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/ADT/STLExtras.h"
12 #include "llvm/ADT/StringRef.h"
13 #include "llvm/ADT/StringSwitch.h"
14 #include "llvm/ADT/Triple.h"
15 #include "llvm/ADT/Twine.h"
16 #include "llvm/MC/MCContext.h"
17 #include "llvm/MC/MCObjectFileInfo.h"
18 #include "llvm/MC/MCParser/MCAsmLexer.h"
19 #include "llvm/MC/MCParser/MCAsmParser.h"
20 #include "llvm/MC/MCSectionMachO.h"
21 #include "llvm/MC/MCStreamer.h"
22 #include "llvm/MC/MCSymbol.h"
23 #include "llvm/Support/FileSystem.h"
24 #include "llvm/Support/MemoryBuffer.h"
25 #include "llvm/Support/SourceMgr.h"
26 using namespace llvm;
27 
28 namespace {
29 
30 /// \brief Implementation of directive handling which is shared across all
31 /// Darwin targets.
32 class DarwinAsmParser : public MCAsmParserExtension {
33   template<bool (DarwinAsmParser::*HandlerMethod)(StringRef, SMLoc)>
34   void addDirectiveHandler(StringRef Directive) {
35     MCAsmParser::ExtensionDirectiveHandler Handler = std::make_pair(
36         this, HandleDirective<DarwinAsmParser, HandlerMethod>);
37     getParser().addDirectiveHandler(Directive, Handler);
38   }
39 
40   bool parseSectionSwitch(StringRef Segment, StringRef Section,
41                           unsigned TAA = 0, unsigned ImplicitAlign = 0,
42                           unsigned StubSize = 0);
43 
44   SMLoc LastVersionMinDirective;
45 
46 public:
47   DarwinAsmParser() {}
48 
49   void Initialize(MCAsmParser &Parser) override {
50     // Call the base implementation.
51     this->MCAsmParserExtension::Initialize(Parser);
52 
53     addDirectiveHandler<&DarwinAsmParser::parseDirectiveAltEntry>(".alt_entry");
54     addDirectiveHandler<&DarwinAsmParser::parseDirectiveDesc>(".desc");
55     addDirectiveHandler<&DarwinAsmParser::parseDirectiveIndirectSymbol>(
56       ".indirect_symbol");
57     addDirectiveHandler<&DarwinAsmParser::parseDirectiveLsym>(".lsym");
58     addDirectiveHandler<&DarwinAsmParser::parseDirectiveSubsectionsViaSymbols>(
59       ".subsections_via_symbols");
60     addDirectiveHandler<&DarwinAsmParser::parseDirectiveDumpOrLoad>(".dump");
61     addDirectiveHandler<&DarwinAsmParser::parseDirectiveDumpOrLoad>(".load");
62     addDirectiveHandler<&DarwinAsmParser::parseDirectiveSection>(".section");
63     addDirectiveHandler<&DarwinAsmParser::parseDirectivePushSection>(
64       ".pushsection");
65     addDirectiveHandler<&DarwinAsmParser::parseDirectivePopSection>(
66       ".popsection");
67     addDirectiveHandler<&DarwinAsmParser::parseDirectivePrevious>(".previous");
68     addDirectiveHandler<&DarwinAsmParser::parseDirectiveSecureLogUnique>(
69       ".secure_log_unique");
70     addDirectiveHandler<&DarwinAsmParser::parseDirectiveSecureLogReset>(
71       ".secure_log_reset");
72     addDirectiveHandler<&DarwinAsmParser::parseDirectiveTBSS>(".tbss");
73     addDirectiveHandler<&DarwinAsmParser::parseDirectiveZerofill>(".zerofill");
74 
75     addDirectiveHandler<&DarwinAsmParser::parseDirectiveDataRegion>(
76       ".data_region");
77     addDirectiveHandler<&DarwinAsmParser::parseDirectiveDataRegionEnd>(
78       ".end_data_region");
79 
80     // Special section directives.
