From cb9b645d3e6b6164317104ed1a2a41c06da37bf4 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 16 Mar 2020 16:56:33 -0400 Subject: gdb: recognize 64 bits Windows executables as Cygwin osabi If I generate two Windows PE executables, one 32 bits and one 64 bits: $ x86_64-w64-mingw32-gcc test.c -g3 -O0 -o test_64 $ i686-w64-mingw32-gcc test.c -g3 -O0 -o test_32 $ file test_64 test_64: PE32+ executable (console) x86-64, for MS Windows $ file test_32 test_32: PE32 executable (console) Intel 80386, for MS Windows When I load the 32 bits binary in my GNU/Linux-hosted GDB, the osabi is correctly recognized as "Cygwin": $ ./gdb --data-directory=data-directory -nx test_32 (gdb) show osabi The current OS ABI is "auto" (currently "Cygwin"). When I load the 64 bits binary in GDB, the osabi is incorrectly recognized as "GNU/Linux": $ ./gdb --data-directory=data-directory -nx test_64 (gdb) show osabi The current OS ABI is "auto" (currently "GNU/Linux"). The 32 bits one gets recognized by the i386_cygwin_osabi_sniffer function, by its target name: if (strcmp (target_name, "pei-i386") == 0) return GDB_OSABI_CYGWIN; The target name for the 64 bits binaries is "pei-x86-64". It doesn't get recognized by any osabi sniffer, so GDB falls back on its default osabi, "GNU/Linux". This patch adds an osabi sniffer function for the Windows 64 bits executables in amd64-windows-tdep.c. With it, the osabi is recognized as "Cygwin", just like with the 32 bits binary. Note that it may seems strange to have a binary generated by MinGW (which has nothing to do with Cygwin) be recognized as a Cygwin binary. This is indeed not accurate, but at the moment GDB uses the Cygwin for everything Windows. Subsequent patches will add a separate "Windows" OS ABI for Windows binaries that are not Cygwin binaries. gdb/ChangeLog: * amd64-windows-tdep.c (amd64_windows_osabi_sniffer): New function. (_initialize_amd64_windows_tdep): Register osabi sniffer. --- gdb/ChangeLog | 6 ++++++ gdb/amd64-windows-tdep.c | 14 ++++++++++++++ 2 files changed, 20 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a0d9758..1b83f42 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2020-03-16 Simon Marchi + + * amd64-windows-tdep.c (amd64_windows_osabi_sniffer): New + function. + (_initialize_amd64_windows_tdep): Register osabi sniffer. + 2020-03-14 Tom Tromey * c-typeprint.c (cp_type_print_method_args): Print "__restrict__" diff --git a/gdb/amd64-windows-tdep.c b/gdb/amd64-windows-tdep.c index d4d7968..2ca9795 100644 --- a/gdb/amd64-windows-tdep.c +++ b/gdb/amd64-windows-tdep.c @@ -1244,10 +1244,24 @@ amd64_windows_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) set_gdbarch_auto_wide_charset (gdbarch, amd64_windows_auto_wide_charset); } +static gdb_osabi +amd64_windows_osabi_sniffer (bfd *abfd) +{ + const char *target_name = bfd_get_target (abfd); + + if (strcmp (target_name, "pei-x86-64") == 0) + return GDB_OSABI_CYGWIN; + + return GDB_OSABI_UNKNOWN; +} + void _initialize_amd64_windows_tdep (); void _initialize_amd64_windows_tdep () { gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_CYGWIN, amd64_windows_init_abi); + + gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour, + amd64_windows_osabi_sniffer); } -- cgit v1.1