d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
freebsd-nq/contrib/llvm/lib/MC/MCParser/AsmParser.cpp
Ed Schouten ffd1746d03 Upgrade our Clang in base to r108428. 
This commit merges the latest LLVM sources from the vendor space. It
also updates the build glue to match the new sources. Clang's version
number is changed to match LLVM's, which means /usr/include/clang/2.0
has been renamed to /usr/include/clang/2.8.

Obtained from:	projects/clangbsd
2010-07-20 17:16:57 +00:00

1489 lines
43 KiB
C++
Raw Blame History

//===- AsmParser.cpp - Parser for Assembly Files --------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements the parser for assembly files.
//
//===----------------------------------------------------------------------===//
#include "llvm/MC/MCParser/AsmParser.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCParser/MCParsedAsmOperand.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetAsmParser.h"
using namespace llvm;
namespace {
/// \brief Generic implementations of directive handling, etc. which is shared
/// (or the default, at least) for all assembler parser.
class GenericAsmParser : public MCAsmParserExtension {
public:
GenericAsmParser() {}
virtual void Initialize(MCAsmParser &Parser) {
// Call the base implementation.
this->MCAsmParserExtension::Initialize(Parser);
// Debugging directives.
Parser.AddDirectiveHandler(this, ".file", MCAsmParser::DirectiveHandler(
&GenericAsmParser::ParseDirectiveFile));
Parser.AddDirectiveHandler(this, ".line", MCAsmParser::DirectiveHandler(
&GenericAsmParser::ParseDirectiveLine));
Parser.AddDirectiveHandler(this, ".loc", MCAsmParser::DirectiveHandler(
&GenericAsmParser::ParseDirectiveLoc));
}
bool ParseDirectiveFile(StringRef, SMLoc DirectiveLoc); // ".file"
bool ParseDirectiveLine(StringRef, SMLoc DirectiveLoc); // ".line"
bool ParseDirectiveLoc(StringRef, SMLoc DirectiveLoc); // ".loc"
};
}
namespace llvm {
extern MCAsmParserExtension *createDarwinAsmParser();
extern MCAsmParserExtension *createELFAsmParser();
}
enum { DEFAULT_ADDRSPACE = 0 };
AsmParser::AsmParser(const Target &T, SourceMgr &_SM, MCContext &_Ctx,
MCStreamer &_Out, const MCAsmInfo &_MAI)
: Lexer(_MAI), Ctx(_Ctx), Out(_Out), SrcMgr(_SM),
GenericParser(new GenericAsmParser), PlatformParser(0),
TargetParser(0), CurBuffer(0) {
Lexer.setBuffer(SrcMgr.getMemoryBuffer(CurBuffer));
// Initialize the generic parser.
GenericParser->Initialize(*this);
// Initialize the platform / file format parser.
//
// FIXME: This is a hack, we need to (majorly) cleanup how these objects are
// created.
if (_MAI.hasSubsectionsViaSymbols()) {
PlatformParser = createDarwinAsmParser();
PlatformParser->Initialize(*this);
} else {
PlatformParser = createELFAsmParser();
PlatformParser->Initialize(*this);
}
}
AsmParser::~AsmParser() {
delete PlatformParser;
delete GenericParser;
}
void AsmParser::setTargetParser(TargetAsmParser &P) {
assert(!TargetParser && "Target parser is already initialized!");
TargetParser = &P;
TargetParser->Initialize(*this);
}
void AsmParser::Warning(SMLoc L, const Twine &Msg) {
PrintMessage(L, Msg.str(), "warning");
}
bool AsmParser::Error(SMLoc L, const Twine &Msg) {
PrintMessage(L, Msg.str(), "error");
return true;
}
void AsmParser::PrintMessage(SMLoc Loc, const std::string &Msg,
const char *Type) const {
SrcMgr.PrintMessage(Loc, Msg, Type);
}
bool AsmParser::EnterIncludeFile(const std::string &Filename) {
int NewBuf = SrcMgr.AddIncludeFile(Filename, Lexer.getLoc());
if (NewBuf == -1)
return true;
CurBuffer = NewBuf;
Lexer.setBuffer(SrcMgr.getMemoryBuffer(CurBuffer));
return false;
}
const AsmToken &AsmParser::Lex() {
const AsmToken *tok = &Lexer.Lex();
if (tok->is(AsmToken::Eof)) {
// If this is the end of an included file, pop the parent file off the
// include stack.
SMLoc ParentIncludeLoc = SrcMgr.getParentIncludeLoc(CurBuffer);
if (ParentIncludeLoc != SMLoc()) {
CurBuffer = SrcMgr.FindBufferContainingLoc(ParentIncludeLoc);
Lexer.setBuffer(SrcMgr.getMemoryBuffer(CurBuffer),
ParentIncludeLoc.getPointer());
tok = &Lexer.Lex();
}
}
if (tok->is(AsmToken::Error))
PrintMessage(Lexer.getErrLoc(), Lexer.getErr(), "error");
return *tok;
}
bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {
// Create the initial section, if requested.
//
// FIXME: Target hook & command line option for initial section.
if (!NoInitialTextSection)
Out.SwitchSection(Ctx.getMachOSection("__TEXT", "__text",
MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
0, SectionKind::getText()));
// Prime the lexer.
Lex();
bool HadError = false;
AsmCond StartingCondState = TheCondState;
// While we have input, parse each statement.
while (Lexer.isNot(AsmToken::Eof)) {
if (!ParseStatement()) continue;
// We had an error, remember it and recover by skipping to the next line.
