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      1 //===- DarwinAsmParser.cpp - Darwin (Mach-O) Assembly Parser --------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 #include "llvm/MC/MCParser/MCAsmParserExtension.h"
     11 #include "llvm/MC/MCContext.h"
     12 #include "llvm/MC/MCSectionMachO.h"
     13 #include "llvm/MC/MCStreamer.h"
     14 #include "llvm/MC/MCSymbol.h"
     15 #include "llvm/MC/MCParser/MCAsmLexer.h"
     16 #include "llvm/MC/MCParser/MCAsmParser.h"
     17 #include "llvm/ADT/StringSwitch.h"
     18 #include "llvm/ADT/StringRef.h"
     19 #include "llvm/ADT/Twine.h"
     20 #include "llvm/Support/MemoryBuffer.h"
     21 #include "llvm/Support/SourceMgr.h"
     22 using namespace llvm;
     23 
     24 namespace {
     25 
     26 /// \brief Implementation of directive handling which is shared across all
     27 /// Darwin targets.
     28 class DarwinAsmParser : public MCAsmParserExtension {
     29   template<bool (DarwinAsmParser::*Handler)(StringRef, SMLoc)>
     30   void AddDirectiveHandler(StringRef Directive) {
     31     getParser().AddDirectiveHandler(this, Directive,
     32                                     HandleDirective<DarwinAsmParser, Handler>);
     33   }
     34 
     35   bool ParseSectionSwitch(const char *Segment, const char *Section,
     36                           unsigned TAA = 0, unsigned ImplicitAlign = 0,
     37                           unsigned StubSize = 0);
     38 
     39 public:
     40   DarwinAsmParser() {}
     41 
     42   virtual void Initialize(MCAsmParser &Parser) {
     43     // Call the base implementation.
     44     this->MCAsmParserExtension::Initialize(Parser);
     45 
     46     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDesc>(".desc");
     47     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveLsym>(".lsym");
     48     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveSubsectionsViaSymbols>(
     49       ".subsections_via_symbols");
     50     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDumpOrLoad>(".dump");
     51     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDumpOrLoad>(".load");
     52     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveSection>(".section");
     53     AddDirectiveHandler<&DarwinAsmParser::ParseDirectivePushSection>(".pushsection");
     54     AddDirectiveHandler<&DarwinAsmParser::ParseDirectivePopSection>(".popsection");
     55     AddDirectiveHandler<&DarwinAsmParser::ParseDirectivePrevious>(".previous");
     56     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveSecureLogUnique>(
     57       ".secure_log_unique");
     58     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveSecureLogReset>(
     59       ".secure_log_reset");
     60     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveTBSS>(".tbss");
     61     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveZerofill>(".zerofill");
     62 
     63     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDataRegion>(".data_region");
     64     AddDirectiveHandler<&DarwinAsmParser::ParseDirectiveDataRegionEnd>(".end_data_region");
     65 
     66     // Special section directives.
     67     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveConst>(".const");
     68     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveConstData>(".const_data");
     69     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveConstructor>(".constructor");
     70     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveCString>(".cstring");
     71     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveData>(".data");
     72     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveDestructor>(".destructor");
     73     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveDyld>(".dyld");
     74     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveFVMLibInit0>(".fvmlib_init0");
     75     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveFVMLibInit1>(".fvmlib_init1");
     76     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveLazySymbolPointers>(".lazy_symbol_pointer");
     77     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveLiteral16>(".literal16");
     78     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveLiteral4>(".literal4");
     79     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveLiteral8>(".literal8");
     80     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveModInitFunc>(".mod_init_func");
     81     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveModTermFunc>(".mod_term_func");
     82     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveNonLazySymbolPointers>(".non_lazy_symbol_pointer");
     83     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCCatClsMeth>(".objc_cat_cls_meth");
     84     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCCatInstMeth>(".objc_cat_inst_meth");
     85     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCCategory>(".objc_category");
     86     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCClass>(".objc_class");
     87     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCClassNames>(".objc_class_names");
