[PATCH v3 5/7] amd64_analyze_prologue: gradually update pc

Victor Collod vcollod@nvidia.com
Wed Jun 24 01:28:55 GMT 2020


It makes the function easier to read, as you don't have to remember
what's the current offset from pc.

2020-06-23  Victor Collod  <vcollod@nvidia.com>

	* amd64-tdep.c (amd64_analyze_prologue): Gradually update pc.
---
 gdb/amd64-tdep.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index 17b02706e54..5c3ad505784 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -2416,19 +2416,22 @@ amd64_analyze_prologue (struct gdbarch *gdbarch,
   cache->saved_regs[AMD64_RBP_REGNUM] = 0;
   cache->sp_offset += 8;
 
+  pc += 1;
+
   /* If we went past the allowed bound, stop.  */
-  if (pc + 1 >= current_pc)
+  if (pc >= current_pc)
     return current_pc;
 
-  read_code (pc + 1, buf, 3);
+  read_code (pc, buf, 3);
 
   /* Check for `movq %rsp, %rbp'.  */
   if (memcmp (buf, mov_rsp_rbp_1, 3) == 0
       || memcmp (buf, mov_rsp_rbp_2, 3) == 0)
     {
+      pc += 3;
       /* OK, we actually have a frame.  */
       cache->frameless_p = 0;
-      return pc + 4;
+      return pc;
     }
 
   /* For X32, also check for `movq %esp, %ebp'.  */
@@ -2437,13 +2440,14 @@ amd64_analyze_prologue (struct gdbarch *gdbarch,
       if (memcmp (buf, mov_esp_ebp_1, 2) == 0
 	  || memcmp (buf, mov_esp_ebp_2, 2) == 0)
 	{
+	  pc += 2;
 	  /* OK, we actually have a frame.  */
 	  cache->frameless_p = 0;
-	  return pc + 3;
+	  return pc;
 	}
     }
 
-  return pc + 1;
+  return pc;
 }
 
 /* Work around false termination of prologue - GCC PR debug/48827.
-- 
2.20.1



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