HadError = true;
EatToEndOfStatement();
}
if (TheCondState.TheCond != StartingCondState.TheCond ||
TheCondState.Ignore != StartingCondState.Ignore)
return TokError("unmatched .ifs or .elses");
// Finalize the output stream if there are no errors and if the client wants
// us to.
if (!HadError && !NoFinalize)
Out.Finish();
return HadError;
}
/// EatToEndOfStatement - Throw away the rest of the line for testing purposes.
void AsmParser::EatToEndOfStatement() {
while (Lexer.isNot(AsmToken::EndOfStatement) &&
Lexer.isNot(AsmToken::Eof))
Lex();
// Eat EOL.
if (Lexer.is(AsmToken::EndOfStatement))
Lex();
}
/// ParseParenExpr - Parse a paren expression and return it.
/// NOTE: This assumes the leading '(' has already been consumed.
///
/// parenexpr ::= expr)
///
bool AsmParser::ParseParenExpr(const MCExpr *&Res, SMLoc &EndLoc) {
if (ParseExpression(Res)) return true;
if (Lexer.isNot(AsmToken::RParen))
return TokError("expected ')' in parentheses expression");
EndLoc = Lexer.getLoc();
Lex();
return false;
}
/// ParsePrimaryExpr - Parse a primary expression and return it.
/// primaryexpr ::= (parenexpr
/// primaryexpr ::= symbol
/// primaryexpr ::= number
/// primaryexpr ::= '.'
/// primaryexpr ::= ~,+,- primaryexpr
bool AsmParser::ParsePrimaryExpr(const MCExpr *&Res, SMLoc &EndLoc) {
switch (Lexer.getKind()) {
default:
return TokError("unknown token in expression");
case AsmToken::Exclaim:
Lex(); // Eat the operator.
if (ParsePrimaryExpr(Res, EndLoc))
return true;
Res = MCUnaryExpr::CreateLNot(Res, getContext());
return false;
case AsmToken::String:
case AsmToken::Identifier: {
// This is a symbol reference.
std::pair<StringRef, StringRef> Split = getTok().getIdentifier().split('@');
MCSymbol *Sym = getContext().GetOrCreateSymbol(Split.first);
// Mark the symbol as used in an expression.
Sym->setUsedInExpr(true);
// Lookup the symbol variant if used.
MCSymbolRefExpr::VariantKind Variant = MCSymbolRefExpr::VK_None;
if (Split.first.size() != getTok().getIdentifier().size())
Variant = MCSymbolRefExpr::getVariantKindForName(Split.second);
EndLoc = Lexer.getLoc();
Lex(); // Eat identifier.
// If this is an absolute variable reference, substitute it now to preserve
// semantics in the face of reassignment.
if (Sym->isVariable() && isa<MCConstantExpr>(Sym->getVariableValue())) {
if (Variant)
return Error(EndLoc, "unexpected modified on variable reference");
Res = Sym->getVariableValue();
return false;
}
// Otherwise create a symbol ref.
Res = MCSymbolRefExpr::Create(Sym, Variant, getContext());
return false;
}
case AsmToken::Integer: {
SMLoc Loc = getTok().getLoc();
int64_t IntVal = getTok().getIntVal();
Res = MCConstantExpr::Create(IntVal, getContext());
EndLoc = Lexer.getLoc();
Lex(); // Eat token.
// Look for 'b' or 'f' following an Integer as a directional label
if (Lexer.getKind() == AsmToken::Identifier) {
StringRef IDVal = getTok().getString();
if (IDVal == "f" || IDVal == "b"){
MCSymbol *Sym = Ctx.GetDirectionalLocalSymbol(IntVal,
IDVal == "f" ? 1 : 0);
Res = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_None,
getContext());
if(IDVal == "b" && Sym->isUndefined())
return Error(Loc, "invalid reference to undefined symbol");
EndLoc = Lexer.getLoc();
Lex(); // Eat identifier.
}
}
return false;
}
case AsmToken::Dot: {
// This is a '.' reference, which references the current PC. Emit a
// temporary label to the streamer and refer to it.
MCSymbol *Sym = Ctx.CreateTempSymbol();
Out.EmitLabel(Sym);
Res = MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_None, getContext());
EndLoc = Lexer.getLoc();
Lex(); // Eat identifier.
return false;
}
case AsmToken::LParen:
Lex(); // Eat the '('.
return ParseParenExpr(Res, EndLoc);
case AsmToken::Minus:
Lex(); // Eat the operator.
if (ParsePrimaryExpr(Res, EndLoc))
return true;
Res = MCUnaryExpr::CreateMinus(Res, getContext());
return false;
case AsmToken::Plus:
Lex(); // Eat the operator.
if (ParsePrimaryExpr(Res, EndLoc))
return true;
Res = MCUnaryExpr::CreatePlus(Res, getContext());
return false;
case AsmToken::Tilde:
Lex(); // Eat the operator.
if (ParsePrimaryExpr(Res, EndLoc))
return true;
Res = MCUnaryExpr::CreateNot(Res, getContext());
return false;
}
}
bool AsmParser::ParseExpression(const MCExpr *&Res) {
SMLoc EndLoc;
return ParseExpression(Res, EndLoc);
}
/// ParseExpression - Parse an expression and return it.
///
/// expr ::= expr +,- expr -> lowest.
/// expr ::= expr |,^,&,! expr -> middle.
/// expr ::= expr *,/,%,<<,>> expr -> highest.
/// expr ::= primaryexpr
///
bool AsmParser::ParseExpression(const MCExpr *&Res, SMLoc &EndLoc) {
// Parse the expression.
