[Sema] Make FunctionType's TSI use unadjusted argument types

This helps preserve the type-as-written in the AST, which we need for
MSVC mangling.  In particular, we need to preserve the types of array
parameters in function pointer types.

The essence of this change is:
-  QualType ArgTy = Param->getType();
+  QualType ArgTy = Param->getTypeSourceInfo()->getType();

... followed by the adjustment in ActOnFunctionDeclarator().

Differential Revision: http://llvm-reviews.chandlerc.com/D883

llvm-svn: 183614

1 files changed, 36 insertions, 31 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e6a89461b45..1db768b28a6 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -5897,23 +5897,40 @@ Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       << DeclSpec::getSpecifierName(TSCS);
 
   // Do not allow returning a objc interface by-value.
-  if (R->getAs<FunctionType>()->getResultType()->isObjCObjectType()) {
+  bool NeedsAdjustment = false;
+  const FunctionType *FT = R->castAs<FunctionType>();
+  QualType ResultTy = FT->getResultType();
+  if (ResultTy->isObjCObjectType()) {
     Diag(D.getIdentifierLoc(),
-         diag::err_object_cannot_be_passed_returned_by_value) << 0
-    << R->getAs<FunctionType>()->getResultType()
-    << FixItHint::CreateInsertion(D.getIdentifierLoc(), "*");
+         diag::err_object_cannot_be_passed_returned_by_value) << 0 << ResultTy
+        << FixItHint::CreateInsertion(D.getIdentifierLoc(), "*");
+    ResultTy = Context.getObjCObjectPointerType(ResultTy);
+    NeedsAdjustment = true;
+  }
 
-    QualType T = R->getAs<FunctionType>()->getResultType();
-    T = Context.getObjCObjectPointerType(T);
-    if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(R)) {
+  // Adjust parameter types from the type as written.
+  SmallVector<QualType, 16> AdjustedParms;
+  const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT);
+  if (FPT) {
+    for (FunctionProtoType::arg_type_iterator I = FPT->arg_type_begin(),
+         E = FPT->arg_type_end(); I != E; ++I) {
+      AdjustedParms.push_back(Context.getAdjustedParameterType(*I));
+      if (AdjustedParms.back() != *I)
+        NeedsAdjustment = true;
+    }
+  }
+
+  // Skip the type recreation if it isn't needed, for performance and to avoid
+  // prematurely desugaring things like typedefs and __typeofs.
+  if (NeedsAdjustment) {
+    if (FPT) {
       FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
-      R = Context.getFunctionType(T,
-                                  ArrayRef<QualType>(FPT->arg_type_begin(),
-                                                     FPT->getNumArgs()),
-                                  EPI);
+      R = Context.getFunctionType(ResultTy, AdjustedParms, EPI);
+    } else {
+      assert(isa<FunctionNoProtoType>(FT));
+      FunctionType::ExtInfo EI = FT->getExtInfo();
+      R = Context.getFunctionNoProtoType(ResultTy, EI);
     }
-    else if (isa<FunctionNoProtoType>(R))
-      R = Context.getFunctionNoProtoType(T);
   }
 
   bool isFriend = false;
@@ -8498,27 +8515,15 @@ ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc,
                                   SourceLocation NameLoc, IdentifierInfo *Name,
                                   QualType T, TypeSourceInfo *TSInfo,
                                   VarDecl::StorageClass StorageClass) {
-  // In ARC, infer a lifetime qualifier for appropriate parameter types.
+  // Diagnose non-const parameter arrays of ARC types.
   if (getLangOpts().ObjCAutoRefCount &&
       T.getObjCLifetime() == Qualifiers::OCL_None &&
-      T->isObjCLifetimeType()) {
-
-    Qualifiers::ObjCLifetime lifetime;
-
-    // Special cases for arrays:
-    //   - if it's const, use __unsafe_unretained
-    //   - otherwise, it's an error
-    if (T->isArrayType()) {
-      if (!T.isConstQualified()) {
-        DelayedDiagnostics.add(
-            sema::DelayedDiagnostic::makeForbiddenType(
+      T->isObjCLifetimeType() &&
+      T->isArrayType() &&
+      !T.isConstQualified()) {
+    DelayedDiagnostics.add(
+        sema::DelayedDiagnostic::makeForbiddenType(
             NameLoc, diag::err_arc_array_param_no_ownership, T, false));
-      }
-      lifetime = Qualifiers::OCL_ExplicitNone;
-    } else {
-      lifetime = T->getObjCARCImplicitLifetime();
-    }
-    T = Context.getLifetimeQualifiedType(T, lifetime);
   }
 
   ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name,