81     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveBss>(".bss");
82     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveConst>(".const");
83     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveConstData>(
84       ".const_data");
85     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveConstructor>(
86       ".constructor");
87     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveCString>(
88       ".cstring");
89     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveData>(".data");
90     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveDestructor>(
91       ".destructor");
92     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveDyld>(".dyld");
93     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveFVMLibInit0>(
94       ".fvmlib_init0");
95     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveFVMLibInit1>(
96       ".fvmlib_init1");
97     addDirectiveHandler<
98       &DarwinAsmParser::parseSectionDirectiveLazySymbolPointers>(
99         ".lazy_symbol_pointer");
100     addDirectiveHandler<&DarwinAsmParser::parseDirectiveLinkerOption>(
101       ".linker_option");
102     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveLiteral16>(
103       ".literal16");
104     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveLiteral4>(
105       ".literal4");
106     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveLiteral8>(
107       ".literal8");
108     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveModInitFunc>(
109       ".mod_init_func");
110     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveModTermFunc>(
111       ".mod_term_func");
112     addDirectiveHandler<
113       &DarwinAsmParser::parseSectionDirectiveNonLazySymbolPointers>(
114         ".non_lazy_symbol_pointer");
115     addDirectiveHandler<
116       &DarwinAsmParser::parseSectionDirectiveThreadLocalVariablePointers>(
117         ".thread_local_variable_pointer");
118     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCCatClsMeth>(
119       ".objc_cat_cls_meth");
120     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCCatInstMeth>(
121       ".objc_cat_inst_meth");
122     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCCategory>(
123       ".objc_category");
124     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCClass>(
125       ".objc_class");
126     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCClassNames>(
127       ".objc_class_names");
128     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCClassVars>(
129       ".objc_class_vars");
130     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCClsMeth>(
131       ".objc_cls_meth");
132     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCClsRefs>(
133       ".objc_cls_refs");
134     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCInstMeth>(
135       ".objc_inst_meth");
136     addDirectiveHandler<
137       &DarwinAsmParser::parseSectionDirectiveObjCInstanceVars>(
138         ".objc_instance_vars");
139     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCMessageRefs>(
140       ".objc_message_refs");
141     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCMetaClass>(
142       ".objc_meta_class");
143     addDirectiveHandler<
144       &DarwinAsmParser::parseSectionDirectiveObjCMethVarNames>(
145         ".objc_meth_var_names");
146     addDirectiveHandler<
147       &DarwinAsmParser::parseSectionDirectiveObjCMethVarTypes>(
148         ".objc_meth_var_types");
149     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCModuleInfo>(
150       ".objc_module_info");
151     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCProtocol>(
152       ".objc_protocol");
153     addDirectiveHandler<
154       &DarwinAsmParser::parseSectionDirectiveObjCSelectorStrs>(
155         ".objc_selector_strs");
156     addDirectiveHandler<
157       &DarwinAsmParser::parseSectionDirectiveObjCStringObject>(
158         ".objc_string_object");
159     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveObjCSymbols>(
160       ".objc_symbols");
161     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectivePICSymbolStub>(
162       ".picsymbol_stub");
163     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveStaticConst>(
164       ".static_const");
165     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveStaticData>(
166       ".static_data");
167     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveSymbolStub>(
168       ".symbol_stub");
169     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveTData>(".tdata");
170     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveText>(".text");
171     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveThreadInitFunc>(
172       ".thread_init_func");
173     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveTLV>(".tlv");
174 
175     addDirectiveHandler<&DarwinAsmParser::parseSectionDirectiveIdent>(".ident");
176     addDirectiveHandler<&DarwinAsmParser::parseVersionMin>(
177       ".watchos_version_min");
178     addDirectiveHandler<&DarwinAsmParser::parseVersionMin>(".tvos_version_min");
179     addDirectiveHandler<&DarwinAsmParser::parseVersionMin>(".ios_version_min");
180     addDirectiveHandler<&DarwinAsmParser::parseVersionMin>(
181       ".macosx_version_min");
182 
183     LastVersionMinDirective = SMLoc();
184   }
185 
186   bool parseDirectiveAltEntry(StringRef, SMLoc);
187   bool parseDirectiveDesc(StringRef, SMLoc);
188   bool parseDirectiveIndirectSymbol(StringRef, SMLoc);
189   bool parseDirectiveDumpOrLoad(StringRef, SMLoc);
190   bool parseDirectiveLsym(StringRef, SMLoc);
191   bool parseDirectiveLinkerOption(StringRef, SMLoc);
192   bool parseDirectiveSection(StringRef, SMLoc);
193   bool parseDirectivePushSection(StringRef, SMLoc);
194   bool parseDirectivePopSection(StringRef, SMLoc);
195   bool parseDirectivePrevious(StringRef, SMLoc);
196   bool parseDirectiveSecureLogReset(StringRef, SMLoc);
197   bool parseDirectiveSecureLogUnique(StringRef, SMLoc);
198   bool parseDirectiveSubsectionsViaSymbols(StringRef, SMLoc);
199   bool parseDirectiveTBSS(StringRef, SMLoc);
200   bool parseDirectiveZerofill(StringRef, SMLoc);
201   bool parseDirectiveDataRegion(StringRef, SMLoc);
202   bool parseDirectiveDataRegionEnd(StringRef, SMLoc);
203 
204   // Named Section Directive
205   bool parseSectionDirectiveBss(StringRef, SMLoc) {
206     return parseSectionSwitch("__DATA", "__bss");
207   }
208 
209   bool parseSectionDirectiveConst(StringRef, SMLoc) {
210     return parseSectionSwitch("__TEXT", "__const");
211   }
212   bool parseSectionDirectiveStaticConst(StringRef, SMLoc) {
213     return parseSectionSwitch("__TEXT", "__static_const");
214   }
215   bool parseSectionDirectiveCString(StringRef, SMLoc) {
216     return parseSectionSwitch("__TEXT","__cstring",
217                               MachO::S_CSTRING_LITERALS);
218   }
219   bool parseSectionDirectiveLiteral4(StringRef, SMLoc) {
220     return parseSectionSwitch("__TEXT", "__literal4",
221                               MachO::S_4BYTE_LITERALS, 4);
222   }
223   bool parseSectionDirectiveLiteral8(StringRef, SMLoc) {
224     return parseSectionSwitch("__TEXT", "__literal8",
225                               MachO::S_8BYTE_LITERALS, 8);
226   }
227   bool parseSectionDirectiveLiteral16(StringRef, SMLoc) {
228     return parseSectionSwitch("__TEXT","__literal16",
229                               MachO::S_16BYTE_LITERALS, 16);
230   }
231   bool parseSectionDirectiveConstructor(StringRef, SMLoc) {
232     return parseSectionSwitch("__TEXT","__constructor");
233   }
234   bool parseSectionDirectiveDestructor(StringRef, SMLoc) {
235     return parseSectionSwitch("__TEXT","__destructor");
236   }
237   bool parseSectionDirectiveFVMLibInit0(StringRef, SMLoc) {
238     return parseSectionSwitch("__TEXT","__fvmlib_init0");
239   }
240   bool parseSectionDirectiveFVMLibInit1(StringRef, SMLoc) {
241     return parseSectionSwitch("__TEXT","__fvmlib_init1");
242   }
243   bool parseSectionDirectiveSymbolStub(StringRef, SMLoc) {
244     return parseSectionSwitch("__TEXT","__symbol_stub",
245                               MachO::S_SYMBOL_STUBS |
246                               MachO::S_ATTR_PURE_INSTRUCTIONS,
247                               // FIXME: Different on PPC and ARM.
