//===- 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(const 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;
}