gcc/testsuite/gcc.dg/format/attr-3.c

/* Test for format attributes: test bad uses of __attribute__.  */
/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
/* { dg-do compile } */
/* { dg-options "-std=gnu99 -Wformat" } */

#include "format.h"

/* Proper uses of the attributes.  */
extern void fa0 (const char *, ...) __attribute__((format(printf, 1, 2)));
extern void fa1 (char *, ...) __attribute__((format(printf, 1, 2)));
extern char *fa2 (const char *) __attribute__((format_arg(1)));
extern char *fa3 (char *) __attribute__((format_arg(1)));

/* Uses with too few or too many arguments.  */
extern void fb0 (const char *, ...) __attribute__((format)); /* { dg-error "wrong number of arguments" "bad format" } */
extern void fb1 (const char *, ...) __attribute__((format())); /* { dg-error "wrong number of arguments" "bad format" } */
extern void fb2 (const char *, ...) __attribute__((format(printf))); /* { dg-error "wrong number of arguments" "bad format" } */
extern void fb3 (const char *, ...) __attribute__((format(printf, 1))); /* { dg-error "wrong number of arguments" "bad format" } */
extern void fb4 (const char *, ...) __attribute__((format(printf, 1, 2, 3))); /* { dg-error "wrong number of arguments" "bad format" } */

extern void fc1 (const char *) __attribute__((format_arg)); /* { dg-error "wrong number of arguments" "bad format_arg" } */
extern void fc2 (const char *) __attribute__((format_arg())); /* { dg-error "wrong number of arguments" "bad format_arg" } */
extern void fc3 (const char *) __attribute__((format_arg(1, 2))); /* { dg-error "wrong number of arguments" "bad format_arg" } */

/* These attributes presently only apply to declarations, not to types.
   Eventually, they should be usable with declarators for function types
   anywhere, but still not with structure/union/enum types.  */
struct s0 { int i; } __attribute__((format(printf, 1, 2))); /* { dg-error "does not apply" "format on struct" } */
union u0 { int i; } __attribute__((format(printf, 1, 2))); /* { dg-error "does not apply" "format on union" } */
enum e0 { E0V0 } __attribute__((format(printf, 1, 2))); /* { dg-error "does not apply" "format on enum" } */

struct s1 { int i; } __attribute__((format_arg(1))); /* { dg-error "does not apply" "format_arg on struct" } */
union u1 { int i; } __attribute__((format_arg(1))); /* { dg-error "does not apply" "format_arg on union" } */
enum e1 { E1V0 } __attribute__((format_arg(1))); /* { dg-error "does not apply" "format_arg on enum" } */

/* At present, only functions can be declared with these attributes.
   Once they can be applied to function types in function pointers, etc.,
   these tests should be removed, and tests should be added (say in a new
   testcase attr-<num>.c) that such attributes work and calls through such
   function pointers (etc.) get checked.  */
extern void (*fd0) (const char *, ...) __attribute__((format(printf, 1, 2))); /* { dg-error "non-function" "format on non-function" } */
extern char *(*fd1) (const char *) __attribute__((format_arg(1))); /* { dg-error "non-function" "format on non-function" } */

/* The format type must be an identifier, one of those recognised.  */
extern void fe0 (const char *, ...) __attribute__((format(12345, 1, 2))); /* { dg-error "format specifier" "non-id format" } */
extern void fe1 (const char *, ...) __attribute__((format(nosuch, 1, 2))); /* { dg-warning "format function type" "unknown format" } */

/* Both the numbers must be integer constant expressions.  */
extern void ff0 (const char *, ...) __attribute__((format(printf, 3-2, (long long)(10/5))));
int foo;
extern void ff1 (const char *, ...) __attribute__((format(printf, foo, 10/5))); /* { dg-error "invalid operand" "bad number" } */
extern void ff2 (const char *, ...) __attribute__((format(printf, 3-2, foo))); /* { dg-error "invalid operand" "bad number" } */
extern char *ff3 (const char *) __attribute__((format_arg(3-2)));
extern char *ff4 (const char *) __attribute__((format_arg(foo))); /* { dg-error "invalid operand" "bad format_arg number" } */

/* The format string argument must precede the arguments to be formatted.
   This includes if no parameter types are specified (which is not valid ISO
   C for variadic functions).  */
extern void fg0 () __attribute__((format(printf, 1, 2)));
extern void fg1 () __attribute__((format(printf, 1, 0)));
extern void fg2 () __attribute__((format(printf, 1, 1))); /* { dg-error "follows" "bad number order" } */
extern void fg3 () __attribute__((format(printf, 2, 1))); /* { dg-error "follows" "bad number order" } */

/* The format string argument must be a string type, and the arguments to
   be formatted must be the "...".  */
extern void fh0 (int, ...) __attribute__((format(printf, 1, 2))); /* { dg-error "not a string" "format int string" } */
extern void fh1 (signed char *, ...) __attribute__((format(printf, 1, 2))); /* { dg-error "not a string" "signed char string" } */
extern void fh2 (unsigned char *, ...) __attribute__((format(printf, 1, 2))); /* { dg-error "not a string" "unsigned char string" } */
extern void fh3 (const char *, ...) __attribute__((format(printf, 1, 3))); /* { dg-error "is not" "not ..." } */
extern void fh4 (const char *, int, ...) __attribute__((format(printf, 1, 2))); /* { dg-error "is not" "not ..." } */

/* format_arg formats must take and return a string.  */
extern char *fi0 (int) __attribute__((format_arg(1))); /* { dg-error "not a string" "format_arg int string" } */
extern char *fi1 (signed char *) __attribute__((format_arg(1))); /* { dg-error "not a string" "format_arg signed char string" } */
extern char *fi2 (unsigned char *) __attribute__((format_arg(1))); /* { dg-error "not a string" "format_arg unsigned char string" } */
extern int fi3 (const char *) __attribute__((format_arg(1))); /* { dg-error "not return string" "format_arg ret int string" } */
extern signed char *fi4 (const char *) __attribute__((format_arg(1))); /* { dg-error "not return string" "format_arg ret signed char string" } */
extern unsigned char *fi5 (const char *) __attribute__((format_arg(1))); /* { dg-error "not return string" "format_arg ret unsigned char string" } */