Don't emit PT_INTERP for -shared outputs#1577
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When --dynamic-linker is passed alongside -shared, mold currently emits a .interp section and a PT_INTERP program header. Both lld and BFD ld silently drop --dynamic-linker for -shared outputs because shared libraries are loaded by the dynamic linker rather than bootstrapped by the kernel, so PT_INTERP serves no purpose there. Gate .interp creation on (!shared || pie) so we keep it for regular executables, -pie executables, and -shared -pie runnable shared libraries (the libc.so.6-style case), and drop it only for the pure shared-library case. The PT_INTERP program header at output-chunks.cc:219 is conditional on ctx.interp being non-null, so the segment vanishes automatically with no second edit. Fixes rui314#1572
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btw, I empirically tested all four cases on lld 18.1.3 and BFD ld 2.42 (Ubuntu 24.04 / aarch64). mold's behavior after the fix is consistent with both linkers on every case, with one exception: lld rejects |
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When --dynamic-linker is passed alongside -shared, mold currently emits a .interp section and a PT_INTERP program header. Both lld and BFD ld silently drop --dynamic-linker for -shared outputs because shared libraries are loaded by the dynamic linker rather than bootstrapped by the kernel, so PT_INTERP serves no purpose there.
Gate .interp creation on (!shared || pie) so we keep it for regular executables, -pie executables, and -shared -pie runnable shared libraries (the libc.so.6-style case), and drop it only for the pure shared-library case. The PT_INTERP program header at output-chunks.cc:219 is conditional on ctx.interp being non-null, so the segment vanishes automatically with no second edit.
Fixes #1572