freebsd-dev/contrib/tcl/generic/tclPkg.c
1997-07-25 19:27:55 +00:00

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/*
* tclPkg.c --
*
* This file implements package and version control for Tcl via
* the "package" command and a few C APIs.
*
* Copyright (c) 1996 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclPkg.c 1.9 97/05/14 13:23:51
*/
#include "tclInt.h"
/*
* Each invocation of the "package ifneeded" command creates a structure
* of the following type, which is used to load the package into the
* interpreter if it is requested with a "package require" command.
*/
typedef struct PkgAvail {
char *version; /* Version string; malloc'ed. */
char *script; /* Script to invoke to provide this version
* of the package. Malloc'ed and protected
* by Tcl_Preserve and Tcl_Release. */
struct PkgAvail *nextPtr; /* Next in list of available versions of
* the same package. */
} PkgAvail;
/*
* For each package that is known in any way to an interpreter, there
* is one record of the following type. These records are stored in
* the "packageTable" hash table in the interpreter, keyed by
* package name such as "Tk" (no version number).
*/
typedef struct Package {
char *version; /* Version that has been supplied in this
* interpreter via "package provide"
* (malloc'ed). NULL means the package doesn't
* exist in this interpreter yet. */
PkgAvail *availPtr; /* First in list of all available versions
* of this package. */
} Package;
/*
* Prototypes for procedures defined in this file:
*/
static int CheckVersion _ANSI_ARGS_((Tcl_Interp *interp,
char *string));
static int ComparePkgVersions _ANSI_ARGS_((char *v1, char *v2,
int *satPtr));
static Package * FindPackage _ANSI_ARGS_((Tcl_Interp *interp,
char *name));
/*
*----------------------------------------------------------------------
*
* Tcl_PkgProvide --
*
* This procedure is invoked to declare that a particular version
* of a particular package is now present in an interpreter. There
* must not be any other version of this package already
* provided in the interpreter.
*
* Results:
* Normally returns TCL_OK; if there is already another version
* of the package loaded then TCL_ERROR is returned and an error
* message is left in interp->result.
*
* Side effects:
* The interpreter remembers that this package is available,
* so that no other version of the package may be provided for
* the interpreter.
*
*----------------------------------------------------------------------
*/
int
Tcl_PkgProvide(interp, name, version)
Tcl_Interp *interp; /* Interpreter in which package is now
* available. */
char *name; /* Name of package. */
char *version; /* Version string for package. */
{
Package *pkgPtr;
pkgPtr = FindPackage(interp, name);
if (pkgPtr->version == NULL) {
pkgPtr->version = ckalloc((unsigned) (strlen(version) + 1));
strcpy(pkgPtr->version, version);
return TCL_OK;
}
if (ComparePkgVersions(pkgPtr->version, version, (int *) NULL) == 0) {
return TCL_OK;
}
Tcl_AppendResult(interp, "conflicting versions provided for package \"",
name, "\": ", pkgPtr->version, ", then ", version, (char *) NULL);
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* Tcl_PkgRequire --
*
* This procedure is called by code that depends on a particular
* version of a particular package. If the package is not already
* provided in the interpreter, this procedure invokes a Tcl script
* to provide it. If the package is already provided, this
* procedure makes sure that the caller's needs don't conflict with
* the version that is present.
*
* Results:
* If successful, returns the version string for the currently
* provided version of the package, which may be different from
* the "version" argument. If the caller's requirements
* cannot be met (e.g. the version requested conflicts with
* a currently provided version, or the required version cannot
* be found, or the script to provide the required version
* generates an error), NULL is returned and an error
* message is left in interp->result.
*
* Side effects:
* The script from some previous "package ifneeded" command may
* be invoked to provide the package.
*
*----------------------------------------------------------------------
*/
char *
Tcl_PkgRequire(interp, name, version, exact)
Tcl_Interp *interp; /* Interpreter in which package is now
* available. */
char *name; /* Name of desired package. */
char *version; /* Version string for desired version;
* NULL means use the latest version
* available. */
int exact; /* Non-zero means that only the particular
* version given is acceptable. Zero means
* use the latest compatible version. */
{
Package *pkgPtr;
PkgAvail *availPtr, *bestPtr;
char *script;
int code, satisfies, result, pass;
Tcl_DString command;
/*
* It can take up to three passes to find the package: one pass to
* run the "package unknown" script, one to run the "package ifneeded"
* script for a specific version, and a final pass to lookup the
* package loaded by the "package ifneeded" script.
