYPE_MIN_VALUE (t)) != REAL_CST && contains_placeholder_p (TYPE_MIN_VALUE (t))) || (TYPE_MAX_VALUE (t) != 0 && TREE_CODE (TYPE_MAX_VALUE (t)) != REAL_CST && contains_placeholder_p (TYPE_MAX_VALUE (t)))) { t = build_type_copy (t); if (TYPE_MIN_VALUE (t)) TYPE_MIN_VALUE (t) = substitute_in_expr (TYPE_MIN_VALUE (t), f, r); if (TYPE_MAX_VALUE (t)) TYPE_MAX_VALUE (t) = substitute_in_expr (TYPE_MAX_VALUE (t), f, r); } return t; case COMPLEX_TYPE: return build_complex_type (substitute_in_type (TREE_TYPE (t), f, r)); case OFFSET_TYPE: case METHOD_TYPE: case REFERENCE_TYPE: case FILE_TYPE: case SET_TYPE: case FUNCTION_TYPE: case LANG_TYPE: /* Don't know how to do these yet. */ abort (); case ARRAY_TYPE: t = build_array_type (substitute_in_type (TREE_TYPE (t), f, r), substitute_in_type (TYPE_DOMAIN (t), f, r)); TYPE_SIZE (t) = 0; layout_type (t); return t; case RECORD_TYPE: case UNION_TYPE: case QUAL_UNION_TYPE: { tree new = copy_node (t); tree field; tree last_field = 0; /* Start out with no fields, make new fields, and chain them in. */ TYPE_FIELDS (new) = 0; TYPE_SIZE (new) = 0; for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) { tree new_field = copy_node (field); TREE_TYPE (new_field) = substitute_in_type (TREE_TYPE (new_field), f, r); /* If this is an anonymous field and the type of this field is a UNION_TYPE or RECORD_TYPE with no elements, ignore it. If the type just has one element, treat that as the field. But don't do this if we are processing a QUAL_UNION_TYPE. */ if (TREE_CODE (t) != QUAL_UNION_TYPE && DECL_NAME (new_field) == 0 && (TREE_CODE (TREE_TYPE (new_field)) == UNION_TYPE || TREE_CODE (TREE_TYPE (new_field)) == RECORD_TYPE)) { if (TYPE_FIELDS (TREE_TYPE (new_field)) == 0) continue; if (TREE_CHAIN (TYPE_FIELDS (TREE_TYPE (new_field))) == 0) new_field = TYPE_FIELDS (TREE_TYPE (new_field)); } DECL_CONTEXT (new_field) = new; DECL_SIZE (new_field) = 0; if (TREE_CODE (t) == QUAL_UNION_TYPE) { /* Do the substitution inside the qualifier and if we find that this field will not be present, omit it. */ DECL_QUALIFIER (new_field) = substitute_in_expr (DECL_QUALIFIER (field), f, r); if (integer_zerop (DECL_QUALIFIER (new_field))) continue; } if (last_field == 0) TYPE_FIELDS (new) = new_field; else TREE_CHAIN (last_field) = new_field; last_field = new_field; /* If this is a qualified type and this field will always be present, we are done. */ if (TREE_CODE (t) == QUAL_UNION_TYPE && integer_onep (DECL_QUALIFIER (new_field))) break; } /* If this used to be a qualified union type, but we now know what field will be present, make this a normal union. */ if (TREE_CODE (new) == QUAL_UNION_TYPE && (TYPE_FIELDS (new) == 0 || integer_onep (DECL_QUALIFIER (TYPE_FIELDS (new))))) TREE_SET_CODE (new, UNION_TYPE); layout_type (new); return new; } } } /* Stabilize a reference so that we can use it any number of times without causing its operands to be evaluated more than once. Returns the stabilized reference. This works by means of save_expr, so see the caveats in the comments about save_expr. Also allows conversion expressions whose operands are references. Any other kind of expression is returned unchanged. */ tree stabilize_reference (ref) tree ref; { register tree result; register enum tree_code code = TREE_CODE (ref); switch (code) { case VAR_DECL: case PARM_DECL: case RESULT_DECL: /* No action is needed in this case. */ return ref; case NOP_EXPR: case CONVERT_EXPR: case FLOAT_EXPR: case FIX_TRUNC_EXPR: case FIX_FLOOR_EXPR: case FIX_ROUND_EXPR: case FIX_CEIL_EXPR: result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0))); break; case INDIRECT_REF: result = build_nt (INDIRECT_REF, stabilize_reference_1 (TREE_OPERAND (ref, 0))); break; case COMPONENT_REF: result = build_nt (COMPONENT_REF, stabilize_reference (TREE_OPERAND (ref, 0)), TREE_OPERAND (ref, 1)); break; case BIT_FIELD_REF: result = build_nt (BIT_FIELD_REF, stabilize_reference (TREE_OPERAND (ref, 0)), stabilize_reference_1 (TREE_OPERAND (ref, 1)), stabilize_reference_1 (TREE_OPERAND (ref, 2))); break; case ARRAY_REF: result = build_nt (ARRAY_REF, stabilize_reference (TREE_OPERAND (ref, 0)), stabilize_reference_1 (TREE_OPERAND (ref, 1))); break; /* If arg isn't a kind of lvalue we recognize, make no change. Caller should recognize the error for an invalid lvalue. */ default: return ref; case ERROR_MARK: return error_mark_node; } TREE_TYPE (result) = TREE_TYPE (ref); TREE_READONLY (result) = TREE_READONLY (ref); TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref); TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref); TREE_RAISES (result) = TREE_RAISES (ref); return result; } /* Subroutine of stabilize_reference; this is called for subtrees of references. Any expression with side-effects must be put in a SAVE_EXPR to ensure that it is only evaluated once. We don't put SAVE_EXPR nodes around everything, because assigning very simple expressions to temporaries causes us to miss good opportunities for optimizations. Among other things, the opportunity to fold in the addition of a constant into an addressing mode often gets lost, e.g. "y[i+1] += x;". In general, we take the approach that we should not make an assignment unless we are forced into it - i.e., that any non-side effect operator should be allowed, and that cse should take care of coalescing multiple utterances of the same expression should that prove fruitful. */ static tree stabilize_reference_1 (e) tree e; { register tree result; register enum tree_code code = TREE_CODE (e); /* We cannot ignore const expressions because it might be a reference to a const array but whose index contains side-effects. But we can ignore things that are actual constant or that already have been handled by this function. */ if (TREE_CONSTANT (e) || code == SAVE_EXPR) return e; switch (TREE_CODE_CLASS (code)) { case 'x': case 't': case 'd': case 'b': case '<': case 's': case 'e': case 'r': /* If the expression has side-effects, then encase it in a SAVE_EXPR so that it will only be evaluated once. */ /* The reference (r) and comparison (<) classes could be handled as below, but it is generally faster to only evaluate them once. */ if (TREE_SIDE_EFFECTS (e)) return save_expr (e); return e; case 'c': /* Constants need no processing. In fact, we should never reach here. */ return e; case '2': /* Division is slow and tends to be compiled with jumps, especially the division by powers of 2 that is often found inside of an array reference. So do it just once. */ if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR) return save_expr (e); /* Recursively stabilize each operand. */ result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)), stabilize_reference_1 (TREE_OPERAND (e, 1))); break; case '1': /* Recursively stabilize each operand. */ result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0))); break; default: abort (); } TREE_TYPE (result) = TREE_TYPE (e); TREE_READONLY (result) = TREE_READONLY (e); TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e); TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e); TREE_RAISES (result) = TREE_RAISES (e); return result; } /* Low-level constructors for expressions. */ /* Build an expression of code CODE, data type TYPE, and operands as specified by the arguments ARG1 and following arguments. Expressions and reference nodes can be created this way. Constants, decls, types and misc nodes cannot be. */ tree build VPROTO((enum tree_code code, tree tt, ...)) { #ifndef __STDC__ enum tree_code code; tree tt; #endif va_list p; register tree t; register int length; register int i; VA_START (p, tt); #ifndef __STDC__ code = va_arg (p, enum tree_code); tt = va_arg (p, tree); #endif t = make_node (code); length = tree_code_length[(int) code]; TREE_TYPE (t) = tt; if (length == 2) { /* This is equivalent to the loop below, but faster. */ register tree arg0 = va_arg (p, tree); register tree arg1 = va_arg (p, tree); TREE_OPERAND (t, 0) = arg0; TREE_OPERAND (t, 1) = arg1; if ((arg0 && TREE_SIDE_EFFECTS (arg0)) || (arg1 && TREE_SIDE_EFFECTS (arg1))) TREE_SIDE_EFFECTS (t) = 1; TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0)) || (arg1 && TREE_RAISES (arg1)); } else if (length == 1) { register tree arg0 = va_arg (p, tree); /* Call build1 for this! */ if (TREE_CODE_CLASS (code) != 's') abort (); TREE_OPERAND (t, 0) = arg0; if (arg0 && TREE_SIDE_EFFECTS (arg0)) TREE_SIDE_EFFECTS (t) = 1; TREE_RAISES (t) = (arg0 && TREE_RAISES (arg0)); } else { for (i = 0; i < length; i++) { register tree operand = va_arg (p, tree); TREE_OPERAND (t, i) = operand; if (operand) { if (TREE_SIDE_EFFECTS (operand)) TREE_SIDE_EFFECTS (t) = 1; if (TREE_RAISES (operand)) TREE_RAISES (t) = 1; } } } va_end (p); return t; } /* Same as above, but only builds for unary operators. Saves lions share of calls to `build'; cuts down use of varargs, which is expensive for RISC machines. */ tree build1 (code, type, node) enum tree_code