//===- 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 "AsmParser.h" #include "AsmExpr.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSymbol.h" #include "llvm/Support/SourceMgr.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetAsmParser.h" using namespace llvm; void AsmParser::Warning(SMLoc L, const char *Msg) { Lexer.PrintMessage(L, Msg, "warning"); } bool AsmParser::Error(SMLoc L, const char *Msg) { Lexer.PrintMessage(L, Msg, "error"); return true; } bool AsmParser::TokError(const char *Msg) { Lexer.PrintMessage(Lexer.getLoc(), Msg, "error"); return true; } bool AsmParser::Run() { // Prime the lexer. Lexer.Lex(); bool HadError = false; // While we have input, parse each statement. while (Lexer.isNot(asmtok::Eof)) { if (!ParseStatement()) continue; // If we had an error, remember it and recover by skipping to the next line. HadError = true; EatToEndOfStatement(); } return HadError; } /// EatToEndOfStatement - Throw away the rest of the line for testing purposes. void AsmParser::EatToEndOfStatement() { while (Lexer.isNot(asmtok::EndOfStatement) && Lexer.isNot(asmtok::Eof)) Lexer.Lex(); // Eat EOL. if (Lexer.is(asmtok::EndOfStatement)) Lexer.Lex(); } /// ParseParenExpr - Parse a paren expression and return it. /// NOTE: This assumes the leading '(' has already been consumed. /// /// parenexpr ::= expr) /// bool AsmParser::ParseParenExpr(AsmExpr *&Res) { if (ParseExpression(Res)) return true; if (Lexer.isNot(asmtok::RParen)) return TokError("expected ')' in parentheses expression"); Lexer.Lex(); return false; } /// ParsePrimaryExpr - Parse a primary expression and return it. /// primaryexpr ::= (parenexpr /// primaryexpr ::= symbol /// primaryexpr ::= number /// primaryexpr ::= ~,+,- primaryexpr bool AsmParser::ParsePrimaryExpr(AsmExpr *&Res) { switch (Lexer.getKind()) { default: return TokError("unknown token in expression"); case asmtok::Exclaim: Lexer.Lex(); // Eat the operator. if (ParsePrimaryExpr(Res)) return true; Res = new AsmUnaryExpr(AsmUnaryExpr::LNot, Res); return false; case asmtok::Identifier: { // This is a label, this should be parsed as part of an expression, to // handle things like LFOO+4. MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); // If this is use of an undefined symbol then mark it external. if (!Sym->getSection() && !Ctx.GetSymbolValue(Sym)) Sym->setExternal(true); Res = new AsmSymbolRefExpr(Sym); Lexer.Lex(); // Eat identifier. return false; } case asmtok::IntVal: Res = new AsmConstantExpr(Lexer.getCurIntVal()); Lexer.Lex(); // Eat identifier. return false; case asmtok::LParen: Lexer.Lex(); // Eat the '('. return ParseParenExpr(Res); case asmtok::Minus: Lexer.Lex(); // Eat the operator. if (ParsePrimaryExpr(Res)) return true; Res = new AsmUnaryExpr(AsmUnaryExpr::Minus, Res); return false; case asmtok::Plus: Lexer.Lex(); // Eat the operator. if (ParsePrimaryExpr(Res)) return true; Res = new AsmUnaryExpr(AsmUnaryExpr::Plus, Res); return false; case asmtok::Tilde: Lexer.Lex(); // Eat the operator. if (ParsePrimaryExpr(Res)) return true; Res = new AsmUnaryExpr(AsmUnaryExpr::Not, Res); return false; } } /// ParseExpression - Parse an expression and return it. /// /// expr ::= expr +,- expr -> lowest. /// expr ::= expr |,^,&,! expr -> middle. /// expr ::= expr *,/,%,<<,>> expr -> highest. /// expr ::= primaryexpr /// bool AsmParser::ParseExpression(AsmExpr *&Res) { Res = 0; return ParsePrimaryExpr(Res) || ParseBinOpRHS(1, Res); } bool AsmParser::ParseAbsoluteExpression(int64_t &Res) { AsmExpr *Expr; SMLoc StartLoc = Lexer.getLoc(); if (ParseExpression(Expr)) return true; if (!Expr->EvaluateAsAbsolute(Ctx, Res)) return Error(StartLoc, "expected absolute expression"); return false; } bool AsmParser::ParseRelocatableExpression(MCValue &Res) { AsmExpr *Expr; SMLoc StartLoc = Lexer.getLoc(); if (ParseExpression(Expr)) return true; if (!Expr->EvaluateAsRelocatable(Ctx, Res)) return