     88     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCClassVars>(".objc_class_vars");
     89     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCClsMeth>(".objc_cls_meth");
     90     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCClsRefs>(".objc_cls_refs");
     91     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCInstMeth>(".objc_inst_meth");
     92     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCInstanceVars>(".objc_instance_vars");
     93     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCMessageRefs>(".objc_message_refs");
     94     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCMetaClass>(".objc_meta_class");
     95     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCMethVarNames>(".objc_meth_var_names");
     96     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCMethVarTypes>(".objc_meth_var_types");
     97     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCModuleInfo>(".objc_module_info");
     98     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCProtocol>(".objc_protocol");
     99     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCSelectorStrs>(".objc_selector_strs");
    100     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCStringObject>(".objc_string_object");
    101     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveObjCSymbols>(".objc_symbols");
    102     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectivePICSymbolStub>(".picsymbol_stub");
    103     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveStaticConst>(".static_const");
    104     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveStaticData>(".static_data");
    105     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveSymbolStub>(".symbol_stub");
    106     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveTData>(".tdata");
    107     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveText>(".text");
    108     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveThreadInitFunc>(".thread_init_func");
    109     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveTLV>(".tlv");
    110 
    111     AddDirectiveHandler<&DarwinAsmParser::ParseSectionDirectiveIdent>(".ident");
    112   }
    113 
    114   bool ParseDirectiveDesc(StringRef, SMLoc);
    115   bool ParseDirectiveDumpOrLoad(StringRef, SMLoc);
    116   bool ParseDirectiveLsym(StringRef, SMLoc);
    117   bool ParseDirectiveSection(StringRef, SMLoc);
    118   bool ParseDirectivePushSection(StringRef, SMLoc);
    119   bool ParseDirectivePopSection(StringRef, SMLoc);
    120   bool ParseDirectivePrevious(StringRef, SMLoc);
    121   bool ParseDirectiveSecureLogReset(StringRef, SMLoc);
    122   bool ParseDirectiveSecureLogUnique(StringRef, SMLoc);
    123   bool ParseDirectiveSubsectionsViaSymbols(StringRef, SMLoc);
    124   bool ParseDirectiveTBSS(StringRef, SMLoc);
    125   bool ParseDirectiveZerofill(StringRef, SMLoc);
    126   bool ParseDirectiveDataRegion(StringRef, SMLoc);
    127   bool ParseDirectiveDataRegionEnd(StringRef, SMLoc);
    128 
    129   // Named Section Directive
    130   bool ParseSectionDirectiveConst(StringRef, SMLoc) {
    131     return ParseSectionSwitch("__TEXT", "__const");
    132   }
    133   bool ParseSectionDirectiveStaticConst(StringRef, SMLoc) {
    134     return ParseSectionSwitch("__TEXT", "__static_const");
    135   }
    136   bool ParseSectionDirectiveCString(StringRef, SMLoc) {
    137     return ParseSectionSwitch("__TEXT","__cstring",
    138                               MCSectionMachO::S_CSTRING_LITERALS);
    139   }
    140   bool ParseSectionDirectiveLiteral4(StringRef, SMLoc) {
    141     return ParseSectionSwitch("__TEXT", "__literal4",
    142                               MCSectionMachO::S_4BYTE_LITERALS, 4);
    143   }
    144   bool ParseSectionDirectiveLiteral8(StringRef, SMLoc) {
    145     return ParseSectionSwitch("__TEXT", "__literal8",
    146                               MCSectionMachO::S_8BYTE_LITERALS, 8);
    147   }
    148   bool ParseSectionDirectiveLiteral16(StringRef, SMLoc) {
    149     return ParseSectionSwitch("__TEXT","__literal16",
    150                               MCSectionMachO::S_16BYTE_LITERALS, 16);
    151   }
    152   bool ParseSectionDirectiveConstructor(StringRef, SMLoc) {
    153     return ParseSectionSwitch("__TEXT","__constructor");
    154   }
    155   bool ParseSectionDirectiveDestructor(StringRef, SMLoc) {
    156     return ParseSectionSwitch("__TEXT","__destructor");
    157   }
    158   bool ParseSectionDirectiveFVMLibInit0(StringRef, SMLoc) {
    159     return ParseSectionSwitch("__TEXT","__fvmlib_init0");
    160   }
    161   bool ParseSectionDirectiveFVMLibInit1(StringRef, SMLoc) {
    162     return ParseSectionSwitch("__TEXT","__fvmlib_init1");
    163   }
    164   bool ParseSectionDirectiveSymbolStub(StringRef, SMLoc) {
    165     return ParseSectionSwitch("__TEXT","__symbol_stub",
    166                               MCSectionMachO::S_SYMBOL_STUBS |
    167                               MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
    168                               // FIXME: Different on PPC and ARM.