248                               0, 16);
249   }
250   bool parseSectionDirectivePICSymbolStub(StringRef, SMLoc) {
251     return parseSectionSwitch("__TEXT","__picsymbol_stub",
252                               MachO::S_SYMBOL_STUBS |
253                               MachO::S_ATTR_PURE_INSTRUCTIONS, 0, 26);
254   }
255   bool parseSectionDirectiveData(StringRef, SMLoc) {
256     return parseSectionSwitch("__DATA", "__data");
257   }
258   bool parseSectionDirectiveStaticData(StringRef, SMLoc) {
259     return parseSectionSwitch("__DATA", "__static_data");
260   }
261   bool parseSectionDirectiveNonLazySymbolPointers(StringRef, SMLoc) {
262     return parseSectionSwitch("__DATA", "__nl_symbol_ptr",
263                               MachO::S_NON_LAZY_SYMBOL_POINTERS, 4);
264   }
265   bool parseSectionDirectiveLazySymbolPointers(StringRef, SMLoc) {
266     return parseSectionSwitch("__DATA", "__la_symbol_ptr",
267                               MachO::S_LAZY_SYMBOL_POINTERS, 4);
268   }
269   bool parseSectionDirectiveThreadLocalVariablePointers(StringRef, SMLoc) {
270     return parseSectionSwitch("__DATA", "__thread_ptr",
271                               MachO::S_THREAD_LOCAL_VARIABLE_POINTERS, 4);
272   }
273   bool parseSectionDirectiveDyld(StringRef, SMLoc) {
274     return parseSectionSwitch("__DATA", "__dyld");
275   }
276   bool parseSectionDirectiveModInitFunc(StringRef, SMLoc) {
277     return parseSectionSwitch("__DATA", "__mod_init_func",
278                               MachO::S_MOD_INIT_FUNC_POINTERS, 4);
279   }
280   bool parseSectionDirectiveModTermFunc(StringRef, SMLoc) {
281     return parseSectionSwitch("__DATA", "__mod_term_func",
282                               MachO::S_MOD_TERM_FUNC_POINTERS, 4);
283   }
284   bool parseSectionDirectiveConstData(StringRef, SMLoc) {
285     return parseSectionSwitch("__DATA", "__const");
286   }
287   bool parseSectionDirectiveObjCClass(StringRef, SMLoc) {
288     return parseSectionSwitch("__OBJC", "__class",
289                               MachO::S_ATTR_NO_DEAD_STRIP);
290   }
291   bool parseSectionDirectiveObjCMetaClass(StringRef, SMLoc) {
292     return parseSectionSwitch("__OBJC", "__meta_class",
293                               MachO::S_ATTR_NO_DEAD_STRIP);
294   }
295   bool parseSectionDirectiveObjCCatClsMeth(StringRef, SMLoc) {
296     return parseSectionSwitch("__OBJC", "__cat_cls_meth",
297                               MachO::S_ATTR_NO_DEAD_STRIP);
298   }
299   bool parseSectionDirectiveObjCCatInstMeth(StringRef, SMLoc) {
300     return parseSectionSwitch("__OBJC", "__cat_inst_meth",
301                               MachO::S_ATTR_NO_DEAD_STRIP);
302   }
303   bool parseSectionDirectiveObjCProtocol(StringRef, SMLoc) {
304     return parseSectionSwitch("__OBJC", "__protocol",
305                               MachO::S_ATTR_NO_DEAD_STRIP);
306   }
307   bool parseSectionDirectiveObjCStringObject(StringRef, SMLoc) {
308     return parseSectionSwitch("__OBJC", "__string_object",
309                               MachO::S_ATTR_NO_DEAD_STRIP);
310   }
311   bool parseSectionDirectiveObjCClsMeth(StringRef, SMLoc) {
312     return parseSectionSwitch("__OBJC", "__cls_meth",
313                               MachO::S_ATTR_NO_DEAD_STRIP);
314   }
315   bool parseSectionDirectiveObjCInstMeth(StringRef, SMLoc) {
316     return parseSectionSwitch("__OBJC", "__inst_meth",
317                               MachO::S_ATTR_NO_DEAD_STRIP);
318   }
319   bool parseSectionDirectiveObjCClsRefs(StringRef, SMLoc) {
320     return parseSectionSwitch("__OBJC", "__cls_refs",
321                               MachO::S_ATTR_NO_DEAD_STRIP |
322                               MachO::S_LITERAL_POINTERS, 4);
323   }
324   bool parseSectionDirectiveObjCMessageRefs(StringRef, SMLoc) {
325     return parseSectionSwitch("__OBJC", "__message_refs",
326                               MachO::S_ATTR_NO_DEAD_STRIP |
327                               MachO::S_LITERAL_POINTERS, 4);
328   }
329   bool parseSectionDirectiveObjCSymbols(StringRef, SMLoc) {
330     return parseSectionSwitch("__OBJC", "__symbols",
331                               MachO::S_ATTR_NO_DEAD_STRIP);
332   }
333   bool parseSectionDirectiveObjCCategory(StringRef, SMLoc) {
334     return parseSectionSwitch("__OBJC", "__category",
335                               MachO::S_ATTR_NO_DEAD_STRIP);
336   }
337   bool parseSectionDirectiveObjCClassVars(StringRef, SMLoc) {
338     return parseSectionSwitch("__OBJC", "__class_vars",
