When a declaration of a function is missing an exception specification
that was present in a prior declaration, emit a warning rather than a
hard error (which we did before, and still do with mismatched
exception specifications). Moreover, provide a fix-it hint with the
throw() clause that should be added, e.g.,
t.C:10:7: warning: 'operator new' is missing exception specification
'throw(std::bad_alloc)'
void *operator new(unsigned long sz)
^
throw(std::bad_alloc)
As part of this, disable the warning when we're missing an exception
specification on operator new, operator new[], operator delete, or
operator delete[] when exceptions are turned off (-fno-exceptions).
Fixes PR5957.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99388 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 85fa4f1..ba6d38f 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -728,6 +728,7 @@
const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
const FunctionProtoType *Old, SourceLocation OldLoc,
const FunctionProtoType *New, SourceLocation NewLoc,
+ bool *MissingExceptionSpecification = 0,
bool *MissingEmptyExceptionSpecification = 0);
bool CheckExceptionSpecSubset(
const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
diff --git a/lib/Sema/SemaExceptionSpec.cpp b/lib/Sema/SemaExceptionSpec.cpp
index 4ce1ce9..5767551 100644
--- a/lib/Sema/SemaExceptionSpec.cpp
+++ b/lib/Sema/SemaExceptionSpec.cpp
@@ -15,6 +15,8 @@
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
+#include "clang/AST/TypeLoc.h"
+#include "clang/Lex/Preprocessor.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/SmallPtrSet.h"
@@ -94,6 +96,7 @@
}
bool Sema::CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New) {
+ bool MissingExceptionSpecification = false;
bool MissingEmptyExceptionSpecification = false;
if (!CheckEquivalentExceptionSpec(diag::err_mismatched_exception_spec,
diag::note_previous_declaration,
@@ -101,12 +104,13 @@
Old->getLocation(),
New->getType()->getAs<FunctionProtoType>(),
New->getLocation(),
+ &MissingExceptionSpecification,
&MissingEmptyExceptionSpecification))
return false;
// The failure was something other than an empty exception
// specification; return an error.
- if (!MissingEmptyExceptionSpecification)
+ if (!MissingExceptionSpecification && !MissingEmptyExceptionSpecification)
return true;
// The new function declaration is only missing an empty exception
@@ -117,8 +121,10 @@
// to many libc functions as an optimization. Unfortunately, that
// optimization isn't permitted by the C++ standard, so we're forced
// to work around it here.
- if (isa<FunctionProtoType>(New->getType()) &&
- Context.getSourceManager().isInSystemHeader(Old->getLocation()) &&
+ if (MissingEmptyExceptionSpecification &&
+ isa<FunctionProtoType>(New->getType()) &&
+ (Old->getLocation().isInvalid() ||
+ Context.getSourceManager().isInSystemHeader(Old->getLocation())) &&
Old->isExternC()) {
const FunctionProtoType *NewProto
= cast<FunctionProtoType>(New->getType());
@@ -134,6 +140,88 @@
return false;
}
+ if (MissingExceptionSpecification && isa<FunctionProtoType>(New->getType())) {
+ const FunctionProtoType *NewProto
+ = cast<FunctionProtoType>(New->getType());
+ const FunctionProtoType *OldProto
+ = Old->getType()->getAs<FunctionProtoType>();
+
+ // Update the type of the function with the appropriate exception
+ // specification.
+ QualType NewType = Context.getFunctionType(NewProto->getResultType(),
+ NewProto->arg_type_begin(),
+ NewProto->getNumArgs(),
+ NewProto->isVariadic(),
+ NewProto->getTypeQuals(),
+ OldProto->hasExceptionSpec(),
+ OldProto->hasAnyExceptionSpec(),
+ OldProto->getNumExceptions(),
+ OldProto->exception_begin(),
+ NewProto->getNoReturnAttr(),
+ NewProto->getCallConv());
+ New->setType(NewType);
+
+ // If exceptions are disabled, suppress the warning about missing
+ // exception specifications for new and delete operators.