    169                               0, 16);
    170   }
    171   bool ParseSectionDirectivePICSymbolStub(StringRef, SMLoc) {
    172     return ParseSectionSwitch("__TEXT","__picsymbol_stub",
    173                               MCSectionMachO::S_SYMBOL_STUBS |
    174                               MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS, 0, 26);
    175   }
    176   bool ParseSectionDirectiveData(StringRef, SMLoc) {
    177     return ParseSectionSwitch("__DATA", "__data");
    178   }
    179   bool ParseSectionDirectiveStaticData(StringRef, SMLoc) {
    180     return ParseSectionSwitch("__DATA", "__static_data");
    181   }
    182   bool ParseSectionDirectiveNonLazySymbolPointers(StringRef, SMLoc) {
    183     return ParseSectionSwitch("__DATA", "__nl_symbol_ptr",
    184                               MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS, 4);
    185   }
    186   bool ParseSectionDirectiveLazySymbolPointers(StringRef, SMLoc) {
    187     return ParseSectionSwitch("__DATA", "__la_symbol_ptr",
    188                               MCSectionMachO::S_LAZY_SYMBOL_POINTERS, 4);
    189   }
    190   bool ParseSectionDirectiveDyld(StringRef, SMLoc) {
    191     return ParseSectionSwitch("__DATA", "__dyld");
    192   }
    193   bool ParseSectionDirectiveModInitFunc(StringRef, SMLoc) {
    194     return ParseSectionSwitch("__DATA", "__mod_init_func",
    195                               MCSectionMachO::S_MOD_INIT_FUNC_POINTERS, 4);
    196   }
    197   bool ParseSectionDirectiveModTermFunc(StringRef, SMLoc) {
    198     return ParseSectionSwitch("__DATA", "__mod_term_func",
    199                               MCSectionMachO::S_MOD_TERM_FUNC_POINTERS, 4);
    200   }
    201   bool ParseSectionDirectiveConstData(StringRef, SMLoc) {
    202     return ParseSectionSwitch("__DATA", "__const");
    203   }
    204   bool ParseSectionDirectiveObjCClass(StringRef, SMLoc) {
    205     return ParseSectionSwitch("__OBJC", "__class",
    206                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    207   }
    208   bool ParseSectionDirectiveObjCMetaClass(StringRef, SMLoc) {
    209     return ParseSectionSwitch("__OBJC", "__meta_class",
    210                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    211   }
    212   bool ParseSectionDirectiveObjCCatClsMeth(StringRef, SMLoc) {
    213     return ParseSectionSwitch("__OBJC", "__cat_cls_meth",
    214                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    215   }
    216   bool ParseSectionDirectiveObjCCatInstMeth(StringRef, SMLoc) {
    217     return ParseSectionSwitch("__OBJC", "__cat_inst_meth",
    218                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    219   }
    220   bool ParseSectionDirectiveObjCProtocol(StringRef, SMLoc) {
    221     return ParseSectionSwitch("__OBJC", "__protocol",
    222                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    223   }
    224   bool ParseSectionDirectiveObjCStringObject(StringRef, SMLoc) {
    225     return ParseSectionSwitch("__OBJC", "__string_object",
    226                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    227   }
    228   bool ParseSectionDirectiveObjCClsMeth(StringRef, SMLoc) {
    229     return ParseSectionSwitch("__OBJC", "__cls_meth",
    230                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    231   }
    232   bool ParseSectionDirectiveObjCInstMeth(StringRef, SMLoc) {
    233     return ParseSectionSwitch("__OBJC", "__inst_meth",
    234                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    235   }
    236   bool ParseSectionDirectiveObjCClsRefs(StringRef, SMLoc) {
    237     return ParseSectionSwitch("__OBJC", "__cls_refs",
    238                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP |
    239                               MCSectionMachO::S_LITERAL_POINTERS, 4);
    240   }
    241   bool ParseSectionDirectiveObjCMessageRefs(StringRef, SMLoc) {
    242     return ParseSectionSwitch("__OBJC", "__message_refs",
    243                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP |
    244                               MCSectionMachO::S_LITERAL_POINTERS, 4);
    245   }
    246   bool ParseSectionDirectiveObjCSymbols(StringRef, SMLoc) {
    247     return ParseSectionSwitch("__OBJC", "__symbols",
