#263 dwarf2: emitting bad references to unused variables

[Peter Dons Tychsen]

​Hello SDCC team,

I found this while compiling some ST STM8 libraries, which declare externs all over that are not all used.

code:

extern int something_non_existent;
int main(void)
{
  return 0;
}

1) with "--debug" this compiles fine.
2) with "--debug --out-fmt-elf" this fails.

It fails with undefined symbol in the linker.

This is because the dwarf 2 emitter indiscriminately emits symbols that are extern and never used.
This is wrong. It should not add such symbols to the REL file, unless they are used.

A small check in the dwarf2 emitter for this special case fixes it up.

Thanks,

/pedro

[Philipp Klaus Krause]

Applied in revision #9465.

Philipp