[PATCH v2 1/5] gdb: xtensa: clean up xtensa_default_isa initialization

[Max Filippov <jcmvbkbc@gmail.com>]

This fixes segfault in native gdb because isa is not initialized at the
point of call to xtensa_isa_maxlength.

gdb/
2017-02-21  Max Filippov  <jcmvbkbc@gmail.com>

	* xtensa-tdep.c (xtensa_scan_prologue, call0_analyze_prologue):
	Drop xtensa_default_isa initialization.
	(xtensa_gdbarch_init): Initialize xtensa_default_isa.
---
Changes v1->v2:
- clean up xtensa_default_isa initialization;
- move directory name up in the commit message.

 gdb/xtensa-tdep.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/gdb/xtensa-tdep.c b/gdb/xtensa-tdep.c
index 376f4c7..efbd5ab 100644
--- a/gdb/xtensa-tdep.c
+++ b/gdb/xtensa-tdep.c
@@ -1151,8 +1151,6 @@ xtensa_scan_prologue (struct gdbarch *gdbarch, CORE_ADDR current_pc)
   if (start_addr == 0)
     return fp_regnum;
 
-  if (!xtensa_default_isa)
-    xtensa_default_isa = xtensa_isa_init (0, 0);
   isa = xtensa_default_isa;
   gdb_assert (XTENSA_ISA_BSZ >= xtensa_isa_maxlength (isa));
   ins = xtensa_insnbuf_alloc (isa);
@@ -2427,8 +2425,6 @@ call0_analyze_prologue (struct gdbarch *gdbarch,
   cache->call0 = 1;
   rtmp = (xtensa_c0reg_t*) alloca(nregs * sizeof(xtensa_c0reg_t));
 
-  if (!xtensa_default_isa)
-    xtensa_default_isa = xtensa_isa_init (0, 0);
   isa = xtensa_default_isa;
   gdb_assert (XTENSA_ISA_BSZ >= xtensa_isa_maxlength (isa));
   ins = xtensa_insnbuf_alloc (isa);
@@ -3186,6 +3182,9 @@ xtensa_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
 
   DEBUGTRACE ("gdbarch_init()\n");
 
+  if (!xtensa_default_isa)
+    xtensa_default_isa = xtensa_isa_init (0, 0);
+
   /* We have to set the byte order before we call gdbarch_alloc.  */
   info.byte_order = XCHAL_HAVE_BE ? BFD_ENDIAN_BIG : BFD_ENDIAN_LITTLE;
 
-- 
2.1.4