    248                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    249   }
    250   bool ParseSectionDirectiveObjCCategory(StringRef, SMLoc) {
    251     return ParseSectionSwitch("__OBJC", "__category",
    252                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    253   }
    254   bool ParseSectionDirectiveObjCClassVars(StringRef, SMLoc) {
    255     return ParseSectionSwitch("__OBJC", "__class_vars",
    256                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    257   }
    258   bool ParseSectionDirectiveObjCInstanceVars(StringRef, SMLoc) {
    259     return ParseSectionSwitch("__OBJC", "__instance_vars",
    260                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    261   }
    262   bool ParseSectionDirectiveObjCModuleInfo(StringRef, SMLoc) {
    263     return ParseSectionSwitch("__OBJC", "__module_info",
    264                               MCSectionMachO::S_ATTR_NO_DEAD_STRIP);
    265   }
    266   bool ParseSectionDirectiveObjCClassNames(StringRef, SMLoc) {
    267     return ParseSectionSwitch("__TEXT", "__cstring",
    268                               MCSectionMachO::S_CSTRING_LITERALS);
    269   }
    270   bool ParseSectionDirectiveObjCMethVarTypes(StringRef, SMLoc) {
    271     return ParseSectionSwitch("__TEXT", "__cstring",
    272                               MCSectionMachO::S_CSTRING_LITERALS);
    273   }
    274   bool ParseSectionDirectiveObjCMethVarNames(StringRef, SMLoc) {
    275     return ParseSectionSwitch("__TEXT", "__cstring",
    276                               MCSectionMachO::S_CSTRING_LITERALS);
    277   }
    278   bool ParseSectionDirectiveObjCSelectorStrs(StringRef, SMLoc) {
    279     return ParseSectionSwitch("__OBJC", "__selector_strs",
    280                               MCSectionMachO::S_CSTRING_LITERALS);
    281   }
    282   bool ParseSectionDirectiveTData(StringRef, SMLoc) {
    283     return ParseSectionSwitch("__DATA", "__thread_data",
    284                               MCSectionMachO::S_THREAD_LOCAL_REGULAR);
    285   }
    286   bool ParseSectionDirectiveText(StringRef, SMLoc) {
    287     return ParseSectionSwitch("__TEXT", "__text",
    288                               MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS);
    289   }
    290   bool ParseSectionDirectiveTLV(StringRef, SMLoc) {
    291     return ParseSectionSwitch("__DATA", "__thread_vars",
    292                               MCSectionMachO::S_THREAD_LOCAL_VARIABLES);
    293   }
    294   bool ParseSectionDirectiveIdent(StringRef, SMLoc) {
    295     // Darwin silently ignores the .ident directive.
    296     getParser().EatToEndOfStatement();
    297     return false;
    298   }
    299   bool ParseSectionDirectiveThreadInitFunc(StringRef, SMLoc) {
    300     return ParseSectionSwitch("__DATA", "__thread_init",
    301                          MCSectionMachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS);
    302   }
    303 
    304 };
    305 
    306 } // end anonymous namespace
    307 
    308 bool DarwinAsmParser::ParseSectionSwitch(const char *Segment,
    309                                          const char *Section,
    310                                          unsigned TAA, unsigned Align,
    311                                          unsigned StubSize) {
    312   if (getLexer().isNot(AsmToken::EndOfStatement))
    313     return TokError("unexpected token in section switching directive");
    314   Lex();
    315 
    316   // FIXME: Arch specific.
    317   bool isText = StringRef(Segment) == "__TEXT";  // FIXME: Hack.
    318   getStreamer().SwitchSection(getContext().getMachOSection(
    319                                 Segment, Section, TAA, StubSize,
    320                                 isText ? SectionKind::getText()
    321                                        : SectionKind::getDataRel()));
    322 
    323   // Set the implicit alignment, if any.
    324   //
    325   // FIXME: This isn't really what 'as' does; I think it just uses the implicit
    326   // alignment on the section (e.g., if one manually inserts bytes into the
    327   // section, then just issuing the section switch directive will not realign
    328   // the section. However, this is arguably more reasonable behavior, and there
    329   // is no good reason for someone to intentionally emit incorrectly sized
    330   // values into the implicitly aligned sections.
