/* Test to verify that the return value of calls to __builtin_sprintf is not folded if the call isn't fully specified, even if it would otherwise produce a known number of bytes on output, and that if the return value is in a known range the range is not made available to subsequent passes and doesn't affect branching and the removal of code. The test is compiled with warnings disabled to make sure the absence of optimizations does not depend on the presence of warnings. */ /* { dg-do compile } */ /* { dg-options "-O2 -fprintf-return-value -fdump-tree-optimized -ftrack-macro-expansion=0 -w" } */ #ifndef LINE # define LINE 0 #endif #define INT_MAX __INT_MAX__ #define INT_MIN (-INT_MAX - 1) #define LONG_MAX __LONG_MAX__ #define LONG_MIN (-LONG_MAX - 1) char *buf; char buf8k [8192]; #define concat(a, b) a ## b #define CAT(a, b) concat (a, b) /* Calls to this function must not be eliminated. */ void must_not_eliminate (void); #define EQL(expect, size, fmt, ...) \ void __attribute__ ((noinline, noclone)) \ CAT (test_on_line_, __LINE__)(void) \ { \ if (!LINE || LINE == __LINE__) \ { \ char *dst = size < 0 ? buf : buf8k + sizeof buf8k - size; \ int result = __builtin_sprintf (dst, fmt, __VA_ARGS__); \ if (result != expect) \ must_not_eliminate (); \ } \ } /* Verify that the return value or range or return values from the call to the formatted function is not treated as a constant or made available to subsequent optimization passes. */ #define RNG(min, max, size, fmt, ...) \ void __attribute__ ((noinline, noclone)) \ CAT (test_on_line_, __LINE__)(void) \ { \ if (!LINE || LINE == __LINE__) \ { \ char *dst = size < 0 ? buf : buf8k + sizeof buf8k - size; \ int result = __builtin_sprintf (dst, fmt, __VA_ARGS__); \ if (result < min || max < result) \ must_not_eliminate (); \ } \ } typedef __SIZE_TYPE__ size_t; extern int i; extern unsigned u; extern long li; extern unsigned long lu; extern size_t sz; extern char *str; extern double d; extern long double ld; /* Verify that overflowing the destination object disables the return value optimization. */ EQL (0, 0, "%c", ' '); EQL (0, 0, "%c", i) EQL (0, 0, "%-s", ""); EQL (1, 1, "%c", 'x'); EQL (1, 1, "%-s", "x"); EQL (1, 2, "%c", 'x'); EQL (4, 4, "%4c", 'x'); /* Verify that exceeding the environmental limit of 4095 bytes for a single conversion specification disables the return value folding. */ EQL ( 4096, sizeof buf8k, "%4096c", 'x'); EQL (INT_MAX, -1, "%*c", INT_MAX, 'x'); EQL ( 4096, sizeof buf8k, "%4096.4094f", 1.0); EQL ( 4096, sizeof buf8k, "%.4094f", 1.0); EQL ( 4097, sizeof buf8k, "%.4095f", 1.0); enum { imax2 = (INT_MAX / 2) * 2 }; EQL (imax2, -1, "%*c%*c", INT_MAX / 2, 'x', INT_MAX / 2, 'y'); /* Verify that range information for calls that overflow the destination isn't available. +-- lower bound of the tested range | +-- upper bound of the tested range | | +-- size of destination buffer | | | +-- format string | | | | +-- argument(s) | | | | | V V V V V */ RNG (0, 0, 0, "%hhi", i) RNG (0, 0, 1, "%hhi", i) RNG (0, 1, 1, "%hhi", i) RNG (0, 0, 2, "%hhi", i) RNG (0, 1, 2, "%hhi", i) RNG (0, 2, 2, "%hhi", i) RNG (0, 0, 3, "%hhi", i) RNG (0, 1, 3, "%hhi", i) RNG (0, 2, 3, "%hhi", i) RNG (0, 3, 3, "%hhi", i) RNG (0, 0, 4, "%hhi", i) RNG (0, 1, 4, "%hhi", i) RNG (0, 2, 4, "%hhi", i) RNG (0, 3, 4, "%hhi", i) RNG (0, 4, 4, "%hhi", i) RNG (0, 0, 0, "%hhu", i) RNG (0, 0, 1, "%hhu", i) RNG (0, 1, 1, "%hhu", i) RNG (0, 0, 2, "%hhu", i) RNG (0, 1, 2, "%hhu", i) RNG (0, 2, 2, "%hhu", i) RNG (0, 0, 3, "%hhu", i) RNG (0, 1, 3, "%hhu", i) RNG (0, 2, 3, "%hhu", i) RNG (0, 3, 3, "%hhu", i) RNG (0, 0, 0, "%i", i) RNG (0, 0, 1, "%i", i) RNG (0, 1, 1, "%i", i) RNG (0, 0, 2, "%i", i) RNG (0, 1, 2, "%i", i) RNG (0, 2, 2, "%i", i) RNG (0, 0, 3, "%i", i) RNG (0, 1, 3, "%i", i) RNG (0, 2, 3, "%i", i) RNG (0, 3, 3, "%i", i) RNG (0, 0, 4, "%i", i) RNG (0, 1, 4, "%i", i) RNG (0, 2, 4, "%i", i) RNG (0, 3, 