From 627c7fb8ea16388f349b6b26e20bf017d71e51fe Mon Sep 17 00:00:00 2001 From: Hannes Domani Date: Mon, 27 Apr 2020 15:58:09 +0200 Subject: [PATCH] Use thiscall calling convention for class members Non-static member functions for Windows 32bit programs need the thiscall calling convention, so the 'this' pointer needs to be passed in ECX. gdb/ChangeLog: 2020-04-30 Hannes Domani PR gdb/15559 * i386-tdep.c (i386_push_dummy_call): Call i386_thiscall_push_dummy_call. (i386_thiscall_push_dummy_call): New function. * i386-tdep.h (i386_thiscall_push_dummy_call): Declare. * i386-windows-tdep.c (i386_windows_push_dummy_call): New function. (i386_windows_init_abi): Call set_gdbarch_push_dummy_call. --- gdb/ChangeLog | 10 ++++++++++ gdb/i386-tdep.c | 35 ++++++++++++++++++++++++++++------- gdb/i386-tdep.h | 13 +++++++++++++ gdb/i386-windows-tdep.c | 32 ++++++++++++++++++++++++++++++++ 4 files changed, 83 insertions(+), 7 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 830bc30979c..d9f2b2c6f6b 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2020-04-30 Hannes Domani + + PR gdb/15559 + * i386-tdep.c (i386_push_dummy_call): Call + i386_thiscall_push_dummy_call. + (i386_thiscall_push_dummy_call): New function. + * i386-tdep.h (i386_thiscall_push_dummy_call): Declare. + * i386-windows-tdep.c (i386_windows_push_dummy_call): New function. + (i386_windows_init_abi): Call set_gdbarch_push_dummy_call. + 2020-04-29 Simon Marchi * gdbarch.sh (do_read): Add shellcheck disable directive for diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c index 84edb3649e9..fc63635317b 100644 --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -2668,12 +2668,15 @@ i386_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, CORE_ADDR funaddr, return sp - 16; } -static CORE_ADDR -i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, - struct regcache *regcache, CORE_ADDR bp_addr, int nargs, - struct value **args, CORE_ADDR sp, - function_call_return_method return_method, - CORE_ADDR struct_addr) +/* The "push_dummy_call" gdbarch method, optionally with the thiscall + calling convention. */ + +CORE_ADDR +i386_thiscall_push_dummy_call (struct gdbarch *gdbarch, struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, + int nargs, struct value **args, CORE_ADDR sp, + function_call_return_method return_method, + CORE_ADDR struct_addr, bool thiscall) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); gdb_byte buf[4]; @@ -2709,7 +2712,7 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, args_space += 4; } - for (i = 0; i < nargs; i++) + for (i = thiscall ? 1 : 0; i < nargs; i++) { int len = TYPE_LENGTH (value_enclosing_type (args[i])); @@ -2761,6 +2764,10 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, /* ...and fake a frame pointer. */ regcache->cooked_write (I386_EBP_REGNUM, buf); + /* The 'this' pointer needs to be in ECX. */ + if (thiscall) + regcache->cooked_write (I386_ECX_REGNUM, value_contents_all (args[0])); + /* MarkK wrote: This "+ 8" is all over the place: (i386_frame_this_id, i386_sigtramp_frame_this_id, i386_dummy_id). It's there, since all frame unwinders for @@ -2773,6 +2780,20 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, return sp + 8; } +/* Implement the "push_dummy_call" gdbarch method. */ + +static CORE_ADDR +i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, int nargs, + struct value **args, CORE_ADDR sp, + function_call_return_method return_method, + CORE_ADDR struct_addr) +{ + return i386_thiscall_push_dummy_call (gdbarch, function, regcache, bp_addr, + nargs, args, sp, return_method, + struct_addr, false); +} + /* These registers are used for returning integers (and on some targets also for returning `struct' and `union' values when their size and alignment match an integer type). */ diff --git a/gdb/i386-tdep.h b/gdb/i386-tdep.h index fa29e316a19..79b3b1f9428 100644 --- a/gdb/i386-tdep.h +++ b/gdb/i386-tdep.h @@ -399,6 +399,19 @@ extern CORE_ADDR i386_pe_skip_trampoline_code (struct frame_info *frame, extern CORE_ADDR i386_skip_main_prologue (struct gdbarch *gdbarch, CORE_ADDR pc); +/* The "push_dummy_call" gdbarch method, optionally with the thiscall + calling convention. */ +extern CORE_ADDR i386_thiscall_push_dummy_call (struct gdbarch *gdbarch, + struct value *function, + struct regcache *regcache, + CORE_ADDR bp_addr, + int nargs, struct value **args, + CORE_ADDR sp, + function_call_return_method + return_method, + CORE_ADDR struct_addr, + bool thiscall); + /* Return whether the THIS_FRAME corresponds to a sigtramp routine. */ extern int i386_sigtramp_p (struct frame_info *this_frame); diff --git a/gdb/i386-windows-tdep.c b/gdb/i386-windows-tdep.c index 3a07c862f23..4824a9e5528 100644 --- a/gdb/i386-windows-tdep.c +++ b/gdb/i386-windows-tdep.c @@ -200,6 +200,36 @@ i386_windows_auto_wide_charset (void) return "UTF-16"; } +/* Implement the "push_dummy_call" gdbarch method. */ + +static CORE_ADDR +i386_windows_push_dummy_call (struct gdbarch *gdbarch, struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, + int nargs, struct value **args, CORE_ADDR sp, + function_call_return_method return_method, + CORE_ADDR struct_addr) +{ + /* For non-static member functions of 32bit Windows programs, the thiscall + calling convention is used, so the 'this' pointer is passed in ECX. */ + bool thiscall = false; + + struct type *type = check_typedef (value_type (function)); + if (TYPE_CODE (type) == TYPE_CODE_PTR) + type = check_typedef (TYPE_TARGET_TYPE (type)); + + /* read_subroutine_type sets for non-static member functions the + artificial flag of the first parameter ('this' pointer). */ + if (TYPE_CODE (type) == TYPE_CODE_METHOD + && TYPE_NFIELDS (type) > 0 + && TYPE_FIELD_ARTIFICIAL (type, 0) + && TYPE_CODE (TYPE_FIELD_TYPE (type, 0)) == TYPE_CODE_PTR) + thiscall = 1; + + return i386_thiscall_push_dummy_call (gdbarch, function, regcache, bp_addr, + nargs, args, sp, return_method, + struct_addr, thiscall); +} + /* Common parts for gdbarch initialization for Windows and Cygwin on i386. */ static void @@ -234,6 +264,8 @@ i386_windows_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { i386_windows_init_abi_common (info, gdbarch); windows_init_abi (info, gdbarch); + + set_gdbarch_push_dummy_call (gdbarch, i386_windows_push_dummy_call); } /* gdbarch initialization for Cygwin on i386. */ -- 2.30.2