Revert "Eliminate dwarf2_frame_cache recursion, don't unwind from the dwarf2 sniffer (move dwarf2_tailcall_sniffer_first elsewhere)."

This reverts commit 1dc8686c48e72fc02723d44ee0fecde0d233c74e.

2 files changed, 15 insertions, 32 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c4bcdf6..4bc944c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,13 +1,3 @@
-2013-11-22  Pedro Alves  <palves@redhat.com>
-
-	PR 16155
-	* dwarf2-frame.c (struct dwarf2_frame_cache)
-	<checked_tailcall_bottom, entry_cfa_sp_offset,
-	entry_cfa_sp_offset_p>: New fields.
-	(dwarf2_frame_cache): Adjust to use the new cache fields instead
-	of locals.  Don't call dwarf2_tailcall_sniffer_first here.
-	(dwarf2_frame_prev_register): Call it here, but only once.
-
 2013-11-21  Doug Evans  <xdje42@gmail.com>
 
 	* gdbtypes.c: #include bcache.h, dwarf2loc.h.
diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c
index c4f8771..91d8802 100644
--- a/gdb/dwarf2-frame.c
+++ b/gdb/dwarf2-frame.c
@@ -993,22 +993,12 @@ struct dwarf2_frame_cache
   /* The .text offset.  */
   CORE_ADDR text_offset;
 
-  /* True if we already checked whether this frame is the bottom frame
-     of a virtual tail call frame chain.  */
-  int checked_tailcall_bottom;
-
   /* If not NULL then this frame is the bottom frame of a TAILCALL_FRAME
      sequence.  If NULL then it is a normal case with no TAILCALL_FRAME
      involved.  Non-bottom frames of a virtual tail call frames chain use
      dwarf2_tailcall_frame_unwind unwinder so this field does not apply for
      them.  */
   void *tailcall_cache;
-
-  /* The number of bytes to subtract from TAILCALL_FRAME frames frame
-     base to get the SP, to simulate the return address pushed on the
-     stack.  */
-  LONGEST entry_cfa_sp_offset;
-  int entry_cfa_sp_offset_p;
 };
 
 /* A cleanup that sets a pointer to NULL.  */
@@ -1033,6 +1023,8 @@ dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache)
   struct dwarf2_fde *fde;
   volatile struct gdb_exception ex;
   CORE_ADDR entry_pc;
+  LONGEST entry_cfa_sp_offset;
+  int entry_cfa_sp_offset_p = 0;
   const gdb_byte *instr;
 
   if (*this_cache)
@@ -1097,8 +1089,8 @@ dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache)
 	  && (gdbarch_dwarf2_reg_to_regnum (gdbarch, fs->regs.cfa_reg)
 	      == gdbarch_sp_regnum (gdbarch)))
 	{
-	  cache->entry_cfa_sp_offset = fs->regs.cfa_offset;
-	  cache->entry_cfa_sp_offset_p = 1;
+	  entry_cfa_sp_offset = fs->regs.cfa_offset;
+	  entry_cfa_sp_offset_p = 1;
 	}
     }
   else
@@ -1247,6 +1239,13 @@ incomplete CFI data; unspecified registers (e.g., %s) at %s"),
     cache->undefined_retaddr = 1;
 
   do_cleanups (old_chain);
+
+  /* Try to find a virtual tail call frames chain with bottom (callee) frame
+     starting at THIS_FRAME.  */
+  dwarf2_tailcall_sniffer_first (this_frame, &cache->tailcall_cache,
+				 (entry_cfa_sp_offset_p
+				  ? &entry_cfa_sp_offset : NULL));
+
   discard_cleanups (reset_cache_cleanup);
   return cache;
 }
@@ -1293,16 +1292,6 @@ dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache,
   CORE_ADDR addr;
   int realnum;
 
-  /* Check whether THIS_FRAME is the bottom frame of a virtual tail
-     call frame chain.  */
-  if (!cache->checked_tailcall_bottom)
-    {
-      cache->checked_tailcall_bottom = 1;
-      dwarf2_tailcall_sniffer_first (this_frame, &cache->tailcall_cache,
-				     (cache->entry_cfa_sp_offset_p
-				      ? &cache->entry_cfa_sp_offset : NULL));
-    }
-
   /* Non-bottom frames of a virtual tail call frames chain use
      dwarf2_tailcall_frame_unwind unwinder so this code does not apply for
      them.  If dwarf2_tailcall_prev_register_first does not have specific value
@@ -1429,6 +1418,10 @@ dwarf2_frame_sniffer (const struct frame_unwind *self,
   if (self->type != NORMAL_FRAME)
     return 0;
 
+  /* Preinitializa the cache so that TAILCALL_FRAME can find the record by
+     dwarf2_tailcall_sniffer_first.  */
+  dwarf2_frame_cache (this_frame, this_cache);
+
   return 1;
 }