clang  11.0.0git
ParseStmtAsm.cpp
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1 //===---- ParseStmtAsm.cpp - Assembly Statement Parser --------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements parsing for GCC and Microsoft inline assembly.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Parse/Parser.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/Basic/Diagnostic.h"
16 #include "clang/Basic/TargetInfo.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/MC/MCAsmInfo.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCInstPrinter.h"
23 #include "llvm/MC/MCInstrInfo.h"
24 #include "llvm/MC/MCObjectFileInfo.h"
25 #include "llvm/MC/MCParser/MCAsmParser.h"
26 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
27 #include "llvm/MC/MCRegisterInfo.h"
28 #include "llvm/MC/MCStreamer.h"
29 #include "llvm/MC/MCSubtargetInfo.h"
30 #include "llvm/MC/MCTargetOptions.h"
31 #include "llvm/Support/SourceMgr.h"
32 #include "llvm/Support/TargetRegistry.h"
33 #include "llvm/Support/TargetSelect.h"
34 using namespace clang;
35 
36 namespace {
37 class ClangAsmParserCallback : public llvm::MCAsmParserSemaCallback {
38  Parser &TheParser;
39  SourceLocation AsmLoc;
40  StringRef AsmString;
41 
42  /// The tokens we streamed into AsmString and handed off to MC.
43  ArrayRef<Token> AsmToks;
44 
45  /// The offset of each token in AsmToks within AsmString.
46  ArrayRef<unsigned> AsmTokOffsets;
47 
48 public:
49  ClangAsmParserCallback(Parser &P, SourceLocation Loc, StringRef AsmString,
50  ArrayRef<Token> Toks, ArrayRef<unsigned> Offsets)
51  : TheParser(P), AsmLoc(Loc), AsmString(AsmString), AsmToks(Toks),
52  AsmTokOffsets(Offsets) {
53  assert(AsmToks.size() == AsmTokOffsets.size());
54  }
55 
56  void LookupInlineAsmIdentifier(StringRef &LineBuf,
57  llvm::InlineAsmIdentifierInfo &Info,
58  bool IsUnevaluatedContext) override;
59 
60  StringRef LookupInlineAsmLabel(StringRef Identifier, llvm::SourceMgr &LSM,
61  llvm::SMLoc Location,
62  bool Create) override;
63 
64  bool LookupInlineAsmField(StringRef Base, StringRef Member,
65  unsigned &Offset) override {
66  return TheParser.getActions().LookupInlineAsmField(Base, Member, Offset,
67  AsmLoc);
68  }
69 
70  static void DiagHandlerCallback(const llvm::SMDiagnostic &D, void *Context) {
71  ((ClangAsmParserCallback *)Context)->handleDiagnostic(D);
72  }
73 
74 private:
75  /// Collect the appropriate tokens for the given string.
76  void findTokensForString(StringRef Str, SmallVectorImpl<Token> &TempToks,
77  const Token *&FirstOrigToken) const;
78 
79  SourceLocation translateLocation(const llvm::SourceMgr &LSM,
80  llvm::SMLoc SMLoc);
81 
82  void handleDiagnostic(const llvm::SMDiagnostic &D);
83 };
84 }
85 
86 void ClangAsmParserCallback::LookupInlineAsmIdentifier(
87  StringRef &LineBuf, llvm::InlineAsmIdentifierInfo &Info,
88  bool IsUnevaluatedContext) {
89  // Collect the desired tokens.
90  SmallVector<Token, 16> LineToks;
91  const Token *FirstOrigToken = nullptr;
92  findTokensForString(LineBuf, LineToks, FirstOrigToken);
93 
94  unsigned NumConsumedToks;
95  ExprResult Result = TheParser.ParseMSAsmIdentifier(LineToks, NumConsumedToks,
96  IsUnevaluatedContext);
97 
98  // If we consumed the entire line, tell MC that.
99  // Also do this if we consumed nothing as a way of reporting failure.
100  if (NumConsumedToks == 0 || NumConsumedToks == LineToks.size()) {
101  // By not modifying LineBuf, we're implicitly consuming it all.
102 
103  // Otherwise, consume up to the original tokens.
104  } else {
105  assert(FirstOrigToken && "not using original tokens?");
106 
107  // Since we're using original tokens, apply that offset.
108  assert(FirstOrigToken[NumConsumedToks].getLocation() ==
109  LineToks[NumConsumedToks].getLocation());
110  unsigned FirstIndex = FirstOrigToken - AsmToks.begin();
111  unsigned LastIndex = FirstIndex + NumConsumedToks - 1;
112 
113  // The total length we've consumed is the relative offset
114  // of the last token we consumed plus its length.
115  unsigned TotalOffset =
116  (AsmTokOffsets[LastIndex] + AsmToks[LastIndex].getLength() -
117  AsmTokOffsets[FirstIndex]);
118  LineBuf = LineBuf.substr(0, TotalOffset);
119  }
120 
121  // Initialize Info with the lookup result.
122  if (!Result.isUsable())
123  return;
124  TheParser.getActions().FillInlineAsmIdentifierInfo(Result.get(), Info);
125 }
126 
127 StringRef ClangAsmParserCallback::LookupInlineAsmLabel(StringRef Identifier,
128  llvm::SourceMgr &LSM,
129  llvm::SMLoc Location,
130  bool Create) {
131  SourceLocation Loc = translateLocation(LSM, Location);
132  LabelDecl *Label =
133  TheParser.getActions().GetOrCreateMSAsmLabel(Identifier, Loc, Create);
134  return Label->getMSAsmLabel();
135 }
136 
137 void ClangAsmParserCallback::findTokensForString(
138  StringRef Str, SmallVectorImpl<Token> &TempToks,
139  const Token *&FirstOrigToken) const {
140  // For now, assert that the string we're working with is a substring
141  // of what we gave to MC. This lets us use the original tokens.
