[MSVC] Implementation of __unaligned as a proper type qualifier

This patch implements __unaligned (MS extension) as a proper type qualifier
(before that, it was implemented as an ignored attribute).

It also fixes PR27367.

Differential Revision: http://reviews.llvm.org/D19654


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@268727 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 62 insertions, 20 deletions

diff --git a/lib/AST/MicrosoftMangle.cpp b/lib/AST/MicrosoftMangle.cpp
index b63b5e5651..f5ba0bdc12 100644
--- a/lib/AST/MicrosoftMangle.cpp
+++ b/lib/AST/MicrosoftMangle.cpp
@@ -1446,6 +1446,9 @@ void MicrosoftCXXNameMangler::manglePointerExtQualifiers(Qualifiers Quals,
 
   if (HasRestrict)
     Out << 'I';
+
+  if (!PointeeType.isNull() && PointeeType.getLocalQualifiers().hasUnaligned())
+    Out << 'F';
 }
 
 void MicrosoftCXXNameMangler::manglePointerCVQualifiers(Qualifiers Quals) {
@@ -1577,6 +1580,8 @@ void MicrosoftCXXNameMangler::mangleType(QualType T, SourceRange Range,
     }
     break;
   case QMM_Result:
+    // Presence of __unaligned qualifier shouldn't affect mangling here.
+    Quals.removeUnaligned();
     if ((!IsPointer && Quals) || isa<TagType>(T)) {
       Out << '?';
       mangleQualifiers(Quals, false);
diff --git a/lib/AST/TypePrinter.cpp b/lib/AST/TypePrinter.cpp
index 0356dc515f..7e04e81e8d 100644
--- a/lib/AST/TypePrinter.cpp
+++ b/lib/AST/TypePrinter.cpp
@@ -1593,6 +1593,12 @@ void Qualifiers::print(raw_ostream &OS, const PrintingPolicy& Policy,
     AppendTypeQualList(OS, quals, Policy.LangOpts.C99);
     addSpace = true;
   }
+  if (hasUnaligned()) {
+    if (addSpace)
+      OS << ' ';
+    OS << "__unaligned";
+    addSpace = true;
+  }
   if (unsigned addrspace = getAddressSpace()) {
     if (addSpace)
       OS << ' ';
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 6b7ffb64fa..404f0a592a 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -609,7 +609,6 @@ void Parser::ParseMicrosoftTypeAttributes(ParsedAttributes &attrs) {
     case tok::kw___ptr64:
     case tok::kw___w64:
     case tok::kw___ptr32:
-    case tok::kw___unaligned:
     case tok::kw___sptr:
     case tok::kw___uptr: {
       IdentifierInfo *AttrName = Tok.getIdentifierInfo();
@@ -3087,6 +3086,11 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
       break;
     }
 
+    case tok::kw___unaligned:
+      isInvalid = DS.SetTypeQual(DeclSpec::TQ_unaligned, Loc, PrevSpec, DiagID,
+                                 getLangOpts());
+      break;
+
     case tok::kw___sptr:
     case tok::kw___uptr:
     case tok::kw___ptr64:
@@ -3097,7 +3101,6 @@ void Parser::ParseDeclarationSpecifiers(DeclSpec &DS,
     case tok::kw___fastcall:
     case tok::kw___thiscall:
     case tok::kw___vectorcall:
-    case tok::kw___unaligned:
       ParseMicrosoftTypeAttributes(DS.getAttributes());
       continue;
 
@@ -4791,6 +4794,10 @@ void Parser::ParseTypeQualifierListOpt(DeclSpec &DS, unsigned AttrReqs,
       ParseOpenCLQualifiers(DS.getAttributes());
       break;
 