    331   if (Align)
    332     getStreamer().EmitValueToAlignment(Align, 0, 1, 0);
    333 
    334   return false;
    335 }
    336 
    337 /// ParseDirectiveDesc
    338 ///  ::= .desc identifier , expression
    339 bool DarwinAsmParser::ParseDirectiveDesc(StringRef, SMLoc) {
    340   StringRef Name;
    341   if (getParser().ParseIdentifier(Name))
    342     return TokError("expected identifier in directive");
    343 
    344   // Handle the identifier as the key symbol.
    345   MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
    346 
    347   if (getLexer().isNot(AsmToken::Comma))
    348     return TokError("unexpected token in '.desc' directive");
    349   Lex();
    350 
    351   int64_t DescValue;
    352   if (getParser().ParseAbsoluteExpression(DescValue))
    353     return true;
    354 
    355   if (getLexer().isNot(AsmToken::EndOfStatement))
    356     return TokError("unexpected token in '.desc' directive");
    357 
    358   Lex();
    359 
    360   // Set the n_desc field of this Symbol to this DescValue
    361   getStreamer().EmitSymbolDesc(Sym, DescValue);
    362 
    363   return false;
    364 }
    365 
    366 /// ParseDirectiveDumpOrLoad
    367 ///  ::= ( .dump | .load ) "filename"
    368 bool DarwinAsmParser::ParseDirectiveDumpOrLoad(StringRef Directive,
    369                                                SMLoc IDLoc) {
    370   bool IsDump = Directive == ".dump";
    371   if (getLexer().isNot(AsmToken::String))
    372     return TokError("expected string in '.dump' or '.load' directive");
    373 
    374   Lex();
    375 
    376   if (getLexer().isNot(AsmToken::EndOfStatement))
    377     return TokError("unexpected token in '.dump' or '.load' directive");
    378 
    379   Lex();
    380 
    381   // FIXME: If/when .dump and .load are implemented they will be done in the
    382   // the assembly parser and not have any need for an MCStreamer API.
    383   if (IsDump)
    384     return Warning(IDLoc, "ignoring directive .dump for now");
    385   else
    386     return Warning(IDLoc, "ignoring directive .load for now");
    387 }
    388 
    389 /// ParseDirectiveLsym
    390 ///  ::= .lsym identifier , expression
    391 bool DarwinAsmParser::ParseDirectiveLsym(StringRef, SMLoc) {
    392   StringRef Name;
    393   if (getParser().ParseIdentifier(Name))
    394     return TokError("expected identifier in directive");
    395 
    396   // Handle the identifier as the key symbol.
    397   MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
    398 
    399   if (getLexer().isNot(AsmToken::Comma))
    400     return TokError("unexpected token in '.lsym' directive");
    401   Lex();
    402 
    403   const MCExpr *Value;
    404   if (getParser().ParseExpression(Value))
    405     return true;
    406 
    407   if (getLexer().isNot(AsmToken::EndOfStatement))
    408     return TokError("unexpected token in '.lsym' directive");
    409 
    410   Lex();
    411 
    412   // We don't currently support this directive.
    413   //
    414   // FIXME: Diagnostic location!
    415   (void) Sym;
    416   return TokError("directive '.lsym' is unsupported");
    417 }
    418 
    419 /// ParseDirectiveSection:
    420 ///   ::= .section identifier (',' identifier)*
    421 bool DarwinAsmParser::ParseDirectiveSection(StringRef, SMLoc) {
    422   SMLoc Loc = getLexer().getLoc();
    423 
    424   StringRef SectionName;
    425   if (getParser().ParseIdentifier(SectionName))
    426     return Error(Loc, "expected identifier after '.section' directive");
    427 
    428   // Verify there is a following comma.
    429   if (!getLexer().is(AsmToken::Comma))
    430     return TokError("unexpected token in '.section' directive");
    431 
    432   std::string SectionSpec = SectionName;
    433   SectionSpec += ",";
    434 
    435   // Add all the tokens until the end of the line, ParseSectionSpecifier will
    436   // handle this.