142  assert(!std::less<const char *>()(Str.begin(), AsmString.begin()) &&
143  !std::less<const char *>()(AsmString.end(), Str.end()));
144 
145  // Try to find a token whose offset matches the first token.
146  unsigned FirstCharOffset = Str.begin() - AsmString.begin();
147  const unsigned *FirstTokOffset =
148  llvm::lower_bound(AsmTokOffsets, FirstCharOffset);
149 
150  // For now, assert that the start of the string exactly
151  // corresponds to the start of a token.
152  assert(*FirstTokOffset == FirstCharOffset);
153 
154  // Use all the original tokens for this line. (We assume the
155  // end of the line corresponds cleanly to a token break.)
156  unsigned FirstTokIndex = FirstTokOffset - AsmTokOffsets.begin();
157  FirstOrigToken = &AsmToks[FirstTokIndex];
158  unsigned LastCharOffset = Str.end() - AsmString.begin();
159  for (unsigned i = FirstTokIndex, e = AsmTokOffsets.size(); i != e; ++i) {
160  if (AsmTokOffsets[i] >= LastCharOffset)
161  break;
162  TempToks.push_back(AsmToks[i]);
163  }
164 }
165 
167 ClangAsmParserCallback::translateLocation(const llvm::SourceMgr &LSM,
168  llvm::SMLoc SMLoc) {
169  // Compute an offset into the inline asm buffer.
170  // FIXME: This isn't right if .macro is involved (but hopefully, no
171  // real-world code does that).
172  const llvm::MemoryBuffer *LBuf =
173  LSM.getMemoryBuffer(LSM.FindBufferContainingLoc(SMLoc));
174  unsigned Offset = SMLoc.getPointer() - LBuf->getBufferStart();
175 
176  // Figure out which token that offset points into.
177  const unsigned *TokOffsetPtr = llvm::lower_bound(AsmTokOffsets, Offset);
178  unsigned TokIndex = TokOffsetPtr - AsmTokOffsets.begin();
179  unsigned TokOffset = *TokOffsetPtr;
180 
181  // If we come up with an answer which seems sane, use it; otherwise,
182  // just point at the __asm keyword.
183  // FIXME: Assert the answer is sane once we handle .macro correctly.
184  SourceLocation Loc = AsmLoc;
185  if (TokIndex < AsmToks.size()) {
186  const Token &Tok = AsmToks[TokIndex];
187  Loc = Tok.getLocation();
188  Loc = Loc.getLocWithOffset(Offset - TokOffset);
189  }
190  return Loc;
191 }
192 
193 void ClangAsmParserCallback::handleDiagnostic(const llvm::SMDiagnostic &D) {
194  const llvm::SourceMgr &LSM = *D.getSourceMgr();
195  SourceLocation Loc = translateLocation(LSM, D.getLoc());
196  TheParser.Diag(Loc, diag::err_inline_ms_asm_parsing) << D.getMessage();
197 }
198 
199 /// Parse an identifier in an MS-style inline assembly block.
201  unsigned &NumLineToksConsumed,
202  bool IsUnevaluatedContext) {
203  // Push a fake token on the end so that we don't overrun the token
204  // stream. We use ';' because it expression-parsing should never
205  // overrun it.
206  const tok::TokenKind EndOfStream = tok::semi;
207  Token EndOfStreamTok;
208  EndOfStreamTok.startToken();
209  EndOfStreamTok.setKind(EndOfStream);
210  LineToks.push_back(EndOfStreamTok);
211 
212  // Also copy the current token over.
213  LineToks.push_back(Tok);
214 
215  PP.EnterTokenStream(LineToks, /*DisableMacroExpansions*/ true,
216  /*IsReinject*/ true);
217 
218  // Clear the current token and advance to the first token in LineToks.
219  ConsumeAnyToken();
220 
221  // Parse an optional scope-specifier if we're in C++.
222  CXXScopeSpec SS;
223  if (getLangOpts().CPlusPlus)
224  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/nullptr,
225  /*ObjectHadErrors=*/false,
226  /*EnteringContext=*/false);
227 
228  // Require an identifier here.
229  SourceLocation TemplateKWLoc;
231  bool Invalid = true;
233  if (Tok.is(tok::kw_this)) {
234  Result = ParseCXXThis();
235  Invalid = false;
236  } else {
237  Invalid =
238  ParseUnqualifiedId(SS, /*ObjectType=*/nullptr,
239  /*ObjectHadErrors=*/false,
240  /*EnteringContext=*/false,
241  /*AllowDestructorName=*/false,
242  /*AllowConstructorName=*/false,
243  /*AllowDeductionGuide=*/false, &TemplateKWLoc, Id);
244  // Perform the lookup.
245  Result = Actions.LookupInlineAsmIdentifier(SS, TemplateKWLoc, Id,
246  IsUnevaluatedContext);
247  }
248  // While the next two tokens are 'period' 'identifier', repeatedly parse it as
249  // a field access. We have to avoid consuming assembler directives that look
250  // like '.' 'else'.
251  while (Result.isUsable() && Tok.is(tok::period)) {
252  Token IdTok = PP.LookAhead(0);
253  if (IdTok.isNot(tok::identifier))
254  break;
255  ConsumeToken(); // Consume the period.
256  IdentifierInfo *Id = Tok.getIdentifierInfo();
257  ConsumeToken(); // Consume the identifier.
258  Result = Actions.LookupInlineAsmVarDeclField(Result.get(), Id->getName(),
259  Tok.getLocation());
260  }
261 
262  // Figure out how many tokens we are into LineToks.