+    case tok::kw___unaligned:
+      isInvalid = DS.SetTypeQual(DeclSpec::TQ_unaligned, Loc, PrevSpec, DiagID,
+                                 getLangOpts());
+      break;
     case tok::kw___uptr:
       // GNU libc headers in C mode use '__uptr' as an identifer which conflicts
       // with the MS modifier keyword.
@@ -4808,7 +4815,6 @@ void Parser::ParseTypeQualifierListOpt(DeclSpec &DS, unsigned AttrReqs,
     case tok::kw___fastcall:
     case tok::kw___thiscall:
     case tok::kw___vectorcall:
-    case tok::kw___unaligned:
       if (AttrReqs & AR_DeclspecAttributesParsed) {
         ParseMicrosoftTypeAttributes(DS.getAttributes());
         continue;
@@ -5031,7 +5037,8 @@ void Parser::ParseDeclaratorInternal(Declarator &D,
                                                 DS.getConstSpecLoc(),
                                                 DS.getVolatileSpecLoc(),
                                                 DS.getRestrictSpecLoc(),
-                                                DS.getAtomicSpecLoc()),
+                                                DS.getAtomicSpecLoc(),
+                                                DS.getUnalignedSpecLoc()),
                     DS.getAttributes(),
                     SourceLocation());
     else
diff --git a/lib/Parse/ParseTentative.cpp b/lib/Parse/ParseTentative.cpp
index 747d0a982c..c74720b444 100644
--- a/lib/Parse/ParseTentative.cpp
+++ b/lib/Parse/ParseTentative.cpp
@@ -833,7 +833,7 @@ Parser::TPResult Parser::TryParseDeclarator(bool mayBeAbstract,
       // '(' abstract-declarator ')'
       if (Tok.isOneOf(tok::kw___attribute, tok::kw___declspec, tok::kw___cdecl,
                       tok::kw___stdcall, tok::kw___fastcall, tok::kw___thiscall,
-                      tok::kw___vectorcall, tok::kw___unaligned))
+                      tok::kw___vectorcall))
         return TPResult::True; // attributes indicate declaration
       TPResult TPR = TryParseDeclarator(mayBeAbstract, mayHaveIdentifier);
       if (TPR != TPResult::Ambiguous)
diff --git a/lib/Sema/DeclSpec.cpp b/lib/Sema/DeclSpec.cpp
index 4bc1d3423b..1d58a6346e 100644
--- a/lib/Sema/DeclSpec.cpp
+++ b/lib/Sema/DeclSpec.cpp
@@ -492,6 +492,7 @@ const char *DeclSpec::getSpecifierName(TQ T) {
   case DeclSpec::TQ_restrict:    return "restrict";
   case DeclSpec::TQ_volatile:    return "volatile";
   case DeclSpec::TQ_atomic:      return "_Atomic";
+  case DeclSpec::TQ_unaligned:   return "__unaligned";
   }
   llvm_unreachable("Unknown typespec!");
 }
@@ -794,6 +795,7 @@ bool DeclSpec::SetTypeQual(TQ T, SourceLocation Loc, const char *&PrevSpec,
   case TQ_restrict: TQ_restrictLoc = Loc; return false;
   case TQ_volatile: TQ_volatileLoc = Loc; return false;
   case TQ_atomic:   TQ_atomicLoc = Loc; return false;
+  case TQ_unaligned: TQ_unalignedLoc = Loc; return false;
   }
 
