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

[Tom de Vries <tdevries@suse.de>]

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(-)

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 ();
+}
 \f
 
 /* The virtual function table is now an array of structures which have the
-- 
2.35.3