263  unsigned LineIndex = 0;
264  if (Tok.is(EndOfStream)) {
265  LineIndex = LineToks.size() - 2;
266  } else {
267  while (LineToks[LineIndex].getLocation() != Tok.getLocation()) {
268  LineIndex++;
269  assert(LineIndex < LineToks.size() - 2); // we added two extra tokens
270  }
271  }
272 
273  // If we've run into the poison token we inserted before, or there
274  // was a parsing error, then claim the entire line.
275  if (Invalid || Tok.is(EndOfStream)) {
276  NumLineToksConsumed = LineToks.size() - 2;
277  } else {
278  // Otherwise, claim up to the start of the next token.
279  NumLineToksConsumed = LineIndex;
280  }
281 
282  // Finally, restore the old parsing state by consuming all the tokens we
283  // staged before, implicitly killing off the token-lexer we pushed.
284  for (unsigned i = 0, e = LineToks.size() - LineIndex - 2; i != e; ++i) {
285  ConsumeAnyToken();
286  }
287  assert(Tok.is(EndOfStream));
288  ConsumeToken();
289 
290  // Leave LineToks in its original state.
291  LineToks.pop_back();
292  LineToks.pop_back();
293 
294  return Result;
295 }
296 
297 /// Turn a sequence of our tokens back into a string that we can hand
298 /// to the MC asm parser.
300  ArrayRef<Token> AsmToks,
301  SmallVectorImpl<unsigned> &TokOffsets,
303  assert(!AsmToks.empty() && "Didn't expect an empty AsmToks!");
304 
305  // Is this the start of a new assembly statement?
306  bool isNewStatement = true;
307 
308  for (unsigned i = 0, e = AsmToks.size(); i < e; ++i) {
309  const Token &Tok = AsmToks[i];
310 
311  // Start each new statement with a newline and a tab.
312  if (!isNewStatement && (Tok.is(tok::kw_asm) || Tok.isAtStartOfLine())) {
313  Asm += "\n\t";
314  isNewStatement = true;
315  }
316 
317  // Preserve the existence of leading whitespace except at the
318  // start of a statement.
319  if (!isNewStatement && Tok.hasLeadingSpace())
320  Asm += ' ';
321 
322  // Remember the offset of this token.
323  TokOffsets.push_back(Asm.size());
324 
325  // Don't actually write '__asm' into the assembly stream.
326  if (Tok.is(tok::kw_asm)) {
327  // Complain about __asm at the end of the stream.
328  if (i + 1 == e) {
329  PP.Diag(AsmLoc, diag::err_asm_empty);
330  return true;
331  }
332 
333  continue;
334  }
335 
336  // Append the spelling of the token.
337  SmallString<32> SpellingBuffer;
338  bool SpellingInvalid = false;
339  Asm += PP.getSpelling(Tok, SpellingBuffer, &SpellingInvalid);
340  assert(!SpellingInvalid && "spelling was invalid after correct parse?");
341 
342  // We are no longer at the start of a statement.
343  isNewStatement = false;
344  }
345 
346  // Ensure that the buffer is null-terminated.
347  Asm.push_back('\0');
348  Asm.pop_back();
349 
350  assert(TokOffsets.size() == AsmToks.size());
351  return false;
352 }
353 
354 // Determine if this is a GCC-style asm statement.
355 bool Parser::isGCCAsmStatement(const Token &TokAfterAsm) const {
356  return TokAfterAsm.is(tok::l_paren) || isGNUAsmQualifier(TokAfterAsm);
357 }
358 
359 bool Parser::isGNUAsmQualifier(const Token &TokAfterAsm) const {
360  return getGNUAsmQualifier(TokAfterAsm) != GNUAsmQualifiers::AQ_unspecified;
361 }
362 
363 /// ParseMicrosoftAsmStatement. When -fms-extensions/-fasm-blocks is enabled,
364 /// this routine is called to collect the tokens for an MS asm statement.
365 ///
366 /// [MS] ms-asm-statement:
367 /// ms-asm-block
368 /// ms-asm-block ms-asm-statement
369 ///
370 /// [MS] ms-asm-block:
371 /// '__asm' ms-asm-line '\n'
372 /// '__asm' '{' ms-asm-instruction-block[opt] '}' ';'[opt]
373 ///
374 /// [MS] ms-asm-instruction-block
375 /// ms-asm-line
376 /// ms-asm-line '\n' ms-asm-instruction-block
377 ///
378 StmtResult Parser::ParseMicrosoftAsmStatement(SourceLocation AsmLoc) {
379  SourceManager &SrcMgr = PP.getSourceManager();
380  SourceLocation EndLoc = AsmLoc;
381  SmallVector<Token, 4> AsmToks;
382 
383  bool SingleLineMode = true;
384  unsigned BraceNesting = 0;
385  unsigned short savedBraceCount = BraceCount;
386  bool InAsmComment = false;
387  FileID FID;
388  unsigned LineNo = 0;
389  unsigned NumTokensRead = 0;
391  bool SkippedStartOfLine = false;
392 
393  if (Tok.is(tok::l_brace)) {
394  // Braced inline asm: consume the opening brace.
395  SingleLineMode = false;
396  BraceNesting = 1;
397  EndLoc = ConsumeBrace();
398  LBraceLocs.push_back(EndLoc);
399  ++NumTokensRead;
400  } else {
401  // Single-line inline asm; compute which line it is on.
402  std::pair<FileID, unsigned> ExpAsmLoc =
403  SrcMgr.getDecomposedExpansionLoc(EndLoc);
404  FID = ExpAsmLoc.first;
405  LineNo = SrcMgr.getLineNumber(FID, ExpAsmLoc.second);
406  LBraceLocs.push_back(SourceLocation());
407  }
408 
409  SourceLocation TokLoc = Tok.getLocation();
410  do {
411  // If we hit EOF, we're done, period.
