Commit Graph

8 Commits

Author SHA1 Message Date
Félix Cloutier 92edd74b37 Allow non-variadic functions to be attributed with `__attribute__((format))`
Clang only allows you to use __attribute__((format)) on variadic functions. There are legit use cases for __attribute__((format)) on non-variadic functions, such as:

(1) variadic templates

```c++
template<typename… Args>
void print(const char *fmt, Args… &&args) __attribute__((format(1, 2))); // error: format attribute requires variadic function
```

(2) functions which take fixed arguments and a custom format:

```c++
void print_number_string(const char *fmt, unsigned number, const char *string) __attribute__((format(1, 2)));
// ^error: format attribute requires variadic function

void foo(void) {
    print_number_string(“%08x %s\n”, 0xdeadbeef, “hello”);
    print_number_string(“%d %s”, 0xcafebabe, “bar”);
}
```

This change allows Clang users to attach __attribute__((format)) to non-variadic functions, including functions with C++ variadic templates. It replaces the error with a GCC compatibility warning and improves the type checker to ensure that received arrays are treated like pointers (this is a possibility in C++ since references to template types can bind to arrays).

Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D112579
rdar://84629099
2022-07-05 17:26:11 -07:00
Dimitry Andric 6b5ed34a40 Add support for analyzing FreeBSD kernel printf extensions.
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
2015-02-19 22:32:33 +00:00
Aaron Ballman be50eb86e6 Refactor some attributes to use checkFunctionOrMethodArgumentIndex instead of using custom logic. No functional changes intended.
llvm-svn: 187398
2013-07-30 00:48:57 +00:00
Douglas Gregor 4f4946aaaa Whenever we complain about a failed initialization of a function or
method parameter, provide a note pointing at the parameter itself so
the user does not have to manually look for the function/method being
called and match up parameters to arguments. For example, we now get:

t.c:4:5: warning: incompatible pointer types passing 'long *' to
parameter of
      type 'int *' [-pedantic]
  f(long_ptr);
    ^~~~~~~~
t.c:1:13: note: passing argument to parameter 'x' here
void f(int *x);
            ^

llvm-svn: 102038
2010-04-22 00:20:18 +00:00
Duncan Sands de4fe3538a Ignore a more comprehensive set of gcc-special format attributes.
llvm-svn: 99277
2010-03-23 14:44:19 +00:00
Chris Lattner 12161d3d1a (re)implement PR6542, accepting and discarding the __gcc_tdiag__
format attribute specifier.

llvm-svn: 99213
2010-03-22 21:08:50 +00:00
Chris Lattner cb5a828a45 merge some tests.
llvm-svn: 99212
2010-03-22 21:05:15 +00:00
Chris Lattner 42ed9a6a2b rename test
llvm-svn: 99211
2010-03-22 21:02:58 +00:00