Error(StartLoc, "expected relocatable expression"); return false; } bool AsmParser::ParseParenRelocatableExpression(MCValue &Res) { AsmExpr *Expr; SMLoc StartLoc = Lexer.getLoc(); if (ParseParenExpr(Expr)) return true; if (!Expr->EvaluateAsRelocatable(Ctx, Res)) return Error(StartLoc, "expected relocatable expression"); return false; } static unsigned getBinOpPrecedence(asmtok::TokKind K, AsmBinaryExpr::Opcode &Kind) { switch (K) { default: return 0; // not a binop. // Lowest Precedence: &&, || case asmtok::AmpAmp: Kind = AsmBinaryExpr::LAnd; return 1; case asmtok::PipePipe: Kind = AsmBinaryExpr::LOr; return 1; // Low Precedence: +, -, ==, !=, <>, <, <=, >, >= case asmtok::Plus: Kind = AsmBinaryExpr::Add; return 2; case asmtok::Minus: Kind = AsmBinaryExpr::Sub; return 2; case asmtok::EqualEqual: Kind = AsmBinaryExpr::EQ; return 2; case asmtok::ExclaimEqual: case asmtok::LessGreater: Kind = AsmBinaryExpr::NE; return 2; case asmtok::Less: Kind = AsmBinaryExpr::LT; return 2; case asmtok::LessEqual: Kind = AsmBinaryExpr::LTE; return 2; case asmtok::Greater: Kind = AsmBinaryExpr::GT; return 2; case asmtok::GreaterEqual: Kind = AsmBinaryExpr::GTE; return 2; // Intermediate Precedence: |, &, ^ // // FIXME: gas seems to support '!' as an infix operator? case asmtok::Pipe: Kind = AsmBinaryExpr::Or; return 3; case asmtok::Caret: Kind = AsmBinaryExpr::Xor; return 3; case asmtok::Amp: Kind = AsmBinaryExpr::And; return 3; // Highest Precedence: *, /, %, <<, >> case asmtok::Star: Kind = AsmBinaryExpr::Mul; return 4; case asmtok::Slash: Kind = AsmBinaryExpr::Div; return 4; case asmtok::Percent: Kind = AsmBinaryExpr::Mod; return 4; case asmtok::LessLess: Kind = AsmBinaryExpr::Shl; return 4; case asmtok::GreaterGreater: Kind = AsmBinaryExpr::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, AsmExpr *&Res) { while (1) { AsmBinaryExpr::Opcode Kind = AsmBinaryExpr::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; Lexer.Lex(); // Eat the next primary expression. AsmExpr *RHS; if (ParsePrimaryExpr(RHS)) return true; // If BinOp binds less tightly with RHS than the operator after RHS, let // the pending operator take RHS as its LHS. AsmBinaryExpr::Opcode Dummy; unsigned NextTokPrec = getBinOpPrecedence(Lexer.getKind(), Dummy); if (TokPrec < NextTokPrec) { if (ParseBinOpRHS(Precedence+1, RHS)) return true; } // Merge LHS and RHS according to operator. Res = new AsmBinaryExpr(Kind, Res, RHS); } } /// ParseStatement: /// ::= EndOfStatement /// ::= Label* Directive ...Operands... EndOfStatement /// ::= Label* Identifier OperandList* EndOfStatement bool AsmParser::ParseStatement() { switch (Lexer.getKind()) { default: return TokError("unexpected token at start of statement"); case asmtok::EndOfStatement: Lexer.Lex(); return false; case asmtok::Identifier: break; // TODO: Recurse on local labels etc. } // If we have an identifier, handle it as the key symbol. SMLoc IDLoc = Lexer.getLoc(); const char *IDVal = Lexer.getCurStrVal(); // Consume the identifier, see what is after it. switch (Lexer.Lex()) { case asmtok::Colon: { // identifier ':' -> Label. Lexer.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 = Ctx.GetOrCreateSymbol(IDVal); if (Sym->getSection()) return Error(IDLoc, "invalid symbol redefinition"); if (Ctx.GetSymbolValue(Sym)) return Error(IDLoc, "symbol already used as assembler variable"); // Since we saw a label, create a symbol and emit it. // FIXME: If the label starts with L it is an assembler temporary label. // Why does the client of this api need to know this? Out.EmitLabel(Sym); return ParseStatement(); } case asmtok::Equal: // identifier '=' ... -> assignment statement Lexer.Lex(); return ParseAssignment(IDVal, false); default: // Normal instruction or directive. break; } // Otherwise, we have a normal instruction or directive. if (IDVal[0] == '.') { // FIXME: This should be driven based on a hash lookup and callback. if (!strcmp(IDVal, ".section")) return ParseDirectiveDarwinSection(); if (!strcmp(IDVal, ".text")) // FIXME: This changes behavior based on the -static flag to the // assembler. return ParseDirectiveSectionSwitch("__TEXT,__text", "regular,pure_instructions"); if (!strcmp(IDVal, ".const")) return ParseDirectiveSectionSwitch("__TEXT,__const"); if (!strcmp(IDVal, ".static_const")) return ParseDirectiveSectionSwitch("__TEXT,__static_const"); if (!strcmp(IDVal, ".cstring")) return ParseDirectiveSectionSwitch("__TEXT,__cstring", "cstring_literals"); if (!strcmp(IDVal, ".literal4")) return ParseDirectiveSectionSwitch("__TEXT,__literal4", "4byte_literals"); if (!strcmp(IDVal, ".literal8")) return ParseDirectiveSectionSwitch("__TEXT,__literal8", "8byte_literals"); if (!strcmp(IDVal, ".literal16")) return ParseDirectiveSectionSwitch("__TEXT,__literal16", "16byte_literals"); if (!strcmp(IDVal, ".constructor")) return ParseDirectiveSectionSwitch("__TEXT,__constructor"); if (!strcmp(IDVal, ".destructor")) return ParseDirectiveSectionSwitch("__TEXT,__destructor"); if (!strcmp(IDVal, ".fvmlib_init0")) return ParseDirectiveSectionSwitch("__TEXT,__fvmlib_init0"); if (!strcmp(IDVal, ".fvmlib_init1")) return ParseDirectiveSectionSwitch("__TEXT,__fvmlib_init1"); if (!strcmp(IDVal, ".symbol_stub")) // FIXME: Different on PPC. return ParseDirectiveSectionSwitch("__IMPORT,__jump_table,symbol_stubs", "self_modifying_code+pure_instructions,5"); // FIXME: .picsymbol_stub on PPC. if (!strcmp(IDVal, ".data")) return ParseDirectiveSectionSwitch("__DATA,__data"); if (!strcmp(IDVal, ".static_data")) return ParseDirectiveSectionSwitch("__DATA,__static_data"); if (!strcmp(IDVal, ".non_lazy_symbol_pointer")) return ParseDirectiveSectionSwitch("__DATA,__nl_symbol_pointer", "non_lazy_symbol_pointers"); if (!strcmp(IDVal, ".lazy_symbol_pointer")) return ParseDirectiveSectionSwitch("__DATA,__la_symbol_pointer", "lazy_symbol_pointers"); if (!strcmp(IDVal, ".dyld")) return ParseDirectiveSectionSwitch("__DATA,__dyld"); if (!strcmp(IDVal, ".mod_init_func")) return ParseDirectiveSectionSwitch("__DATA,__mod_init_func", "mod_init_funcs"); if (!strcmp(IDVal, ".mod_term_func")) return ParseDirectiveSectionSwitch("__DATA,__mod_term_func", "mod_term_funcs"); if (!strcmp(IDVal, ".const_data")) return ParseDirectiveSectionSwitch("__DATA,__const", "regular"); // FIXME: Verify attributes on sections. if (!strcmp(IDVal, ".objc_class")) return ParseDirectiveSectionSwitch("__OBJC,__class"); if (!strcmp(IDVal, ".objc_meta_class")) return ParseDirectiveSectionSwitch("__OBJC,__meta_class"); if (!strcmp(IDVal, ".objc_cat_cls_meth")) return ParseDirectiveSectionSwitch("__OBJC,__cat_cls_meth"); if (!strcmp(IDVal, ".objc_cat_inst_meth")) return ParseDirectiveSectionSwitch("__OBJC,__cat_inst_meth"); if (!strcmp(IDVal, ".objc_protocol")) return ParseDirectiveSectionSwitch("__OBJC,__protocol"); if (!strcmp(IDVal, ".objc_string_object")) return ParseDirectiveSectionSwitch("__OBJC,__string_object"); if (!strcmp(IDVal, ".objc_cls_meth")) return ParseDirectiveSectionSwitch("__OBJC,__cls_meth"); if (!strcmp(IDVal, ".objc_inst_meth")) return ParseDirectiveSectionSwitch("__OBJC,__inst_meth"); if (!strcmp(IDVal, ".objc_cls_refs")) return ParseDirectiveSectionSwitch("__OBJC,__cls_refs"); if (!strcmp(IDVal, ".objc_message_refs")) return ParseDirectiveSectionSwitch("__OBJC,__message_refs"); if (!strcmp(IDVal, ".objc_symbols")) return ParseDirectiveSectionSwitch("__OBJC,__symbols"); if (!strcmp(IDVal, ".objc_category")) return ParseDirectiveSectionSwitch("__OBJC,__category"); if (!strcmp(IDVal, ".objc_class_vars")) return ParseDirectiveSectionSwitch("__OBJC,__class_vars"); if (!strcmp(IDVal, ".objc_instance_vars")) return ParseDirectiveSectionSwitch("__OBJC,__instance_vars"); if (!strcmp(IDVal, ".objc_module_info")) return ParseDirectiveSectionSwitch("__OBJC,__module_info"); if (!strcmp(IDVal, ".objc_class_names")) return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals"); if (!strcmp(IDVal, ".objc_meth_var_types")) return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals"); if (!strcmp(IDVal, ".objc_meth_var_names")) return ParseDirectiveSectionSwitch("__TEXT,__cstring","cstring_literals"); if (!strcmp(IDVal, ".objc_selector_strs")) return ParseDirectiveSectionSwitch("__OBJC,__selector_strs"); // Assembler features if (!strcmp(IDVal, ".set")) return ParseDirectiveSet(); // Data directives if (!strcmp(IDVal, ".ascii")) return ParseDirectiveAscii(false); if (!strcmp(IDVal, ".asciz")) return ParseDirectiveAscii(true); // FIXME: Target hooks for size? Also for "word", "hword". if (!strcmp(IDVal, ".byte")) return ParseDirectiveValue(1); if (!strcmp(IDVal, ".short")) return ParseDirectiveValue(2); if (!strcmp(IDVal, ".long")) return ParseDirectiveValue(4); if (!strcmp(IDVal, ".quad")) return ParseDirectiveValue(8); // FIXME: Target hooks for IsPow2. if (!strcmp(IDVal, ".align")) return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/1); if (!strcmp(IDVal, ".align32")) return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/4); if (!strcmp(IDVal, ".balign")) return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/1); if (!strcmp(IDVal, ".balignw")) return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/2); if (!strcmp(IDVal, ".balignl")) return ParseDirectiveAlign(/*IsPow2=*/false, /*ExprSize=*/4); if (!strcmp(IDVal, ".p2align")) return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/1); if (!strcmp(IDVal, ".p2alignw")) return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/2); if (!strcmp(IDVal, ".p2alignl")) return ParseDirectiveAlign(/*IsPow2=*/true, /*ExprSize=*/4); if (!strcmp(IDVal, ".org")) return ParseDirectiveOrg(); if (!strcmp(IDVal, ".fill")) return ParseDirectiveFill(); if (!strcmp(IDVal, ".space")) return ParseDirectiveSpace(); // Symbol attribute directives if (!strcmp(IDVal, ".globl") || !strcmp(IDVal, ".global")) return ParseDirectiveSymbolAttribute(MCStreamer::Global); if (!strcmp(IDVal, ".hidden")) return ParseDirectiveSymbolAttribute(MCStreamer::Hidden); if (!strcmp(IDVal, ".indirect_symbol")) return ParseDirectiveSymbolAttribute(MCStreamer::IndirectSymbol); if (!strcmp(IDVal, ".internal")) return ParseDirectiveSymbolAttribute(MCStreamer::Internal); if (!strcmp(IDVal, ".lazy_reference")) return ParseDirectiveSymbolAttribute(MCStreamer::LazyReference); if (!strcmp(IDVal, ".no_dead_strip")) return ParseDirectiveSymbolAttribute(MCStreamer::NoDeadStrip); if (!strcmp(IDVal, ".private_extern")) return ParseDirectiveSymbolAttribute(MCStreamer::PrivateExtern); if (!strcmp(IDVal, ".protected")) return ParseDirectiveSymbolAttribute(MCStreamer::Protected); if (!strcmp(IDVal, ".reference")) return ParseDirectiveSymbolAttribute(MCStreamer::Reference); if (!strcmp(IDVal, ".weak")) return ParseDirectiveSymbolAttribute(MCStreamer::Weak); if (!strcmp(IDVal, ".weak_definition")) return ParseDirectiveSymbolAttribute(MCStreamer::WeakDefinition); if (!strcmp(IDVal, ".weak_reference")) return ParseDirectiveSymbolAttribute(MCStreamer::WeakReference); if (!strcmp(IDVal, ".comm")) return ParseDirectiveComm(/*IsLocal=*/false); if (!strcmp(IDVal, ".lcomm")) return ParseDirectiveComm(/*IsLocal=*/true); if (!strcmp(IDVal, ".zerofill")) return ParseDirectiveDarwinZerofill(); if (!strcmp(IDVal, ".desc")) return ParseDirectiveDarwinSymbolDesc(); if (!strcmp(IDVal, ".lsym")) return ParseDirectiveDarwinLsym(); if (!strcmp(IDVal, ".subsections_via_symbols")) return ParseDirectiveDarwinSubsectionsViaSymbols(); if (!strcmp(IDVal, ".abort")) return ParseDirectiveAbort(); if (!strcmp(IDVal, ".include")) return ParseDirectiveInclude(); if (!strcmp(IDVal, ".dump")) return ParseDirectiveDarwinDumpOrLoad(IDLoc, /*IsDump=*/true); if (!strcmp(IDVal, ".load")) return ParseDirectiveDarwinDumpOrLoad(IDLoc, /*IsLoad=*/false); Warning(IDLoc, "ignoring