412  if (isEofOrEom())
413  break;
414 
415  if (!InAsmComment && Tok.is(tok::l_brace)) {
416  // Consume the opening brace.
417  SkippedStartOfLine = Tok.isAtStartOfLine();
418  AsmToks.push_back(Tok);
419  EndLoc = ConsumeBrace();
420  BraceNesting++;
421  LBraceLocs.push_back(EndLoc);
422  TokLoc = Tok.getLocation();
423  ++NumTokensRead;
424  continue;
425  } else if (!InAsmComment && Tok.is(tok::semi)) {
426  // A semicolon in an asm is the start of a comment.
427  InAsmComment = true;
428  if (!SingleLineMode) {
429  // Compute which line the comment is on.
430  std::pair<FileID, unsigned> ExpSemiLoc =
431  SrcMgr.getDecomposedExpansionLoc(TokLoc);
432  FID = ExpSemiLoc.first;
433  LineNo = SrcMgr.getLineNumber(FID, ExpSemiLoc.second);
434  }
435  } else if (SingleLineMode || InAsmComment) {
436  // If end-of-line is significant, check whether this token is on a
437  // new line.
438  std::pair<FileID, unsigned> ExpLoc =
439  SrcMgr.getDecomposedExpansionLoc(TokLoc);
440  if (ExpLoc.first != FID ||
441  SrcMgr.getLineNumber(ExpLoc.first, ExpLoc.second) != LineNo) {
442  // If this is a single-line __asm, we're done, except if the next
443  // line is MS-style asm too, in which case we finish a comment
444  // if needed and then keep processing the next line as a single
445  // line __asm.
446  bool isAsm = Tok.is(tok::kw_asm);
447  if (SingleLineMode && (!isAsm || isGCCAsmStatement(NextToken())))
448  break;
449  // We're no longer in a comment.
450  InAsmComment = false;
451  if (isAsm) {
452  // If this is a new __asm {} block we want to process it separately
453  // from the single-line __asm statements
454  if (PP.LookAhead(0).is(tok::l_brace))
455  break;
456  LineNo = SrcMgr.getLineNumber(ExpLoc.first, ExpLoc.second);
457  SkippedStartOfLine = Tok.isAtStartOfLine();
458  } else if (Tok.is(tok::semi)) {
459  // A multi-line asm-statement, where next line is a comment
460  InAsmComment = true;
461  FID = ExpLoc.first;
462  LineNo = SrcMgr.getLineNumber(FID, ExpLoc.second);
463  }
464  } else if (!InAsmComment && Tok.is(tok::r_brace)) {
465  // In MSVC mode, braces only participate in brace matching and
466  // separating the asm statements. This is an intentional
467  // departure from the Apple gcc behavior.
468  if (!BraceNesting)
469  break;
470  }
471  }
472  if (!InAsmComment && BraceNesting && Tok.is(tok::r_brace) &&
473  BraceCount == (savedBraceCount + BraceNesting)) {
474  // Consume the closing brace.
475  SkippedStartOfLine = Tok.isAtStartOfLine();
476  // Don't want to add the closing brace of the whole asm block
477  if (SingleLineMode || BraceNesting > 1) {
479  AsmToks.push_back(Tok);
480  }
481  EndLoc = ConsumeBrace();
482  BraceNesting--;
483  // Finish if all of the opened braces in the inline asm section were
484  // consumed.
485  if (BraceNesting == 0 && !SingleLineMode)
486  break;
487  else {
488  LBraceLocs.pop_back();
489  TokLoc = Tok.getLocation();
490  ++NumTokensRead;
491  continue;
492  }
493  }
494 
495  // Consume the next token; make sure we don't modify the brace count etc.
496  // if we are in a comment.
497  EndLoc = TokLoc;
498  if (InAsmComment)
499  PP.Lex(Tok);
500  else {
501  // Set the token as the start of line if we skipped the original start
502  // of line token in case it was a nested brace.
503  if (SkippedStartOfLine)
505  AsmToks.push_back(Tok);
506  ConsumeAnyToken();
507  }
508  TokLoc = Tok.getLocation();
509  ++NumTokensRead;
510  SkippedStartOfLine = false;
511  } while (1);
512 
513  if (BraceNesting && BraceCount != savedBraceCount) {
514  // __asm without closing brace (this can happen at EOF).
515  for (unsigned i = 0; i < BraceNesting; ++i) {
516  Diag(Tok, diag::err_expected) << tok::r_brace;
517  Diag(LBraceLocs.back(), diag::note_matching) << tok::l_brace;
518  LBraceLocs.pop_back();
519  }
520  return StmtError();
521  } else if (NumTokensRead == 0) {
522  // Empty __asm.
523  Diag(Tok, diag::err_expected) << tok::l_brace;
524  return StmtError();
525  }
526 
527  // Okay, prepare to use MC to parse the assembly.
528  SmallVector<StringRef, 4> ConstraintRefs;
530  SmallVector<StringRef, 4> ClobberRefs;
531 
532  // We need an actual supported target.
533  const llvm::Triple &TheTriple = Actions.Context.getTargetInfo().getTriple();
534  const std::string &TT = TheTriple.getTriple();
535  const llvm::Target *TheTarget = nullptr;
536  if (!TheTriple.isX86()) {
537  Diag(AsmLoc, diag::err_msasm_unsupported_arch) << TheTriple.getArchName();
538  } else {
539  std::string Error;
540  TheTarget = llvm::TargetRegistry::lookupTarget(TT, Error);
541  if (!TheTarget)
542  Diag(AsmLoc, diag::err_msasm_unable_to_create_target) << Error;
543  }
544 
545  assert(!LBraceLocs.empty() && "Should have at least one location here");
546 
547  SmallString<512> AsmString;
548  auto EmptyStmt = [&] {
549  return Actions.ActOnMSAsmStmt(AsmLoc, LBraceLocs[0], AsmToks, AsmString,
550  /*NumOutputs*/ 0, /*NumInputs*/ 0,
551  ConstraintRefs, ClobberRefs, Exprs, EndLoc);
552  };
553  // If we don't support assembly, or the assembly is empty, we don't
554  // need to instantiate the AsmParser, etc.