*/
for (pass = 1; ; pass++) {
pkgPtr = FindPackage(interp, name);
if (pkgPtr->version != NULL) {
break;
}
/*
* The package isn't yet present. Search the list of available
* versions and invoke the script for the best available version.
*/
bestPtr = NULL;
for (availPtr = pkgPtr->availPtr; availPtr != NULL;
availPtr = availPtr->nextPtr) {
if ((bestPtr != NULL) && (ComparePkgVersions(availPtr->version,
bestPtr->version, (int *) NULL) <= 0)) {
continue;
}
if (version != NULL) {
result = ComparePkgVersions(availPtr->version, version,
&satisfies);
if ((result != 0) && exact) {
continue;
}
if (!satisfies) {
continue;
}
}
bestPtr = availPtr;
}
if (bestPtr != NULL) {
/*
* We found an ifneeded script for the package. Be careful while
* executing it: this could cause reentrancy, so (a) protect the
* script itself from deletion and (b) don't assume that bestPtr
* will still exist when the script completes.
*/
script = bestPtr->script;
Tcl_Preserve((ClientData) script);
code = Tcl_GlobalEval(interp, script);
Tcl_Release((ClientData) script);
if (code != TCL_OK) {
if (code == TCL_ERROR) {
Tcl_AddErrorInfo(interp,
"\n (\"package ifneeded\" script)");
}
return NULL;
}
Tcl_ResetResult(interp);
pkgPtr = FindPackage(interp, name);
break;
}
/*
* Package not in the database. If there is a "package unknown"
* command, invoke it (but only on the first pass; after that,
* we should not get here in the first place).
*/
if (pass > 1) {
break;
}
script = ((Interp *) interp)->packageUnknown;
if (script != NULL) {
Tcl_DStringInit(&command);
Tcl_DStringAppend(&command, script, -1);
Tcl_DStringAppendElement(&command, name);
Tcl_DStringAppend(&command, " ", 1);
Tcl_DStringAppend(&command, (version != NULL) ? version : "{}",
-1);
if (exact) {
Tcl_DStringAppend(&command, " -exact", 7);
}
code = Tcl_GlobalEval(interp, Tcl_DStringValue(&command));
Tcl_DStringFree(&command);
if (code != TCL_OK) {
if (code == TCL_ERROR) {
Tcl_AddErrorInfo(interp,
"\n (\"package unknown\" script)");
}
return NULL;
}
Tcl_ResetResult(interp);
}
}
if (pkgPtr->version == NULL) {
Tcl_AppendResult(interp, "can't find package ", name,
(char *) NULL);
if (version != NULL) {
Tcl_AppendResult(interp, " ", version, (char *) NULL);
}
return NULL;
}
/*
* At this point we now that the package is present. Make sure that the
* provided version meets the current requirement.
*/
if (version == NULL) {
return pkgPtr->version;
}
result = ComparePkgVersions(pkgPtr->version, version, &satisfies);
if ((satisfies && !exact) || (result == 0)) {
return pkgPtr->version;
}
Tcl_AppendResult(interp, "version conflict for package \"",
name, "\": have ", pkgPtr->version, ", need ", version,
(char *) NULL);
return NULL;
}
/*
*----------------------------------------------------------------------
*
* Tcl_PackageCmd --
*
* This procedure is invoked to process the "package" Tcl command.
* See the user documentation for details on what it does.
*
* Results:
* A standard Tcl result.
*
* Side effects:
* See the user documentation.
