debug info depends on -Wl,--export=

When compiling a C program with -Wl,--export-all, more debug info is generated.

For example, take this program:

#include <stdio.h>
#include <errno.h>

int main() {
    FILE *f = fopen("/etc/issue", "r");
    if (!f) {
        return errno;
    }
    return fclose(f);
}

Compile with -g -O3 -Wl,--export-all and run wasm2wat

  (func $main (type $t0) (param $p0 i32) (param $p1 i32) (result i32)
    call $__original_main)

Now compile with -g -O3 -Wl,--export=main and run wasm2wat

  (func $main (type $t2) (param $p0 i32) (param $p1 i32) (result i32)
    call $f11)

Why is there a difference?

Reproduce the C example with -g -O3 using both -Wl,--export-all and -Wl,--export=main, then inspect the resulting output with wasm2wat. Compare the generated function names, signatures, and debug information to determine why the export choice changes them; done means the behavior is explained and any needed wasi-sdk change is identified.