339                               MachO::S_ATTR_NO_DEAD_STRIP);
340   }
341   bool parseSectionDirectiveObjCInstanceVars(StringRef, SMLoc) {
342     return parseSectionSwitch("__OBJC", "__instance_vars",
343                               MachO::S_ATTR_NO_DEAD_STRIP);
344   }
345   bool parseSectionDirectiveObjCModuleInfo(StringRef, SMLoc) {
346     return parseSectionSwitch("__OBJC", "__module_info",
347                               MachO::S_ATTR_NO_DEAD_STRIP);
348   }
349   bool parseSectionDirectiveObjCClassNames(StringRef, SMLoc) {
350     return parseSectionSwitch("__TEXT", "__cstring",
351                               MachO::S_CSTRING_LITERALS);
352   }
353   bool parseSectionDirectiveObjCMethVarTypes(StringRef, SMLoc) {
354     return parseSectionSwitch("__TEXT", "__cstring",
355                               MachO::S_CSTRING_LITERALS);
356   }
357   bool parseSectionDirectiveObjCMethVarNames(StringRef, SMLoc) {
358     return parseSectionSwitch("__TEXT", "__cstring",
359                               MachO::S_CSTRING_LITERALS);
360   }
361   bool parseSectionDirectiveObjCSelectorStrs(StringRef, SMLoc) {
362     return parseSectionSwitch("__OBJC", "__selector_strs",
363                               MachO::S_CSTRING_LITERALS);
364   }
365   bool parseSectionDirectiveTData(StringRef, SMLoc) {
366     return parseSectionSwitch("__DATA", "__thread_data",
367                               MachO::S_THREAD_LOCAL_REGULAR);
368   }
369   bool parseSectionDirectiveText(StringRef, SMLoc) {
370     return parseSectionSwitch("__TEXT", "__text",
371                               MachO::S_ATTR_PURE_INSTRUCTIONS);
372   }
373   bool parseSectionDirectiveTLV(StringRef, SMLoc) {
374     return parseSectionSwitch("__DATA", "__thread_vars",
375                               MachO::S_THREAD_LOCAL_VARIABLES);
376   }
377   bool parseSectionDirectiveIdent(StringRef, SMLoc) {
378     // Darwin silently ignores the .ident directive.
379     getParser().eatToEndOfStatement();
380     return false;
381   }
382   bool parseSectionDirectiveThreadInitFunc(StringRef, SMLoc) {
383     return parseSectionSwitch("__DATA", "__thread_init",
384                          MachO::S_THREAD_LOCAL_INIT_FUNCTION_POINTERS);
385   }
386   bool parseVersionMin(StringRef, SMLoc);
387 
388 };
389 
390 } // end anonymous namespace
391 
392 bool DarwinAsmParser::parseSectionSwitch(StringRef Segment, StringRef Section,
393                                          unsigned TAA, unsigned Align,
394                                          unsigned StubSize) {
395   if (getLexer().isNot(AsmToken::EndOfStatement))
396     return TokError("unexpected token in section switching directive");
397   Lex();
398 
399   // FIXME: Arch specific.
400   bool isText = TAA & MachO::S_ATTR_PURE_INSTRUCTIONS;
401   getStreamer().SwitchSection(getContext().getMachOSection(
402       Segment, Section, TAA, StubSize,
403       isText ? SectionKind::getText() : SectionKind::getData()));
404 
405   // Set the implicit alignment, if any.
406   //
407   // FIXME: This isn't really what 'as' does; I think it just uses the implicit
408   // alignment on the section (e.g., if one manually inserts bytes into the
409   // section, then just issuing the section switch directive will not realign
410   // the section. However, this is arguably more reasonable behavior, and there
411   // is no good reason for someone to intentionally emit incorrectly sized
412   // values into the implicitly aligned sections.
413   if (Align)
414     getStreamer().EmitValueToAlignment(Align);
415 
416   return false;
417 }
418 
419 /// parseDirectiveAltEntry
420 ///  ::= .alt_entry identifier
421 bool DarwinAsmParser::parseDirectiveAltEntry(StringRef, SMLoc) {
422   StringRef Name;
423   if (getParser().parseIdentifier(Name))
424     return TokError("expected identifier in directive");
425 
426   // Look up symbol.
427   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
428 
429   if (Sym->isDefined())
430     return TokError(".alt_entry must preceed symbol definition");
431 
432   if (!getStreamer().EmitSymbolAttribute(Sym, MCSA_AltEntry))
433     return TokError("unable to emit symbol attribute");
434 
435   Lex();
436   return false;
437 }
438 
439 /// parseDirectiveDesc
440 ///  ::= .desc identifier , expression
441 bool DarwinAsmParser::parseDirectiveDesc(StringRef, SMLoc) {
442   StringRef Name;
443   if (getParser().parseIdentifier(Name))
444     return TokError("expected identifier in directive");
445 
446   // Handle the identifier as the key symbol.