4, "%i", i) RNG (0, 4, 4, "%i", i) RNG (0, 0, 5, "%i", i) RNG (0, 1, 5, "%i", i) RNG (0, 2, 5, "%i", i) RNG (0, 3, 5, "%i", i) RNG (0, 4, 5, "%i", i) RNG (0, 5, 5, "%i", i) RNG (0, 0, 6, "%i", i) RNG (0, 1, 6, "%i", i) RNG (0, 2, 6, "%i", i) RNG (0, 3, 6, "%i", i) RNG (0, 4, 6, "%i", i) RNG (0, 5, 6, "%i", i) RNG (0, 6, 6, "%i", i) RNG (0, 0, 7, "%i", i) RNG (0, 1, 7, "%i", i) RNG (0, 2, 7, "%i", i) RNG (0, 3, 7, "%i", i) RNG (0, 4, 7, "%i", i) RNG (0, 5, 7, "%i", i) RNG (0, 6, 7, "%i", i) RNG (4, 4, 32, "%i", i) RNG (4, 4, 32, "%u", u) RNG (4, 4, 32, "%li", li) RNG (4, 4, 32, "%lu", lu) RNG (4, 4, 32, "%zu", sz) /* Exercise bug 78586. */ RNG (4, 4, 32, "%lu", (unsigned long)i) RNG (4, 4, 32, "%lu", (unsigned long)u) RNG (4, 4, 32, "%lu", (unsigned long)li) RNG (4, 4, 32, "%lu", (unsigned long)lu) RNG (4, 4, 32, "%lu", (unsigned long)sz) #if __SIZEOF_INT__ == 4 /* A 32-bit int takes up at most 11 bytes (-2147483648) not including the terminating nul. */ RNG (0, 7, 7, "%i", i) RNG (0, 0, 8, "%i", i) RNG (0, 1, 8, "%i", i) RNG (0, 2, 8, "%i", i) RNG (0, 3, 8, "%i", i) RNG (0, 4, 8, "%i", i) RNG (0, 5, 8, "%i", i) RNG (0, 6, 8, "%i", i) RNG (0, 7, 8, "%i", i) RNG (0, 8, 8, "%i", i) RNG (0, 0, 9, "%i", i) RNG (0, 1, 9, "%i", i) RNG (0, 2, 9, "%i", i) RNG (0, 3, 9, "%i", i) RNG (0, 4, 9, "%i", i) RNG (0, 5, 9, "%i", i) RNG (0, 6, 9, "%i", i) RNG (0, 7, 9, "%i", i) RNG (0, 8, 9, "%i", i) RNG (0, 9, 9, "%i", i) RNG (0, 0, 10, "%i", i) RNG (0, 1, 10, "%i", i) RNG (0, 2, 10, "%i", i) RNG (0, 3, 10, "%i", i) RNG (0, 4, 10, "%i", i) RNG (0, 5, 10, "%i", i) RNG (0, 6, 10, "%i", i) RNG (0, 7, 10, "%i", i) RNG (0, 8, 10, "%i", i) RNG (0, 9, 10, "%i", i) RNG (0, 10, 10, "%i", i) #endif /* Verify that the output of a "%a" directive with no precision is not considered constant or within a known range (the number of digits after the decimal point is unspecified in this case). The hardcoded ranges correspond to Glibc values. */ RNG (6, 6, 7, "%a", 0.0) /* Glibc output: "0x0p+0" */ RNG (6, 6, 7, "%a", d) RNG (6, 6, 7, "%.4096a", d) RNG (6, 6, 7, "%La", 0.0L) /* Glibc output: "0x0p+0" */ RNG (6, 6, 7, "%La", ld) RNG (6, 6, 7, "%.4096La", ld) /* Verify that the result of formatting an unknown string isn't optimized into a non-negative range. The string could be longer that 4,095 bytes, resulting in the formatting function having undefined behavior (and returning a negative value as Glibc can for some directives). */ RNG (0, INT_MAX, -1, "%-s", str); /* Verify the result of a conditional expression involving a string literal and an unknown string isn't optimized. */ RNG (0, 1, 4, "%-s", i ? str : "123"); RNG (0, 1, 4, "%-s", i ? "123" : str); /* Verfy that the output involving wide strings is not optimized (the output is actually bounded by a function of MB_LEN_MAX which should be at least 6 to accommodate UTF-8 but this isn't implemented yet). */ RNG (0, 5, 7, "%ls", L"1"); RNG (0, 6, 8, "%s%ls", "1", L"2"); /* Verify that no call to abort has been eliminated and that each call is at the beginning of a basic block (and thus the result of a branch). This latter test tries to verify that the test preceding the call to the must_not_eliminate() function has not been eliminated either. The expected output looks something like this: : result_3 = __builtin_sprintf (&MEM[(void *)&buf8k + 8192B], "%c", 32); if (result_3 != 0) goto ; [50.0%] else goto ; [50.0%] [50.0%]: must_not_eliminate (); */ /* Only conditional calls to abort should be made (with any probability): { dg-final { scan-tree-dump-times "> \\\[\[0-9.\]+%\\\]:\n *must_not_eliminate" 124 "optimized" { target { ilp32 || lp64 } } } } { dg-final { scan-tree-dump-times "> \\\[\[0-9.\]+%\\\]:\n *must_not_eliminate" 93 "optimized" { target { { ! ilp32 } && { ! lp64 } } } } } No unconditional calls to abort should be made: { dg-final { scan-tree-dump-not ";\n *must_not_eliminate" "optimized" } } */