From 7398ce15b79daf038cd07fbae4e37e183e99788d Mon Sep 17 00:00:00 2001 From: Mark Mentovai Date: Fri, 23 Sep 2016 14:22:42 -0400 Subject: Initial support for dumping DWARF corresponding to Swift code The DWARF data for Swift code has a top-level DW_TAG_module DIE as the child of the DW_TAG_compile_unit DIE and the parent of the DW_TAG_subprogram DIEs that dump_syms uses to locate functions. dump_syms needs to process DW_TAG_module DIEs as introducing nested scopes to make it work with Swift. This also reworks demangling to be language-specific, so that the C++ demangler isn't invoked when processing Swift code. The DWARF data for Swift code presents its mangled names in the same form as used for C++ (DW_AT_MIPS_linkage_name or DW_AT_linkage_name) but the mangling is Swift-specific (beginning with _T instead of _Z). There is no programmatic interface to a Swift name demangler as an analogue to C++'s __cxa_demangle(), so mangled Swift names are exposed as-is. Xcode's "xcrun swift-demangle" can be used to post-process these mangled Swift names on macOS. Support for mangled names presented in a DW_AT_linkage_name attribute, as used by DWARF 4, is added. This supersedes the earlier use of DW_AT_MIPS_linkage_name. BUG=google-breakpad:702,google-breakpad:715 R=ted.mielczarek@gmail.com Review URL: https://codereview.chromium.org/2147523005 . --- src/common/dwarf/dwarf2enums.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'src/common/dwarf') diff --git a/src/common/dwarf/dwarf2enums.h b/src/common/dwarf/dwarf2enums.h index 6b8a7245..09567555 100644 --- a/src/common/dwarf/dwarf2enums.h +++ b/src/common/dwarf/dwarf2enums.h @@ -232,6 +232,8 @@ enum DwarfAttribute { DW_AT_call_column = 0x57, DW_AT_call_file = 0x58, DW_AT_call_line = 0x59, + // DWARF 4 + DW_AT_linkage_name = 0x6e, // SGI/MIPS extensions. DW_AT_MIPS_fde = 0x2001, DW_AT_MIPS_loop_begin = 0x2002, @@ -499,7 +501,7 @@ enum DwarfOpcode { DW_OP_call_frame_cfa =0x9c, DW_OP_bit_piece =0x9d, DW_OP_lo_user =0xe0, - DW_OP_hi_user =0xff, + DW_OP_hi_user =0xff, // GNU extensions DW_OP_GNU_push_tls_address =0xe0, // Extensions for Fission. See http://gcc.gnu.org/wiki/DebugFission. @@ -542,6 +544,7 @@ enum DwarfLanguage DW_LANG_ObjC_plus_plus =0x0011, DW_LANG_UPC =0x0012, DW_LANG_D =0x0013, + DW_LANG_Swift =0x001e, // Implementation-defined language code range. DW_LANG_lo_user = 0x8000, DW_LANG_hi_user = 0xffff, @@ -668,7 +671,7 @@ enum DwarfPointerEncoding // encoding (except DW_EH_PE_aligned), and indicates that the // encoded value represents the address at which the true address // is stored, not the true address itself. - DW_EH_PE_indirect = 0x80 + DW_EH_PE_indirect = 0x80 }; } // namespace dwarf2reader -- cgit v1.2.1