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Fix int and long handling and the use of (u)intptr_t in _mi_vsnprintf

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'va_arg' with type 'long' was used for both 'int' and 'long' arguments, but x86_64 Linux has 64-bit 'long', so passing an 'int' argument to '_mi_vsnprintf` results in undefined behaviour.

'intptr_t' was used as the largest integer type, but on 32-bit systems it is 32-bit wide, while 'long long' is 64-bit. 'intmax_t' can be used instead.
This commit is contained in:
ArtSin 2024-10-15 13:39:28 +04:00
parent db3d8485d2
commit bf251b27b1
1 changed files with 11 additions and 9 deletions
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20
src/libc.c
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@ -130,7 +130,7 @@ static void mi_out_alignright(char fill, char* start, size_t len, size_t extra,
}
static void mi_out_num(uintptr_t x, size_t base, char prefix, char** out, char* end)
static void mi_out_num(uintmax_t x, size_t base, char prefix, char** out, char* end)
{
if (x == 0 || base == 0 || base > 16) {
if (prefix != 0) { mi_outc(prefix, out, end); }
@ -206,12 +206,13 @@ void _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args) {
}
else if (c == 'p' || c == 'x' || c == 'u') {
// unsigned
uintptr_t x = 0;
uintmax_t x = 0;
if (c == 'x' || c == 'u') {
if (numtype == 'z') x = va_arg(args, size_t);
else if (numtype == 't') x = va_arg(args, uintptr_t); // unsigned ptrdiff_t
else if (numtype == 'L') x = (uintptr_t)va_arg(args, unsigned long long);
else x = va_arg(args, unsigned long);
else if (numtype == 'L') x = va_arg(args, unsigned long long);
else if (numtype == 'l') x = va_arg(args, unsigned long);
else x = va_arg(args, unsigned int);
}
else if (c == 'p') {
x = va_arg(args, uintptr_t);
@ -228,20 +229,21 @@ void _mi_vsnprintf(char* buf, size_t bufsize, const char* fmt, va_list args) {
}
else if (c == 'i' || c == 'd') {
// signed
intptr_t x = 0;
intmax_t x = 0;
if (numtype == 'z') x = va_arg(args, intptr_t );
else if (numtype == 't') x = va_arg(args, ptrdiff_t);
else if (numtype == 'L') x = (intptr_t)va_arg(args, long long);
else x = va_arg(args, long);
else if (numtype == 'L') x = va_arg(args, long long);
else if (numtype == 'l') x = va_arg(args, long);
else x = va_arg(args, int);
char pre = 0;
if (x < 0) {
pre = '-';
if (x > INTPTR_MIN) { x = -x; }
if (x > INTMAX_MIN) { x = -x; }
}
else if (numplus != 0) {
pre = numplus;
}
mi_out_num((uintptr_t)x, 10, pre, &out, end);
mi_out_num((uintmax_t)x, 10, pre, &out, end);
}
else if (c >= ' ' && c <= '~') {
// unknown format