diff mbox series

[v2,1/5,gdb/symtab] Factor out compunit_epilogue_unwind_valid

Message ID 20230213142309.24366-2-tdevries@suse.de
State Committed
Headers
Series Assume epilogue unwind info is valid unless gcc < 4.5.0 |

Commit Message

Tom de Vries Feb. 13, 2023, 2:23 p.m. UTC 
  Factor out compunit_epilogue_unwind_valid from both
amd64_stack_frame_destroyed_p and i386_stack_frame_destroyed_p.  NFC.

Also add a comment in the new function about the assumption that in absence of
producer information, epilogue unwind info is invalid.
---
 gdb/amd64-tdep.c |  4 +---
 gdb/i386-tdep.c  |  4 +---
 gdb/symtab.h     | 13 +++++++++++++
 3 files changed, 15 insertions(+), 6 deletions(-)

Comments

Tom Tromey Feb. 14, 2023, 3:56 p.m. UTC | #1 
>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:

Tom> Factor out compunit_epilogue_unwind_valid from both
Tom> amd64_stack_frame_destroyed_p and i386_stack_frame_destroyed_p.  NFC.

What does NFC means?

Tom> Also add a comment in the new function about the assumption that in absence of
Tom> producer information, epilogue unwind info is invalid.

Thanks.
Approved-By: Tom Tromey <tom@tromey.com>

Tom
Tom de Vries Feb. 14, 2023, 10:36 p.m. UTC | #2 
On 2/14/23 16:56, Tom Tromey wrote:
>>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Tom> Factor out compunit_epilogue_unwind_valid from both
> Tom> amd64_stack_frame_destroyed_p and i386_stack_frame_destroyed_p.  NFC.
> 
> What does NFC means?
> 

No Functional Changes.

I guess I picked this up when working on clang/llvm.

Mentioned here: https://llvm.org/docs/Lexicon.html#n .

> Tom> Also add a comment in the new function about the assumption that in absence of
> Tom> producer information, epilogue unwind info is invalid.
> 
> Thanks.
> Approved-By: Tom Tromey <tom@tromey.com>
> 

Thanks.
- Tom
Tom de Vries Feb. 20, 2023, 10:27 a.m. UTC | #3 
On 2/14/23 23:36, Tom de Vries via Gdb-patches wrote:
> On 2/14/23 16:56, Tom Tromey wrote:
>>>>>>> "Tom" == Tom de Vries via Gdb-patches 
>>>>>>> <gdb-patches@sourceware.org> writes:
>>
>> Tom> Factor out compunit_epilogue_unwind_valid from both
>> Tom> amd64_stack_frame_destroyed_p and i386_stack_frame_destroyed_p.  
>> NFC.
>>
>> What does NFC means?
>>
> 
> No Functional Changes.
> 
> I guess I picked this up when working on clang/llvm.
> 
> Mentioned here: https://llvm.org/docs/Lexicon.html#n .
> 

And grepping through the commit log, I see I used it before.

Anyway, replaced by "No functional changes".

>> Tom> Also add a comment in the new function about the assumption that 
>> in absence of
>> Tom> producer information, epilogue unwind info is invalid.
>>
>> Thanks.
>> Approved-By: Tom Tromey <tom@tromey.com>
>>

Thanks, I've added the tag to this commit and will commit the series 
after retesting.

Thanks,
- Tom
diff mbox series

Patch

diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index 328e001f5bb..d2e683b6fa8 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -2902,10 +2902,8 @@  static int
 amd64_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 {
   gdb_byte insn;
-  struct compunit_symtab *cust;
 
-  cust = find_pc_compunit_symtab (pc);
-  if (cust != NULL && cust->epilogue_unwind_valid ())
+  if (compunit_epilogue_unwind_valid (find_pc_compunit_symtab (pc)))
     return 0;
 
   if (target_read_memory (pc, &insn, 1))
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 8dccae633f7..3fe548d8c68 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -2219,10 +2219,8 @@  static int
 i386_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 {
   gdb_byte insn;
-  struct compunit_symtab *cust;
 
-  cust = find_pc_compunit_symtab (pc);
-  if (cust != NULL && cust->epilogue_unwind_valid ())
+  if (compunit_epilogue_unwind_valid (find_pc_compunit_symtab (pc)))
     return 0;
 
   if (target_read_memory (pc, &insn, 1))
diff --git a/gdb/symtab.h b/gdb/symtab.h
index 11ff875c6b8..cd6b5f722fd 100644
--- a/gdb/symtab.h
+++ b/gdb/symtab.h
@@ -1917,6 +1917,19 @@  is_main_symtab_of_compunit_symtab (struct symtab *symtab)
 {
   return symtab == symtab->compunit ()->primary_filetab ();
 }
+
+/* Return true if epilogue unwind info of CUST is valid.  */
+
+static inline bool
+compunit_epilogue_unwind_valid (struct compunit_symtab *cust)
+{
+  /* In absence of producer information, assume epilogue unwind info is
+     invalid.  */
+  if (cust == nullptr)
+    return false;
+
+  return cust->epilogue_unwind_valid ();
+}
 
 
 /* The virtual function table is now an array of structures which have the