replica
/
hanchenye-llvm-project
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

[Sema][ObjC] Fix spurious -Wcast-qual warnings. 

We do not meaningfully track object const-ness of Objective-C object
types. Silence the -Wcast-qual warning that is issued when casting to or
from Objective-C object types results in losing const qualification.

rdar://problem/33807915

llvm-svn: 310672
This commit is contained in:
Akira Hatanaka 2017-08-11 00:06:49 +00:00
parent 6315d2d21d
commit 8d7bdf6dff
2 changed files with 23 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
clang/lib/Sema/SemaCast.cpp
View File

@ -552,7 +552,14 @@ CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
Qualifiers SrcQuals, DestQuals;
Self.Context.getUnqualifiedArrayType(UnwrappedSrcType, SrcQuals);
Self.Context.getUnqualifiedArrayType(UnwrappedDestType, DestQuals);
// We do not meaningfully track object const-ness of Objective-C object
// types. Remove const from the source type if either the source or
// the destination is an Objective-C object type.
if (UnwrappedSrcType->isObjCObjectType() ||
UnwrappedDestType->isObjCObjectType())
SrcQuals.removeConst();
Qualifiers RetainedSrcQuals, RetainedDestQuals;
if (CheckCVR) {
RetainedSrcQuals.setCVRQualifiers(SrcQuals.getCVRQualifiers());

17
clang/test/SemaObjC/illegal-nonarc-bridged-cast.m
View File

@ -1,8 +1,9 @@
// RUN: %clang_cc1 -triple x86_64-apple-darwin11 -fsyntax-only -fblocks -verify %s
// RUN: %clang_cc1 -triple x86_64-apple-darwin11 -fsyntax-only -fblocks -Wcast-qual -verify %s
// rdar://10597832
typedef const void *CFTypeRef;
typedef const struct __CFString *CFStringRef;
@class NSString;
@interface NSString
@end
@ -18,7 +19,7 @@ NSString *CreateNSString();
void from_cf() {
id obj1 = (__bridge_transfer id)CFCreateSomething(); // expected-warning {{'__bridge_transfer' casts have no effect when not using ARC}}
id obj2 = (__bridge_transfer NSString*)CFCreateString(); // expected-warning {{'__bridge_transfer' casts have no effect when not using ARC}}
(__bridge int*)CFCreateSomething(); // expected-warning {{expression result unused}}
(__bridge int*)CFCreateSomething(); // expected-warning {{expression result unused}} expected-warning {{cast from 'const void *' to 'int *' drops const qualifier}}
id obj3 = (__bridge id)CFGetSomething();
id obj4 = (__bridge NSString*)CFGetString();
}
@ -41,3 +42,15 @@ void to_cf_ignored(id obj) {
CFTypeRef cf1 = (__bridge_retained CFTypeRef)CreateSomething(); // no-warning
CFTypeRef cf3 = (__bridge CFTypeRef)CreateSomething(); // no-warning
}
// Check that clang doesn't warn about dropping const from Objective-C object
// types.
void test_wcast_qual() {
CFStringRef c;
NSString *n0 = (NSString *)c;
NSString **n1 = (NSString **)&c;
const NSString *n2;
const NSString **n3;
void *p0 = (void *)n2;
void **p1 = (void **)n3;
}