   llvm_unreachable("Unknown type qualifier!");
@@ -959,10 +961,10 @@ void DeclSpec::Finish(Sema &S, const PrintingPolicy &Policy) {
        TypeSpecSign != TSS_unspecified ||
        TypeAltiVecVector || TypeAltiVecPixel || TypeAltiVecBool ||
        TypeQualifiers)) {
-    const unsigned NumLocs = 8;
+    const unsigned NumLocs = 9;
     SourceLocation ExtraLocs[NumLocs] = {
       TSWLoc, TSCLoc, TSSLoc, AltiVecLoc,
-      TQ_constLoc, TQ_restrictLoc, TQ_volatileLoc, TQ_atomicLoc
+      TQ_constLoc, TQ_restrictLoc, TQ_volatileLoc, TQ_atomicLoc, TQ_unalignedLoc
     };
     FixItHint Hints[NumLocs];
     SourceLocation FirstLoc;
diff --git a/lib/Sema/SemaCodeComplete.cpp b/lib/Sema/SemaCodeComplete.cpp
index ab2e718c85..739d70288c 100644
--- a/lib/Sema/SemaCodeComplete.cpp
+++ b/lib/Sema/SemaCodeComplete.cpp
@@ -3812,6 +3812,9 @@ void Sema::CodeCompleteTypeQualifiers(DeclSpec &DS) {
   if (getLangOpts().C11 &&
       !(DS.getTypeQualifiers() & DeclSpec::TQ_atomic))
     Results.AddResult("_Atomic");
+  if (getLangOpts().MSVCCompat &&
+      !(DS.getTypeQualifiers() & DeclSpec::TQ_unaligned))
+    Results.AddResult("__unaligned");
   Results.ExitScope();
   HandleCodeCompleteResults(this, CodeCompleter, 
                             Results.getCompletionContext(),
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index c979cd015c..ed8c35fcba 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3983,6 +3983,8 @@ Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
     // Restrict is covered above.
     if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
       Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
+    if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
+      Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
   }
 
   // Warn about ignored type attributes, for example:
@@ -4240,6 +4242,11 @@ Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
              diag::ext_anonymous_struct_union_qualified)
           << Record->isUnion() << "_Atomic"
           << FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
+      if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
+        Diag(DS.getUnalignedSpecLoc(),
+             diag::ext_anonymous_struct_union_qualified)
+          << Record->isUnion() << "__unaligned"
+          << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());
 
       DS.ClearTypeQualifiers();
     }
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 400dc63775..3fb29d46cf 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1503,6 +1503,7 @@ void Sema::actOnObjCTypeArgsOrProtocolQualifiers(
                                                 SourceLocation(),
                                                 SourceLocation(),
                                                 SourceLocation(),
+                                                SourceLocation(),
                                                 SourceLocation()),
                                                 parsedAttrs,
                                                 starLoc);
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 2b89b6bd03..95a9752ff6 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -7080,7 +7080,7 @@ checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType) {
     else if (lhq.getObjCLifetime() != rhq.getObjCLifetime())
       ConvTy = Sema::IncompatiblePointerDiscardsQualifiers;
     
-    // For GCC compatibility, other qualifier mismatches are treated
+    // For GCC/MS compatibility, other qualifier mismatches are treated
     // as still compatible in C.
     else ConvTy = Sema::CompatiblePointerDiscardsQualifiers;
   }
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 0b36fef144..443bd89bff 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -2936,6 +2936,10 @@ Sema::IsQualificationConversion(QualType FromType, QualType ToType,
 
     Qualifiers FromQuals = FromType.getQualifiers();
     Qualifiers ToQuals = ToType.getQualifiers();
+
+    // Ignore __unaligned qualifier if this type is void.
+    if (ToType.getUnqualifiedType()->isVoidType())
+      FromQuals.removeUnaligned();
     
     // Objective-C ARC:
     //   Check Objective-C lifetime conversions.
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index c8c8af109b..52f78f063f 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -1778,12 +1778,13 @@ QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
 }
 
 QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
-                                  unsigned CVRA, const DeclSpec *DS) {
+                                  unsigned CVRAU, const DeclSpec *DS) {
   if (T.isNull())
     return QualType();
 
-  // Convert from DeclSpec::TQ to Qualifiers::TQ by just dropping TQ_atomic.
-  unsigned CVR = CVRA & ~DeclSpec::TQ_atomic;
+  // Convert from DeclSpec::TQ to Qualifiers::TQ by just dropping TQ_atomic and
+  // TQ_unaligned;
+  unsigned CVR = CVRAU & ~(DeclSpec::TQ_atomic | DeclSpec::TQ_unaligned);
 