Res = 0;
if (ParsePrimaryExpr(Res, EndLoc) || ParseBinOpRHS(1, Res, EndLoc))
return true;
// Try to constant fold it up front, if possible.
int64_t Value;
if (Res->EvaluateAsAbsolute(Value))
Res = MCConstantExpr::Create(Value, getContext());
return false;
}
bool AsmParser::ParseParenExpression(const MCExpr *&Res, SMLoc &EndLoc) {
Res = 0;
return ParseParenExpr(Res, EndLoc) ||
ParseBinOpRHS(1, Res, EndLoc);
}
bool AsmParser::ParseAbsoluteExpression(int64_t &Res) {
const MCExpr *Expr;
SMLoc StartLoc = Lexer.getLoc();
if (ParseExpression(Expr))
return true;
if (!Expr->EvaluateAsAbsolute(Res))
return Error(StartLoc, "expected absolute expression");
return false;
}
static unsigned getBinOpPrecedence(AsmToken::TokenKind K,
MCBinaryExpr::Opcode &Kind) {
switch (K) {
default:
return 0; // not a binop.
// Lowest Precedence: &&, ||
case AsmToken::AmpAmp:
Kind = MCBinaryExpr::LAnd;
return 1;
case AsmToken::PipePipe:
Kind = MCBinaryExpr::LOr;
return 1;
// Low Precedence: +, -, ==, !=, <>, <, <=, >, >=
case AsmToken::Plus:
Kind = MCBinaryExpr::Add;
return 2;
case AsmToken::Minus:
Kind = MCBinaryExpr::Sub;
return 2;
case AsmToken::EqualEqual:
Kind = MCBinaryExpr::EQ;
return 2;
case AsmToken::ExclaimEqual:
case AsmToken::LessGreater:
Kind = MCBinaryExpr::NE;
return 2;
case AsmToken::Less:
Kind = MCBinaryExpr::LT;
return 2;
case AsmToken::LessEqual:
Kind = MCBinaryExpr::LTE;
return 2;
case AsmToken::Greater:
Kind = MCBinaryExpr::GT;
return 2;
case AsmToken::GreaterEqual:
Kind = MCBinaryExpr::GTE;
return 2;
// Intermediate Precedence: |, &, ^
//
// FIXME: gas seems to support '!' as an infix operator?
case AsmToken::Pipe:
Kind = MCBinaryExpr::Or;
return 3;
case AsmToken::Caret:
Kind = MCBinaryExpr::Xor;
return 3;
case AsmToken::Amp:
Kind = MCBinaryExpr::And;
return 3;
// Highest Precedence: *, /, %, <<, >>
case AsmToken::Star:
Kind = MCBinaryExpr::Mul;
return 4;
case AsmToken::Slash:
Kind = MCBinaryExpr::Div;
return 4;
case AsmToken::Percent:
Kind = MCBinaryExpr::Mod;
return 4;
case AsmToken::LessLess:
Kind = MCBinaryExpr::Shl;
return 4;
case AsmToken::GreaterGreater:
Kind = MCBinaryExpr::Shr;
return 4;
}
}
/// ParseBinOpRHS - Parse all binary operators with precedence >= 'Precedence'.
/// Res contains the LHS of the expression on input.
bool AsmParser::ParseBinOpRHS(unsigned Precedence, const MCExpr *&Res,
SMLoc &EndLoc) {
while (1) {
MCBinaryExpr::Opcode Kind = MCBinaryExpr::Add;
unsigned TokPrec = getBinOpPrecedence(Lexer.getKind(), Kind);
// If the next token is lower precedence than we are allowed to eat, return
// successfully with what we ate already.
if (TokPrec < Precedence)
return false;
Lex();
// Eat the next primary expression.
const MCExpr *RHS;
if (ParsePrimaryExpr(RHS, EndLoc)) return true;
// If BinOp binds less tightly with RHS than the operator after RHS, let
// the pending operator take RHS as its LHS.
MCBinaryExpr::Opcode Dummy;
unsigned NextTokPrec = getBinOpPrecedence(Lexer.getKind(), Dummy);
if (TokPrec < NextTokPrec) {
if (ParseBinOpRHS(Precedence+1, RHS, EndLoc)) return true;
}
// Merge LHS and RHS according to operator.
Res = MCBinaryExpr::Create(Kind, Res, RHS, getContext());
}
}
/// ParseStatement:
/// ::= EndOfStatement
/// ::= Label* Directive ...Operands... EndOfStatement
/// ::= Label* Identifier OperandList* EndOfStatement
bool AsmParser::ParseStatement() {
if (Lexer.is(AsmToken::EndOfStatement)) {
Out.AddBlankLine();
Lex();
return false;
}
// Statements always start with an identifier.
AsmToken ID = getTok();
SMLoc IDLoc = ID.getLoc();
StringRef IDVal;
int64_t LocalLabelVal = -1;
// GUESS allow an integer followed by a ':' as a directional local label
if (Lexer.is(AsmToken::Integer)) {
LocalLabelVal = getTok().getIntVal();
if (LocalLabelVal < 0) {
if (!TheCondState.Ignore)
return TokError("unexpected token at start of statement");
IDVal = "";
}
else {
IDVal = getTok().getString();
Lex(); // Consume the integer token to be used as an identifier token.
if (Lexer.getKind() != AsmToken::Colon) {
if (!TheCondState.Ignore)
return TokError("unexpected token at start of statement");
}
}
}
else if (ParseIdentifier(IDVal)) {
if (!TheCondState.Ignore)
return TokError("unexpected token at start of statement");
IDVal = "";
}
// Handle conditional assembly here before checking for skipping. We
// have to do this so that .endif isn't skipped in a ".if 0" block for
// example.
if (IDVal == ".if")
return ParseDirectiveIf(IDLoc);
if (IDVal == ".elseif")
return ParseDirectiveElseIf(IDLoc);
if (IDVal == ".else")
return ParseDirectiveElse(IDLoc);
if (IDVal == ".endif")
return ParseDirectiveEndIf(IDLoc);
// If we are in a ".if 0" block, ignore this statement.
if (TheCondState.Ignore) {
EatToEndOfStatement();
return false;
}
// FIXME: Recurse on local labels?
