diff options
author | Reid Kleckner <rnk@google.com> | 2016-05-11 17:43:13 +0000 |
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committer | Reid Kleckner <rnk@google.com> | 2016-05-11 17:43:13 +0000 |
commit | 9afbd500cf6a4f0b20b5a81c37028d27b567ba52 (patch) | |
tree | 5944ee2845543296e78c6cb9e65e09a3d1a340d9 | |
parent | 22dbcfe84e6eb926e4f77dcd4716e02cf9583f7f (diff) |
Relax -Wcalling-convention-cast when casting to the default convention (cdecl)
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@269214 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r-- | lib/Sema/SemaCast.cpp | 10 | ||||
-rw-r--r-- | test/Sema/callingconv-cast.c | 9 |
2 files changed, 18 insertions, 1 deletions
diff --git a/lib/Sema/SemaCast.cpp b/lib/Sema/SemaCast.cpp index 646b884ce1..1d95b1f9f1 100644 --- a/lib/Sema/SemaCast.cpp +++ b/lib/Sema/SemaCast.cpp @@ -1760,7 +1760,15 @@ static void DiagnoseCallingConvCast(Sema &Self, const ExprResult &SrcExpr, if (!FD || !FD->hasBody(Definition)) return; - // The source expression is a pointer to a known function defined in this TU. + // Only warn if we are casting from the default convention to a non-default + // convention. This can happen when the programmer forgot to apply the calling + // convention to the function definition and then inserted this cast to + // satisfy the type system. + CallingConv DefaultCC = Self.getASTContext().getDefaultCallingConvention( + FD->isVariadic(), FD->isCXXInstanceMember()); + if (DstCC == DefaultCC || SrcCC != DefaultCC) + return; + // Diagnose this cast, as it is probably bad. StringRef SrcCCName = FunctionType::getNameForCallConv(SrcCC); StringRef DstCCName = FunctionType::getNameForCallConv(DstCC); diff --git a/test/Sema/callingconv-cast.c b/test/Sema/callingconv-cast.c index 9f1855baeb..88b25e8f17 100644 --- a/test/Sema/callingconv-cast.c +++ b/test/Sema/callingconv-cast.c @@ -21,6 +21,10 @@ void mismatched(int x) {} typedef void (WINAPI *callback_t)(int); void take_callback(callback_t callback); +void WINAPI mismatched_stdcall(int x) {} + +void take_opaque_fn(void (*callback)(int)); + int main() { // expected-warning@+1 {{cast between incompatible calling conventions 'cdecl' and 'stdcall'}} take_callback((callback_t)mismatched); @@ -44,6 +48,11 @@ int main() { // Another way to suppress the warning. take_callback((callback_t)(void*)mismatched); + + // Don't warn, because we're casting from stdcall to cdecl. Usually that means + // the programmer is rinsing the function pointer through some kind of opaque + // API. + take_opaque_fn((void (*)(int))mismatched_stdcall); } // MSFIXIT: fix-it:"{{.*}}callingconv-cast.c":{19:6-19:6}:"WINAPI " |