447   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
448 
449   if (getLexer().isNot(AsmToken::Comma))
450     return TokError("unexpected token in '.desc' directive");
451   Lex();
452 
453   int64_t DescValue;
454   if (getParser().parseAbsoluteExpression(DescValue))
455     return true;
456 
457   if (getLexer().isNot(AsmToken::EndOfStatement))
458     return TokError("unexpected token in '.desc' directive");
459 
460   Lex();
461 
462   // Set the n_desc field of this Symbol to this DescValue
463   getStreamer().EmitSymbolDesc(Sym, DescValue);
464 
465   return false;
466 }
467 
468 /// parseDirectiveIndirectSymbol
469 ///  ::= .indirect_symbol identifier
470 bool DarwinAsmParser::parseDirectiveIndirectSymbol(StringRef, SMLoc Loc) {
471   const MCSectionMachO *Current = static_cast<const MCSectionMachO *>(
472       getStreamer().getCurrentSectionOnly());
473   MachO::SectionType SectionType = Current->getType();
474   if (SectionType != MachO::S_NON_LAZY_SYMBOL_POINTERS &&
475       SectionType != MachO::S_LAZY_SYMBOL_POINTERS &&
476       SectionType != MachO::S_THREAD_LOCAL_VARIABLE_POINTERS &&
477       SectionType != MachO::S_SYMBOL_STUBS)
478     return Error(Loc, "indirect symbol not in a symbol pointer or stub "
479                       "section");
480 
481   StringRef Name;
482   if (getParser().parseIdentifier(Name))
483     return TokError("expected identifier in .indirect_symbol directive");
484 
485   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
486 
487   // Assembler local symbols don't make any sense here. Complain loudly.
488   if (Sym->isTemporary())
489     return TokError("non-local symbol required in directive");
490 
491   if (!getStreamer().EmitSymbolAttribute(Sym, MCSA_IndirectSymbol))
492     return TokError("unable to emit indirect symbol attribute for: " + Name);
493 
494   if (getLexer().isNot(AsmToken::EndOfStatement))
495     return TokError("unexpected token in '.indirect_symbol' directive");
496 
497   Lex();
498 
499   return false;
500 }
501 
502 /// parseDirectiveDumpOrLoad
503 ///  ::= ( .dump | .load ) "filename"
504 bool DarwinAsmParser::parseDirectiveDumpOrLoad(StringRef Directive,
505                                                SMLoc IDLoc) {
506   bool IsDump = Directive == ".dump";
507   if (getLexer().isNot(AsmToken::String))
508     return TokError("expected string in '.dump' or '.load' directive");
509 
510   Lex();
511 
512   if (getLexer().isNot(AsmToken::EndOfStatement))
513     return TokError("unexpected token in '.dump' or '.load' directive");
514 
515   Lex();
516 
517   // FIXME: If/when .dump and .load are implemented they will be done in the
518   // the assembly parser and not have any need for an MCStreamer API.
519   if (IsDump)
520     return Warning(IDLoc, "ignoring directive .dump for now");
521   else
522     return Warning(IDLoc, "ignoring directive .load for now");
523 }
524 
525 /// ParseDirectiveLinkerOption
526 ///  ::= .linker_option "string" ( , "string" )*
527 bool DarwinAsmParser::parseDirectiveLinkerOption(StringRef IDVal, SMLoc) {
528   SmallVector<std::string, 4> Args;
529   for (;;) {
530     if (getLexer().isNot(AsmToken::String))
531       return TokError("expected string in '" + Twine(IDVal) + "' directive");
532 
533     std::string Data;
534     if (getParser().parseEscapedString(Data))
535       return true;
536 
537     Args.push_back(Data);
538 
539     if (getLexer().is(AsmToken::EndOfStatement))
540       break;
541 
542     if (getLexer().isNot(AsmToken::Comma))
543       return TokError("unexpected token in '" + Twine(IDVal) + "' directive");
544     Lex();
545   }
546 
547   getStreamer().EmitLinkerOptions(Args);
548   return false;
549 }
550 
551 /// parseDirectiveLsym
552 ///  ::= .lsym identifier , expression
553 bool DarwinAsmParser::parseDirectiveLsym(StringRef, SMLoc) {
554   StringRef Name;
555   if (getParser().parseIdentifier(Name))
556     return TokError("expected identifier in directive");
557 
558   // Handle the identifier as the key symbol.
559   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
560 
561   if (getLexer().isNot(AsmToken::Comma))
562     return TokError("unexpected token in '.lsym' directive");
563   Lex();
564 
565   const MCExpr *Value;
566   if (getParser().parseExpression(Value))
567     return true;
568 
569   if (getLexer().isNot(AsmToken::EndOfStatement))
570     return TokError("unexpected token in '.lsym' directive");
571 
572   Lex();
573 
574   // We don't currently support this directive.
575   //
576   // FIXME: Diagnostic location!
577   (void) Sym;
578   return TokError("directive '.lsym' is unsupported");
579 }
580 
581 /// parseDirectiveSection:
582 ///   ::= .section identifier (',' identifier)*
583 bool DarwinAsmParser::parseDirectiveSection(StringRef, SMLoc) {
584   SMLoc Loc = getLexer().getLoc();
585 
586   StringRef SectionName;
587   if (getParser().parseIdentifier(SectionName))
588     return Error(Loc, "expected identifier after '.section' directive");
589 
590   // Verify there is a following comma.
591   if (!getLexer().is(AsmToken::Comma))
592     return TokError("unexpected token in '.section' directive");
593 
594   std::string SectionSpec = SectionName;
595   SectionSpec += ",";
596 
597   // Add all the tokens until the end of the line, ParseSectionSpecifier will
598   // handle this.
