GCC -pedantic produces a format warning when the "%p" specifier is used with
arguments that are not void*. It's useful for portability to be able to
catch such warnings with clang as well. The warning is off by default in
both gcc and with this patch. This patch enables it either when extensions
are disabled with -pedantic, or with the specific flag -Wformat-pedantic.
The C99 and C11 specs do appear to require arguments corresponding to 'p'
specifiers to be void*: "If any argument is not the correct type for the
corresponding conversion specification, the behavior is undefined."
[7.19.6.1 p9], and of the 'p' format specifier "The argument shall be a
pointer to void." [7.19.6.1 p8]
Both printf and scanf format checking are covered.
llvm-svn: 231211
This adds a new __freebsd_kprintf__ format string type, which enables
checking when used in __attribute__((format(...))) attributes. It can
check the FreeBSD kernel specific %b, %D, %r and %y specifiers, using
existing diagnostic messages. Also adds test cases for all these
specifiers.
Differential Revision: http://reviews.llvm.org/D7154
llvm-svn: 229921
MSVC provides __wchar_t. This is the same as the built-in wchar_t type
from C++, but it is also available with -fno-wchar and in C.
The commit changes ASTContext to have two different types for this:
- WCharTy is the built-in type used for wchar_t in C++ and __wchar_t.
- WideCharTy is the type of a wide character literal. In C++ this is
the same as WCharTy, and in C it is an integer type compatible with
the type in <stddef.h>.
This fixes PR15815.
llvm-svn: 181587
This is useful for example for %n in printf, which expects
a pointer to int with the same logic for checking as %d
would have in scanf.
llvm-svn: 161407
Clang's -Wformat fix-its currently suggest using "%zu" for values of
type size_t (in C99 or C++11 mode). However, for a type such as
std::vector<T>::size_type, it does not notice that type is actually
typedeffed to size_t, and instead suggests a format for the underlying
type, such as "%lu" or "%u".
This commit makes the format string fix mechanism walk the typedef chain
so that it notices if the type is size_t, even if that isn't "at the
top".
llvm-svn: 160886
For "%hhx", printf expects an unsigned char. This makes Clang
accept a 'char' argument for that also when using -funsigned-char.
This fixes PR12761.
llvm-svn: 156388
Teach ASTContext about WIntType, and have it taken from TargetInfo like WCharType. Should fix test/Sema/format-strings.c for ARM, with the exception of one subtest which will fail if wint_t and wchar_t are the same size and wint_t is signed, wchar_t is unsigned.
There'll be a followup commit to fix that.
Reviewed by Chandler and Hans at http://llvm.org/reviews/r/8
llvm-svn: 156165
This renames the -Wformat-non-standard flag to -Wformat-non-iso,
rewords the current warnings a bit (pointing out that a format string
is not supported by ISO C rather than being "non standard"),
and adds a warning about positional arguments.
llvm-svn: 152403
This adds the -Wformat-non-standard flag (off by default,
enabled by -pedantic), which warns about non-standard
things in format strings (such as the 'q' length modifier,
the 'S' conversion specifier, etc.)
llvm-svn: 151154
This is in preparation for being able to warn about 'q' and other
non-standard format string features.
It also allows us to print its name correctly.
llvm-svn: 150697
This fixes the case where Clang would output:
error: format specifies type 'wchar_t *' (aka 'wchar_t *')
ArgTypeResult::getRepresentativeTypeName needs to take into account
that wchar_t can be a built-in type (as opposed to in C, where it is a
typedef).
llvm-svn: 149387
in addition to underlying type.
For example, the warning for printf("%zu", 42.0);
changes from "conversion specifies type 'unsigned long'" to "conversion
specifies type 'size_t' (aka 'unsigned long')"
(This is a second attempt after r145697, which got reverted.)
llvm-svn: 146032
For example, the warning for printf("%zu", 42.0);
changes from "conversion specifies type 'unsigned long'" to "conversion
specifies type 'size_t' (aka 'unsigned long')"
llvm-svn: 145697
Seth Cantrell