On Thu, Mar 27, 2025 at 08:02:20AM -0400, Jason Merrill wrote: > On 3/26/25 9:24 AM, Nathaniel Shead wrote: > > Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk? > > > > -- >8 -- > > > > The ICE in the linked PR is caused because out_ptr_t inherits an ABI tag > > in a module that it does not in the importing module. When we try to > > build a qualified 'const out_ptr_t' during stream-in, we find the > > existing 'const out_ptr_t' variant type that has been built, but discard > > it due to having a mismatching attribute list. This causes us to build > > a new copy of this variant, and ultimately fail a checking assertion due > > to this being an identical type with different TYPE_CANONICAL. > > > > This patch adds checking that ABI tags between an imported and existing > > declaration match, and errors if they are incompatible. We make use of > > 'equal_abi_tags' from mangle.cc to determine if we should error; in the > > case in the PR, because the ABI tag was an implicit tag that doesn't > > affect name mangling, we don't need to error. To fix the ICE we ensure > > that (regardless of whether we errored or not) later processing > > considers the ABI tags as equivalent. > > > > PR c++/118920 > > > > gcc/cp/ChangeLog: > > > > * cp-tree.h (equal_abi_tags): Declare. > > * mangle.cc (equal_abi_tags): Make external, fix comparison. > > (tree_string_cmp): Make internal. > > * module.cc (trees_in::check_abi_tags): New function. > > (trees_in::decl_value): Use it. > > (trees_in::is_matching_decl): Likewise. > > > > @@ -1738,7 +1737,8 @@ equal_abi_tags (tree t1, tree t2) > > if (len1 != v2->length()) > > return false; > > for (unsigned i = 0; i < len1; ++i) > > - if (tree_string_cmp (v1[i], v2[i]) != 0) > > + if (strcmp (TREE_STRING_POINTER (v1[i]), > > + TREE_STRING_POINTER (v2[i])) != 0) > > How does this "fix" the comparison? It looks equivalent to me. > > Jason >
I was getting segfaults in my testcases; I think this was unfortunate conversions to void*, and intended was 'tree_string_cmp(&v1[i], &v2[i])'. But rather than messing around with that I elected to go with the more obviously correct approach. Nathaniel
