* i386-tdep.c (i386_frame_cache): Assume valid anonymous

	functions use a frame pointer.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 991d3a6..b00c9a7 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2010-02-01  Michael Matz  <matz@suse.de>
+           Daniel Jacobowitz  <dan@codesourcery.com>
+
+        * i386-tdep.c (i386_frame_cache): Assume valid anonymous
+       functions use a frame pointer.
+
 2010-02-01  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
        * solib-svr4.c (scan_dyntag): New variable dyn_addr.  Replace gdb_assert

diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index eea4ff4..83aa81f 100644 (file)
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -1395,12 +1395,24 @@ i386_frame_cache (struct frame_info *this_frame, void **this_cache)
          /* This will be added back below.  */
          cache->saved_regs[I386_EIP_REGNUM] -= cache->base;
        }
-      else
+      else if (cache->pc != 0
+              || target_read_memory (get_frame_pc (this_frame), buf, 1))
        {
+         /* We're in a known function, but did not find a frame
+            setup.  Assume that the function does not use %ebp.
+            Alternatively, we may have jumped to an invalid
+            address; in that case there is definitely no new
+            frame in %ebp.  */
          get_frame_register (this_frame, I386_ESP_REGNUM, buf);
          cache->base = extract_unsigned_integer (buf, 4, byte_order)
                        + cache->sp_offset;
        }
+      else
+       /* We're in an unknown function.  We could not find the start
+          of the function to analyze the prologue; our best option is
+          to assume a typical frame layout with the caller's %ebp
+          saved.  */
+       cache->saved_regs[I386_EBP_REGNUM] = 0;
     }
 
   /* Now that we have the base address for the stack frame we can