Wraps lazily generated builtins in an extern "C" context
Differential Revision: http://llvm-reviews.chandlerc.com/D2082
Adds a lang_c LinkageSpecDecl to lazily generated builtins. This enforces correct
behavior for builtins in a variety of cases without special treatment elsewhere within
the compiler (special treatment is removed by the patch). It also allows for C++
overloads of builtin functions, which Microsoft uses in their headers e.g.
_InterlockedExchangeAdd is an extern C builtin for the long type but an inline wrapper
for int type.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193896 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index c1cfd36..69de78b 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1534,8 +1534,17 @@
<< Context.BuiltinInfo.GetName(BID);
}
+ DeclContext *Parent = Context.getTranslationUnitDecl();
+ if (getLangOpts().CPlusPlus) {
+ LinkageSpecDecl *CLinkageDecl =
+ LinkageSpecDecl::Create(Context, Parent, Loc, Loc,
+ LinkageSpecDecl::lang_c, false);
+ Parent->addDecl(CLinkageDecl);
+ Parent = CLinkageDecl;
+ }
+
FunctionDecl *New = FunctionDecl::Create(Context,
- Context.getTranslationUnitDecl(),
+ Parent,
Loc, Loc, II, R, /*TInfo=*/0,
SC_Extern,
false,
@@ -1559,13 +1568,14 @@
}
AddKnownFunctionAttributes(New);
+ RegisterLocallyScopedExternCDecl(New, S);
// TUScope is the translation-unit scope to insert this function into.
// FIXME: This is hideous. We need to teach PushOnScopeChains to
// relate Scopes to DeclContexts, and probably eliminate CurContext
// entirely, but we're not there yet.
DeclContext *SavedContext = CurContext;
- CurContext = Context.getTranslationUnitDecl();
+ CurContext = Parent;
PushOnScopeChains(New, TUScope);
CurContext = SavedContext;
return New;
@@ -7608,7 +7618,7 @@
// during delayed parsing anyway.
if (!CurContext->isRecord())
CheckCXXDefaultArguments(NewFD);
-
+
// If this function declares a builtin function, check the type of this
// declaration against the expected type for the builtin.
if (unsigned BuiltinID = NewFD->getBuiltinID()) {
@@ -7621,7 +7631,7 @@
Context.BuiltinInfo.ForgetBuiltin(BuiltinID, Context.Idents);
}
}
-
+
// If this function is declared as being extern "C", then check to see if
// the function returns a UDT (class, struct, or union type) that is not C
// compatible, and if it does, warn the user.