    437   StringRef EOL = getLexer().LexUntilEndOfStatement();
    438   SectionSpec.append(EOL.begin(), EOL.end());
    439 
    440   Lex();
    441   if (getLexer().isNot(AsmToken::EndOfStatement))
    442     return TokError("unexpected token in '.section' directive");
    443   Lex();
    444 
    445 
    446   StringRef Segment, Section;
    447   unsigned StubSize;
    448   unsigned TAA;
    449   bool TAAParsed;
    450   std::string ErrorStr =
    451     MCSectionMachO::ParseSectionSpecifier(SectionSpec, Segment, Section,
    452                                           TAA, TAAParsed, StubSize);
    453 
    454   if (!ErrorStr.empty())
    455     return Error(Loc, ErrorStr.c_str());
    456 
    457   // FIXME: Arch specific.
    458   bool isText = Segment == "__TEXT";  // FIXME: Hack.
    459   getStreamer().SwitchSection(getContext().getMachOSection(
    460                                 Segment, Section, TAA, StubSize,
    461                                 isText ? SectionKind::getText()
    462                                 : SectionKind::getDataRel()));
    463   return false;
    464 }
    465 
    466 /// ParseDirectivePushSection:
    467 ///   ::= .pushsection identifier (',' identifier)*
    468 bool DarwinAsmParser::ParseDirectivePushSection(StringRef S, SMLoc Loc) {
    469   getStreamer().PushSection();
    470 
    471   if (ParseDirectiveSection(S, Loc)) {
    472     getStreamer().PopSection();
    473     return true;
    474   }
    475 
    476   return false;
    477 }
    478 
    479 /// ParseDirectivePopSection:
    480 ///   ::= .popsection
    481 bool DarwinAsmParser::ParseDirectivePopSection(StringRef, SMLoc) {
    482   if (!getStreamer().PopSection())
    483     return TokError(".popsection without corresponding .pushsection");
    484   return false;
    485 }
    486 
    487 /// ParseDirectivePrevious:
    488 ///   ::= .previous
    489 bool DarwinAsmParser::ParseDirectivePrevious(StringRef DirName, SMLoc) {
    490   const MCSection *PreviousSection = getStreamer().getPreviousSection();
    491   if (PreviousSection == NULL)
    492       return TokError(".previous without corresponding .section");
    493   getStreamer().SwitchSection(PreviousSection);
    494   return false;
    495 }
    496 
    497 /// ParseDirectiveSecureLogUnique
    498 ///  ::= .secure_log_unique ... message ...
    499 bool DarwinAsmParser::ParseDirectiveSecureLogUnique(StringRef, SMLoc IDLoc) {
    500   StringRef LogMessage = getParser().ParseStringToEndOfStatement();
    501   if (getLexer().isNot(AsmToken::EndOfStatement))
    502     return TokError("unexpected token in '.secure_log_unique' directive");
    503 
    504   if (getContext().getSecureLogUsed() != false)
    505     return Error(IDLoc, ".secure_log_unique specified multiple times");
    506 
    507   // Get the secure log path.
    508   const char *SecureLogFile = getContext().getSecureLogFile();
    509   if (SecureLogFile == NULL)
    510     return Error(IDLoc, ".secure_log_unique used but AS_SECURE_LOG_FILE "
    511                  "environment variable unset.");
    512 
    513   // Open the secure log file if we haven't already.
    514   raw_ostream *OS = getContext().getSecureLog();
    515   if (OS == NULL) {
    516     std::string Err;
    517     OS = new raw_fd_ostream(SecureLogFile, Err, raw_fd_ostream::F_Append);
    518     if (!Err.empty()) {
    519        delete OS;
    520        return Error(IDLoc, Twine("can't open secure log file: ") +
    521                     SecureLogFile + " (" + Err + ")");
    522     }
    523     getContext().setSecureLog(OS);
    524   }
    525 
    526   // Write the message.
