[PATCH] D33102: [clang] Implement -Wcast-qual for C++
David Blaikie via cfe-commits
cfe-commits at lists.llvm.org
Tue Jun 6 10:52:13 PDT 2017
On Tue, Jun 6, 2017 at 3:59 AM Roman Lebedev via Phabricator <
reviews at reviews.llvm.org> wrote:
> lebedev.ri added a comment.
>
> In https://reviews.llvm.org/D33102#773296, @dblaikie wrote:
>
> > I still feel like that's more testing than would be ideal (does the
> context of the cast matter? Wether it's dereferenced, a struct member
> access, assigned, initialized, etc - it doesn't look like it from the code,
> etc).
>
>
> Looking at the `CastsAwayConstness()` function in lib/Sema/SemaCast.cpp:
> https://github.com/llvm-mirror/clang/blob/432ed0e4a6d58f7dda8992a167aad43bc91f76c6/lib/Sema/SemaCast.cpp#L505-L510
> You can see that it asserts that the pointer is one of three types. So i
> think it it is best to have maybe slightly overlapping test coverage here,
> rather than be surprised one day that such trivial cases no longer warn...
>
> > But sure. Could you also (manually, I guess) confirm that this matches
> GCC's cast-qual behavior (insofar as the warning fires in the same
> situations). If there are any deviations, let's chat about them.
>
> Sure.
>
> 1. Gcc produces the same //count// of the warnings:
>
> $ pwd
> llvm/tools/clang/test
> $ grep -o "expected-warning" Sema/warn-cast-qual.c | wc -l
> 14
> $ gcc -x c -fsyntax-only -Wcast-qual -c Sema/warn-cast-qual.c 2>&1 |
> grep ": warning: " | wc -l
> 14
> $ gcc -x c++ -fsyntax-only -Wcast-qual -c Sema/warn-cast-qual.c 2>&1 |
> grep ": warning: " | wc -l
> 14
> $ grep -o "expected-warning" SemaCXX/warn-cast-qual.cpp | wc -l
> 39
> $ gcc -x c++ -fsyntax-only -Wcast-qual -c SemaCXX/warn-cast-qual.cpp
> 2>&1 | grep ": warning: " | wc -l
> 39
>
> 2. I'm not quite sure how to non-manually compare the warnings, so i'll
> just show the gcc output on these three cases. Since the clang warnings are
> appended as comments at the end of the each line that should warn, visual
> comparison is possible:
>
Works for the positive cases, not the negative ones. (though if the counts
are exactly the same, then so long as there are no false positives there
aren't any false negatives either)
>
> 2.1.
>
> $ gcc -x c -fsyntax-only -Wcast-qual -c Sema/warn-cast-qual.c
> Sema/warn-cast-qual.c: In function ‘foo’:
> Sema/warn-cast-qual.c:9:13: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> char *y = (char *)ptr; // expected-warning {{cast from 'const char *'
> to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:10:15: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> char **y1 = (char **)ptrptr; // expected-warning {{cast from 'const
> char *const' to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:11:21: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> const char **y2 = (const char **)ptrptr; // expected-warning {{cast
> from 'const char *const *' to 'const char **' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:14:14: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> char *z1 = (char *)(const void *)ptr; // expected-warning {{cast from
> 'const void *' to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:17:16: warning: cast discards ‘volatile’ qualifier
> from pointer target type [-Wcast-qual]
> char *vol2 = (char *)vol; // expected-warning {{cast from 'volatile
> char *' to 'char *' drops volatile qualifier}}
> ^
> Sema/warn-cast-qual.c:19:17: warning: cast discards ‘const volatile’
> qualifier from pointer target type [-Wcast-qual]
> char *volc2 = (char *)volc; // expected-warning {{cast from 'const
> volatile char *' to 'char *' drops const and volatile qualifiers}}
> ^
> Sema/warn-cast-qual.c:22:28: warning: to be safe all intermediate
> pointers in cast from ‘int **’ to ‘const int **’ must be ‘const’ qualified
> [-Wcast-qual]
> const int **intptrptrc = (const int **)intptrptr; // expected-warning
> {{cast from 'int **' to 'const int **' must have all intermediate pointers
> const qualified}}
> ^
> Sema/warn-cast-qual.c:23:31: warning: to be safe all intermediate
> pointers in cast from ‘int **’ to ‘volatile int **’ must be ‘const’
> qualified [-Wcast-qual]
> volatile int **intptrptrv = (volatile int **)intptrptr; //
> expected-warning {{cast from 'int **' to 'volatile int **' must have all
> intermediate pointers const qualified}}
> ^
> Sema/warn-cast-qual.c:29:23: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> char **charptrptr = (char **)charptrptrc; // expected-warning {{cast
> from 'const char *' to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:32:19: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> char *charptr = (char *)constcharptr; // expected-warning {{cast from