555  if (!TheTarget || AsmToks.empty()) {
556  return EmptyStmt();
557  }
558 
559  // Expand the tokens into a string buffer.
560  SmallVector<unsigned, 8> TokOffsets;
561  if (buildMSAsmString(PP, AsmLoc, AsmToks, TokOffsets, AsmString))
562  return StmtError();
563 
564  const TargetOptions &TO = Actions.Context.getTargetInfo().getTargetOpts();
565  std::string FeaturesStr =
566  llvm::join(TO.Features.begin(), TO.Features.end(), ",");
567 
568  std::unique_ptr<llvm::MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT));
569  if (!MRI) {
570  Diag(AsmLoc, diag::err_msasm_unable_to_create_target)
571  << "target MC unavailable";
572  return EmptyStmt();
573  }
574  // FIXME: init MCOptions from sanitizer flags here.
575  llvm::MCTargetOptions MCOptions;
576  std::unique_ptr<llvm::MCAsmInfo> MAI(
577  TheTarget->createMCAsmInfo(*MRI, TT, MCOptions));
578  // Get the instruction descriptor.
579  std::unique_ptr<llvm::MCInstrInfo> MII(TheTarget->createMCInstrInfo());
580  std::unique_ptr<llvm::MCObjectFileInfo> MOFI(new llvm::MCObjectFileInfo());
581  std::unique_ptr<llvm::MCSubtargetInfo> STI(
582  TheTarget->createMCSubtargetInfo(TT, TO.CPU, FeaturesStr));
583  // Target MCTargetDesc may not be linked in clang-based tools.
584  if (!MAI || !MII | !MOFI || !STI) {
585  Diag(AsmLoc, diag::err_msasm_unable_to_create_target)
586  << "target MC unavailable";
587  return EmptyStmt();
588  }
589 
590  llvm::SourceMgr TempSrcMgr;
591  llvm::MCContext Ctx(MAI.get(), MRI.get(), MOFI.get(), &TempSrcMgr);
592  MOFI->InitMCObjectFileInfo(TheTriple, /*PIC*/ false, Ctx);
593  std::unique_ptr<llvm::MemoryBuffer> Buffer =
594  llvm::MemoryBuffer::getMemBuffer(AsmString, "<MS inline asm>");
595 
596  // Tell SrcMgr about this buffer, which is what the parser will pick up.
597  TempSrcMgr.AddNewSourceBuffer(std::move(Buffer), llvm::SMLoc());
598 
599  std::unique_ptr<llvm::MCStreamer> Str(createNullStreamer(Ctx));
600  std::unique_ptr<llvm::MCAsmParser> Parser(
601  createMCAsmParser(TempSrcMgr, Ctx, *Str.get(), *MAI));
602 
603  std::unique_ptr<llvm::MCTargetAsmParser> TargetParser(
604  TheTarget->createMCAsmParser(*STI, *Parser, *MII, MCOptions));
605  // Target AsmParser may not be linked in clang-based tools.
606  if (!TargetParser) {
607  Diag(AsmLoc, diag::err_msasm_unable_to_create_target)
608  << "target ASM parser unavailable";
609  return EmptyStmt();
610  }
611 
612  std::unique_ptr<llvm::MCInstPrinter> IP(
613  TheTarget->createMCInstPrinter(llvm::Triple(TT), 1, *MAI, *MII, *MRI));
614 
615  // Change to the Intel dialect.
616  Parser->setAssemblerDialect(1);
617  Parser->setTargetParser(*TargetParser.get());
618  Parser->setParsingMSInlineAsm(true);
619  TargetParser->setParsingMSInlineAsm(true);
620 
621  ClangAsmParserCallback Callback(*this, AsmLoc, AsmString, AsmToks,
622  TokOffsets);
623  TargetParser->setSemaCallback(&Callback);
624  TempSrcMgr.setDiagHandler(ClangAsmParserCallback::DiagHandlerCallback,
625  &Callback);
626 
627  unsigned NumOutputs;
628  unsigned NumInputs;
629  std::string AsmStringIR;
631  SmallVector<std::string, 4> Constraints;
633  if (Parser->parseMSInlineAsm(AsmLoc.getPtrEncoding(), AsmStringIR, NumOutputs,
634  NumInputs, OpExprs, Constraints, Clobbers,
635  MII.get(), IP.get(), Callback))
636  return StmtError();
637 
638  // Filter out "fpsw" and "mxcsr". They aren't valid GCC asm clobber
639  // constraints. Clang always adds fpsr to the clobber list anyway.
640  llvm::erase_if(Clobbers, [](const std::string &C) {
641  return C == "fpsr" || C == "mxcsr";
642  });
643 
644  // Build the vector of clobber StringRefs.
645  ClobberRefs.insert(ClobberRefs.end(), Clobbers.begin(), Clobbers.end());
646 
647  // Recast the void pointers and build the vector of constraint StringRefs.
648  unsigned NumExprs = NumOutputs + NumInputs;
649  ConstraintRefs.resize(NumExprs);
650  Exprs.resize(NumExprs);
651  for (unsigned i = 0, e = NumExprs; i != e; ++i) {
652  Expr *OpExpr = static_cast<Expr *>(OpExprs[i].first);
653  if (!OpExpr)
654  return StmtError();
655 
656  // Need address of variable.
