On Mon, Jan 29, 2024 at 2:51 PM Jakub Jelinek <ja...@redhat.com> wrote: > > On Mon, Jan 29, 2024 at 11:29:22PM +0100, Jakub Jelinek wrote: > > On Mon, Jan 29, 2024 at 11:22:44PM +0100, Jakub Jelinek wrote: > > > On Mon, Jan 29, 2024 at 02:01:56PM -0800, H.J. Lu wrote: > > > > > A function accesses a function symbol defined in a comdat group. > > > > > If the function symbol is public, any comdat definition of the same > > > > > group > > > > > signature should provide the function definition. If the function > > > > > symbol > > > > > is private to the comdat group, only functions in the same comdat > > > > > group can access the private function symbol. If a function in a > > > > > different > > > > > comdat group accesses a private symbol, it is a compiler bug and > > > > > link may catch it like in this case. > > > > > > > > > > > > > My patch simply puts the constant pool of the function symbol reference > > > > in the same comdat group as the function definition. I believe it is > > > > the > > > > right thing to do. > > > > > > I disagree, I think we should use something like > > > if (current_function_decl) > > > > Or perhaps && DECL_COMDAT_GROUP (current_function_decl) added here as well, > > just to make it change things less often. > > > > > return targetm.asm_out.function_rodata_section (current_function_decl, > > > true); > > > > > > Obviously, for non-reloc or non-pic, we don't want an unconditional > > > if (current_function_decl) > > > return targetm.asm_out.function_rodata_section (current_function_decl, > > > false); > > > that would kill mergeable sections, so perhaps > > > if (current_function_decl > > > && reloc > > > && DECL_COMDAT_GROUP (current_function_decl)) > > > return targetm.asm_out.function_rodata_section (current_function_decl, > > > false); > > Now, that doesn't actually work, because current_function_decl is always > NULL when the constant pool entries are emitted. > But basing the output section on what it refers rather than what refers to > it seems wrong, plus there is the section anchors support, which treats them > yet differently. > So, I wonder if force_const_mem shouldn't punt if asked to emit from > DECL_COMDAT_GROUP (current_function_decl) a SYMBOL_REF (or CONST PLUS > SYMBOL_REF ...) with the same DECL_COMDAT_GROUP with a private symbol, > or shouldn't punt unless using a per-function (i.e. non-shared) constant > pool, or force a per-function constant pool in that case somehow. >
Here is the patch to only call function_rodata_section for COMDAT function symbol reference: https://patchwork.sourceware.org/project/gcc/list/?series=30329 -- H.J.
