PowerPC PLT stub matching

This patch fixes a number of bugs in ppc32 plt stub matching code.
1) The 4-insn stubs for shared libs and PIEs weren't matched.
2) The executable stub miscalculated PLT entry address (by oring a
   sign-extended quantity rather than adding).
3) Comments were not accurate.

In addition, the insn arrays are made const.

	* ppc-linux-tdep.c (powerpc32_plt_stub): Make const.
	(powerpc32_plt_stub_so_1): Rename from powerpc32_plt_stub_so.
	Remove nop.  Make const.  Comment.
	(powerpc32_plt_stub_so_2): New.
	(POWERPC32_PLT_CHECK_LEN): Rename from POWERPC32_PLT_STUB_LEN.
	Correct count.  Update uses.
	(ppc_skip_trampoline_code): Match powerpc32_plt_stub_so_2 too.
	Move common code reading PLT entry word.  Correct
	powerpc32_plt_stub PLT address calculation.
	* ppc64-tdep.c (ppc64_standard_linkage1): Make const.
	(ppc64_standard_linkage2, ppc64_standard_linkage3): Likewise.
	(ppc64_standard_linkage4, ppc64_standard_linkage5): Likewise.
	(ppc64_standard_linkage6, ppc64_standard_linkage7): Likewise.
	(ppc64_standard_linkage8): Likewise.
	* rs6000-tdep.c (ppc_insns_match_pattern): Make pattern const.
	Correct insns description.
	* ppc-tdep.h (ppc_insns_match_pattern): Update prototype.

Reviewed-By: Yao Qi <qiyaoltc@gmail.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c
index 7417232..5d8ccb4 100644
--- a/gdb/ppc64-tdep.c
+++ b/gdb/ppc64-tdep.c
@@ -80,7 +80,7 @@ ppc64_plt_entry_point (struct frame_info *frame, CORE_ADDR plt_off)
 
 /* Old ELFv1 PLT call stub.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage1[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage1[] =
   {
     /* addis r12, r2, <any> */
     { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
@@ -119,7 +119,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage1[] =
    instructions following "cmpldi r2, 0", "bnectr+" and "b <glink_i>",
    but there isn't any need to match them.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage2[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage2[] =
   {
     /* std r2, 40(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 40, 0), 1 },
@@ -162,7 +162,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage2[] =
 
 /* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage3[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage3[] =
   {
     /* std r2, 40(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 40, 0), 1 },
@@ -201,7 +201,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage3[] =
    A more modern variant of ppc64_standard_linkage2 differing in
    register usage.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage4[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage4[] =
   {
     /* std r2, 40(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 40, 0), 1 },
@@ -243,7 +243,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage4[] =
    A more modern variant of ppc64_standard_linkage3 differing in
    register usage.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage5[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage5[] =
   {
     /* std r2, 40(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 40, 0), 1 },
@@ -280,7 +280,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage5[] =
 
 /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage6[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage6[] =
   {
     /* std r2, 24(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 24, 0), 1 },
@@ -302,7 +302,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage6[] =
 
 /* ELFv2 PLT call stub to access PLT entries within +/- 32k of r2.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage7[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage7[] =
   {
     /* std r2, 24(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 24, 0), 1 },
@@ -322,7 +322,7 @@ static struct ppc_insn_pattern ppc64_standard_linkage7[] =
 /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2,
    supporting fusion.  */
 
-static struct ppc_insn_pattern ppc64_standard_linkage8[] =
+static const struct ppc_insn_pattern ppc64_standard_linkage8[] =
   {
     /* std r2, 24(r1) <optional> */
     { -1, insn_ds (62, 2, 1, 24, 0), 1 },