// See what kind of statement we have.
switch (Lexer.getKind()) {
case AsmToken::Colon: {
// identifier ':' -> Label.
Lex();
// Diagnose attempt to use a variable as a label.
//
// FIXME: Diagnostics. Note the location of the definition as a label.
// FIXME: This doesn't diagnose assignment to a symbol which has been
// implicitly marked as external.
MCSymbol *Sym;
if (LocalLabelVal == -1)
Sym = getContext().GetOrCreateSymbol(IDVal);
else
Sym = Ctx.CreateDirectionalLocalSymbol(LocalLabelVal);
if (!Sym->isUndefined() || Sym->isVariable())
return Error(IDLoc, "invalid symbol redefinition");
// Emit the label.
Out.EmitLabel(Sym);
// Consume any end of statement token, if present, to avoid spurious
// AddBlankLine calls().
if (Lexer.is(AsmToken::EndOfStatement)) {
Lex();
if (Lexer.is(AsmToken::Eof))
return false;
}
return ParseStatement();
}
case AsmToken::Equal:
// identifier '=' ... -> assignment statement
Lex();
return ParseAssignment(IDVal);
default: // Normal instruction or directive.
break;
}
// Otherwise, we have a normal instruction or directive.
if (IDVal[0] == '.') {
// Assembler features
if (IDVal == ".set")
return ParseDirectiveSet();
// Data directives
if (IDVal == ".ascii")
return ParseDirectiveAscii(false);
if (IDVal == ".asciz")
return ParseDirectiveAscii(true);
if (IDVal == ".byte")
return ParseDirectiveValue(1);
if (IDVal == ".short")
return ParseDirectiveValue(2);
if (IDVal == ".long")
return ParseDirectiveValue(4);
if (IDVal == ".quad")
return ParseDirectiveValue(8);
// FIXME: Target hooks for IsPow2.
if (IDVal == ".align")
return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/1);
if (IDVal == ".align32")
return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/4);
if (IDVal == ".balign")
return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/1);
if (IDVal == ".balignw")
return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/2);
if (IDVal == ".balignl")
return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/4);
if (IDVal == ".p2align")
return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/1);
if (IDVal == ".p2alignw")
return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/2);
if (IDVal == ".p2alignl")
return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/4);
if (IDVal == ".org")
return ParseDirectiveOrg();
if (IDVal == ".fill")
return ParseDirectiveFill();
if (IDVal == ".space")
return ParseDirectiveSpace();
// Symbol attribute directives
if (IDVal == ".globl" || IDVal == ".global")
return ParseDirectiveSymbolAttribute(MCSA_Global);
if (IDVal == ".hidden")
return ParseDirectiveSymbolAttribute(MCSA_Hidden);
if (IDVal == ".indirect_symbol")
return ParseDirectiveSymbolAttribute(MCSA_IndirectSymbol);
if (IDVal == ".internal")
return ParseDirectiveSymbolAttribute(MCSA_Internal);
if (IDVal == ".lazy_reference")
return ParseDirectiveSymbolAttribute(MCSA_LazyReference);
if (IDVal == ".no_dead_strip")
return ParseDirectiveSymbolAttribute(MCSA_NoDeadStrip);
if (IDVal == ".private_extern")
return ParseDirectiveSymbolAttribute(MCSA_PrivateExtern);
if (IDVal == ".protected")
return ParseDirectiveSymbolAttribute(MCSA_Protected);
if (IDVal == ".reference")
return ParseDirectiveSymbolAttribute(MCSA_Reference);
if (IDVal == ".type")
return ParseDirectiveELFType();
if (IDVal == ".weak")
return ParseDirectiveSymbolAttribute(MCSA_Weak);
if (IDVal == ".weak_definition")
return ParseDirectiveSymbolAttribute(MCSA_WeakDefinition);
if (IDVal == ".weak_reference")
return ParseDirectiveSymbolAttribute(MCSA_WeakReference);
if (IDVal == ".weak_def_can_be_hidden")
return ParseDirectiveSymbolAttribute(MCSA_WeakDefAutoPrivate);
if (IDVal == ".comm")
return ParseDirectiveComm(/*IsLocal=*/false);
if (IDVal == ".lcomm")
return ParseDirectiveComm(/*IsLocal=*/true);
if (IDVal == ".abort")
return ParseDirectiveAbort();
if (IDVal == ".include")
return ParseDirectiveInclude();
// Look up the handler in the handler table.
std::pair<MCAsmParserExtension*, DirectiveHandler> Handler =
DirectiveMap.lookup(IDVal);
if (Handler.first)
return (Handler.first->*Handler.second)(IDVal, IDLoc);
// Target hook for parsing target specific directives.
if (!getTargetParser().ParseDirective(ID))
return false;
Warning(IDLoc, "ignoring directive for now");
EatToEndOfStatement();
return false;
}
// Canonicalize the opcode to lower case.