directive for now"); EatToEndOfStatement(); return false; } MCInst Inst; if (ParseX86InstOperands(IDVal, Inst) && getTargetParser().ParseInstruction(*this, IDVal, Inst)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in argument list"); // Eat the end of statement marker. Lexer.Lex(); // Instruction is good, process it. Out.EmitInstruction(Inst); // Skip to end of line for now. return false; } bool AsmParser::ParseAssignment(const char *Name, bool IsDotSet) { // FIXME: Use better location, we should use proper tokens. SMLoc EqualLoc = Lexer.getLoc(); MCValue Value; if (ParseRelocatableExpression(Value)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in assignment"); // Eat the end of statement marker. Lexer.Lex(); // Diagnose assignment to 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. // FIXME: Handle '.'. // FIXME: Diagnose assignment to protected identifier (e.g., register name). MCSymbol *Sym = Ctx.GetOrCreateSymbol(Name); if (Sym->getSection()) return Error(EqualLoc, "invalid assignment to symbol emitted as a label"); if (Sym->isExternal()) return Error(EqualLoc, "invalid assignment to external symbol"); // Do the assignment. Out.EmitAssignment(Sym, Value, IsDotSet); return false; } /// ParseDirectiveSet: /// ::= .set identifier ',' expression bool AsmParser::ParseDirectiveSet() { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier after '.set' directive"); const char *Name = Lexer.getCurStrVal(); if (Lexer.Lex() != asmtok::Comma) return TokError("unexpected token in '.set'"); Lexer.Lex(); return ParseAssignment(Name, true); } /// ParseDirectiveSection: /// ::= .section identifier (',' identifier)* /// FIXME: This should actually parse out the segment, section, attributes and /// sizeof_stub fields. bool AsmParser::ParseDirectiveDarwinSection() { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier after '.section' directive"); std::string Section = Lexer.getCurStrVal(); Lexer.Lex(); // Accept a comma separated list of modifiers. while (Lexer.is(asmtok::Comma)) { Lexer.Lex(); if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in '.section' directive"); Section += ','; Section += Lexer.getCurStrVal(); Lexer.Lex(); } if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.section' directive"); Lexer.Lex(); Out.SwitchSection(Ctx.GetSection(Section.c_str())); return false; } bool AsmParser::ParseDirectiveSectionSwitch(const char *Section, const char *Directives) { if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in section switching directive"); Lexer.Lex(); std::string SectionStr = Section; if (Directives && Directives[0]) { SectionStr += ","; SectionStr += Directives; } Out.SwitchSection(Ctx.GetSection(Section)); return false; } /// ParseDirectiveAscii: /// ::= ( .ascii | .asciz ) [ "string" ( , "string" )* ] bool AsmParser::ParseDirectiveAscii(bool ZeroTerminated) { if (Lexer.isNot(asmtok::EndOfStatement)) { for (;;) { if (Lexer.isNot(asmtok::String)) return TokError("expected string in '.ascii' or '.asciz' directive"); // FIXME: This shouldn't use a const char* + strlen, the string could have // embedded nulls. // FIXME: Should have accessor for getting string contents. const char *Str = Lexer.getCurStrVal(); Out.EmitBytes(Str + 1, strlen(Str) - 2); if (ZeroTerminated) Out.EmitBytes("\0", 1); Lexer.Lex(); if (Lexer.is(asmtok::EndOfStatement)) break; if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.ascii' or '.asciz' directive"); Lexer.Lex(); } } Lexer.Lex(); return false; } /// ParseDirectiveValue /// ::= (.byte | .short | ... ) [ expression (, expression)* ] bool AsmParser::ParseDirectiveValue(unsigned Size) { if (Lexer.isNot(asmtok::EndOfStatement)) { for (;;) { MCValue Expr; if (ParseRelocatableExpression(Expr)) return true; Out.EmitValue(Expr, Size); if (Lexer.is(asmtok::EndOfStatement)) break; // FIXME: Improve diagnostic. if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); } } Lexer.Lex(); return false; } /// ParseDirectiveSpace /// ::= .space expression [ , expression ] bool AsmParser::ParseDirectiveSpace() { int64_t NumBytes; if (ParseAbsoluteExpression(NumBytes)) return true; int64_t FillExpr = 0; bool HasFillExpr = false; if (Lexer.isNot(asmtok::EndOfStatement)) { if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.space' directive"); Lexer.Lex(); if (ParseAbsoluteExpression(FillExpr)) return true; HasFillExpr = true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.space' directive"); } Lexer.