code; tree type; tree node; { register struct obstack *obstack = current_obstack; register int i, length; register tree_node_kind kind; register tree t; #ifdef GATHER_STATISTICS if (TREE_CODE_CLASS (code) == 'r') kind = r_kind; else kind = e_kind; #endif obstack = expression_obstack; length = sizeof (struct tree_exp); t = (tree) obstack_alloc (obstack, length); #ifdef GATHER_STATISTICS tree_node_counts[(int)kind]++; tree_node_sizes[(int)kind] += length; #endif for (i = (length / sizeof (int)) - 1; i >= 0; i--) ((int *) t)[i] = 0; TREE_TYPE (t) = type; TREE_SET_CODE (t, code); if (obstack == &permanent_obstack) TREE_PERMANENT (t) = 1; TREE_OPERAND (t, 0) = node; if (node) { if (TREE_SIDE_EFFECTS (node)) TREE_SIDE_EFFECTS (t) = 1; if (TREE_RAISES (node)) TREE_RAISES (t) = 1; } return t; } /* Similar except don't specify the TREE_TYPE and leave the TREE_SIDE_EFFECTS as 0. It is permissible for arguments to be null, or even garbage if their values do not matter. */ tree build_nt VPROTO((enum tree_code code, ...)) { #ifndef __STDC__ enum tree_code code; #endif va_list p; register tree t; register int length; register int i; VA_START (p, code); #ifndef __STDC__ code = va_arg (p, enum tree_code); #endif t = make_node (code); length = tree_code_length[(int) code]; for (i = 0; i < length; i++) TREE_OPERAND (t, i) = va_arg (p, tree); va_end (p); return t; } /* Similar to `build_nt', except we build on the temp_decl_obstack, regardless. */ tree build_parse_node VPROTO((enum tree_code code, ...)) { #ifndef __STDC__ enum tree_code code; #endif register struct obstack *ambient_obstack = expression_obstack; va_list p; register tree t; register int length; register int i; VA_START (p, code); #ifndef __STDC__ code = va_arg (p, enum tree_code); #endif expression_obstack = &temp_decl_obstack; t = make_node (code); length = tree_code_length[(int) code]; for (i = 0; i < length; i++) TREE_OPERAND (t, i) = va_arg (p, tree); va_end (p); expression_obstack = ambient_obstack; return t; } #if 0 /* Commented out because this wants to be done very differently. See cp-lex.c. */ tree build_op_identifier (op1, op2) tree op1, op2; { register tree t = make_node (OP_IDENTIFIER); TREE_PURPOSE (t) = op1; TREE_VALUE (t) = op2; return t; } #endif /* Create a DECL_... node of code CODE, name NAME and data type TYPE. We do NOT enter this node in any sort of symbol table. layout_decl is used to set up the decl's storage layout. Other slots are initialized to 0 or null pointers. */ tree build_decl (code, name, type) enum tree_code code; tree name, type; { register tree t; t = make_node (code); /* if (type == error_mark_node) type = integer_type_node; */ /* That is not done, deliberately, so that having error_mark_node as the type can suppress useless errors in the use of this variable. */ DECL_NAME (t) = name; DECL_ASSEMBLER_NAME (t) = name; TREE_TYPE (t) = type; if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL) layout_decl (t, 0); else if (code == FUNCTION_DECL) DECL_MODE (t) = FUNCTION_MODE; return t; } /* BLOCK nodes are used to represent the structure of binding contours and declarations, once those contours have been exited and their contents compiled. This information is used for outputting debugging info. */ tree build_block (vars, tags, subblocks, supercontext, chain) tree vars, tags, subblocks, supercontext, chain; { register tree block = make_node (BLOCK); BLOCK_VARS (block) = vars; BLOCK_TYPE_TAGS (block) = tags; BLOCK_SUBBLOCKS (block) = subblocks; BLOCK_SUPERCONTEXT (block) = supercontext; BLOCK_CHAIN (block) = chain; return block; } /* Return a type like TTYPE except that its TYPE_ATTRIBUTE is ATTRIBUTE. Such modified types already made are recorded so that duplicates are not made. */ tree build_type_attribute_variant (ttype, attribute) tree ttype, attribute; { if ( ! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute)) { register int hashcode; register struct obstack *ambient_obstack = current_obstack; tree ntype; if (ambient_obstack != &permanent_obstack) current_obstack = TYPE_OBSTACK (ttype); ntype = copy_node (ttype); current_obstack = ambient_obstack; TYPE_POINTER_TO (ntype) = 0; TYPE_REFERENCE_TO (ntype) = 0; TYPE_ATTRIBUTES (ntype) = attribute; /* Create a new main variant of TYPE. */ TYPE_MAIN_VARIANT (ntype) = ntype; TYPE_NEXT_VARIANT (ntype) = 0; TYPE_READONLY (ntype) = TYPE_VOLATILE (ntype) = 0; hashcode = TYPE_HASH (TREE_CODE (ntype)) + TYPE_HASH (TREE_TYPE (ntype)) + type_hash_list (attribute); switch (TREE_CODE (ntype)) { case FUNCTION_TYPE: hashcode += TYPE_HASH (TYPE_ARG_TYPES (ntype)); break; case ARRAY_TYPE: hashcode += TYPE_HASH (TYPE_DOMAIN (ntype)); break; case INTEGER_TYPE: hashcode += TYPE_HASH (TYPE_MAX_VALUE (ntype)); break; case REAL_TYPE: hashcode += TYPE_HASH (TYPE_PRECISION (ntype)); break; } ntype = type_hash_canon (hashcode, ntype); ttype = build_type_variant (ntype, TYPE_READONLY (ttype), TYPE_VOLATILE (ttype)); } return ttype; } /* Return a type like TYPE except that its TYPE_READONLY is CONSTP and its TYPE_VOLATILE is VOLATILEP. Such variant types already made are recorded so that duplicates are not made. A variant types should never be used as the type of an expression. Always copy the variant information into the TREE_READONLY and TREE_THIS_VOLATILE of the expression, and then give the expression as its type the "main variant", the variant whose TYPE_READONLY and TYPE_VOLATILE are zero. Use TYPE_MAIN_VARIANT to find the main variant. */ tree build_type_variant (type, constp, volatilep) tree type; int constp, volatilep; { register tree t; /* Treat any nonzero argument as 1. */ constp = !!constp; volatilep = !!volatilep; /* If not generating auxiliary info, search the chain of variants to see if there is already one there just like the one we need to have. If so, use that existing one. We don't do this in the case where we are generating aux info because in that case we want each typedef names to get it's own distinct type node, even if the type of this new typedef is the same as some other (existing) type. */ if (!flag_gen_aux_info) for (t = TYPE_MAIN_VARIANT(type); t; t = TYPE_NEXT_VARIANT (t)) if (constp == TYPE_READONLY (t) && volatilep == TYPE_VOLATILE (t)) return t; /* We need a new one. */ t = build_type_copy (type); TYPE_READONLY (t) = constp; TYPE_VOLATILE (t) = volatilep; return t; } /* Give TYPE a new main variant: NEW_MAIN. This is the right thing to do only when something else about TYPE is modified in place. */ tree change_main_variant (type, new_main) tree type, new_main; { tree t; tree omain = TYPE_MAIN_VARIANT (type); /* Remove TYPE from the TYPE_NEXT_VARIANT chain of its main variant. */ if (TYPE_NEXT_VARIANT (omain) == type) TYPE_NEXT_VARIANT (omain) = TYPE_NEXT_VARIANT (type); else for (t = TYPE_NEXT_VARIANT (omain); t && TYPE_NEXT_VARIANT (t); t = TYPE_NEXT_VARIANT (t)) if (TYPE_NEXT_VARIANT (t) == type) { TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (type); break; } TYPE_MAIN_VARIANT (type) = new_main; TYPE_NEXT_VARIANT (type) = TYPE_NEXT_VARIANT (new_main); TYPE_NEXT_VARIANT (new_main) = type; } /* Create a new variant of TYPE, equivalent but distinct. This is so the caller can modify it. */ tree build_type_copy (type) tree type; { register tree t, m = TYPE_MAIN_VARIANT (type); register struct obstack *ambient_obstack = current_obstack; current_obstack = TYPE_OBSTACK (type); t = copy_node (type); current_obstack = ambient_obstack; TYPE_POINTER_TO (t) = 0; TYPE_REFERENCE_TO (t) = 0; /* Add this type to the chain of variants of TYPE. */ TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m); TYPE_NEXT_VARIANT (m) = t; return t; } /* Hashing of types so that we don't make duplicates. The entry point is `type_hash_canon'. */ /* Each hash table slot is a bucket containing a chain of these structures. */ struct type_hash { struct type_hash *next; /* Next structure in the bucket. */ int hashcode; /* Hash code of this type. */ tree type; /* The type recorded here. */ }; /* Now here is the hash table. When recording a type, it is added to the slot whose index is the hash code mod the table size. Note that the hash table is used for several kinds of types (function types, array types and array index range types, for now). While all these live in the same table, they are completely independent, and the hash code is computed differently for each of these. */ #define TYPE_HASH_SIZE 59 struct type_hash *type_hash_table[TYPE_HASH_SIZE]; /* Compute a hash code for a list of types (chain of TREE_LIST nodes with types in the TREE_VALUE slots), by adding the hash codes of the individual types. */ int type_hash_list (list) tree list; { register int hashcode; register tree tail; for (hashcode = 0, tail = list; tail; tail = TREE_CHAIN (tail)) hashcode += TYPE_HASH (TREE_VALUE (tail)); return hashcode; } /* Look in the type hash table for a type isomorphic to TYPE. If one is found, return it. Otherwise return 