    527   int CurBuf = getSourceManager().FindBufferContainingLoc(IDLoc);
    528   *OS << getSourceManager().getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
    529       << ":" << getSourceManager().FindLineNumber(IDLoc, CurBuf) << ":"
    530       << LogMessage + "\n";
    531 
    532   getContext().setSecureLogUsed(true);
    533 
    534   return false;
    535 }
    536 
    537 /// ParseDirectiveSecureLogReset
    538 ///  ::= .secure_log_reset
    539 bool DarwinAsmParser::ParseDirectiveSecureLogReset(StringRef, SMLoc IDLoc) {
    540   if (getLexer().isNot(AsmToken::EndOfStatement))
    541     return TokError("unexpected token in '.secure_log_reset' directive");
    542 
    543   Lex();
    544 
    545   getContext().setSecureLogUsed(false);
    546 
    547   return false;
    548 }
    549 
    550 /// ParseDirectiveSubsectionsViaSymbols
    551 ///  ::= .subsections_via_symbols
    552 bool DarwinAsmParser::ParseDirectiveSubsectionsViaSymbols(StringRef, SMLoc) {
    553   if (getLexer().isNot(AsmToken::EndOfStatement))
    554     return TokError("unexpected token in '.subsections_via_symbols' directive");
    555 
    556   Lex();
    557 
    558   getStreamer().EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
    559 
    560   return false;
    561 }
    562 
    563 /// ParseDirectiveTBSS
    564 ///  ::= .tbss identifier, size, align
    565 bool DarwinAsmParser::ParseDirectiveTBSS(StringRef, SMLoc) {
    566   SMLoc IDLoc = getLexer().getLoc();
    567   StringRef Name;
    568   if (getParser().ParseIdentifier(Name))
    569     return TokError("expected identifier in directive");
    570 
    571   // Handle the identifier as the key symbol.
    572   MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
    573 
    574   if (getLexer().isNot(AsmToken::Comma))
    575     return TokError("unexpected token in directive");
    576   Lex();
    577 
    578   int64_t Size;
    579   SMLoc SizeLoc = getLexer().getLoc();
    580   if (getParser().ParseAbsoluteExpression(Size))
    581     return true;
    582 
    583   int64_t Pow2Alignment = 0;
    584   SMLoc Pow2AlignmentLoc;
    585   if (getLexer().is(AsmToken::Comma)) {
    586     Lex();
    587     Pow2AlignmentLoc = getLexer().getLoc();
    588     if (getParser().ParseAbsoluteExpression(Pow2Alignment))
    589       return true;
    590   }
    591 
    592   if (getLexer().isNot(AsmToken::EndOfStatement))
    593     return TokError("unexpected token in '.tbss' directive");
    594 
    595   Lex();
    596 
    597   if (Size < 0)
    598     return Error(SizeLoc, "invalid '.tbss' directive size, can't be less than"
    599                  "zero");
    600 
    601   // FIXME: Diagnose overflow.
    602   if (Pow2Alignment < 0)
    603     return Error(Pow2AlignmentLoc, "invalid '.tbss' alignment, can't be less"
    604                  "than zero");
    605 
    606   if (!Sym->isUndefined())
    607     return Error(IDLoc, "invalid symbol redefinition");
    608 
    609   getStreamer().EmitTBSSSymbol(getContext().getMachOSection(
    610                                  "__DATA", "__thread_bss",
    611                                  MCSectionMachO::S_THREAD_LOCAL_ZEROFILL,
    612                                  0, SectionKind::getThreadBSS()),
    613                                Sym, Size, 1 << Pow2Alignment);
    614 
    615   return false;
    616 }
    617 
    618 /// ParseDirectiveZerofill
    619 ///  ::= .zerofill segname , sectname [, identifier , size_expression [
    620 ///      , align_expression ]]
    621 bool DarwinAsmParser::ParseDirectiveZerofill(StringRef, SMLoc) {
    622   StringRef Segment;
    623   if (getParser().ParseIdentifier(Segment))
    624     return TokError("expected segment name after '.zerofill' directive");
    625 
    626   if (getLexer().isNot(AsmToken::Comma))
    627     return TokError("unexpected token in directive");
    628   Lex();
    629 
    630   StringRef Section;
    631   if (getParser().ParseIdentifier(Section))
    632     return TokError("expected section name after comma in '.zerofill' "
    633                     "directive");
    634 
    635   // If this is the end of the line all that was wanted was to create the
    636   // the section but with no symbol.
    637   if (getLexer().is(AsmToken::EndOfStatement)) {
    638     // Create the zerofill section but no symbol
    639     getStreamer().EmitZerofill(getContext().getMachOSection(
    640                                  Segment, Section, MCSectionMachO::S_ZEROFILL,
    641                                  0, SectionKind::getBSS()));
    642     return false;
    643   }
    644 
    645   if (getLexer().isNot(AsmToken::Comma))
    646     return TokError("unexpected token in directive");
    647   Lex();
    648 
    649   SMLoc IDLoc = getLexer().getLoc();
    650   StringRef IDStr;
    651   if (getParser().ParseIdentifier(IDStr))
    652     return TokError("expected identifier in directive");
    653 
    654   // handle the identifier as the key symbol.
