[PATCH] Prevent internal-error when computing $pc in ARM assembly code

[Martin Simmons <martin@lispworks.com>]

This patch prevents a gdb internal-error when computing $pc for ARM assembly
code that doesn't use the normal stack frame convention.

It might also help with gdb/12223.

I'm not subscribed to the list so please include me on any replies.


gdb/ChangeLog:

	* arm-tdep.c (arm_analyze_prologue): Read memory without throwing an
	exception, to allow debugging of assembly code.

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 8181f25..d47b4af 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -1669,8 +1669,11 @@ arm_analyze_prologue (struct gdbarch *gdbarch,
        current_pc < prologue_end;
        current_pc += 4)
     {
-      unsigned int insn
-	= read_memory_unsigned_integer (current_pc, 4, byte_order_for_code);
+      unsigned int insn;
+      gdb_byte buf[4];
+      if (target_read_memory (current_pc, buf, 4))
+	break;
+      insn = extract_unsigned_integer (buf, 4, byte_order_for_code);
 
       if (insn == 0xe1a0c00d)		/* mov ip, sp */
 	{