657  if (OpExprs[i].second)
658  OpExpr =
659  Actions.BuildUnaryOp(getCurScope(), AsmLoc, UO_AddrOf, OpExpr).get();
660 
661  ConstraintRefs[i] = StringRef(Constraints[i]);
662  Exprs[i] = OpExpr;
663  }
664 
665  // FIXME: We should be passing source locations for better diagnostics.
666  return Actions.ActOnMSAsmStmt(AsmLoc, LBraceLocs[0], AsmToks, AsmStringIR,
667  NumOutputs, NumInputs, ConstraintRefs,
668  ClobberRefs, Exprs, EndLoc);
669 }
670 
671 /// parseGNUAsmQualifierListOpt - Parse a GNU extended asm qualifier list.
672 /// asm-qualifier:
673 /// volatile
674 /// inline
675 /// goto
676 ///
677 /// asm-qualifier-list:
678 /// asm-qualifier
679 /// asm-qualifier-list asm-qualifier
680 bool Parser::parseGNUAsmQualifierListOpt(GNUAsmQualifiers &AQ) {
681  while (1) {
682  const GNUAsmQualifiers::AQ A = getGNUAsmQualifier(Tok);
683  if (A == GNUAsmQualifiers::AQ_unspecified) {
684  if (Tok.isNot(tok::l_paren)) {
685  Diag(Tok.getLocation(), diag::err_asm_qualifier_ignored);
686  SkipUntil(tok::r_paren, StopAtSemi);
687  return true;
688  }
689  return false;
690  }
691  if (AQ.setAsmQualifier(A))
692  Diag(Tok.getLocation(), diag::err_asm_duplicate_qual)
693  << GNUAsmQualifiers::getQualifierName(A);
694  ConsumeToken();
695  }
696  return false;
697 }
698 
699 /// ParseAsmStatement - Parse a GNU extended asm statement.
700 /// asm-statement:
701 /// gnu-asm-statement
702 /// ms-asm-statement
703 ///
704 /// [GNU] gnu-asm-statement:
705 /// 'asm' asm-qualifier-list[opt] '(' asm-argument ')' ';'
706 ///
707 /// [GNU] asm-argument:
708 /// asm-string-literal
709 /// asm-string-literal ':' asm-operands[opt]
710 /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
711 /// asm-string-literal ':' asm-operands[opt] ':' asm-operands[opt]
712 /// ':' asm-clobbers
713 ///
714 /// [GNU] asm-clobbers:
715 /// asm-string-literal
716 /// asm-clobbers ',' asm-string-literal
717 ///
718 StmtResult Parser::ParseAsmStatement(bool &msAsm) {
719  assert(Tok.is(tok::kw_asm) && "Not an asm stmt");
720  SourceLocation AsmLoc = ConsumeToken();
721 
722  if (getLangOpts().AsmBlocks && !isGCCAsmStatement(Tok)) {
723  msAsm = true;
724  return ParseMicrosoftAsmStatement(AsmLoc);
725  }
726 
727  SourceLocation Loc = Tok.getLocation();
728  GNUAsmQualifiers GAQ;
729  if (parseGNUAsmQualifierListOpt(GAQ))
730  return StmtError();
731 
732  if (GAQ.isGoto() && getLangOpts().SpeculativeLoadHardening)
733  Diag(Loc, diag::warn_slh_does_not_support_asm_goto);
734 
735  BalancedDelimiterTracker T(*this, tok::l_paren);
736  T.consumeOpen();
737 
738  ExprResult AsmString(ParseAsmStringLiteral(/*ForAsmLabel*/ false));
739 
740  // Check if GNU-style InlineAsm is disabled.
741  // Error on anything other than empty string.
742  if (!(getLangOpts().GNUAsm || AsmString.isInvalid())) {
743  const auto *SL = cast<StringLiteral>(AsmString.get());
744  if (!SL->getString().trim().empty())
745  Diag(Loc, diag::err_gnu_inline_asm_disabled);
746  }
747 
748  if (AsmString.isInvalid()) {
749  // Consume up to and including the closing paren.
750  T.skipToEnd();
751  return StmtError();
752  }
753 
755  ExprVector Constraints;
756  ExprVector Exprs;
757  ExprVector Clobbers;
758 
759  if (Tok.is(tok::r_paren)) {
760  // We have a simple asm expression like 'asm("foo")'.
761  T.consumeClose();
762  return Actions.ActOnGCCAsmStmt(
763  AsmLoc, /*isSimple*/ true, GAQ.isVolatile(),
764  /*NumOutputs*/ 0, /*NumInputs*/ 0, nullptr, Constraints, Exprs,
765  AsmString.get(), Clobbers, /*NumLabels*/ 0, T.getCloseLocation());
766  }
767 
768  // Parse Outputs, if present.
769  bool AteExtraColon = false;
770  if (Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
771  // In C++ mode, parse "::" like ": :".
772  AteExtraColon = Tok.is(tok::coloncolon);
773  ConsumeToken();
774 
775  if (!AteExtraColon && ParseAsmOperandsOpt(Names, Constraints, Exprs))
776  return StmtError();
777  }
778 
779  unsigned NumOutputs = Names.size();
780 
781  // Parse Inputs, if present.
782  if (AteExtraColon || Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
783  // In C++ mode, parse "::" like ": :".
784  if (AteExtraColon)
785  AteExtraColon = false;
786  else {
787  AteExtraColon = Tok.is(tok::coloncolon);
788  ConsumeToken();
789  }
790 
791  if (!AteExtraColon && ParseAsmOperandsOpt(Names, Constraints, Exprs))
792  return StmtError();
793  }
794 
795  assert(Names.size() == Constraints.size() &&
796  Constraints.size() == Exprs.size() && "Input operand size mismatch!");
797 
798  unsigned NumInputs = Names.size() - NumOutputs;
799 
800  // Parse the clobbers, if present.