0. */ tree type_hash_lookup (hashcode, type) int hashcode; tree type; { register struct type_hash *h; for (h = type_hash_table[hashcode % TYPE_HASH_SIZE]; h; h = h->next) if (h->hashcode == hashcode && TREE_CODE (h->type) == TREE_CODE (type) && TREE_TYPE (h->type) == TREE_TYPE (type) && attribute_list_equal (TYPE_ATTRIBUTES (h->type), TYPE_ATTRIBUTES (type)) && (TYPE_MAX_VALUE (h->type) == TYPE_MAX_VALUE (type) || tree_int_cst_equal (TYPE_MAX_VALUE (h->type), TYPE_MAX_VALUE (type))) && (TYPE_MIN_VALUE (h->type) == TYPE_MIN_VALUE (type) || tree_int_cst_equal (TYPE_MIN_VALUE (h->type), TYPE_MIN_VALUE (type))) && (TYPE_DOMAIN (h->type) == TYPE_DOMAIN (type) || (TYPE_DOMAIN (h->type) && TREE_CODE (TYPE_DOMAIN (h->type)) == TREE_LIST && TYPE_DOMAIN (type) && TREE_CODE (TYPE_DOMAIN (type)) == TREE_LIST && type_list_equal (TYPE_DOMAIN (h->type), TYPE_DOMAIN (type))))) return h->type; return 0; } /* Add an entry to the type-hash-table for a type TYPE whose hash code is HASHCODE. */ void type_hash_add (hashcode, type) int hashcode; tree type; { register struct type_hash *h; h = (struct type_hash *) oballoc (sizeof (struct type_hash)); h->hashcode = hashcode; h->type = type; h->next = type_hash_table[hashcode % TYPE_HASH_SIZE]; type_hash_table[hashcode % TYPE_HASH_SIZE] = h; } /* Given TYPE, and HASHCODE its hash code, return the canonical object for an identical type if one already exists. Otherwise, return TYPE, and record it as the canonical object if it is a permanent object. To use this function, first create a type of the sort you want. Then compute its hash code from the fields of the type that make it different from other similar types. Then call this function and use the value. This function frees the type you pass in if it is a duplicate. */ /* Set to 1 to debug without canonicalization. Never set by program. */ int debug_no_type_hash = 0; tree type_hash_canon (hashcode, type) int hashcode; tree type; { tree t1; if (debug_no_type_hash) return type; t1 = type_hash_lookup (hashcode, type); if (t1 != 0) { obstack_free (TYPE_OBSTACK (type), type); #ifdef GATHER_STATISTICS tree_node_counts[(int)t_kind]--; tree_node_sizes[(int)t_kind] -= sizeof (struct tree_type); #endif return t1; } /* If this is a permanent type, record it for later reuse. */ if (TREE_PERMANENT (type)) type_hash_add (hashcode, type); return type; } /* Given two lists of attributes, return true if list l2 is equivalent to l1. */ int attribute_list_equal (l1, l2) tree l1, l2; { return attribute_list_contained (l1, l2) && attribute_list_contained (l2, l1); } /* Given two lists of attributes, return true if list l2 is completely contained within l1. */ int attribute_list_contained (l1, l2) tree l1, l2; { register tree t1, t2; /* First check the obvious, maybe the lists are identical. */ if (l1 == l2) return 1; /* Then check the obvious, maybe the lists are similar. */ for (t1 = l1, t2 = l2; t1 && t2 && TREE_VALUE (t1) == TREE_VALUE (t2); t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2)); /* Maybe the lists are equal. */ if (t1 == 0 && t2 == 0) return 1; for (; t2; t2 = TREE_CHAIN (t2)) if (!value_member (l1, t2)) return 0; return 1; } /* Given two lists of types (chains of TREE_LIST nodes with types in the TREE_VALUE slots) return 1 if the lists contain the same types in the same order. Also, the TREE_PURPOSEs must match. */ int type_list_equal (l1, l2) tree l1, l2; { register tree t1, t2; for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2)) { if (TREE_VALUE (t1) != TREE_VALUE (t2)) return 0; if (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)) { int cmp = simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2)); if (cmp < 0) abort (); if (cmp == 0) return 0; } } return t1 == t2; } /* Nonzero if integer constants T1 and T2 represent the same constant value. */ int tree_int_cst_equal (t1, t2) tree t1, t2; { if (t1 == t2) return 1; if (t1 == 0 || t2 == 0) return 0; if (TREE_CODE (t1) == INTEGER_CST && TREE_CODE (t2) == INTEGER_CST && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2) && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2)) return 1; return 0; } /* Nonzero if integer constants T1 and T2 represent values that satisfy <. The precise way of comparison depends on their data type. */ int tree_int_cst_lt (t1, t2) tree t1, t2; { if (t1 == t2) return 0; if (!TREE_UNSIGNED (TREE_TYPE (t1))) return INT_CST_LT (t1, t2); return INT_CST_LT_UNSIGNED (t1, t2); } /* Return an indication