SmallString<128> Opcode;
for (unsigned i = 0, e = IDVal.size(); i != e; ++i)
Opcode.push_back(tolower(IDVal[i]));
SmallVector<MCParsedAsmOperand*, 8> ParsedOperands;
bool HadError = getTargetParser().ParseInstruction(Opcode.str(), IDLoc,
ParsedOperands);
if (!HadError && Lexer.isNot(AsmToken::EndOfStatement))
HadError = TokError("unexpected token in argument list");
// If parsing succeeded, match the instruction.
if (!HadError) {
MCInst Inst;
if (!getTargetParser().MatchInstruction(ParsedOperands, Inst)) {
// Emit the instruction on success.
Out.EmitInstruction(Inst);
} else {
// Otherwise emit a diagnostic about the match failure and set the error
// flag.
//
// FIXME: We should give nicer diagnostics about the exact failure.
Error(IDLoc, "unrecognized instruction");
HadError = true;
}
}
// If there was no error, consume the end-of-statement token. Otherwise this
// will be done by our caller.
if (!HadError)
Lex();
// Free any parsed operands.
for (unsigned i = 0, e = ParsedOperands.size(); i != e; ++i)
delete ParsedOperands[i];
return HadError;
}
bool AsmParser::ParseAssignment(StringRef Name) {
// FIXME: Use better location, we should use proper tokens.
SMLoc EqualLoc = Lexer.getLoc();
const MCExpr *Value;
if (ParseExpression(Value))
return true;
if (Lexer.isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in assignment");
// Eat the end of statement marker.
Lex();
// Validate that the LHS is allowed to be a variable (either it has not been
// used as a symbol, or it is an absolute symbol).
MCSymbol *Sym = getContext().LookupSymbol(Name);
if (Sym) {
// Diagnose assignment to a label.
//
// FIXME: Diagnostics. Note the location of the definition as a label.
// FIXME: Diagnose assignment to protected identifier (e.g., register name).
if (Sym->isUndefined() && !Sym->isUsedInExpr())
; // Allow redefinitions of undefined symbols only used in directives.
else if (!Sym->isUndefined() && !Sym->isAbsolute())
return Error(EqualLoc, "redefinition of '" + Name + "'");
else if (!Sym->isVariable())
return Error(EqualLoc, "invalid assignment to '" + Name + "'");
else if (!isa<MCConstantExpr>(Sym->getVariableValue()))
return Error(EqualLoc, "invalid reassignment of non-absolute variable '" +
Name + "'");
} else
Sym = getContext().GetOrCreateSymbol(Name);
// FIXME: Handle '.'.
Sym->setUsedInExpr(true);
// Do the assignment.
Out.EmitAssignment(Sym, Value);
return false;
}
/// ParseIdentifier:
/// ::= identifier
/// ::= string
bool AsmParser::ParseIdentifier(StringRef &Res) {
if (Lexer.isNot(AsmToken::Identifier) &&
Lexer.isNot(AsmToken::String))
return true;
Res = getTok().getIdentifier();
Lex(); // Consume the identifier token.
return false;
}
/// ParseDirectiveSet:
/// ::= .set identifier ',' expression
bool AsmParser::ParseDirectiveSet() {
StringRef Name;
if (ParseIdentifier(Name))
return TokError("expected identifier after '.set' directive");
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.set'");
Lex();
return ParseAssignment(Name);
}
bool AsmParser::ParseEscapedString(std::string &Data) {
assert(getLexer().is(AsmToken::String) && "Unexpected current token!");
Data = "";
StringRef Str = getTok().getStringContents();
for (unsigned i = 0, e = Str.size(); i != e; ++i) {
if (Str[i] != '\\') {
Data += Str[i];
continue;
}
// Recognize escaped characters. Note that this escape semantics currently
// loosely follows Darwin 'as'. Notably, it doesn't support hex escapes.
++i;
if (i == e)
return TokError("unexpected backslash at end of string");
// Recognize octal sequences.
if ((unsigned) (Str[i] - '0') <= 7) {
// Consume up to three octal characters.
unsigned Value = Str[i] - '0';
if (i + 1 != e && ((unsigned) (Str[i + 1] - '0')) <= 7) {
++i;
Value = Value * 8 + (Str[i] - '0');
if (i + 1 != e && ((unsigned) (Str[i + 1] - '0')) <= 7) {
++i;
Value = Value * 8 + (Str[i] - '0');
}
}
if (Value > 255)
return TokError("invalid octal escape sequence (out of range)");
Data += (unsigned char) Value;
continue;
}
// Otherwise recognize individual escapes.
switch (Str[i]) {
default:
// Just reject invalid escape sequences for now.
return TokError("invalid escape sequence (unrecognized character)");
case 'b': Data += '\b'; break;
case 'f': Data += '\f'; break;
case 'n': Data += '\n'; break;
case 'r': Data += '\r'; break;
case 't': Data += '\t'; break;
case '"': Data += '"'; break;
case '\\': Data += '\\'; break;
}
}
return false;
}
/// ParseDirectiveAscii:
/// ::= ( .ascii | .asciz ) [ "string" ( , "string" )* ]
bool AsmParser::ParseDirectiveAscii(bool ZeroTerminated) {
if (getLexer().isNot(AsmToken::EndOfStatement)) {
for (;;) {
if (getLexer().isNot(AsmToken::String))
return TokError("expected string in '.ascii' or '.asciz' directive");
std::string Data;
if (ParseEscapedString(Data))
return true;
getStreamer().EmitBytes(Data, DEFAULT_ADDRSPACE);
if (ZeroTerminated)
getStreamer().EmitBytes(StringRef("\0", 1), DEFAULT_ADDRSPACE);
Lex();
if (getLexer().is(AsmToken::EndOfStatement))
break;
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.ascii' or '.asciz' directive");
Lex();
}
}
Lex();
return false;
}
/// ParseDirectiveValue
/// ::= (.byte | .short | ... ) [ expression (, expression)* ]
bool AsmParser::ParseDirectiveValue(unsigned Size) {
if (getLexer().isNot(AsmToken::EndOfStatement)) {
for (;;) {
const MCExpr *Value;
SMLoc ATTRIBUTE_UNUSED StartLoc = getLexer().getLoc();
if (ParseExpression(Value))
return true;
// Special case constant expressions to match code generator.