599   StringRef EOL = getLexer().LexUntilEndOfStatement();
600   SectionSpec.append(EOL.begin(), EOL.end());
601 
602   Lex();
603   if (getLexer().isNot(AsmToken::EndOfStatement))
604     return TokError("unexpected token in '.section' directive");
605   Lex();
606 
607 
608   StringRef Segment, Section;
609   unsigned StubSize;
610   unsigned TAA;
611   bool TAAParsed;
612   std::string ErrorStr =
613     MCSectionMachO::ParseSectionSpecifier(SectionSpec, Segment, Section,
614                                           TAA, TAAParsed, StubSize);
615 
616   if (!ErrorStr.empty())
617     return Error(Loc, ErrorStr);
618 
619   // Issue a warning if the target is not powerpc and Section is a *coal* section.
620   Triple TT = getParser().getContext().getObjectFileInfo()->getTargetTriple();
621   Triple::ArchType ArchTy = TT.getArch();
622 
623   if (ArchTy != Triple::ppc && ArchTy != Triple::ppc64) {
624     StringRef NonCoalSection = StringSwitch<StringRef>(Section)
625                                    .Case("__textcoal_nt", "__text")
626                                    .Case("__const_coal", "__const")
627                                    .Case("__datacoal_nt", "__data")
628                                    .Default(Section);
629 
630     if (!Section.equals(NonCoalSection)) {
631       StringRef SectionVal(Loc.getPointer());
632       size_t B = SectionVal.find(',') + 1, E = SectionVal.find(',', B);
633       SMLoc BLoc = SMLoc::getFromPointer(SectionVal.data() + B);
634       SMLoc ELoc = SMLoc::getFromPointer(SectionVal.data() + E);
635       getParser().Warning(Loc, "section \"" + Section + "\" is deprecated",
636                           SMRange(BLoc, ELoc));
637       getParser().Note(Loc, "change section name to \"" + NonCoalSection +
638                        "\"", SMRange(BLoc, ELoc));
639     }
640   }
641 
642   // FIXME: Arch specific.
643   bool isText = Segment == "__TEXT";  // FIXME: Hack.
644   getStreamer().SwitchSection(getContext().getMachOSection(
645       Segment, Section, TAA, StubSize,
646       isText ? SectionKind::getText() : SectionKind::getData()));
647   return false;
648 }
649 
650 /// ParseDirectivePushSection:
651 ///   ::= .pushsection identifier (',' identifier)*
652 bool DarwinAsmParser::parseDirectivePushSection(StringRef S, SMLoc Loc) {
653   getStreamer().PushSection();
654 
655   if (parseDirectiveSection(S, Loc)) {
656     getStreamer().PopSection();
657     return true;
658   }
659 
660   return false;
661 }
662 
663 /// ParseDirectivePopSection:
664 ///   ::= .popsection
665 bool DarwinAsmParser::parseDirectivePopSection(StringRef, SMLoc) {
666   if (!getStreamer().PopSection())
667     return TokError(".popsection without corresponding .pushsection");
668   return false;
669 }
670 
671 /// ParseDirectivePrevious:
672 ///   ::= .previous
673 bool DarwinAsmParser::parseDirectivePrevious(StringRef DirName, SMLoc) {
674   MCSectionSubPair PreviousSection = getStreamer().getPreviousSection();
675   if (!PreviousSection.first)
676     return TokError(".previous without corresponding .section");
677   getStreamer().SwitchSection(PreviousSection.first, PreviousSection.second);
678   return false;
679 }
680 
681 /// ParseDirectiveSecureLogUnique
682 ///  ::= .secure_log_unique ... message ...
683 bool DarwinAsmParser::parseDirectiveSecureLogUnique(StringRef, SMLoc IDLoc) {
684   StringRef LogMessage = getParser().parseStringToEndOfStatement();
685   if (getLexer().isNot(AsmToken::EndOfStatement))
686     return TokError("unexpected token in '.secure_log_unique' directive");
687 
688   if (getContext().getSecureLogUsed())
689     return Error(IDLoc, ".secure_log_unique specified multiple times");
690 
691   // Get the secure log path.
692   const char *SecureLogFile = getContext().getSecureLogFile();
693   if (!SecureLogFile)
694     return Error(IDLoc, ".secure_log_unique used but AS_SECURE_LOG_FILE "
695                  "environment variable unset.");
696 
697   // Open the secure log file if we haven't already.
698   raw_fd_ostream *OS = getContext().getSecureLog();
699   if (!OS) {
700     std::error_code EC;
701     auto NewOS = llvm::make_unique<raw_fd_ostream>(
702         StringRef(SecureLogFile), EC, sys::fs::F_Append | sys::fs::F_Text);
703     if (EC)
704        return Error(IDLoc, Twine("can't open secure log file: ") +
705                                SecureLogFile + " (" + EC.message() + ")");
706     OS = NewOS.get();
707     getContext().setSecureLog(std::move(NewOS));
708   }
709 
710   // Write the message.