*
*----------------------------------------------------------------------
*/
/* ARGSUSED */
int
Tcl_PackageCmd(dummy, interp, argc, argv)
ClientData dummy; /* Not used. */
Tcl_Interp *interp; /* Current interpreter. */
int argc; /* Number of arguments. */
char **argv; /* Argument strings. */
{
Interp *iPtr = (Interp *) interp;
size_t length;
int c, exact, i, satisfies;
PkgAvail *availPtr, *prevPtr;
Package *pkgPtr;
Tcl_HashEntry *hPtr;
Tcl_HashSearch search;
Tcl_HashTable *tablePtr;
char *version;
char buf[30];
if (argc < 2) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" option ?arg arg ...?\"", (char *) NULL);
return TCL_ERROR;
}
c = argv[1][0];
length = strlen(argv[1]);
if ((c == 'f') && (strncmp(argv[1], "forget", length) == 0)) {
for (i = 2; i < argc; i++) {
hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv[i]);
if (hPtr == NULL) {
return TCL_OK;
}
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
Tcl_DeleteHashEntry(hPtr);
if (pkgPtr->version != NULL) {
ckfree(pkgPtr->version);
}
while (pkgPtr->availPtr != NULL) {
availPtr = pkgPtr->availPtr;
pkgPtr->availPtr = availPtr->nextPtr;
ckfree(availPtr->version);
Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
ckfree((char *) availPtr);
}
ckfree((char *) pkgPtr);
}
} else if ((c == 'i') && (strncmp(argv[1], "ifneeded", length) == 0)) {
if ((argc != 4) && (argc != 5)) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" ifneeded package version ?script?\"", (char *) NULL);
return TCL_ERROR;
}
if (CheckVersion(interp, argv[3]) != TCL_OK) {
return TCL_ERROR;
}
if (argc == 4) {
hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv[2]);
if (hPtr == NULL) {
return TCL_OK;
}
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
} else {
pkgPtr = FindPackage(interp, argv[2]);
}
for (availPtr = pkgPtr->availPtr, prevPtr = NULL; availPtr != NULL;
prevPtr = availPtr, availPtr = availPtr->nextPtr) {
if (ComparePkgVersions(availPtr->version, argv[3], (int *) NULL)
== 0) {
if (argc == 4) {
Tcl_SetResult(interp, availPtr->script, TCL_VOLATILE);
return TCL_OK;
}
Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
break;
}
}
if (argc == 4) {
return TCL_OK;
}
if (availPtr == NULL) {
availPtr = (PkgAvail *) ckalloc(sizeof(PkgAvail));
availPtr->version = ckalloc((unsigned) (strlen(argv[3]) + 1));
strcpy(availPtr->version, argv[3]);
if (prevPtr == NULL) {
availPtr->nextPtr = pkgPtr->availPtr;
pkgPtr->availPtr = availPtr;
} else {
availPtr->nextPtr = prevPtr->nextPtr;
prevPtr->nextPtr = availPtr;
}
}
availPtr->script = ckalloc((unsigned) (strlen(argv[4]) + 1));
strcpy(availPtr->script, argv[4]);
} else if ((c == 'n') && (strncmp(argv[1], "names", length) == 0)) {
if (argc != 2) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" names\"", (char *) NULL);
return TCL_ERROR;
}
tablePtr = &iPtr->packageTable;
for (hPtr = Tcl_FirstHashEntry(tablePtr, &search); hPtr != NULL;
hPtr = Tcl_NextHashEntry(&search)) {
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
if ((pkgPtr->version != NULL) || (pkgPtr->availPtr != NULL)) {
Tcl_AppendElement(interp, Tcl_GetHashKey(tablePtr, hPtr));
}
}
} else if ((c == 'p') && (strncmp(argv[1], "provide", length) == 0)) {
if ((argc != 3) && (argc != 4)) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" provide package ?version?\"", (char *) NULL);
return TCL_ERROR;
}
if (argc == 3) {
hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv[2]);
if (hPtr != NULL) {
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
if (pkgPtr->version != NULL) {
Tcl_SetResult(interp, pkgPtr->version, TCL_VOLATILE);
}
}
return TCL_OK;
}
if (CheckVersion(interp, argv[3]) != TCL_OK) {
return TCL_ERROR;
}
return Tcl_PkgProvide(interp, argv[2], argv[3]);
} else if ((c == 'r') && (strncmp(argv[1], "require", length) == 0)) {
if (argc < 3) {
requireSyntax:
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" require ?-exact? package ?version?\"", (char *) NULL);