+ if (!getLangOptions().Exceptions) {
+ switch (New->getDeclName().getCXXOverloadedOperator()) {
+ case OO_New:
+ case OO_Array_New:
+ case OO_Delete:
+ case OO_Array_Delete:
+ if (New->getDeclContext()->isTranslationUnit())
+ return false;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ // Warn about the lack of exception specification.
+ llvm::SmallString<128> ExceptionSpecString;
+ llvm::raw_svector_ostream OS(ExceptionSpecString);
+ OS << "throw(";
+ bool OnFirstException = true;
+ for (FunctionProtoType::exception_iterator E = OldProto->exception_begin(),
+ EEnd = OldProto->exception_end();
+ E != EEnd;
+ ++E) {
+ if (OnFirstException)
+ OnFirstException = false;
+ else
+ OS << ", ";
+
+ OS << E->getAsString(Context.PrintingPolicy);
+ }
+ OS << ")";
+ OS.flush();
+
+ SourceLocation AfterParenLoc;
+ if (TypeSourceInfo *TSInfo = New->getTypeSourceInfo()) {
+ TypeLoc TL = TSInfo->getTypeLoc();
+ if (const FunctionTypeLoc *FTLoc = dyn_cast<FunctionTypeLoc>(&TL))
+ AfterParenLoc = PP.getLocForEndOfToken(FTLoc->getRParenLoc());
+ }
+
+ if (AfterParenLoc.isInvalid())
+ Diag(New->getLocation(), diag::warn_missing_exception_specification)
+ << New << OS.str();
+ else {
+ // FIXME: This will get more complicated with C++0x
+ // late-specified return types.
+ Diag(New->getLocation(), diag::warn_missing_exception_specification)
+ << New << OS.str()
+ << CodeModificationHint::CreateInsertion(AfterParenLoc,
+ " " + OS.str().str());
+ }
+
+ if (!Old->getLocation().isInvalid())
+ Diag(Old->getLocation(), diag::note_previous_declaration);
+
+ return false;
+ }
+
Diag(New->getLocation(), diag::err_mismatched_exception_spec);
Diag(Old->getLocation(), diag::note_previous_declaration);
return true;
@@ -155,11 +243,17 @@
/// exception specifications. Exception specifications are equivalent if
/// they allow exactly the same set of exception types. It does not matter how
/// that is achieved. See C++ [except.spec]p2.
-bool Sema::CheckEquivalentExceptionSpec(
- const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
- const FunctionProtoType *Old, SourceLocation OldLoc,
- const FunctionProtoType *New, SourceLocation NewLoc,
- bool *MissingEmptyExceptionSpecification) {
+bool Sema::CheckEquivalentExceptionSpec(const PartialDiagnostic &DiagID,
+ const PartialDiagnostic & NoteID,
+ const FunctionProtoType *Old,
+ SourceLocation OldLoc,
+ const FunctionProtoType *New,
+ SourceLocation NewLoc,
+ bool *MissingExceptionSpecification,
+ bool *MissingEmptyExceptionSpecification) {
+ if (MissingExceptionSpecification)
+ *MissingExceptionSpecification = false;
+
if (MissingEmptyExceptionSpecification)
*MissingEmptyExceptionSpecification = false;
@@ -168,13 +262,20 @@
if (OldAny && NewAny)
return false;
if (OldAny || NewAny) {
- if (MissingEmptyExceptionSpecification && Old->hasExceptionSpec() &&
- !Old->hasAnyExceptionSpec() && Old->getNumExceptions() == 0 &&
+ if (MissingExceptionSpecification && Old->hasExceptionSpec() &&
!New->hasExceptionSpec()) {
- // The old type has a throw() exception specification and the
- // new type has no exception specification, and the caller asked
- // to handle this itself.
- *MissingEmptyExceptionSpecification = true;
+ // The old type has an exception specification of some sort, but
+ // the new type does not.
+ *MissingExceptionSpecification = true;
+
+ if (MissingEmptyExceptionSpecification &&
+ !Old->hasAnyExceptionSpec() && Old->getNumExceptions() == 0) {
+ // The old type has a throw() exception specification and the
+ // new type has no exception specification, and the caller asked
+ // to handle this itself.
+ *MissingEmptyExceptionSpecification = true;
+ }
+
return true;
}