if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(Value))
getStreamer().EmitIntValue(MCE->getValue(), Size, DEFAULT_ADDRSPACE);
else
getStreamer().EmitValue(Value, Size, DEFAULT_ADDRSPACE);
if (getLexer().is(AsmToken::EndOfStatement))
break;
// FIXME: Improve diagnostic.
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in directive");
Lex();
}
}
Lex();
return false;
}
/// ParseDirectiveSpace
/// ::= .space expression [ , expression ]
bool AsmParser::ParseDirectiveSpace() {
int64_t NumBytes;
if (ParseAbsoluteExpression(NumBytes))
return true;
int64_t FillExpr = 0;
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.space' directive");
Lex();
if (ParseAbsoluteExpression(FillExpr))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.space' directive");
}
Lex();
if (NumBytes <= 0)
return TokError("invalid number of bytes in '.space' directive");
// FIXME: Sometimes the fill expr is 'nop' if it isn't supplied, instead of 0.
getStreamer().EmitFill(NumBytes, FillExpr, DEFAULT_ADDRSPACE);
return false;
}
/// ParseDirectiveFill
/// ::= .fill expression , expression , expression
bool AsmParser::ParseDirectiveFill() {
int64_t NumValues;
if (ParseAbsoluteExpression(NumValues))
return true;
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.fill' directive");
Lex();
int64_t FillSize;
if (ParseAbsoluteExpression(FillSize))
return true;
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.fill' directive");
Lex();
int64_t FillExpr;
if (ParseAbsoluteExpression(FillExpr))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.fill' directive");
Lex();
if (FillSize != 1 && FillSize != 2 && FillSize != 4 && FillSize != 8)
return TokError("invalid '.fill' size, expected 1, 2, 4, or 8");
for (uint64_t i = 0, e = NumValues; i != e; ++i)
getStreamer().EmitIntValue(FillExpr, FillSize, DEFAULT_ADDRSPACE);
return false;
}
/// ParseDirectiveOrg
/// ::= .org expression [ , expression ]
bool AsmParser::ParseDirectiveOrg() {
const MCExpr *Offset;
if (ParseExpression(Offset))
return true;
// Parse optional fill expression.
int64_t FillExpr = 0;
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.org' directive");
Lex();
if (ParseAbsoluteExpression(FillExpr))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.org' directive");
}
Lex();
// FIXME: Only limited forms of relocatable expressions are accepted here, it
// has to be relative to the current section.
getStreamer().EmitValueToOffset(Offset, FillExpr);
return false;
}
/// ParseDirectiveAlign
/// ::= {.align, ...} expression [ , expression [ , expression ]]
bool AsmParser::ParseDirectiveAlign(bool IsPow2, unsigned ValueSize) {
SMLoc AlignmentLoc = getLexer().getLoc();
int64_t Alignment;
if (ParseAbsoluteExpression(Alignment))
return true;
SMLoc MaxBytesLoc;
bool HasFillExpr = false;
int64_t FillExpr = 0;
int64_t MaxBytesToFill = 0;
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in directive");
Lex();
// The fill expression can be omitted while specifying a maximum number of
// alignment bytes, e.g:
// .align 3,,4
if (getLexer().isNot(AsmToken::Comma)) {
HasFillExpr = true;
if (ParseAbsoluteExpression(FillExpr))
return true;
}
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in directive");
Lex();
MaxBytesLoc = getLexer().getLoc();
if (ParseAbsoluteExpression(MaxBytesToFill))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in directive");
}
}
Lex();
if (!HasFillExpr)
FillExpr = 0;
// Compute alignment in bytes.
if (IsPow2) {
// FIXME: Diagnose overflow.
if (Alignment >= 32) {
Error(AlignmentLoc, "invalid alignment value");
Alignment = 31;
}
Alignment = 1ULL << Alignment;
}
// Diagnose non-sensical max bytes to align.
if (MaxBytesLoc.isValid()) {
if (MaxBytesToFill < 1) {
Error(MaxBytesLoc, "alignment directive can never be satisfied in this "
"many bytes, ignoring maximum bytes expression");
MaxBytesToFill = 0;
}
if (MaxBytesToFill >= Alignment) {
Warning(MaxBytesLoc, "maximum bytes expression exceeds alignment and "
"has no effect");
MaxBytesToFill = 0;
}
}
// Check whether we should use optimal code alignment for this .align
// directive.
