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/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index f2b1963..0543490 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1475,10 +1475,8 @@
const auto *ToFPT = cast<FunctionProtoType>(ToFn);
if (FromFPT->isNothrow(Context) && !ToFPT->isNothrow(Context)) {
FromFn = cast<FunctionType>(
- Context.getFunctionType(FromFPT->getReturnType(),
- FromFPT->getParamTypes(),
- FromFPT->getExtProtoInfo().withExceptionSpec(
- FunctionProtoType::ExceptionSpecInfo()))
+ Context.getFunctionTypeWithExceptionSpec(QualType(FromFPT, 0),
+ EST_None)
.getTypePtr());
Changed = true;
}