> 'const char *' to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:33:31: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> const char *constcharptr2 = (char *)constcharptr; // expected-warning
> {{cast from 'const char *' to 'char *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c: In function ‘bar_0’:
> Sema/warn-cast-qual.c:45:4: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:46:4: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> *(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c: In function ‘bar_1’:
> Sema/warn-cast-qual.c:58:4: warning: cast discards ‘const’ qualifier
> from pointer target type [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
>
> One thing to note:
>
> Sema/warn-cast-qual.c:23:31: warning: to be safe all intermediate
> pointers in cast from ‘int **’ to ‘volatile int **’ must be ‘const’
> qualified [-Wcast-qual]
> volatile int **intptrptrv = (volatile int **)intptrptr; //
> expected-warning {{cast from 'int **' to 'volatile int **' must have all
> intermediate pointers const qualified}}
> ^
>
> ^ both compilers talk about `const qualified`, even though the `volatile`
> is dropped.
>
Fair enough - 'cv qualified' (or detecting which qualifier was being
dropped) would probably be more technically correct. (detecting's probably
better because 'cv qualifeid' might be confusing to the average user that's
more likely to hit this over const than volatile)
> 2.2.
>
> $ gcc -x c++ -fsyntax-only -Wcast-qual -c Sema/warn-cast-qual.c
> Sema/warn-cast-qual.c: In function ‘void foo()’:
> Sema/warn-cast-qual.c:9:21: warning: cast from type ‘const char* const’
> to type ‘char*’ casts away qualifiers [-Wcast-qual]
> char *y = (char *)ptr; // expected-warning {{cast from 'const char *'
> to 'char *' drops const qualifier}}
> ^~~
> Sema/warn-cast-qual.c:10:24: warning: cast from type ‘const char*
> const*’ to type ‘char**’ casts away qualifiers [-Wcast-qual]
> char **y1 = (char **)ptrptr; // expected-warning {{cast from 'const
> char *const' to 'char *' drops const qualifier}}
> ^~~~~~
> Sema/warn-cast-qual.c:11:36: warning: cast from type ‘const char*
> const*’ to type ‘const char**’ casts away qualifiers [-Wcast-qual]
> const char **y2 = (const char **)ptrptr; // expected-warning {{cast
> from 'const char *const *' to 'const char **' drops const qualifier}}
> ^~~~~~
> Sema/warn-cast-qual.c:14:36: warning: cast from type ‘const void*’ to
> type ‘char*’ casts away qualifiers [-Wcast-qual]
> char *z1 = (char *)(const void *)ptr; // expected-warning {{cast from
> 'const void *' to 'char *' drops const qualifier}}
> ^~~
> Sema/warn-cast-qual.c:17:24: warning: cast from type ‘volatile char*’ to
> type ‘char*’ casts away qualifiers [-Wcast-qual]
> char *vol2 = (char *)vol; // expected-warning {{cast from 'volatile
> char *' to 'char *' drops volatile qualifier}}
> ^~~
> Sema/warn-cast-qual.c:19:25: warning: cast from type ‘const volatile
> char*’ to type ‘char*’ casts away qualifiers [-Wcast-qual]
> char *volc2 = (char *)volc; // expected-warning {{cast from 'const
> volatile char *' to 'char *' drops const and volatile qualifiers}}
> ^~~~
> Sema/warn-cast-qual.c:22:42: warning: cast from type ‘int**’ to type
> ‘const int**’ casts away qualifiers [-Wcast-qual]
> const int **intptrptrc = (const int **)intptrptr; // expected-warning
> {{cast from 'int **' to 'const int **' must have all intermediate pointers
> const qualified}}
> ^~~~~~~~~
> Sema/warn-cast-qual.c:23:48: warning: cast from type ‘int**’ to type
> ‘volatile int**’ casts away qualifiers [-Wcast-qual]
> volatile int **intptrptrv = (volatile int **)intptrptr; //
> expected-warning {{cast from 'int **' to 'volatile int **' must have all
> intermediate pointers const qualified}}
> ^~~~~~~~~
> Sema/warn-cast-qual.c:29:32: warning: cast from type ‘const char**’ to
> type ‘char**’ casts away qualifiers [-Wcast-qual]
> char **charptrptr = (char **)charptrptrc; // expected-warning {{cast
> from 'const char *' to 'char *' drops const qualifier}}
> ^~~~~~~~~~~
> Sema/warn-cast-qual.c:32:27: warning: cast from type ‘const char*’ to
> type ‘char*’ casts away qualifiers [-Wcast-qual]
> char *charptr = (char *)constcharptr; // expected-warning {{cast from
> 'const char *' to 'char *' drops const qualifier}}
> ^~~~~~~~~~~~
> Sema/warn-cast-qual.c:33:39: warning: cast from type ‘const char*’ to
> type ‘char*’ casts away qualifiers [-Wcast-qual]
> const char *constcharptr2 = (char *)constcharptr; // expected-warning
> {{cast from 'const char *' to 'char *' drops const qualifier}}
> ^~~~~~~~~~~~
> Sema/warn-cast-qual.c: In function ‘void bar_0()’:
