Re: [Tinycc-devel] backtrace() on Linux

[Yakov]

Here is what tcc gives me:

$ tcc -g -rdynamic tcc-bt.c -o tcc-bt && ./tcc-bt
./tcc-bt(show_bt+0x22) [0x40079c]

Here is the output of gcc compiled binary:

$ gcc -g -rdynamic tcc-bt.c -o gcc-bt && ./gcc-bt
./gcc-bt(_start+0x29) [0x400849]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7fe80c15c830]
./gcc-bt(main+0xe) [0x400a03]
./gvc-bt(a+0xe) [0x4009f2]
./gcc-bt(b+0xe) [0x4009e1]
./gcc-bt(c+0xe) [0x4009d0]
./gcc-bt(show_bt+0x2e) [0x400944]

2018-03-09 17:24 GMT+05:45 Yakov <address@hidden>:

Just installed 0.27, issue stands.

2018-03-09 15:25 GMT+05:45 Yakov <address@hidden>:

I had to write this code to be able to get the stack trace under TinyC:


#ifdef __TINYC__
int backtrace(void **buffer, int size) {
	extern uint64_t *__libc_stack_end;
	uint64_t **p, *bp, *frame;
	asm ("mov %%rbp, %0;" : "=r" (bp));
	p = (uint64_t**) bp;
	int i = 0;
	while (i < size) {
		frame = p[0];
		if (frame < bp || frame > __libc_stack_end) {
			return i;
		}
		buffer[i++] = p[1];
		p = (uint64_t**) frame;
	}
	return i;
}
#endif

2018-03-09 15:24 GMT+05:45 Yakov <address@hidden>:

#include <execinfo.h>
#include <stdio.h>

void show_bt() {
    int n;
    void *buffer[111];
    char **strings;
    n = backtrace(buffer, 111);
    strings = backtrace_symbols(buffer, n);
    while (strings && n) printf("%s\n", strings[n---1]);
}

void c() { show_bt(); }
void b() { c(); }
void a() { b(); }
int main() { a(); }

The above code does not work on Tiny. Although works on GCC/Clang for me.

$ tcc -version
tcc version 0.9.26 (x86-64 Linux)


I have tried to no avail: "-bt 100", "-g", "-rdynamic", also tried to link with gcc and ld.