Disallow reinterpret_cast from pointer to bool on Windows
This became allowed by accident in r131201, but triggers an assert.
That patch added an exception to allow conversion from pointers to
narrow integral types for MSVC compatibility. However, a pointer can
already be converted to bool in a civilized manner; allowing conversion
via reinterpret_cast is a bad idea.
Fixes PR16222.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183394 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaCast.cpp b/lib/Sema/SemaCast.cpp
index 3f0a1a3..b4e7113 100644
--- a/lib/Sema/SemaCast.cpp
+++ b/lib/Sema/SemaCast.cpp
@@ -1813,10 +1813,12 @@
assert(srcIsPtr && "One type must be a pointer");
// C++ 5.2.10p4: A pointer can be explicitly converted to any integral
// type large enough to hold it; except in Microsoft mode, where the
- // integral type size doesn't matter.
+ // integral type size doesn't matter (except we don't allow bool).
+ bool MicrosoftException = Self.getLangOpts().MicrosoftExt &&
+ !DestType->isBooleanType();
if ((Self.Context.getTypeSize(SrcType) >
Self.Context.getTypeSize(DestType)) &&
- !Self.getLangOpts().MicrosoftExt) {
+ !MicrosoftException) {
msg = diag::err_bad_reinterpret_cast_small_int;
return TC_Failed;
}
diff --git a/test/Sema/MicrosoftExtensions.c b/test/Sema/MicrosoftExtensions.c
index a66d9a9..5215e72 100644
--- a/test/Sema/MicrosoftExtensions.c
+++ b/test/Sema/MicrosoftExtensions.c
@@ -76,6 +76,9 @@
short sh = (short)ptr;
ch = (char)ptr;
sh = (short)ptr;
+
+ // This is valid ISO C.
+ _Bool b = (_Bool)ptr;
}
diff --git a/test/SemaCXX/MicrosoftExtensions.cpp b/test/SemaCXX/MicrosoftExtensions.cpp
index 93a6d30..c0e7a5a 100644
--- a/test/SemaCXX/MicrosoftExtensions.cpp
+++ b/test/SemaCXX/MicrosoftExtensions.cpp
@@ -167,8 +167,14 @@
short sh = (short)ptr;
ch = (char)ptr;
sh = (short)ptr;
-}
+ // These are valid C++.
+ bool b = (bool)ptr;
+ b = static_cast<bool>(ptr);
+
+ // This is bad.
+ b = reinterpret_cast<bool>(ptr); // expected-error {{cast from pointer to smaller type 'bool' loses information}}
+}
namespace friend_as_a_forward_decl {
