[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #10 from Tom Tromey --- See also bug #49130 and bug #49537, which we filed when gdb hit these same problems.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #9 from robert at ocallahan dot org --- That makes sense ... well, except implementing a full C++ parser and reserializer is horrific.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #8 from Tom Tromey --- (In reply to rob...@ocallahan.org from comment #7) > So gdb reads DW_AT_name "func", parses it, reserializes it to > "func", and uses that? Yeah. (Actually it's even worse than that, because at least one compiler doesn't emit the template parameters in the name, so in that case gdb will read the children of the DIE to try to construct this form.) I think the reasoning behind the canonicalization is two-fold. First, I think we tried to get g++ changed, back in the day, without success. Second, gdb has to canonicalize user input anyway, so that things like "print func(3)" or "break func" work. And once you have a canonicalizer it is simpler to just use it to work around the problem.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #7 from robert at ocallahan dot org --- So gdb reads DW_AT_name "func", parses it, reserializes it to "func", and uses that?
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 Tom Tromey changed: What|Removed |Added CC||tromey at gcc dot gnu.org --- Comment #6 from Tom Tromey --- gdb does this canonicalization precisely because the form in the DWARF cannot be relied upon. It would be great to remove this, because it is expensive. One idea for a migration route would be for g++ to promise to emit the same form that the demangler emits; then add an attribute to the comp-unit DIE saying that the names have been canonicalized. (Or, I suppose gdb could use producer sniffing; but I'd rather avoid that as much as possible.)
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #5 from robert at ocallahan dot org --- We do our best to consume what g++ produces, but in the situation of comment #1 that is difficult. Whether or not it's "correct DWARF" is really irrelevant; not matching the demangler causes real problems. Thanks for the link to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81932. That is very similar to the problem I'm facing. No strategy was decided on there, but it seems to me that matching the demanged name would be a clear step in the right direction. I can't see how it could *hurt*.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #4 from Andrew Pinski --- See also PR 81932 where we talked about 2 and 2u
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #3 from Andrew Pinski --- But that is just best practices, that does not mean an consumer of the dwarf does not need to consume slightly different but still correct dwarf code.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #2 from Andrew Pinski --- Hmm from http://wiki.dwarfstd.org/index.php?title=Best_Practices For template instantiations, the DW_AT_name attribute should contain both the source language name of the object and the template parameters that distinguish one instantiation from another. The resulting string should be in the natural form for the language, and should have a canonical representation (i.e., different producers should generate the same representation). For C++, the string should match that produced by the target platform's canonical demangler; spaces should only be inserted where syntactically required by the compiler.
[Bug c++/94845] DWARF function name doesn't match demangled name in base type template parameters
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94845 --- Comment #1 from robert at ocallahan dot org --- One case where this causes problems is implementing a debugger where you want to be able to evaluate expressions containing type names. Type names containing template type parameters that are base types need to be normalized to match the type names in the debuginfo. g++ requires us to normalize those type names in a way that's different from the C++ demangler and from clang++.