> Sema/warn-cast-qual.c:45:16: warning: cast from type ‘const int*’ to
> type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c:46:16: warning: cast from type ‘const int*’ to
> type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
> Sema/warn-cast-qual.c: In function ‘void bar_1()’:
> Sema/warn-cast-qual.c:58:16: warning: cast from type ‘const int*’ to
> type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *' to
> 'int *' drops const qualifier}}
> ^
>
> 2.3.
> And here are the C++ reference warnings. As you can see, gcc warnings are
> rather broken i'd say...
>
There's a lot to read through - what sort of brokenness were you referring
to? The fact that the error messages talk about pointers when the code is
about references? Fair. Anything else?
>
> $ gcc -x c++ -fsyntax-only -Wcast-qual -c SemaCXX/warn-cast-qual.cpp
> SemaCXX/warn-cast-qual.cpp: In function ‘void foo_0()’:
> SemaCXX/warn-cast-qual.cpp:24:20: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a2 = (int &)a; // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:25:26: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const int &a3 = (int &)a; // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:26:35: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a4 = (int &)((const int &)a); // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:27:28: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a5 = (int &)((int &)a); // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:28:34: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const int &a6 = (int &)((int &)a); // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:29:41: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const int &a7 = (int &)((const int &)a); // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:30:40: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const int &a8 = (const int &)((int &)a); // expected-warning {{cast
> from 'const int' to 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void foo_1()’:
> SemaCXX/warn-cast-qual.cpp:39:20: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a2 = (int &)a; // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:40:29: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> volatile int &a3 = (int &)a; // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:41:38: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a4 = (int &)((volatile int &)a); // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:42:28: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a5 = (int &)((int &)a); // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:43:37: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> volatile int &a6 = (int &)((int &)a); // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:44:47: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> volatile int &a7 = (int &)((volatile int &)a); // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:45:46: warning: cast from type ‘volatile
> int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> volatile int &a8 = (volatile int &)((int &)a); // expected-warning
> {{cast from 'volatile int' to 'int &' drops volatile qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void foo_2()’:
> SemaCXX/warn-cast-qual.cpp:54:20: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a2 = (int &)a; //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:55:35: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const volatile int &a3 = (int &)a; //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:56:44: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a4 = (int &)((const volatile int &)a); //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:57:28: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> int &a5 = (int &)((int &)a); //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:58:43: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const volatile int &a6 = (int &)((int &)a); //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:59:59: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const volatile int &a7 = (int &)((const volatile int &)a); //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp:60:58: warning: cast from type ‘const
> volatile int*’ to type ‘int*’ casts away qualifiers [-Wcast-qual]
> const volatile int &a8 = (const volatile int &)((int &)a); //
> expected-warning {{cast from 'const volatile int' to 'int &' drops const
> and volatile qualifiers}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void bar_0()’:
> SemaCXX/warn-cast-qual.cpp:67:38: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> int **a0 = (int **)((const int **)a); // expected-warning {{cast from
