Re: Teach gdb how to step into ARM Windows CE dlls.

[Pedro Alves <pedro_alves at portugalmail dot pt>]

Pedro Alves wrote:
> Hi,
>
> This patch teaches gdb how to step into ARM Windows CE dlls in a similar 
> fashion
> to how it is done for i386 in i386-tdep.c:i386_pe_skip_trampoline_code.
>
> Tested against a arm-wince-mingw32ce gdbserver, there where no 
> regressions, and
> the tests related to stepping into dlls now pass.

Looking over my unreviewed patches, I noticed I forgot to
update the dependencies on this one.

OK now?

Cheers,
Pedro Alves


2007-08-29  Pedro Alves  <pedro_alves@portugalmail.pt>

	* arm-tdep.h (arm_skip_stub): Declare.
	* arm-wince-tdep.c: Don't include "solib-svr4.h".  Include
	"gdbcore.h".
	(arm_pe_skip_trampoline_code): New function.
	(arm_wince_init_abi): Register arm_pe_skip_trampoline_code as
	gdbarch_skip_trampoline_code callback.
	* Makefile.in: Update dependencies.

---
 gdb/Makefile.in      |    4 ++--
 gdb/arm-tdep.h       |    1 +
 gdb/arm-wince-tdep.c |   42 ++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 43 insertions(+), 4 deletions(-)

Index: src/gdb/arm-tdep.h
===================================================================
--- src.orig/gdb/arm-tdep.h	2007-08-26 14:20:56.000000000 +0100
+++ src/gdb/arm-tdep.h	2007-08-26 14:46:16.000000000 +0100
@@ -182,6 +182,7 @@ struct gdbarch_tdep
 #define LOWEST_PC (gdbarch_tdep (current_gdbarch)->lowest_pc)
 #endif
 
+CORE_ADDR arm_skip_stub (struct frame_info *, CORE_ADDR);
 int arm_software_single_step (struct frame_info *);
 
 /* Functions exported from armbsd-tdep.h.  */
Index: src/gdb/arm-wince-tdep.c
===================================================================
--- src.orig/gdb/arm-wince-tdep.c	2007-08-26 14:44:58.000000000 +0100
+++ src/gdb/arm-wince-tdep.c	2007-08-29 23:29:12.000000000 +0100
@@ -20,7 +20,7 @@
 
 #include "defs.h"
 #include "osabi.h"
-#include "solib-svr4.h"
+#include "gdbcore.h"
 #include "target.h"
 
 #include "gdb_string.h"
@@ -34,6 +34,44 @@ static const char arm_wince_thumb_le_bre
 #define ARM_WINCE_JB_ELEMENT_SIZE	INT_REGISTER_SIZE
 #define ARM_WINCE_JB_PC			10
 
+static CORE_ADDR
+arm_pe_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
+{
+  ULONGEST indirect;
+  struct minimal_symbol *indsym;
+  char *symname;
+  CORE_ADDR next_pc;
+
+  /* The format of an ARM DLL trampoline is:
+       ldr  ip, [pc]
+       ldr  pc, [ip]
+       .dw __imp_<func>  */
+
+  if (pc == 0
+      || read_memory_unsigned_integer (pc + 0, 4) != 0xe59fc000
+      || read_memory_unsigned_integer (pc + 4, 4) != 0xe59cf000)
+    return 0;
+
+  indirect = read_memory_unsigned_integer (pc + 8, 4);
+  if (indirect == 0)
+    return 0;
+
+  indsym = lookup_minimal_symbol_by_pc (indirect);
+  if (indsym == NULL)
+    return 0;
+
+  symname = SYMBOL_LINKAGE_NAME (indsym);
+  if (symname == NULL || strncmp (symname, "__imp_", 6) != 0)
+    return 0;
+
+  next_pc = read_memory_unsigned_integer (indirect, 4);
+  if (next_pc != 0)
+    return next_pc;
+
+  /* Check with the default arm gdbarch_skip_trampoline.  */
+  return arm_skip_stub (frame, pc);
+}
+
 static void
 arm_wince_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
@@ -54,7 +92,7 @@ arm_wince_init_abi (struct gdbarch_info 
   set_gdbarch_char_signed (gdbarch, 1);
 
   /* Shared library handling.  */
-  set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
+  set_gdbarch_skip_trampoline_code (gdbarch, arm_pe_skip_trampoline_code);
 
   /* Single stepping.  */
   set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
Index: src/gdb/Makefile.in
===================================================================
--- src.orig/gdb/Makefile.in	2007-08-26 14:20:48.000000000 +0100
+++ src/gdb/Makefile.in	2007-08-29 23:26:20.000000000 +0100
@@ -1822,8 +1822,8 @@ arm-tdep.o: arm-tdep.c $(defs_h) $(frame
 	$(gdb_assert_h) $(bfd_in2_h) $(libcoff_h) $(objfiles_h) \
 	$(dwarf2_frame_h) $(gdbtypes_h) $(prologue_value_h) \
 	$(target_descriptions_h) $(user_regs_h)
-arm-wince-tdep.o: arm-wince-tdep.c $(defs_h) $(osabi_h) $(solib_svr4_h) \
-	$(target_h) $(gdb_string_h) $(arm_tdep_h)
+arm-wince-tdep.o: arm-wince-tdep.c $(defs_h) $(osabi_h) \
+	$(gdbcore_h) $(target_h) $(gdb_string_h) $(arm_tdep_h)
 auxv.o: auxv.c $(defs_h) $(target_h) $(gdbtypes_h) $(command_h) \
 	$(inferior_h) $(valprint_h) $(gdb_assert_h) $(auxv_h) \
 	$(elf_common_h)