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. for (uint64_t i = 0, e = NumBytes; i != e; ++i) Out.EmitValue(MCValue::get(FillExpr), 1); return false; } /// ParseDirectiveFill /// ::= .fill expression , expression , expression bool AsmParser::ParseDirectiveFill() { int64_t NumValues; if (ParseAbsoluteExpression(NumValues)) return true; if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.fill' directive"); Lexer.Lex(); int64_t FillSize; if (ParseAbsoluteExpression(FillSize)) return true; if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.fill' directive"); Lexer.Lex(); int64_t FillExpr; if (ParseAbsoluteExpression(FillExpr)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.fill' directive"); Lexer.Lex(); if (FillSize != 1 && FillSize != 2 && FillSize != 4) return TokError("invalid '.fill' size, expected 1, 2, or 4"); for (uint64_t i = 0, e = NumValues; i != e; ++i) Out.EmitValue(MCValue::get(FillExpr), FillSize); return false; } /// ParseDirectiveOrg /// ::= .org expression [ , expression ] bool AsmParser::ParseDirectiveOrg() { MCValue Offset; if (ParseRelocatableExpression(Offset)) return true; // Parse optional fill expression. int64_t FillExpr = 0; if (Lexer.isNot(asmtok::EndOfStatement)) { if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.org' directive"); Lexer.Lex(); if (ParseAbsoluteExpression(FillExpr)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.org' directive"); } Lexer.Lex(); // FIXME: Only limited forms of relocatable expressions are accepted here, it // has to be relative to the current section. Out.EmitValueToOffset(Offset, FillExpr); return false; } /// ParseDirectiveAlign /// ::= {.align, ...} expression [ , expression [ , expression ]] bool AsmParser::ParseDirectiveAlign(bool IsPow2, unsigned ValueSize) { int64_t Alignment; if (ParseAbsoluteExpression(Alignment)) return true; SMLoc MaxBytesLoc; bool HasFillExpr = false; int64_t FillExpr = 0; int64_t MaxBytesToFill = 0; if (Lexer.isNot(asmtok::EndOfStatement)) { if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); // The fill expression can be omitted while specifying a maximum number of // alignment bytes, e.g: // .align 3,,4 if (Lexer.isNot(asmtok::Comma)) { HasFillExpr = true; if (ParseAbsoluteExpression(FillExpr)) return true; } if (Lexer.isNot(asmtok::EndOfStatement)) { if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); MaxBytesLoc = Lexer.getLoc(); if (ParseAbsoluteExpression(MaxBytesToFill)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in directive"); } } Lexer.Lex(); if (!HasFillExpr) { // FIXME: Sometimes fill with nop. FillExpr = 0; } // Compute alignment in bytes. if (IsPow2) { // FIXME: Diagnose overflow. Alignment = 1LL << Alignment; } // Diagnose non-sensical max bytes to fill. if (MaxBytesLoc.isValid()) { if (MaxBytesToFill < 1) { Warning(MaxBytesLoc, "alignment directive can never be satisfied in this " "many bytes, ignoring"); return false; } if (MaxBytesToFill >= Alignment) { Warning(MaxBytesLoc, "maximum bytes expression exceeds alignment and " "has no effect"); MaxBytesToFill = 0; } } // FIXME: Target specific behavior about how the "extra" bytes are filled. Out.EmitValueToAlignment(Alignment, FillExpr, ValueSize, MaxBytesToFill); return false; } /// ParseDirectiveSymbolAttribute /// ::= { ".globl", ".weak", ... } [ identifier ( , identifier )* ] bool