No -fsanitize=function warning when calling noexcept function through non-noexcept pointer in C++17
As discussed in the mail thread <https://groups.google.com/a/isocpp.org/forum/
#!topic/std-discussion/T64_dW3WKUk> "Calling noexcept function throug non-
noexcept pointer is undefined behavior?", such a call should not be UB.
However, Clang currently warns about it.
This change removes exception specifications from the function types recorded
for -fsanitize=function, both in the functions themselves and at the call sites.
That means that calling a non-noexcept function through a noexcept pointer will
also not be flagged as UB. In the review of this change, that was deemed
acceptable, at least for now. (See the "TODO" in compiler-rt
test/ubsan/TestCases/TypeCheck/Function/function.cpp.)
To remove exception specifications from types, the existing internal
ASTContext::getFunctionTypeWithExceptionSpec was made public, and some places
otherwise unrelated to this change have been adapted to call it, too.
This is the cfe part of a patch covering both cfe and compiler-rt.
Differential Revision: https://reviews.llvm.org/D40720
llvm-svn: 321859
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 3dc961d..b9a23ed9 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -2582,26 +2582,24 @@
/// specified exception specification. Type sugar that can be present on a
/// declaration of a function with an exception specification is permitted
/// and preserved. Other type sugar (for instance, typedefs) is not.
-static QualType getFunctionTypeWithExceptionSpec(
- ASTContext &Context, QualType Orig,
- const FunctionProtoType::ExceptionSpecInfo &ESI) {
+QualType ASTContext::getFunctionTypeWithExceptionSpec(
+ QualType Orig, const FunctionProtoType::ExceptionSpecInfo &ESI) {
// Might have some parens.
if (auto *PT = dyn_cast<ParenType>(Orig))
- return Context.getParenType(
- getFunctionTypeWithExceptionSpec(Context, PT->getInnerType(), ESI));
+ return getParenType(
+ getFunctionTypeWithExceptionSpec(PT->getInnerType(), ESI));
// Might have a calling-convention attribute.
if (auto *AT = dyn_cast<AttributedType>(Orig))
- return Context.getAttributedType(
+ return getAttributedType(
AT->getAttrKind(),
- getFunctionTypeWithExceptionSpec(Context, AT->getModifiedType(), ESI),
- getFunctionTypeWithExceptionSpec(Context, AT->getEquivalentType(),
- ESI));
+ getFunctionTypeWithExceptionSpec(AT->getModifiedType(), ESI),
+ getFunctionTypeWithExceptionSpec(AT->getEquivalentType(), ESI));
// Anything else must be a function type. Rebuild it with the new exception
// specification.
const FunctionProtoType *Proto = cast<FunctionProtoType>(Orig);
- return Context.getFunctionType(
+ return getFunctionType(
Proto->getReturnType(), Proto->getParamTypes(),
Proto->getExtProtoInfo().withExceptionSpec(ESI));
}
@@ -2610,8 +2608,8 @@
QualType U) {
return hasSameType(T, U) ||
(getLangOpts().CPlusPlus17 &&
- hasSameType(getFunctionTypeWithExceptionSpec(*this, T, EST_None),
- getFunctionTypeWithExceptionSpec(*this, U, EST_None)));
+ hasSameType(getFunctionTypeWithExceptionSpec(T, EST_None),
+ getFunctionTypeWithExceptionSpec(U, EST_None)));
}
void ASTContext::adjustExceptionSpec(
@@ -2619,7 +2617,7 @@
bool AsWritten) {
// Update the type.
QualType Updated =
- getFunctionTypeWithExceptionSpec(*this, FD->getType(), ESI);
+ getFunctionTypeWithExceptionSpec(FD->getType(), ESI);
FD->setType(Updated);
if (!AsWritten)
@@ -2630,7 +2628,7 @@
// If the type and the type-as-written differ, we may need to update
// the type-as-written too.
if (TSInfo->getType() != FD->getType())
- Updated = getFunctionTypeWithExceptionSpec(*this, TSInfo->getType(), ESI);
+ Updated = getFunctionTypeWithExceptionSpec(TSInfo->getType(), ESI);
// FIXME: When we get proper type location information for exceptions,
// we'll also have to rebuild the TypeSourceInfo. For now, we just patch