711   unsigned CurBuf = getSourceManager().FindBufferContainingLoc(IDLoc);
712   *OS << getSourceManager().getBufferInfo(CurBuf).Buffer->getBufferIdentifier()
713       << ":" << getSourceManager().FindLineNumber(IDLoc, CurBuf) << ":"
714       << LogMessage + "\n";
715 
716   getContext().setSecureLogUsed(true);
717 
718   return false;
719 }
720 
721 /// ParseDirectiveSecureLogReset
722 ///  ::= .secure_log_reset
723 bool DarwinAsmParser::parseDirectiveSecureLogReset(StringRef, SMLoc IDLoc) {
724   if (getLexer().isNot(AsmToken::EndOfStatement))
725     return TokError("unexpected token in '.secure_log_reset' directive");
726 
727   Lex();
728 
729   getContext().setSecureLogUsed(false);
730 
731   return false;
732 }
733 
734 /// parseDirectiveSubsectionsViaSymbols
735 ///  ::= .subsections_via_symbols
736 bool DarwinAsmParser::parseDirectiveSubsectionsViaSymbols(StringRef, SMLoc) {
737   if (getLexer().isNot(AsmToken::EndOfStatement))
738     return TokError("unexpected token in '.subsections_via_symbols' directive");
739 
740   Lex();
741 
742   getStreamer().EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
743 
744   return false;
745 }
746 
747 /// ParseDirectiveTBSS
748 ///  ::= .tbss identifier, size, align
749 bool DarwinAsmParser::parseDirectiveTBSS(StringRef, SMLoc) {
750   SMLoc IDLoc = getLexer().getLoc();
751   StringRef Name;
752   if (getParser().parseIdentifier(Name))
753     return TokError("expected identifier in directive");
754 
755   // Handle the identifier as the key symbol.
756   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
757 
758   if (getLexer().isNot(AsmToken::Comma))
759     return TokError("unexpected token in directive");
760   Lex();
761 
762   int64_t Size;
763   SMLoc SizeLoc = getLexer().getLoc();
764   if (getParser().parseAbsoluteExpression(Size))
765     return true;
766 
767   int64_t Pow2Alignment = 0;
768   SMLoc Pow2AlignmentLoc;
769   if (getLexer().is(AsmToken::Comma)) {
770     Lex();
771     Pow2AlignmentLoc = getLexer().getLoc();
772     if (getParser().parseAbsoluteExpression(Pow2Alignment))
773       return true;
774   }
775 
776   if (getLexer().isNot(AsmToken::EndOfStatement))
777     return TokError("unexpected token in '.tbss' directive");
778 
779   Lex();
780 
781   if (Size < 0)
782     return Error(SizeLoc, "invalid '.tbss' directive size, can't be less than"
783                  "zero");
784 
785   // FIXME: Diagnose overflow.
786   if (Pow2Alignment < 0)
787     return Error(Pow2AlignmentLoc, "invalid '.tbss' alignment, can't be less"
788                  "than zero");
789 
790   if (!Sym->isUndefined())
791     return Error(IDLoc, "invalid symbol redefinition");
792 
793   getStreamer().EmitTBSSSymbol(getContext().getMachOSection(
794                                  "__DATA", "__thread_bss",
795                                  MachO::S_THREAD_LOCAL_ZEROFILL,
796                                  0, SectionKind::getThreadBSS()),
797                                Sym, Size, 1 << Pow2Alignment);
798 
799   return false;
800 }
801 
802 /// ParseDirectiveZerofill
803 ///  ::= .zerofill segname , sectname [, identifier , size_expression [
804 ///      , align_expression ]]
805 bool DarwinAsmParser::parseDirectiveZerofill(StringRef, SMLoc) {
806   StringRef Segment;
807   if (getParser().parseIdentifier(Segment))
808     return TokError("expected segment name after '.zerofill' directive");
809 
810   if (getLexer().isNot(AsmToken::Comma))
811     return TokError("unexpected token in directive");
812   Lex();
813 
814   StringRef Section;
815   if (getParser().parseIdentifier(Section))
816     return TokError("expected section name after comma in '.zerofill' "
817                     "directive");
818 
819   // If this is the end of the line all that was wanted was to create the
820   // the section but with no symbol.
821   if (getLexer().is(AsmToken::EndOfStatement)) {
822     // Create the zerofill section but no symbol
823     getStreamer().EmitZerofill(getContext().getMachOSection(
824                                  Segment, Section, MachO::S_ZEROFILL,
825                                  0, SectionKind::getBSS()));
826     return false;
827   }
828 
829   if (getLexer().isNot(AsmToken::Comma))
830     return TokError("unexpected token in directive");
831   Lex();
832 
833   SMLoc IDLoc = getLexer().getLoc();
834   StringRef IDStr;
835   if (getParser().parseIdentifier(IDStr))
836     return TokError("expected identifier in directive");
837 
838   // handle the identifier as the key symbol.
839   MCSymbol *Sym = getContext().getOrCreateSymbol(IDStr);
840 
841   if (getLexer().isNot(AsmToken::Comma))
842     return TokError("unexpected token in directive");
843   Lex();
844 
845   int64_t Size;
846   SMLoc SizeLoc = getLexer().getLoc();
847   if (getParser().parseAbsoluteExpression(Size))
848     return true;
849 
850   int64_t Pow2Alignment = 0;
851   SMLoc Pow2AlignmentLoc;
852   if (getLexer().is(AsmToken::Comma)) {
853     Lex();
854     Pow2AlignmentLoc = getLexer().getLoc();
855     if (getParser().parseAbsoluteExpression(Pow2Alignment))
856       return true;
857   }
858 
859   if (getLexer().isNot(AsmToken::EndOfStatement))
860     return TokError("unexpected token in '.zerofill' directive");
861 
862   Lex();
863 
864   if (Size < 0)
865     return Error(SizeLoc, "invalid '.zerofill' directive size, can't be less "
866                  "than zero");
867 
868   // NOTE: The alignment in the directive is a power of 2 value, the assembler
869   // may internally end up wanting an alignment in bytes.
870   // FIXME: Diagnose overflow.
