rnk updated this revision to Diff 56802.
rnk marked 3 inline comments as done.
rnk added a comment.
- address comments
http://reviews.llvm.org/D17348
Files:
include/clang/Basic/DiagnosticSemaKinds.td
lib/Sema/SemaCast.cpp
test/Sema/callingconv-cast.c
Index: test/Sema/callingconv-cast.c
===================================================================
--- /dev/null
+++ test/Sema/callingconv-cast.c
@@ -0,0 +1,54 @@
+// RUN: %clang_cc1 -fms-extensions -triple i686-pc-windows-msvc -Wcast-calling-convention -DMSVC -Wno-pointer-bool-conversion -verify -x c %s
+// RUN: %clang_cc1 -fms-extensions -triple i686-pc-windows-msvc -Wcast-calling-convention -DMSVC -Wno-pointer-bool-conversion -verify -x c++ %s
+// RUN: %clang_cc1 -fms-extensions -triple i686-pc-windows-msvc -Wcast-calling-convention -DMSVC -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s --check-prefix=MSFIXIT
+// RUN: %clang_cc1 -triple i686-pc-windows-gnu -Wcast-calling-convention -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s --check-prefix=GNUFIXIT
+
+// expected-note@+1 {{consider defining 'mismatched_before_winapi' with the 'stdcall' calling convention}}
+void mismatched_before_winapi(int x) {}
+
+#ifdef MSVC
+#define WINAPI __stdcall
+#else
+#define WINAPI __attribute__((stdcall))
+#endif
+
+// expected-note@+1 3 {{consider defining 'mismatched' with the 'stdcall' calling convention}}
+void mismatched(int x) {}
+
+typedef void (WINAPI *callback_t)(int);
+void take_callback(callback_t callback);
+
+int main() {
+ // expected-warning@+1 {{cast between incompatible calling conventions 'cdecl' and 'stdcall'}}
+ take_callback((callback_t)mismatched);
+
+ // expected-warning@+1 {{cast between incompatible calling conventions 'cdecl' and 'stdcall'}}
+ callback_t callback = (callback_t)mismatched; // warns
+ (void)callback;
+
+ // expected-warning@+1 {{cast between incompatible calling conventions 'cdecl' and 'stdcall'}}
+ callback = (callback_t)&mismatched; // warns
+
+ // No warning, just to show we don't drill through other kinds of unary operators.
+ callback = (callback_t)!mismatched;
+
+ // expected-warning@+1 {{cast between incompatible calling conventions 'cdecl' and 'stdcall'}}
+ callback = (callback_t)&mismatched_before_winapi; // warns
+
+ // Probably a bug, but we don't warn.
+ void (*callback2)(int) = mismatched;
+ take_callback((callback_t)callback2);
+
+ // Another way to suppress the warning.
+ take_callback((callback_t)(void*)mismatched);
+}
+
+// MSFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// MSFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// MSFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// MSFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{7:6-7:6}:"__stdcall "
+
+// GNUFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// GNUFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// GNUFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{16:6-16:6}:"WINAPI "
+// GNUFIXIT: fix-it:"D:\\src\\llvm\\tools\\clang\\test\\Sema\\callingconv-cast.c":{7:6-7:6}:"__attribute__((stdcall)) "
Index: lib/Sema/SemaCast.cpp
===================================================================
--- lib/Sema/SemaCast.cpp
+++ lib/Sema/SemaCast.cpp
@@ -22,6 +22,7 @@
#include "clang/AST/RecordLayout.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "clang/Basic/TargetInfo.h"
+#include "clang/Lex/Preprocessor.h"
#include "clang/Sema/Initialization.h"
#include "llvm/ADT/SmallVector.h"
#include <set>
@@ -1726,6 +1727,86 @@
}
}
+/// Diagnose casts that change the calling convention of a pointer to a function
+/// defined in the current TU.
+static void DiagnoseCallingConvCast(Sema &Self, const ExprResult &SrcExpr,
+ QualType DstType, SourceRange OpRange) {
+ if (Self.Diags.isIgnored(diag::warn_cast_calling_conv, OpRange.getBegin()))
+ return;
+
+ // Check if this cast would change the calling convention of a function
+ // pointer type.