return TCL_ERROR;
}
if ((argv[2][0] == '-') && (strcmp(argv[2], "-exact") == 0)) {
exact = 1;
} else {
exact = 0;
}
version = NULL;
if (argc == (4+exact)) {
version = argv[3+exact];
if (CheckVersion(interp, version) != TCL_OK) {
return TCL_ERROR;
}
} else if ((argc != 3) || exact) {
goto requireSyntax;
}
version = Tcl_PkgRequire(interp, argv[2+exact], version, exact);
if (version == NULL) {
return TCL_ERROR;
}
Tcl_SetResult(interp, version, TCL_VOLATILE);
} else if ((c == 'u') && (strncmp(argv[1], "unknown", length) == 0)) {
if (argc == 2) {
if (iPtr->packageUnknown != NULL) {
Tcl_SetResult(interp, iPtr->packageUnknown, TCL_VOLATILE);
}
} else if (argc == 3) {
if (iPtr->packageUnknown != NULL) {
ckfree(iPtr->packageUnknown);
}
if (argv[2][0] == 0) {
iPtr->packageUnknown = NULL;
} else {
iPtr->packageUnknown = (char *) ckalloc((unsigned)
(strlen(argv[2]) + 1));
strcpy(iPtr->packageUnknown, argv[2]);
}
} else {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" unknown ?command?\"", (char *) NULL);
return TCL_ERROR;
}
} else if ((c == 'v') && (strncmp(argv[1], "vcompare", length) == 0)
&& (length >= 2)) {
if (argc != 4) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" vcompare version1 version2\"", (char *) NULL);
return TCL_ERROR;
}
if ((CheckVersion(interp, argv[2]) != TCL_OK)
|| (CheckVersion(interp, argv[3]) != TCL_OK)) {
return TCL_ERROR;
}
TclFormatInt(buf, ComparePkgVersions(argv[2], argv[3], (int *) NULL));
Tcl_SetResult(interp, buf, TCL_VOLATILE);
} else if ((c == 'v') && (strncmp(argv[1], "versions", length) == 0)
&& (length >= 2)) {
if (argc != 3) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" versions package\"", (char *) NULL);
return TCL_ERROR;
}
hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv[2]);
if (hPtr != NULL) {
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
for (availPtr = pkgPtr->availPtr; availPtr != NULL;
availPtr = availPtr->nextPtr) {
Tcl_AppendElement(interp, availPtr->version);
}
}
} else if ((c == 'v') && (strncmp(argv[1], "vsatisfies", length) == 0)
&& (length >= 2)) {
if (argc != 4) {
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" vsatisfies version1 version2\"", (char *) NULL);
return TCL_ERROR;
}
if ((CheckVersion(interp, argv[2]) != TCL_OK)
|| (CheckVersion(interp, argv[3]) != TCL_OK)) {
return TCL_ERROR;
}
ComparePkgVersions(argv[2], argv[3], &satisfies);
TclFormatInt(buf, satisfies);
Tcl_SetResult(interp, buf, TCL_VOLATILE);
} else {
Tcl_AppendResult(interp, "bad option \"", argv[1],
"\": should be forget, ifneeded, names, ",
"provide, require, unknown, vcompare, ",
"versions, or vsatisfies", (char *) NULL);
return TCL_ERROR;
}
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* FindPackage --
*
* This procedure finds the Package record for a particular package
* in a particular interpreter, creating a record if one doesn't
* already exist.
*
* Results:
* The return value is a pointer to the Package record for the
* package.
*
* Side effects:
* A new Package record may be created.
*
*----------------------------------------------------------------------
*/
static Package *
FindPackage(interp, name)
Tcl_Interp *interp; /* Interpreter to use for package lookup. */
char *name; /* Name of package to fine. */
{
Interp *iPtr = (Interp *) interp;
Tcl_HashEntry *hPtr;
int new;
Package *pkgPtr;
hPtr = Tcl_CreateHashEntry(&iPtr->packageTable, name, &new);
if (new) {
pkgPtr = (Package *) ckalloc(sizeof(Package));
pkgPtr->version = NULL;
pkgPtr->availPtr = NULL;
Tcl_SetHashValue(hPtr, pkgPtr);
} else {
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
}
return pkgPtr;
}
/*
*----------------------------------------------------------------------
*
* TclFreePackageInfo --
*
* This procedure is called during interpreter deletion to
* free all of the package-related information for the
* interpreter.