801  if (AteExtraColon || Tok.is(tok::colon) || Tok.is(tok::coloncolon)) {
802  if (AteExtraColon)
803  AteExtraColon = false;
804  else {
805  AteExtraColon = Tok.is(tok::coloncolon);
806  ConsumeToken();
807  }
808  // Parse the asm-string list for clobbers if present.
809  if (!AteExtraColon && isTokenStringLiteral()) {
810  while (1) {
811  ExprResult Clobber(ParseAsmStringLiteral(/*ForAsmLabel*/ false));
812 
813  if (Clobber.isInvalid())
814  break;
815 
816  Clobbers.push_back(Clobber.get());
817 
818  if (!TryConsumeToken(tok::comma))
819  break;
820  }
821  }
822  }
823  if (!GAQ.isGoto() && (Tok.isNot(tok::r_paren) || AteExtraColon)) {
824  Diag(Tok, diag::err_expected) << tok::r_paren;
825  SkipUntil(tok::r_paren, StopAtSemi);
826  return StmtError();
827  }
828 
829  // Parse the goto label, if present.
830  unsigned NumLabels = 0;
831  if (AteExtraColon || Tok.is(tok::colon)) {
832  if (!AteExtraColon)
833  ConsumeToken();
834 
835  while (true) {
836  if (Tok.isNot(tok::identifier)) {
837  Diag(Tok, diag::err_expected) << tok::identifier;
838  SkipUntil(tok::r_paren, StopAtSemi);
839  return StmtError();
840  }
841  LabelDecl *LD = Actions.LookupOrCreateLabel(Tok.getIdentifierInfo(),
842  Tok.getLocation());
843  Names.push_back(Tok.getIdentifierInfo());
844  if (!LD) {
845  SkipUntil(tok::r_paren, StopAtSemi);
846  return StmtError();
847  }
848  ExprResult Res =
849  Actions.ActOnAddrLabel(Tok.getLocation(), Tok.getLocation(), LD);
850  Exprs.push_back(Res.get());
851  NumLabels++;
852  ConsumeToken();
853  if (!TryConsumeToken(tok::comma))
854  break;
855  }
856  } else if (GAQ.isGoto()) {
857  Diag(Tok, diag::err_expected) << tok::colon;
858  SkipUntil(tok::r_paren, StopAtSemi);
859  return StmtError();
860  }
861  T.consumeClose();
862  return Actions.ActOnGCCAsmStmt(AsmLoc, false, GAQ.isVolatile(), NumOutputs,
863  NumInputs, Names.data(), Constraints, Exprs,
864  AsmString.get(), Clobbers, NumLabels,
865  T.getCloseLocation());
866 }
867 
868 /// ParseAsmOperands - Parse the asm-operands production as used by
869 /// asm-statement, assuming the leading ':' token was eaten.
870 ///
871 /// [GNU] asm-operands:
872 /// asm-operand
873 /// asm-operands ',' asm-operand
874 ///
875 /// [GNU] asm-operand:
876 /// asm-string-literal '(' expression ')'
877 /// '[' identifier ']' asm-string-literal '(' expression ')'
878 ///
879 //
880 // FIXME: Avoid unnecessary std::string trashing.
881 bool Parser::ParseAsmOperandsOpt(SmallVectorImpl<IdentifierInfo *> &Names,
882  SmallVectorImpl<Expr *> &Constraints,
883  SmallVectorImpl<Expr *> &Exprs) {
884  // 'asm-operands' isn't present?
885  if (!isTokenStringLiteral() && Tok.isNot(tok::l_square))
886  return false;
887 
888  while (1) {
889  // Read the [id] if present.
890  if (Tok.is(tok::l_square)) {
891  BalancedDelimiterTracker T(*this, tok::l_square);
892  T.consumeOpen();
893 
894  if (Tok.isNot(tok::identifier)) {
895  Diag(Tok, diag::err_expected) << tok::identifier;
896  SkipUntil(tok::r_paren, StopAtSemi);
897  return true;
898  }
899 
900  IdentifierInfo *II = Tok.getIdentifierInfo();
901  ConsumeToken();
902 
903  Names.push_back(II);
904  T.consumeClose();
905  } else
906  Names.push_back(nullptr);
907 
908  ExprResult Constraint(ParseAsmStringLiteral(/*ForAsmLabel*/ false));
909  if (Constraint.isInvalid()) {
910  SkipUntil(tok::r_paren, StopAtSemi);
911  return true;
912  }
913  Constraints.push_back(Constraint.get());
914 
915  if (Tok.isNot(tok::l_paren)) {
916  Diag(Tok, diag::err_expected_lparen_after) << "asm operand";
917  SkipUntil(tok::r_paren, StopAtSemi);
918  return true;
919  }
920 
921  // Read the parenthesized expression.
922  BalancedDelimiterTracker T(*this, tok::l_paren);
923  T.consumeOpen();
924  ExprResult Res = Actions.CorrectDelayedTyposInExpr(ParseExpression());
925  T.consumeClose();
926  if (Res.isInvalid()) {
927  SkipUntil(tok::r_paren, StopAtSemi);
928  return true;
929  }
930  Exprs.push_back(Res.get());
931  // Eat the comma and continue parsing if it exists.