of the sign of the integer constant T. The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0. Note that -1 will never be returned it T's type is unsigned. */ int tree_int_cst_sgn (t) tree t; { if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0) return 0; else if (TREE_UNSIGNED (TREE_TYPE (t))) return 1; else if (TREE_INT_CST_HIGH (t) < 0) return -1; else return 1; } /* Compare two constructor-element-type constants. */ int simple_cst_list_equal (l1, l2) tree l1, l2; { while (l1 != NULL_TREE && l2 != NULL_TREE) { int cmp = simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)); if (cmp < 0) abort (); if (cmp == 0) return 0; l1 = TREE_CHAIN (l1); l2 = TREE_CHAIN (l2); } return (l1 == l2); } /* Return truthvalue of whether T1 is the same tree structure as T2. Return 1 if they are the same. Return 0 if they are understandably different. Return -1 if either contains tree structure not understood by this function. */ int simple_cst_equal (t1, t2) tree t1, t2; { register enum tree_code code1, code2; int cmp; if (t1 == t2) return 1; if (t1 == 0 || t2 == 0) return 0; code1 = TREE_CODE (t1); code2 = TREE_CODE (t2); if (code1 == NOP_EXPR || code1 == CONVERT_EXPR || code1 == NON_LVALUE_EXPR) if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR) return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); else return simple_cst_equal (TREE_OPERAND (t1, 0), t2); else if (code2 == NOP_EXPR || code2 == CONVERT_EXPR || code2 == NON_LVALUE_EXPR) return simple_cst_equal (t1, TREE_OPERAND (t2, 0)); if (code1 != code2) return 0; switch (code1) { case INTEGER_CST: return TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2) && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2); case REAL_CST: return REAL_VALUES_EQUAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2)); case STRING_CST: return TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2) && !bcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2), TREE_STRING_LENGTH (t1)); case CONSTRUCTOR: abort (); case SAVE_EXPR: return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); case CALL_EXPR: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); if (cmp <= 0) return cmp; return simple_cst_list_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)); case TARGET_EXPR: /* Special case: if either target is an unallocated VAR_DECL, it means that it's going to be unified with whatever the TARGET_EXPR is really supposed to initialize, so treat it as being equivalent to anything. */ if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE && DECL_RTL (TREE_OPERAND (t1, 0)) == 0) || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE && DECL_RTL (TREE_OPERAND (t2, 0)) == 0)) cmp = 1; else cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); if (cmp <= 0) return cmp; return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1)); case WITH_CLEANUP_EXPR: cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); if (cmp <= 0) return cmp; return simple_cst_equal (TREE_OPERAND (t1, 2), TREE_OPERAND (t1, 2)); case COMPONENT_REF: if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1)) return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0)); return 0; case VAR_DECL: case PARM_DECL: case CONST_DECL: case FUNCTION_DECL: return 0; } /* This general rule works for most tree codes. All exceptions should be handled above. */ switch (TREE_CODE_CLASS (code1)) { int i; case '1': case '2': case '<': case 'e': case 'r': case 's': cmp = 1; for (i=0; i TYPE_PRECISION (type) && TREE_UNSIGNED (type)); register tree win = op; while (TREE_CODE (op) == NOP_EXPR) { register int bitschange = TYPE_PRECISION (TREE_TYPE (op)) - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))); /* Truncations are many-one so cannot be removed. Unless we are later going to truncate down even farther. */ if (bitschange < 0 && final_prec > TYPE_PRECISION (TREE_TYPE (op))) break; /* See what's inside this conversion. If we decide to strip it, we will set WIN. */ op = TREE_OPERAND (op, 0); /* If we have not stripped any zero-extensions (uns is 0), we can strip any kind of extension. If we have previously stripped a zero-extension, only zero-extensions can safely be stripped. Any extension can be stripped if the bits it would produce are all going to be discarded later by truncating to FOR_TYPE. */ if (bitschange > 0) { if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op))) win = op; /* TREE_UNSIGNED says whether this is a zero-extension. Let's