*
* Results:
* None.
*
* Side effects:
* Memory is freed.
*
*----------------------------------------------------------------------
*/
void
TclFreePackageInfo(iPtr)
Interp *iPtr; /* Interpereter that is being deleted. */
{
Package *pkgPtr;
Tcl_HashSearch search;
Tcl_HashEntry *hPtr;
PkgAvail *availPtr;
for (hPtr = Tcl_FirstHashEntry(&iPtr->packageTable, &search);
hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
pkgPtr = (Package *) Tcl_GetHashValue(hPtr);
if (pkgPtr->version != NULL) {
ckfree(pkgPtr->version);
}
while (pkgPtr->availPtr != NULL) {
availPtr = pkgPtr->availPtr;
pkgPtr->availPtr = availPtr->nextPtr;
ckfree(availPtr->version);
Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
ckfree((char *) availPtr);
}
ckfree((char *) pkgPtr);
}
Tcl_DeleteHashTable(&iPtr->packageTable);
if (iPtr->packageUnknown != NULL) {
ckfree(iPtr->packageUnknown);
}
}
/*
*----------------------------------------------------------------------
*
* CheckVersion --
*
* This procedure checks to see whether a version number has
* valid syntax.
*
* Results:
* If string is a properly formed version number the TCL_OK
* is returned. Otherwise TCL_ERROR is returned and an error
* message is left in interp->result.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
CheckVersion(interp, string)
Tcl_Interp *interp; /* Used for error reporting. */
char *string; /* Supposedly a version number, which is
* groups of decimal digits separated
* by dots. */
{
char *p = string;
if (!isdigit(UCHAR(*p))) {
goto error;
}
for (p++; *p != 0; p++) {
if (!isdigit(UCHAR(*p)) && (*p != '.')) {
goto error;
}
}
if (p[-1] != '.') {
return TCL_OK;
}
error:
Tcl_AppendResult(interp, "expected version number but got \"",
string, "\"", (char *) NULL);
return TCL_ERROR;
}
/*
*----------------------------------------------------------------------
*
* ComparePkgVersions --
*
* This procedure compares two version numbers.
*
* Results:
* The return value is -1 if v1 is less than v2, 0 if the two
* version numbers are the same, and 1 if v1 is greater than v2.
* If *satPtr is non-NULL, the word it points to is filled in
* with 1 if v2 >= v1 and both numbers have the same major number
* or 0 otherwise.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static int
ComparePkgVersions(v1, v2, satPtr)
char *v1, *v2; /* Versions strings, of form 2.1.3 (any
* number of version numbers). */
int *satPtr; /* If non-null, the word pointed to is
* filled in with a 0/1 value. 1 means
* v1 "satisfies" v2: v1 is greater than
* or equal to v2 and both version numbers
* have the same major number. */
{
int thisIsMajor, n1, n2;
/*
* Each iteration of the following loop processes one number from
* each string, terminated by a ".". If those numbers don't match
* then the comparison is over; otherwise, we loop back for the
* next number.
*/
thisIsMajor = 1;
while (1) {
/*
* Parse one decimal number from the front of each string.
*/
n1 = n2 = 0;
while ((*v1 != 0) && (*v1 != '.')) {
n1 = 10*n1 + (*v1 - '0');
v1++;
}
while ((*v2 != 0) && (*v2 != '.')) {
n2 = 10*n2 + (*v2 - '0');
v2++;
}
/*
* Compare and go on to the next version number if the
* current numbers match.
*/
if (n1 != n2) {
break;
}
if (*v1 != 0) {
v1++;
} else if (*v2 == 0) {
break;
}
if (*v2 != 0) {
v2++;
}
thisIsMajor = 0;
}
if (satPtr != NULL) {
*satPtr = (n1 == n2) || ((n1 > n2) && !thisIsMajor);
}
if (n1 > n2) {
return 1;
} else if (n1 == n2) {
return 0;
} else {
return -1;
}
}