871   if (Pow2Alignment < 0)
872     return Error(Pow2AlignmentLoc, "invalid '.zerofill' directive alignment, "
873                  "can't be less than zero");
874 
875   if (!Sym->isUndefined())
876     return Error(IDLoc, "invalid symbol redefinition");
877 
878   // Create the zerofill Symbol with Size and Pow2Alignment
879   //
880   // FIXME: Arch specific.
881   getStreamer().EmitZerofill(getContext().getMachOSection(
882                                Segment, Section, MachO::S_ZEROFILL,
883                                0, SectionKind::getBSS()),
884                              Sym, Size, 1 << Pow2Alignment);
885 
886   return false;
887 }
888 
889 /// ParseDirectiveDataRegion
890 ///  ::= .data_region [ ( jt8 | jt16 | jt32 ) ]
891 bool DarwinAsmParser::parseDirectiveDataRegion(StringRef, SMLoc) {
892   if (getLexer().is(AsmToken::EndOfStatement)) {
893     Lex();
894     getStreamer().EmitDataRegion(MCDR_DataRegion);
895     return false;
896   }
897   StringRef RegionType;
898   SMLoc Loc = getParser().getTok().getLoc();
899   if (getParser().parseIdentifier(RegionType))
900     return TokError("expected region type after '.data_region' directive");
901   int Kind = StringSwitch<int>(RegionType)
902     .Case("jt8", MCDR_DataRegionJT8)
903     .Case("jt16", MCDR_DataRegionJT16)
904     .Case("jt32", MCDR_DataRegionJT32)
905     .Default(-1);
906   if (Kind == -1)
907     return Error(Loc, "unknown region type in '.data_region' directive");
908   Lex();
909 
910   getStreamer().EmitDataRegion((MCDataRegionType)Kind);
911   return false;
912 }
913 
914 /// ParseDirectiveDataRegionEnd
915 ///  ::= .end_data_region
916 bool DarwinAsmParser::parseDirectiveDataRegionEnd(StringRef, SMLoc) {
917   if (getLexer().isNot(AsmToken::EndOfStatement))
918     return TokError("unexpected token in '.end_data_region' directive");
919 
920   Lex();
921   getStreamer().EmitDataRegion(MCDR_DataRegionEnd);
922   return false;
923 }
924 
925 /// parseVersionMin
926 ///  ::= .ios_version_min major,minor[,update]
927 ///  ::= .macosx_version_min major,minor[,update]
928 bool DarwinAsmParser::parseVersionMin(StringRef Directive, SMLoc Loc) {
929   int64_t Major = 0, Minor = 0, Update = 0;
930   int Kind = StringSwitch<int>(Directive)
931     .Case(".watchos_version_min", MCVM_WatchOSVersionMin)
932     .Case(".tvos_version_min", MCVM_TvOSVersionMin)
933     .Case(".ios_version_min", MCVM_IOSVersionMin)
934     .Case(".macosx_version_min", MCVM_OSXVersionMin);
935   // Get the major version number.
936   if (getLexer().isNot(AsmToken::Integer))
937     return TokError("invalid OS major version number");
938   Major = getLexer().getTok().getIntVal();
939   if (Major > 65535 || Major <= 0)
940     return TokError("invalid OS major version number");
941   Lex();
942   if (getLexer().isNot(AsmToken::Comma))
943     return TokError("minor OS version number required, comma expected");
944   Lex();
945   // Get the minor version number.
946   if (getLexer().isNot(AsmToken::Integer))
947     return TokError("invalid OS minor version number");
948   Minor = getLexer().getTok().getIntVal();
949   if (Minor > 255 || Minor < 0)
950     return TokError("invalid OS minor version number");
951   Lex();
952   // Get the update level, if specified
953   if (getLexer().isNot(AsmToken::EndOfStatement)) {
954     if (getLexer().isNot(AsmToken::Comma))
955       return TokError("invalid update specifier, comma expected");
956     Lex();
957     if (getLexer().isNot(AsmToken::Integer))
958       return TokError("invalid OS update number");
959     Update = getLexer().getTok().getIntVal();
960     if (Update > 255 || Update < 0)
961       return TokError("invalid OS update number");
962     Lex();
963   }
964 
965   const Triple &T = getContext().getObjectFileInfo()->getTargetTriple();
966   Triple::OSType ExpectedOS = Triple::UnknownOS;
967   switch ((MCVersionMinType)Kind) {
968   case MCVM_WatchOSVersionMin: ExpectedOS = Triple::WatchOS; break;
969   case MCVM_TvOSVersionMin:    ExpectedOS = Triple::TvOS;    break;
970   case MCVM_IOSVersionMin:     ExpectedOS = Triple::IOS;     break;
971   case MCVM_OSXVersionMin:     ExpectedOS = Triple::MacOSX;  break;
972   }
973   if (T.getOS() != ExpectedOS)
974     Warning(Loc, Directive + " should only be used for " +
975             Triple::getOSTypeName(ExpectedOS) + " targets");
976 
977   if (LastVersionMinDirective.isValid()) {
978     Warning(Loc, "overriding previous version_min directive");
979     Note(LastVersionMinDirective, "previous definition is here");
980   }
981   LastVersionMinDirective = Loc;
982 
983   // We've parsed a correct version specifier, so send it to the streamer.
984   getStreamer().EmitVersionMin((MCVersionMinType)Kind, Major, Minor, Update);
985 
986   return false;
987 }
988 
989 namespace llvm {
990 
991 MCAsmParserExtension *createDarwinAsmParser() {
992   return new DarwinAsmParser;
993 }
994 
995 } // end llvm namespace
996