   // C11 6.7.3/5:
   //   If the same qualifier appears more than once in the same
@@ -1793,7 +1794,7 @@ QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
   // It's not specified what happens when the _Atomic qualifier is applied to
   // a type specified with the _Atomic specifier, but we assume that this
   // should be treated as if the _Atomic qualifier appeared multiple times.
-  if (CVRA & DeclSpec::TQ_atomic && !T->isAtomicType()) {
+  if (CVRAU & DeclSpec::TQ_atomic && !T->isAtomicType()) {
     // C11 6.7.3/5:
     //   If other qualifiers appear along with the _Atomic qualifier in a
     //   specifier-qualifier-list, the resulting type is the so-qualified
@@ -1810,7 +1811,9 @@ QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
     return BuildQualifiedType(T, Loc, Split.Quals);
   }
 
-  return BuildQualifiedType(T, Loc, Qualifiers::fromCVRMask(CVR), DS);
+  Qualifiers Q = Qualifiers::fromCVRMask(CVR);
+  Q.setUnaligned(CVRAU & DeclSpec::TQ_unaligned);
+  return BuildQualifiedType(T, Loc, Q, DS);
 }
 
 /// \brief Build a paren type including \p T.
@@ -2645,7 +2648,8 @@ void Sema::diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
                                      SourceLocation ConstQualLoc,
                                      SourceLocation VolatileQualLoc,
                                      SourceLocation RestrictQualLoc,
-                                     SourceLocation AtomicQualLoc) {
+                                     SourceLocation AtomicQualLoc,
+                                     SourceLocation UnalignedQualLoc) {
   if (!Quals)
     return;
 
@@ -2653,20 +2657,21 @@ void Sema::diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
     const char *Name;
     unsigned Mask;
     SourceLocation Loc;
-  } const QualKinds[4] = {
+  } const QualKinds[5] = {
     { "const", DeclSpec::TQ_const, ConstQualLoc },
     { "volatile", DeclSpec::TQ_volatile, VolatileQualLoc },
     { "restrict", DeclSpec::TQ_restrict, RestrictQualLoc },
-    { "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc }
+    { "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc },
+    { "__unaligned", DeclSpec::TQ_unaligned, UnalignedQualLoc }
   };
 
   SmallString<32> QualStr;
   unsigned NumQuals = 0;
   SourceLocation Loc;
-  FixItHint FixIts[4];
+  FixItHint FixIts[5];
 
   // Build a string naming the redundant qualifiers.
-  for (unsigned I = 0; I != 4; ++I) {
+  for (unsigned I = 0; I != 5; ++I) {
     if (Quals & QualKinds[I].Mask) {
       if (!QualStr.empty()) QualStr += ' ';
       QualStr += QualKinds[I].Name;
@@ -2718,7 +2723,8 @@ static void diagnoseRedundantReturnTypeQualifiers(Sema &S, QualType RetTy,
           SourceLocation::getFromRawEncoding(PTI.ConstQualLoc),
           SourceLocation::getFromRawEncoding(PTI.VolatileQualLoc),
           SourceLocation::getFromRawEncoding(PTI.RestrictQualLoc),
-          SourceLocation::getFromRawEncoding(PTI.AtomicQualLoc));
+          SourceLocation::getFromRawEncoding(PTI.AtomicQualLoc),
+          SourceLocation::getFromRawEncoding(PTI.UnalignedQualLoc));
       return;
     }
 
@@ -2754,7 +2760,8 @@ static void diagnoseRedundantReturnTypeQualifiers(Sema &S, QualType RetTy,
                               D.getDeclSpec().getConstSpecLoc(),
                               D.getDeclSpec().getVolatileSpecLoc(),
                               D.getDeclSpec().getRestrictSpecLoc(),
-                              D.getDeclSpec().getAtomicSpecLoc());
+                              D.getDeclSpec().getAtomicSpecLoc(),
+                              D.getDeclSpec().getUnalignedSpecLoc());
 }
 
 static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,