+ QualType SrcType = SrcExpr.get()->getType();
+ if (Self.Context.hasSameType(SrcType, DstType) ||
+ !SrcType->isFunctionPointerType() || !DstType->isFunctionPointerType())
+ return;
+ const auto *SrcFTy =
+ SrcType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
+ const auto *DstFTy =
+ DstType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
+ CallingConv SrcCC = SrcFTy->getCallConv();
+ CallingConv DstCC = DstFTy->getCallConv();
+ if (SrcCC == DstCC)
+ return;
+
+ // We have a calling convention cast. Check if the source is a pointer to a
+ // known, specific function that has already been defined.
+ Expr *Src = SrcExpr.get()->IgnoreParenImpCasts();
+ if (auto *UO = dyn_cast<UnaryOperator>(Src))
+ if (UO->getOpcode() == UO_AddrOf)
+ Src = UO->getSubExpr()->IgnoreParenImpCasts();
+ auto *DRE = dyn_cast<DeclRefExpr>(Src);
+ if (!DRE)
+ return;
+ auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
+ const FunctionDecl *Definition;
+ if (!FD || !FD->hasBody(Definition))
+ return;
+
+ // The source expression is a pointer to a known function defined in this TU.
+ // Diagnose this cast, as it is probably bad.
+ StringRef SrcCCName = FunctionType::getNameForCallConv(SrcCC);
+ StringRef DstCCName = FunctionType::getNameForCallConv(DstCC);
+ Self.Diag(OpRange.getBegin(), diag::warn_cast_calling_conv)
+ << SrcCCName << DstCCName << OpRange;
+
+ // Try to suggest a fixit to change the calling convention of the function
+ // whose address was taken. Try to use the latest macro for the convention.
+ // For example, users probably want to write "WINAPI" instead of "__stdcall"
+ // to match the Windows header declarations.
+ SourceLocation NameLoc = Definition->getNameInfo().getLoc();
+ Preprocessor &PP = Self.getPreprocessor();
+ SmallVector<TokenValue, 6> AttrTokens;
+ SmallString<64> CCAttrText;
+ llvm::raw_svector_ostream OS(CCAttrText);
+ if (Self.getLangOpts().MicrosoftExt) {
+ // __stdcall or __vectorcall
+ OS << "__" << DstCCName;
+ IdentifierInfo *II = PP.getIdentifierInfo(OS.str());
+ AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
+ ? TokenValue(II->getTokenID())
+ : TokenValue(II));
+ } else {
+ // __attribute__((stdcall)) or __attribute__((vectorcall))
+ OS << "__attribute__((" << DstCCName << "))";
+ AttrTokens.push_back(tok::kw___attribute);
+ AttrTokens.push_back(tok::l_paren);
+ AttrTokens.push_back(tok::l_paren);
+ IdentifierInfo *II = PP.getIdentifierInfo(DstCCName);
+ AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
+ ? TokenValue(II->getTokenID())
+ : TokenValue(II));
+ AttrTokens.push_back(tok::r_paren);
+ AttrTokens.push_back(tok::r_paren);
+ }
+ StringRef AttrSpelling = PP.getLastMacroWithSpelling(NameLoc, AttrTokens);
+ if (!AttrSpelling.empty())
+ CCAttrText = AttrSpelling;
+ OS << ' ';
+ Self.Diag(NameLoc, diag::note_change_calling_conv_fixit)
+ << FD << DstCCName << FixItHint::CreateInsertion(NameLoc, CCAttrText);
+}
+
static void checkIntToPointerCast(bool CStyle, SourceLocation Loc,
const Expr *SrcExpr, QualType DestType,
Sema &Self) {
@@ -2042,7 +2123,9 @@
}
if (CStyle)
DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
-
+
+ DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
+
// Not casting away constness, so the only remaining check is for compatible
// pointer categories.
@@ -2461,6 +2544,7 @@
}
DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
+ DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
DiagnoseBadFunctionCast(Self, SrcExpr, DestType);
Kind = Self.PrepareScalarCast(SrcExpr, DestType);
if (SrcExpr.isInvalid())
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -6621,7 +6621,13 @@
def warn_function_def_in_objc_container : Warning<
"function definition inside an Objective-C container is deprecated">,
InGroup<FunctionDefInObjCContainer>;
-
+
+def warn_cast_calling_conv : Warning<
+ "cast between incompatible calling conventions '%0' and '%1'; "
+ "calls through this pointer may abort at runtime">,
+ InGroup<DiagGroup<"cast-calling-convention">>;
+def note_change_calling_conv_fixit : Note<
+ "consider defining %0 with the '%1' calling convention">;
def warn_bad_function_cast : Warning<
"cast from function call of type %0 to non-matching type %1">,
InGroup<BadFunctionCast>, DefaultIgnore;
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