From 168c07b93510aabd2a19af323d1132fffe498ee4 Mon Sep 17 00:00:00 2001 From: Hans Wennborg Date: Tue, 24 Jul 2012 17:59:41 +0000 Subject: [PATCH] Tweak warning text for returning incomplete type from extern "C" functions. A warning was added in r150128 for returning non-C compatible user-defined types from functions with C linkage. This makes the text more clear for the case when the type isn't decidedly non-C compatible, but incomplete. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160681 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/clang/Basic/DiagnosticSemaKinds.td | 3 +++ lib/Sema/SemaDecl.cpp | 9 +++++---- test/SemaCXX/function-extern-c.cpp | 2 ++ 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td index 5c3f1150c3..67f43d22c8 100644 --- a/include/clang/Basic/DiagnosticSemaKinds.td +++ b/include/clang/Basic/DiagnosticSemaKinds.td @@ -192,6 +192,9 @@ def warn_return_value_size: Warning< def warn_return_value_udt: Warning< "%0 has C-linkage specified, but returns user-defined type %1 which is " "incompatible with C">, InGroup; +def warn_return_value_udt_incomplete: Warning< + "%0 has C-linkage specified, but returns incomplete type %1 which could be " + "incompatible with C">, InGroup; def warn_implicit_function_decl : Warning< "implicit declaration of function %0">, InGroup, DefaultIgnore; diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 52aa5b72d1..12444e5559 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -6086,10 +6086,11 @@ bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD, // compatible, and if it does, warn the user. if (NewFD->isExternC()) { QualType R = NewFD->getResultType(); - if (!R.isPODType(Context) && - !R->isVoidType()) - Diag( NewFD->getLocation(), diag::warn_return_value_udt ) - << NewFD << R; + if (R->isIncompleteType() && !R->isVoidType()) + Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete) + << NewFD << R; + else if (!R.isPODType(Context) && !R->isVoidType()) + Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R; } } return Redeclaration; diff --git a/test/SemaCXX/function-extern-c.cpp b/test/SemaCXX/function-extern-c.cpp index f20cd38a3c..16dbbb26fc 100644 --- a/test/SemaCXX/function-extern-c.cpp +++ b/test/SemaCXX/function-extern-c.cpp @@ -36,3 +36,5 @@ extern "C" void f7( U u ); extern "C" double f8(void); extern "C" long long f11( void ); extern "C" A *f10( void ); + +extern "C" struct mypodstruct f12(); // expected-warning {{'f12' has C-linkage specified, but returns incomplete type 'struct mypodstruct' which could be incompatible with C}} -- 2.40.0