avoid computing it if it does not affect WIN and if UNS will not be needed again. */ if ((uns || TREE_CODE (op) == NOP_EXPR) && TREE_UNSIGNED (TREE_TYPE (op))) { uns = 1; win = op; } } } if (TREE_CODE (op) == COMPONENT_REF /* Since type_for_size always gives an integer type. */ && TREE_CODE (type) != REAL_TYPE) { unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1))); type = type_for_size (innerprec, TREE_UNSIGNED (TREE_OPERAND (op, 1))); /* We can get this structure field in the narrowest type it fits in. If FOR_TYPE is 0, do this only for a field that matches the narrower type exactly and is aligned for it The resulting extension to its nominal type (a fullword type) must fit the same conditions as for other extensions. */ if (innerprec < TYPE_PRECISION (TREE_TYPE (op)) && (for_type || ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))) && (! uns || final_prec <= innerprec || TREE_UNSIGNED (TREE_OPERAND (op, 1))) && type != 0) { win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0), TREE_OPERAND (op, 1)); TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op); TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op); TREE_RAISES (win) = TREE_RAISES (op); } } return win; } /* Return OP or a simpler expression for a narrower value which can be sign-extended or zero-extended to give back OP. Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended or 0 if the value should be sign-extended. */ tree get_narrower (op, unsignedp_ptr) register tree op; int *unsignedp_ptr; { register int uns = 0; int first = 1; register tree win = op; while (TREE_CODE (op) == NOP_EXPR) { register int bitschange = TYPE_PRECISION (TREE_TYPE (op)) - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))); /* Truncations are many-one so cannot be removed. */ if (bitschange < 0) break; /* See what's inside this conversion. If we decide to strip it, we will set WIN. */ op = TREE_OPERAND (op, 0); if (bitschange > 0) { /* An extension: the outermost one can be stripped, but remember whether it is zero or sign extension. */ if (first) uns = TREE_UNSIGNED (TREE_TYPE (op)); /* Otherwise, if a sign extension has been stripped, only sign extensions can now be stripped; if a zero extension has been stripped, only zero-extensions. */ else if (uns != TREE_UNSIGNED (TREE_TYPE (op))) break; first = 0; } else /* bitschange == 0 */ { /* A change in nominal type can always be stripped, but we must preserve the unsignedness. */ if (first) uns = TREE_UNSIGNED (TREE_TYPE (op)); first = 0; } win = op; } if (TREE_CODE (op) == COMPONENT_REF /* Since type_for_size always gives an integer type. */ && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE) { unsigned innerprec = TREE_INT_CST_LOW (DECL_SIZE (TREE_OPERAND (op, 1))); tree type = type_for_size (innerprec, TREE_UNSIGNED (op)); /* We can get this structure field in a narrower type that fits it, but the resulting extension to its nominal type (a fullword type) must satisfy the same conditions as for other extensions. Do this only for fields that are aligned (not bit-fields), because when bit-field insns will be used there is no advantage in doing this. */ if (innerprec < TYPE_PRECISION (TREE_TYPE (op)) && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1)) && (first || uns == TREE_UNSIGNED (TREE_OPERAND (op, 1))) && type != 0) { if (first) uns = TREE_UNSIGNED (TREE_OPERAND (op, 1)); win = build (COMPONENT_REF, type, TREE_OPERAND (op, 0), TREE_OPERAND (op, 1)); TREE_SIDE_EFFECTS (win) = TREE_SIDE_EFFECTS (op); TREE_THIS_VOLATILE (win) = TREE_THIS_VOLATILE (op); TREE_RAISES (win) = TREE_RAISES (op); } } *unsignedp_ptr = uns; return win; } /* Return the precision of a type, for arithmetic purposes. Supports all types on which arithmetic is possible (including pointer types). It's not clear yet what will be right for complex types. */ int type_precision (type) register tree type; { return ((TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE || TREE_CODE (type) == REAL_TYPE) ? TYPE_PRECISION (type) : POINTER_SIZE); } /* Nonzero if integer constant C has a value that is permissible for type TYPE (an INTEGER_TYPE). */ int int_fits_type_p (c, type) tree c, type; { if (TREE_UNSIGNED (type)) return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST && INT_CST_LT_UNSIGNED (TYPE_MAX_VALUE (type), c)) && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST && INT_CST_LT_UNSIGNED (c, TYPE_MIN_VALUE (type)))); else return (! (TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST && INT_CST_LT (TYPE_MAX_VALUE (type), c)) && ! (TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST && INT_CST_LT (c, TYPE_MIN_VALUE (type)))); } /* Return the innermost context enclosing DECL that is a FUNCTION_DECL, or zero if none. */ tree decl_function_context (decl) tree decl; { tree context; if (TREE_CODE (decl) == ERROR_MARK) return 0; if (TREE_CODE (decl) == SAVE_EXPR) context = SAVE_EXPR_CONTEXT (decl); else context = DECL_CONTEXT (decl); while (context && TREE_CODE (context) != FUNCTION_DECL) { if (TREE_CODE (context) == RECORD_TYPE || TREE_CODE (context) == UNION_TYPE) context = TYPE_CONTEXT (context); else if (TREE_CODE (context) == TYPE_DECL) context = DECL_CONTEXT (context); else if (TREE_CODE (context) == BLOCK) context = BLOCK_SUPERCONTEXT (context); else /* Unhandled CONTEXT !? */ abort (); } return context; } /* Return the innermost context enclosing DECL that is a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none. TYPE_DECLs and FUNCTION_DECLs are transparent to this function. */ tree decl_type_context (decl) tree decl; { tree context = DECL_CONTEXT (decl); while (context) { if (TREE_CODE (context) == RECORD_TYPE || TREE_CODE (context) == UNION_TYPE || TREE_CODE (context) == QUAL_UNION_TYPE) return context; if (TREE_CODE (context) == TYPE_DECL || TREE_CODE (context) == FUNCTION_DECL) context = DECL_CONTEXT (context); else if (TREE_CODE (context) == BLOCK) context = BLOCK_SUPERCONTEXT (context); else /* Unhandled CONTEXT!? */ abort (); } return NULL_TREE; } void print_obstack_statistics (str, o) char *str; struct obstack *o; { struct _obstack_chunk *chunk = o->chunk; int n_chunks = 0; int n_alloc = 0; while (chunk) { n_chunks += 1; n_alloc += chunk->limit - &chunk->contents[0]; chunk = chunk->prev; } fprintf (stderr, "obstack %s: %d bytes, %d chunks\n", str, n_alloc, n_chunks); } void dump_tree_statistics () { int i; int total_nodes, total_bytes; fprintf (stderr, "\n??? tree nodes created\n\n"); #ifdef GATHER_STATISTICS fprintf (stderr, "Kind Nodes Bytes\n"); fprintf (stderr, "-------------------------------------\n"); total_nodes = total_bytes = 0; for (i = 0; i < (int) all_kinds; i++) { fprintf (stderr, "%-20s %6d %9d\n", tree_node_kind_names[i], tree_node_counts[i], tree_node_sizes[i]); total_nodes += tree_node_counts[i]; total_bytes += tree_node_sizes[i]; } fprintf (stderr, "%-20s %9d\n", "identifier names", id_string_size); fprintf (stderr, "-------------------------------------\n"); fprintf (stderr, "%-20s %6d %9d\n", "Total", total_nodes, total_bytes); fprintf (stderr, "-------------------------------------\n"); #else fprintf (stderr, "(No per-node statistics)\n"); #endif print_lang_statistics (); } #define FILE_FUNCTION_PREFIX_LEN 9 #ifndef NO_DOLLAR_IN_LABEL #define FILE_FUNCTION_FORMAT "_GLOBAL_$D$%s" #else /* NO_DOLLAR_IN_LABEL */ #ifndef NO_DOT_IN_LABEL #define FILE_FUNCTION_FORMAT "_GLOBAL_.D.%s" #else /* NO_DOT_IN_LABEL */ #define FILE_FUNCTION_FORMAT "_GLOBAL__D_%s" #endif /* NO_DOT_IN_LABEL */ #endif /* NO_DOLLAR_IN_LABEL */ extern char * first_global_object_name; /* If KIND=='I', return a suitable global initializer (constructor) name. If KIND=='D', return a suitable global clean-up (destructor) name. */ tree get_file_function_name (kind) int kind; { char *buf; register char *p; if (first_global_object_name) p = first_global_object_name; else if (main_input_filename) p = main_input_filename; else p = input_filename; buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)); /* Set up the name of the file-level functions we may need. */ /* Use a global object (which is already required to be unique over the program) rather than the file name (which imposes extra constraints). -- Raeburn@MIT.EDU, 10 Jan 1990. */ sprintf (buf, FILE_FUNCTION_FORMAT, p); /* Don't need to pull wierd characters out of global names. */ if (p != first_global_object_name) { for (p = buf+11; *p; p++) if (! ((*p >= '0' && *p <= '9') #if 0 /* we always want labels, which are valid C++ identifiers (+ `$') */ #ifndef ASM_IDENTIFY_GCC /* this is required if `.' is invalid -- k. raeburn */ || *p == '.' #endif #endif #ifndef NO_DOLLAR_IN_LABEL /* this for `$'; unlikely, but... -- kr */ || *p == '$' #endif #ifndef NO_DOT_IN_LABEL /* this for `.'; unlikely, but... */ || *p == '.' #endif || (*p >= 'A' && *p <= 'Z') || (*p >= 'a' && *p <= 'z'))) *p = '_'; } buf[FILE_FUNCTION_PREFIX_LEN] = kind; return get_identifier (buf); }