932  if (!TryConsumeToken(tok::comma))
933  return false;
934  }
935 }
936 
937 const char *Parser::GNUAsmQualifiers::getQualifierName(AQ Qualifier) {
938  switch (Qualifier) {
939  case AQ_volatile: return "volatile";
940  case AQ_inline: return "inline";
941  case AQ_goto: return "goto";
942  case AQ_unspecified: return "unspecified";
943  }
944  llvm_unreachable("Unknown GNUAsmQualifier");
945 }
946 
947 Parser::GNUAsmQualifiers::AQ
948 Parser::getGNUAsmQualifier(const Token &Tok) const {
949  switch (Tok.getKind()) {
950  case tok::kw_volatile: return GNUAsmQualifiers::AQ_volatile;
951  case tok::kw_inline: return GNUAsmQualifiers::AQ_inline;
952  case tok::kw_goto: return GNUAsmQualifiers::AQ_goto;
953  default: return GNUAsmQualifiers::AQ_unspecified;
954  }
955 }
956 bool Parser::GNUAsmQualifiers::setAsmQualifier(AQ Qualifier) {
957  bool IsDuplicate = Qualifiers & Qualifier;
958  Qualifiers |= Qualifier;
959  return IsDuplicate;
960 }
Defines the clang::ASTContext interface.
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
StringRef Identifier
Definition: Format.cpp:2026
SourceLocation getLocWithOffset(int Offset) const
Return a source location with the specified offset from this SourceLocation.
void FillInlineAsmIdentifierInfo(Expr *Res, llvm::InlineAsmIdentifierInfo &Info)
bool is(tok::TokenKind K) const
is/isNot - Predicates to check if this token is a specific kind, as in "if (Tok.is(tok::l_brace)) {...
Definition: Token.h:97
StringRef P
SourceLocation getCloseLocation() const
void setFlag(TokenFlags Flag)
Set the specified flag.
Definition: Token.h:236
Parser - This implements a parser for the C family of languages.
Definition: Parser.h:61
ActionResult< Stmt * > StmtResult
Definition: Ownership.h:264
Options for controlling the target.
Definition: TargetOptions.h:26
tok::TokenKind getKind() const
Definition: Token.h:92
The collection of all-type qualifiers we support.
Definition: Type.h:144
One of these records is kept for each identifier that is lexed.
Token - This structure provides full information about a lexed token.
Definition: Token.h:34
void setKind(tok::TokenKind K)
Definition: Token.h:93
RAII class that helps handle the parsing of an open/close delimiter pair, such as braces { ...
LabelDecl * GetOrCreateMSAsmLabel(StringRef ExternalLabelName, SourceLocation Location, bool AlwaysCreate)
std::pair< FileID, unsigned > getDecomposedExpansionLoc(SourceLocation Loc) const
Decompose the specified location into a raw FileID + Offset pair.
Represents a C++ unqualified-id that has been parsed.
Definition: DeclSpec.h:955
PtrTy get() const
Definition: Ownership.h:170
StringRef getSpelling(SourceLocation loc, SmallVectorImpl< char > &buffer, bool *invalid=nullptr) const
Return the &#39;spelling&#39; of the token at the given location; does not go up to the spelling location or ...
const FormatToken & Tok
StmtResult StmtError()
Definition: Ownership.h:280
Defines the Diagnostic-related interfaces.
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:64
unsigned Offset
Definition: Format.cpp:2020
This represents one expression.
Definition: Expr.h:110
std::string Label
int Id
Definition: ASTDiff.cpp:191
static bool buildMSAsmString(Preprocessor &PP, SourceLocation AsmLoc, ArrayRef< Token > AsmToks, SmallVectorImpl< unsigned > &TokOffsets, SmallString< 512 > &Asm)
Turn a sequence of our tokens back into a string that we can hand to the MC asm parser.
Sema & getActions() const
Definition: Parser.h:436
SourceLocation getLocation() const
Return a source location identifier for the specified offset in the current file. ...
Definition: Token.h:126
bool isInvalid() const
Definition: Ownership.h:166
bool isUsable() const
Definition: Ownership.h:167
The result type of a method or function.
std::string CPU
If given, the name of the target CPU to generate code for.
Definition: TargetOptions.h:36
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
Encodes a location in the source.
IdentifierInfo * getIdentifierInfo() const
Definition: Token.h:179
Represents the declaration of a label.
Definition: Decl.h:451
ExprResult ParseMSAsmIdentifier(llvm::SmallVectorImpl< Token > &LineToks, unsigned &NumLineToksConsumed, bool IsUnevaluated)
Parse an identifier in an MS-style inline assembly block.
unsigned getLineNumber(FileID FID, unsigned FilePos, bool *Invalid=nullptr) const
Given a SourceLocation, return the spelling line number for the position indicated.
std::vector< std::string > Features
The list of target specific features to enable or disable – this should be a list of strings startin...
Definition: TargetOptions.h:55
bool isAtStartOfLine() const
isAtStartOfLine - Return true if this token is at the start of a line.
Definition: Token.h:268
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:25
bool LookupInlineAsmField(StringRef Base, StringRef Member, unsigned &Offset, SourceLocation AsmLoc)
StringRef getName() const
Return the actual identifier string.
An opaque identifier used by SourceManager which refers to a source file (MemoryBuffer) along with it...
bool isNot(tok::TokenKind K) const
Definition: Token.h:98
Dataflow Directional Tag Classes.
StringRef getMSAsmLabel() const
Definition: Decl.h:488
Assembly: we accept this only so that we can preprocess it.
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Definition: Parser.cpp:73
Defines the clang::TargetInfo interface.
void clearFlag(TokenFlags Flag)
Unset the specified flag.
Definition: Token.h:246
bool hasLeadingSpace() const
Return true if this token has whitespace before it.
Definition: Token.h:272
DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID) const
Forwarding function for diagnostics.
This class handles loading and caching of source files into memory.
void startToken()
Reset all flags to cleared.
Definition: Token.h:171
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:128
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
void * getPtrEncoding() const
When a SourceLocation itself cannot be used, this returns an (opaque) pointer encoding for it...