    655   MCSymbol *Sym = getContext().GetOrCreateSymbol(IDStr);
    656 
    657   if (getLexer().isNot(AsmToken::Comma))
    658     return TokError("unexpected token in directive");
    659   Lex();
    660 
    661   int64_t Size;
    662   SMLoc SizeLoc = getLexer().getLoc();
    663   if (getParser().ParseAbsoluteExpression(Size))
    664     return true;
    665 
    666   int64_t Pow2Alignment = 0;
    667   SMLoc Pow2AlignmentLoc;
    668   if (getLexer().is(AsmToken::Comma)) {
    669     Lex();
    670     Pow2AlignmentLoc = getLexer().getLoc();
    671     if (getParser().ParseAbsoluteExpression(Pow2Alignment))
    672       return true;
    673   }
    674 
    675   if (getLexer().isNot(AsmToken::EndOfStatement))
    676     return TokError("unexpected token in '.zerofill' directive");
    677 
    678   Lex();
    679 
    680   if (Size < 0)
    681     return Error(SizeLoc, "invalid '.zerofill' directive size, can't be less "
    682                  "than zero");
    683 
    684   // NOTE: The alignment in the directive is a power of 2 value, the assembler
    685   // may internally end up wanting an alignment in bytes.
    686   // FIXME: Diagnose overflow.
    687   if (Pow2Alignment < 0)
    688     return Error(Pow2AlignmentLoc, "invalid '.zerofill' directive alignment, "
    689                  "can't be less than zero");
    690 
    691   if (!Sym->isUndefined())
    692     return Error(IDLoc, "invalid symbol redefinition");
    693 
    694   // Create the zerofill Symbol with Size and Pow2Alignment
    695   //
    696   // FIXME: Arch specific.
    697   getStreamer().EmitZerofill(getContext().getMachOSection(
    698                                Segment, Section, MCSectionMachO::S_ZEROFILL,
    699                                0, SectionKind::getBSS()),
    700                              Sym, Size, 1 << Pow2Alignment);
    701 
    702   return false;
    703 }
    704 
    705 /// ParseDirectiveDataRegion
    706 ///  ::= .data_region [ ( jt8 | jt16 | jt32 ) ]
    707 bool DarwinAsmParser::ParseDirectiveDataRegion(StringRef, SMLoc) {
    708   if (getLexer().is(AsmToken::EndOfStatement)) {
    709     Lex();
    710     getStreamer().EmitDataRegion(MCDR_DataRegion);
    711     return false;
    712   }
    713   StringRef RegionType;
    714   SMLoc Loc = getParser().getTok().getLoc();
    715   if (getParser().ParseIdentifier(RegionType))
    716     return TokError("expected region type after '.data_region' directive");
    717   int Kind = StringSwitch<int>(RegionType)
    718     .Case("jt8", MCDR_DataRegionJT8)
    719     .Case("jt16", MCDR_DataRegionJT16)
    720     .Case("jt32", MCDR_DataRegionJT32)
    721     .Default(-1);
    722   if (Kind == -1)
    723     return Error(Loc, "unknown region type in '.data_region' directive");
    724   Lex();
    725 
    726   getStreamer().EmitDataRegion((MCDataRegionType)Kind);
    727   return false;
    728 }
    729 
    730 /// ParseDirectiveDataRegionEnd
    731 ///  ::= .end_data_region
    732 bool DarwinAsmParser::ParseDirectiveDataRegionEnd(StringRef, SMLoc) {
    733   if (getLexer().isNot(AsmToken::EndOfStatement))
    734     return TokError("unexpected token in '.end_data_region' directive");
    735 
    736   Lex();
    737   getStreamer().EmitDataRegion(MCDR_DataRegionEnd);
    738   return false;
    739 }
    740 
    741 namespace llvm {
    742 
    743 MCAsmParserExtension *createDarwinAsmParser() {
    744   return new DarwinAsmParser;
    745 }
    746 
    747 } // end llvm namespace
    748