| /* { dg-do compile } */ |
| /* { dg-options "-O2 -Wformat -Wformat-truncation=2 -ftrack-macro-expansion=0" } */ |
| |
| typedef struct |
| { |
| char a0[0]; |
| /* Separate a0 from a1 to prevent the former from being substituted |
| for the latter and causing false positives. */ |
| int: 8; |
| char a1[1]; |
| char a2[2]; |
| char a3[3]; |
| char a4[4]; |
| char ax[]; |
| } Arrays; |
| |
| char buffer[1024]; |
| #define buffer(size) (buffer + sizeof buffer - size) |
| |
| static int value_range (int min, int max) |
| { |
| extern int value (void); |
| int val = value (); |
| return val < min || max < val ? min : val; |
| } |
| |
| #define R(min, max) value_range (min, max) |
| |
| /* Verify that calls to snprintf whose return value is unused are |
| diagnosed if certain or possible truncation is detected. */ |
| |
| #define T(size, ...) \ |
| __builtin_snprintf (buffer (size), size, __VA_ARGS__) |
| |
| void test_int_retval_unused (void) |
| { |
| T (2, "%i", 123); /* { dg-warning "output truncated" } */ |
| T (2, "%i", R (1, 99)); /* { dg-warning "output may be truncated" } */ |
| T (2, "%i", R (10, 99)); /* { dg-warning "output truncated" } */ |
| T (3, "%i%i", R (1, 99), R (1, 99)); /* { dg-warning "output may be truncated" } */ |
| } |
| |
| void test_string_retval_unused (const Arrays *ar) |
| { |
| /* At level 2 strings of unknown length are assumed to be 1 character |
| long, so the following is diagnosed. */ |
| T (1, "%-s", ar->a0); /* { dg-warning "output may be truncated" } */ |
| T (1, "%-s", ar->a1); |
| T (1, "%-s", ar->a2); /* { dg-warning "output may be truncated" } */ |
| } |
| |
| |
| /* Verify that (at -Wformat-trunc=2) calls to snprintf whose return value |
| is used are diagnosed the same way as those whose value is unused. */ |
| |
| volatile int retval; |
| |
| #undef T |
| #define T(size, ...) \ |
| retval = __builtin_snprintf (buffer (size), size, __VA_ARGS__) |
| |
| void test_int_retval_used (void) |
| { |
| T (2, "%i", 123); /* { dg-warning "output truncated" } */ |
| T (2, "%i", R (1, 99)); /* { dg-warning "output may be truncated" } */ |
| T (2, "%i", R (10, 99)); /* { dg-warning "output truncated" } */ |
| T (3, "%i%i", R (1, 99), R (1, 99)); /* { dg-warning "output may be truncated" } */ |
| } |
| |
| void test_string_retval_used (const Arrays *ar) |
| { |
| T (1, "%-s", ar->a0); /* { dg-warning "output may be truncated" } */ |
| T (1, "%-s", ar->a1); |
| T (1, "%-s", ar->a2); /* { dg-warning "output may be truncated" } */ |
| } |