AsmParser::ParseDirectiveSymbolAttribute(MCStreamer::SymbolAttr Attr) { if (Lexer.isNot(asmtok::EndOfStatement)) { for (;;) { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in directive"); MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); Lexer.Lex(); // If this is use of an undefined symbol then mark it external. if (!Sym->getSection() && !Ctx.GetSymbolValue(Sym)) Sym->setExternal(true); Out.EmitSymbolAttribute(Sym, Attr); if (Lexer.is(asmtok::EndOfStatement)) break; if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); } } Lexer.Lex(); return false; } /// ParseDirectiveDarwinSymbolDesc /// ::= .desc identifier , expression bool AsmParser::ParseDirectiveDarwinSymbolDesc() { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in directive"); // handle the identifier as the key symbol. SMLoc IDLoc = Lexer.getLoc(); MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); Lexer.Lex(); if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.desc' directive"); Lexer.Lex(); SMLoc DescLoc = Lexer.getLoc(); int64_t DescValue; if (ParseAbsoluteExpression(DescValue)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.desc' directive"); Lexer.Lex(); // Set the n_desc field of this Symbol to this DescValue Out.EmitSymbolDesc(Sym, DescValue); return false; } /// ParseDirectiveComm /// ::= ( .comm | .lcomm ) identifier , size_expression [ , align_expression ] bool AsmParser::ParseDirectiveComm(bool IsLocal) { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in directive"); // handle the identifier as the key symbol. SMLoc IDLoc = Lexer.getLoc(); MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); Lexer.Lex(); if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); int64_t Size; SMLoc SizeLoc = Lexer.getLoc(); if (ParseAbsoluteExpression(Size)) return true; int64_t Pow2Alignment = 0; SMLoc Pow2AlignmentLoc; if (Lexer.is(asmtok::Comma)) { Lexer.Lex(); Pow2AlignmentLoc = Lexer.getLoc(); if (ParseAbsoluteExpression(Pow2Alignment)) return true; } if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.comm' or '.lcomm' directive"); Lexer.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 assember // 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"); // TODO: Symbol must be undefined or it is a error to re-defined the symbol if (Sym->getSection() || Ctx.GetSymbolValue(Sym)) return Error(IDLoc, "invalid symbol redefinition"); // Create the Symbol as a common or local common with Size and Pow2Alignment Out.EmitCommonSymbol(Sym, Size, Pow2Alignment, IsLocal); return false; } /// ParseDirectiveDarwinZerofill /// ::= .zerofill segname , sectname [, identifier , size_expression [ /// , align_expression ]] bool AsmParser::ParseDirectiveDarwinZerofill() { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected segment name after '.zerofill' directive"); std::string Section = Lexer.getCurStrVal(); Lexer.Lex(); if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Section += ','; Lexer.Lex(); if (Lexer.isNot(asmtok::Identifier)) return TokError("expected section name after comma in '.zerofill' " "directive"); Section += Lexer.getCurStrVal(); Lexer.Lex(); // FIXME: we will need to tell GetSection() that this is to be created with or // must have the Mach-O section type of S_ZEROFILL. Something like the code // below could be done but for now it is not as EmitZerofill() does not know // how to deal with a section type in the section name like // ParseDirectiveDarwinSection() allows. // Section += ','; // Section += "zerofill"; // If this is the end of the line all that was wanted was to create the // the section but with no symbol. if (Lexer.is(asmtok::EndOfStatement)) { // Create the zerofill section but no symbol Out.EmitZerofill(Ctx.GetSection(Section.c_str())); return false; } if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in directive"); // handle the identifier as the key symbol. SMLoc IDLoc = Lexer.getLoc(); MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); Lexer.Lex(); if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in directive"); Lexer.Lex(); int64_t Size; SMLoc SizeLoc = Lexer.getLoc(); if (ParseAbsoluteExpression(Size)) return true; int64_t Pow2Alignment = 0; SMLoc Pow2AlignmentLoc; if (Lexer.is(asmtok::Comma)) { Lexer.Lex(); Pow2AlignmentLoc = Lexer.getLoc(); if (ParseAbsoluteExpression(Pow2Alignment)) return true; } if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.zerofill' directive"); Lexer.Lex(); if (Size < 0) return Error(SizeLoc, "invalid '.zerofill' directive size, can't be less " "than zero"); // NOTE: The alignment in the directive is a power of 2 value, the assember // may internally end up wanting an alignment in bytes. // FIXME: Diagnose overflow. if (Pow2Alignment < 0) return Error(Pow2AlignmentLoc, "invalid '.zerofill' directive alignment, " "can't be less than zero"); // TODO: Symbol must be undefined or it is a error to re-defined the symbol if (Sym->getSection() || Ctx.GetSymbolValue(Sym)) return Error(IDLoc, "invalid symbol redefinition"); // Create the zerofill Symbol with Size and Pow2Alignment Out.EmitZerofill(Ctx.GetSection(Section.c_str()), Sym, Size, Pow2Alignment); return false; } /// ParseDirectiveDarwinSubsectionsViaSymbols /// ::= .subsections_via_symbols bool AsmParser::ParseDirectiveDarwinSubsectionsViaSymbols() { if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.subsections_via_symbols' directive"); Lexer.Lex(); Out.EmitAssemblerFlag(MCStreamer::SubsectionsViaSymbols); return false; } /// ParseDirectiveAbort /// ::= .abort [ "abort_string" ] bool AsmParser::ParseDirectiveAbort() { const char *Str = NULL; if (Lexer.isNot(asmtok::EndOfStatement)) { if (Lexer.isNot(asmtok::String)) return TokError("expected string in '.abort' directive"); Str = Lexer.getCurStrVal(); Lexer.Lex(); } if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.abort' directive"); Lexer.Lex(); Out.AbortAssembly(Str); return false; } /// ParseDirectiveLsym /// ::= .lsym identifier , expression bool AsmParser::ParseDirectiveDarwinLsym() { if (Lexer.isNot(asmtok::Identifier)) return TokError("expected identifier in directive"); // handle the identifier as the key symbol. SMLoc IDLoc = Lexer.getLoc(); MCSymbol *Sym = Ctx.GetOrCreateSymbol(Lexer.getCurStrVal()); Lexer.Lex(); if (Lexer.isNot(asmtok::Comma)) return TokError("unexpected token in '.lsym' directive"); Lexer.Lex(); MCValue Expr; if (ParseRelocatableExpression(Expr)) return true; if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.lsym' directive"); Lexer.Lex(); // Create the Sym with the value of the Expr Out.EmitLocalSymbol(Sym, Expr); return false; } /// ParseDirectiveInclude /// ::= .include "filename" bool AsmParser::ParseDirectiveInclude() { if (Lexer.isNot(asmtok::String)) return TokError("expected string in '.include' directive"); std::string Filename = Lexer.getCurStrVal(); SMLoc IncludeLoc = Lexer.getLoc(); Lexer.Lex(); if (Lexer.isNot(asmtok::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 (Lexer.EnterIncludeFile(Filename)) { Lexer.PrintMessage(IncludeLoc, "Could not find include file '" + Filename + "'", "error"); return true; } return false; } /// ParseDirectiveDarwinDumpOrLoad /// ::= ( .dump | .load ) "filename" bool AsmParser::ParseDirectiveDarwinDumpOrLoad(SMLoc IDLoc, bool IsDump) { if (Lexer.isNot(asmtok::String)) return TokError("expected string in '.dump' or '.load' directive"); Lexer.getCurStrVal(); Lexer.Lex(); if (Lexer.isNot(asmtok::EndOfStatement)) return TokError("unexpected token in '.dump' or '.load' directive"); Lexer.Lex(); // FIXME: If/when .dump and .load are implemented they will be done in the // the assembly parser and not have any need for an MCStreamer API. if (IsDump) Warning(IDLoc, "ignoring directive .dump for now"); else Warning(IDLoc, "ignoring directive .load for now"); return false; }