//
// FIXME: This should be using a target hook.
bool UseCodeAlign = false;
if (const MCSectionMachO *S = dyn_cast<MCSectionMachO>(
getStreamer().getCurrentSection()))
UseCodeAlign = S->hasAttribute(MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS);
if ((!HasFillExpr || Lexer.getMAI().getTextAlignFillValue() == FillExpr) &&
ValueSize == 1 && UseCodeAlign) {
getStreamer().EmitCodeAlignment(Alignment, MaxBytesToFill);
} else {
// FIXME: Target specific behavior about how the "extra" bytes are filled.
getStreamer().EmitValueToAlignment(Alignment, FillExpr, ValueSize, MaxBytesToFill);
}
return false;
}
/// ParseDirectiveSymbolAttribute
/// ::= { ".globl", ".weak", ... } [ identifier ( , identifier )* ]
bool AsmParser::ParseDirectiveSymbolAttribute(MCSymbolAttr Attr) {
if (getLexer().isNot(AsmToken::EndOfStatement)) {
for (;;) {
StringRef Name;
if (ParseIdentifier(Name))
return TokError("expected identifier in directive");
MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
getStreamer().EmitSymbolAttribute(Sym, Attr);
if (getLexer().is(AsmToken::EndOfStatement))
break;
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in directive");
Lex();
}
}
Lex();
return false;
}
/// ParseDirectiveELFType
/// ::= .type identifier , @attribute
bool AsmParser::ParseDirectiveELFType() {
StringRef Name;
if (ParseIdentifier(Name))
return TokError("expected identifier in directive");
// Handle the identifier as the key symbol.
MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in '.type' directive");
Lex();
if (getLexer().isNot(AsmToken::At))
return TokError("expected '@' before type");
Lex();
StringRef Type;
SMLoc TypeLoc;
TypeLoc = getLexer().getLoc();
if (ParseIdentifier(Type))
return TokError("expected symbol type in directive");
MCSymbolAttr Attr = StringSwitch<MCSymbolAttr>(Type)
.Case("function", MCSA_ELF_TypeFunction)
.Case("object", MCSA_ELF_TypeObject)
.Case("tls_object", MCSA_ELF_TypeTLS)
.Case("common", MCSA_ELF_TypeCommon)
.Case("notype", MCSA_ELF_TypeNoType)
.Default(MCSA_Invalid);
if (Attr == MCSA_Invalid)
return Error(TypeLoc, "unsupported attribute in '.type' directive");
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.type' directive");
Lex();
getStreamer().EmitSymbolAttribute(Sym, Attr);
return false;
}
/// ParseDirectiveComm
/// ::= ( .comm | .lcomm ) identifier , size_expression [ , align_expression ]
bool AsmParser::ParseDirectiveComm(bool IsLocal) {
SMLoc IDLoc = getLexer().getLoc();
StringRef Name;
if (ParseIdentifier(Name))
return TokError("expected identifier in directive");
// Handle the identifier as the key symbol.
MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
if (getLexer().isNot(AsmToken::Comma))
return TokError("unexpected token in directive");
Lex();
int64_t Size;
SMLoc SizeLoc = getLexer().getLoc();
if (ParseAbsoluteExpression(Size))
return true;
int64_t Pow2Alignment = 0;
SMLoc Pow2AlignmentLoc;
if (getLexer().is(AsmToken::Comma)) {
Lex();
Pow2AlignmentLoc = getLexer().getLoc();
if (ParseAbsoluteExpression(Pow2Alignment))
return true;
// If this target takes alignments in bytes (not log) validate and convert.
if (Lexer.getMAI().getAlignmentIsInBytes()) {
if (!isPowerOf2_64(Pow2Alignment))
return Error(Pow2AlignmentLoc, "alignment must be a power of 2");
Pow2Alignment = Log2_64(Pow2Alignment);
}
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.comm' or '.lcomm' directive");
Lex();
// NOTE: a size of zero for a .comm should create a undefined symbol
// but a size of .lcomm creates a bss symbol of size zero.
if (Size < 0)
return Error(SizeLoc, "invalid '.comm' or '.lcomm' directive size, can't "
"be less than zero");
// NOTE: The alignment in the directive is a power of 2 value, the assembler
// may internally end up wanting an alignment in bytes.
// FIXME: Diagnose overflow.
if (Pow2Alignment < 0)
return Error(Pow2AlignmentLoc, "invalid '.comm' or '.lcomm' directive "
"alignment, can't be less than zero");
if (!Sym->isUndefined())
return Error(IDLoc, "invalid symbol redefinition");
// '.lcomm' is equivalent to '.zerofill'.
// Create the Symbol as a common or local common with Size and Pow2Alignment
if (IsLocal) {
getStreamer().EmitZerofill(Ctx.getMachOSection(
"__DATA", "__bss", MCSectionMachO::S_ZEROFILL,
0, SectionKind::getBSS()),
Sym, Size, 1 << Pow2Alignment);
return false;
}
getStreamer().EmitCommonSymbol(Sym, Size, 1 << Pow2Alignment);
return false;
}
/// ParseDirectiveAbort
/// ::= .abort [ "abort_string" ]
bool AsmParser::ParseDirectiveAbort() {
// FIXME: Use loc from directive.
SMLoc Loc = getLexer().getLoc();
StringRef Str = "";
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::String))
return TokError("expected string in '.abort' directive");
Str = getTok().getString();
Lex();
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.abort' directive");
Lex();
// FIXME: Handle here.
if (Str.empty())
Error(Loc, ".abort detected. Assembly stopping.");
else
Error(Loc, ".abort '" + Str + "' detected. Assembly stopping.");
return false;
}
/// ParseDirectiveInclude
/// ::= .include "filename"
bool AsmParser::ParseDirectiveInclude() {
if (getLexer().isNot(AsmToken::String))
return TokError("expected string in '.include' directive");
std::string Filename = getTok().getString();
SMLoc IncludeLoc = getLexer().getLoc();
Lex();
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.include' directive");
// Strip the quotes.
