Bug ID 37893
Summary Unable to resolve std::vector type in gmodules build on android (linux)
Component All Bugs
To reproduce this, create a simple c++ program with std::vector<int> (from libc++), compile with -gmodules, and try to display the variable in the debugger. The variable will show up as empty (no data members). I've done a bit of digging, and it seems that the issue is that we are unable to complete the forward-declaration of the "__vector_base" from the main file with the full declaration in the module. The interesting bits of dwarf are: 0x000022fd: DW_TAG_variable DW_AT_location (DW_OP_breg13 SP+116) DW_AT_name ("numbers") DW_AT_decl_file ("main.cpp") DW_AT_decl_line (8) DW_AT_type (0x00000a1a "vector<int, std::__ndk1::allocator<int> >") 0x00000a1a: DW_TAG_class_type DW_AT_name ("vector<int, std::__ndk1::allocator<int> >") DW_AT_byte_size (0x0c) DW_AT_decl_file ("llvm-libc++/include/vector") DW_AT_decl_line (447) 0x00000a23: DW_TAG_inheritance DW_AT_type (0x00000053 "__vector_base<int, std::__ndk1::allocator<int> >") DW_AT_data_member_location (0x00) 0x00000053: DW_TAG_class_type DW_AT_name ("__vector_base<int, std::__ndk1::allocator<int> >") DW_AT_declaration (true) The __vector_base type contains a bunch of DW_TAG_typedefs and DW_TAG_subprograms, but no information on data members. If I open up the same type in the std.pcm file, I can find the DW_TAG_member entries there. However, AFAICT, lldb does not try to look for the information in that file. I don't think this is a recent regression. It has probably been that way since gmodules was introduced. I just ran into this now because I have started building lldb tests with libc++, and that meant that gmodules tests actually started to test something (libstdc++ had no module map file). Until this and other problems (failure to resolve relocations in the pcm files) are resolved, I am going to disable the gmodules tests on android.