> 'const int *' to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:68:31: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> int **a1 = (int **)((int **)a); // expected-warning {{cast from
> 'const int *' to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:73:43: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> const int **a4 = (const int **)((int **)a); //
> expected-warning {{cast from 'const int *' to 'int *' drops const
> qualifier}} expected-warning {{cast from 'int **' to 'const int **' must
> have all intermediate pointers const qualified to be safe}}
> ^
> SemaCXX/warn-cast-qual.cpp:73:44: warning: cast from type ‘int**’ to
> type ‘const int**’ casts away qualifiers [-Wcast-qual]
> const int **a4 = (const int **)((int **)a); //
> expected-warning {{cast from 'const int *' to 'int *' drops const
> qualifier}} expected-warning {{cast from 'int **' to 'const int **' must
> have all intermediate pointers const qualified to be safe}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void bar_1()’:
> SemaCXX/warn-cast-qual.cpp:81:38: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> int *&a0 = (int *&)((const int *&)a); // expected-warning {{cast from
> 'const int *' to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:82:31: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> int *&a1 = (int *&)((int *&)a); // expected-warning {{cast from
> 'const int *' to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:87:43: warning: cast from type ‘const int**’
> to type ‘int**’ casts away qualifiers [-Wcast-qual]
> const int *&a4 = (const int *&)((int *&)a); //
> expected-warning {{cast from 'const int *' to 'int *' drops const
> qualifier}} expected-warning {{cast from 'int *' to 'const int *&' must
> have all intermediate pointers const qualified to be safe}}
> ^
> SemaCXX/warn-cast-qual.cpp:87:44: warning: cast from type ‘int**’ to
> type ‘const int**’ casts away qualifiers [-Wcast-qual]
> const int *&a4 = (const int *&)((int *&)a); //
> expected-warning {{cast from 'const int *' to 'int *' drops const
> qualifier}} expected-warning {{cast from 'int *' to 'const int *&' must
> have all intermediate pointers const qualified to be safe}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void baz_0()’:
> SemaCXX/warn-cast-qual.cpp:100:9: warning: cast from type ‘const
> baz_0()::C*’ to type ‘baz_0()::C*’ casts away qualifiers [-Wcast-qual]
> ((C &)S).B(); // expected-warning {{cast from 'const C' to 'C &'
> drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:101:9: warning: cast from type ‘const
> baz_0()::C*’ to type ‘baz_0()::C*’ casts away qualifiers [-Wcast-qual]
> ((C &)S).A(); // expected-warning {{cast from 'const C' to 'C &'
> drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:103:10: warning: cast from type ‘const
> baz_0()::C*’ to type ‘baz_0()::C*’ casts away qualifiers [-Wcast-qual]
> ((C *)&S)->B(); // expected-warning {{cast from 'const C *' to 'C *'
> drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:104:10: warning: cast from type ‘const
> baz_0()::C*’ to type ‘baz_0()::C*’ casts away qualifiers [-Wcast-qual]
> ((C *)&S)->A(); // expected-warning {{cast from 'const C *' to 'C *'
> drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp: In function ‘void baz_1()’:
> SemaCXX/warn-cast-qual.cpp:119:16: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> (int &)(S.a) = 0; // expected-warning {{cast from 'const int' to
> 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:122:18: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *'
> to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:128:16: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> (int &)(S.a) = 0; // expected-warning {{cast from 'const int' to
> 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:129:16: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> (int &)(S.b) = 0; // expected-warning {{cast from 'const int' to
> 'int &' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:131:18: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.a) = 0; // expected-warning {{cast from 'const int *'
> to 'int *' drops const qualifier}}
> ^
> SemaCXX/warn-cast-qual.cpp:132:18: warning: cast from type ‘const int*’
> to type ‘int*’ casts away qualifiers [-Wcast-qual]
> *(int *)(&S.b) = 0; // expected-warning {{cast from 'const int *'
> to 'int *' drops const qualifier}}
> ^
>
> So to me it seems that for our clang's testcases, both compilers produce
> the compatible set of warnings...
>
>
> Repository:
> rL LLVM
>
> https://reviews.llvm.org/D33102
>
>
>
>
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