Filename = Filename.substr(1, Filename.size()-2);
// Attempt to switch the lexer to the included file before consuming the end
// of statement to avoid losing it when we switch.
if (EnterIncludeFile(Filename)) {
PrintMessage(IncludeLoc,
"Could not find include file '" + Filename + "'",
"error");
return true;
}
return false;
}
/// ParseDirectiveIf
/// ::= .if expression
bool AsmParser::ParseDirectiveIf(SMLoc DirectiveLoc) {
TheCondStack.push_back(TheCondState);
TheCondState.TheCond = AsmCond::IfCond;
if(TheCondState.Ignore) {
EatToEndOfStatement();
}
else {
int64_t ExprValue;
if (ParseAbsoluteExpression(ExprValue))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.if' directive");
Lex();
TheCondState.CondMet = ExprValue;
TheCondState.Ignore = !TheCondState.CondMet;
}
return false;
}
/// ParseDirectiveElseIf
/// ::= .elseif expression
bool AsmParser::ParseDirectiveElseIf(SMLoc DirectiveLoc) {
if (TheCondState.TheCond != AsmCond::IfCond &&
TheCondState.TheCond != AsmCond::ElseIfCond)
Error(DirectiveLoc, "Encountered a .elseif that doesn't follow a .if or "
" an .elseif");
TheCondState.TheCond = AsmCond::ElseIfCond;
bool LastIgnoreState = false;
if (!TheCondStack.empty())
LastIgnoreState = TheCondStack.back().Ignore;
if (LastIgnoreState || TheCondState.CondMet) {
TheCondState.Ignore = true;
EatToEndOfStatement();
}
else {
int64_t ExprValue;
if (ParseAbsoluteExpression(ExprValue))
return true;
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.elseif' directive");
Lex();
TheCondState.CondMet = ExprValue;
TheCondState.Ignore = !TheCondState.CondMet;
}
return false;
}
/// ParseDirectiveElse
/// ::= .else
bool AsmParser::ParseDirectiveElse(SMLoc DirectiveLoc) {
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.else' directive");
Lex();
if (TheCondState.TheCond != AsmCond::IfCond &&
TheCondState.TheCond != AsmCond::ElseIfCond)
Error(DirectiveLoc, "Encountered a .else that doesn't follow a .if or an "
".elseif");
TheCondState.TheCond = AsmCond::ElseCond;
bool LastIgnoreState = false;
if (!TheCondStack.empty())
LastIgnoreState = TheCondStack.back().Ignore;
if (LastIgnoreState || TheCondState.CondMet)
TheCondState.Ignore = true;
else
TheCondState.Ignore = false;
return false;
}
/// ParseDirectiveEndIf
/// ::= .endif
bool AsmParser::ParseDirectiveEndIf(SMLoc DirectiveLoc) {
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.endif' directive");
Lex();
if ((TheCondState.TheCond == AsmCond::NoCond) ||
TheCondStack.empty())
Error(DirectiveLoc, "Encountered a .endif that doesn't follow a .if or "
".else");
if (!TheCondStack.empty()) {
TheCondState = TheCondStack.back();
TheCondStack.pop_back();
}
return false;
}
/// ParseDirectiveFile
/// ::= .file [number] string
bool GenericAsmParser::ParseDirectiveFile(StringRef, SMLoc DirectiveLoc) {
// FIXME: I'm not sure what this is.
int64_t FileNumber = -1;
if (getLexer().is(AsmToken::Integer)) {
FileNumber = getTok().getIntVal();
Lex();
if (FileNumber < 1)
return TokError("file number less than one");
}
if (getLexer().isNot(AsmToken::String))
return TokError("unexpected token in '.file' directive");
StringRef Filename = getTok().getString();
Filename = Filename.substr(1, Filename.size()-2);
Lex();
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.file' directive");
if (FileNumber == -1)
getStreamer().EmitFileDirective(Filename);
else
getStreamer().EmitDwarfFileDirective(FileNumber, Filename);
return false;
}
/// ParseDirectiveLine
/// ::= .line [number]
bool GenericAsmParser::ParseDirectiveLine(StringRef, SMLoc DirectiveLoc) {
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Integer))
return TokError("unexpected token in '.line' directive");
int64_t LineNumber = getTok().getIntVal();
(void) LineNumber;
Lex();
// FIXME: Do something with the .line.
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.line' directive");
return false;
}
/// ParseDirectiveLoc
/// ::= .loc number [number [number]]
bool GenericAsmParser::ParseDirectiveLoc(StringRef, SMLoc DirectiveLoc) {
if (getLexer().isNot(AsmToken::Integer))
return TokError("unexpected token in '.loc' directive");
// FIXME: What are these fields?
int64_t FileNumber = getTok().getIntVal();
(void) FileNumber;
// FIXME: Validate file.
Lex();
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Integer))
return TokError("unexpected token in '.loc' directive");
int64_t Param2 = getTok().getIntVal();
(void) Param2;
Lex();
if (getLexer().isNot(AsmToken::EndOfStatement)) {
if (getLexer().isNot(AsmToken::Integer))
return TokError("unexpected token in '.loc' directive");
int64_t Param3 = getTok().getIntVal();
(void) Param3;
Lex();
// FIXME: Do something with the .loc.
}
}
if (getLexer().isNot(AsmToken::EndOfStatement))
return TokError("unexpected token in '.file' directive");
return false;
}
Reference in New Issue View Git Blame Copy Permalink