From 24449fc0f55ba99d4dbc6b3ab7ed495f43591c51 Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Mon, 7 Nov 2022 08:28:47 +1100
Subject: [PATCH] disas/nanomips: Move setjmp into nanomips_dis
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Reduce the number of local variables within the scope of the
setjmp by moving it to the existing helper.  The actual length
returned from Disassemble is not used, because we have already
determined the length while reading bytes.  Fixes:

nanomips.c: In function ‘print_insn_nanomips’:
nanomips.c:21925:14: error: variable ‘insn1’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]
nanomips.c:21925:25: error: variable ‘insn2’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]
nanomips.c:21925:36: error: variable ‘insn3’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]
nanomips.c:21926:22: error: variable ‘buf’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Werror=clobbered]

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221106212852.152384-2-richard.henderson@linaro.org>
---
 disas/nanomips.c | 42 +++++++++++++++++-------------------------
 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/disas/nanomips.c b/disas/nanomips.c
index 821d4f8832..83a39a878c 100644
--- a/disas/nanomips.c
+++ b/disas/nanomips.c
@@ -21907,22 +21907,24 @@ static const Pool MAJOR[2] = {
        0x0                 },        /* P16 */
 };
 
-static int nanomips_dis(char **buf,
-                 Dis_info *info,
-                 unsigned short one,
-                 unsigned short two,
-                 unsigned short three)
+static bool nanomips_dis(char **buf, Dis_info *info,
+                         unsigned short one,
+                         unsigned short two,
+                         unsigned short three)
 {
     uint16 bits[3] = {one, two, three};
-
     TABLE_ENTRY_TYPE type;
-    int size = Disassemble(bits, buf, &type, MAJOR, 2, info);
-    return size;
+
+    /* Handle runtime errors. */
+    if (unlikely(sigsetjmp(info->buf, 0) != 0)) {
+        return false;
+    }
+    return Disassemble(bits, buf, &type, MAJOR, ARRAY_SIZE(MAJOR), info) >= 0;
 }
 
 int print_insn_nanomips(bfd_vma memaddr, struct disassemble_info *info)
 {
-    int status;
+    int status, length;
     bfd_byte buffer[2];
     uint16_t insn1 = 0, insn2 = 0, insn3 = 0;
     g_autofree char *buf = NULL;
@@ -21952,6 +21954,7 @@ int print_insn_nanomips(bfd_vma memaddr, struct disassemble_info *info)
     } else {
         insn1 = bfd_getl16(buffer);
     }
+    length = 2;
     (*info->fprintf_func)(info->stream, "%04x ", insn1);
 
     /* Handle 32-bit opcodes.  */
@@ -21967,6 +21970,7 @@ int print_insn_nanomips(bfd_vma memaddr, struct disassemble_info *info)
         } else {
             insn2 = bfd_getl16(buffer);
         }
+        length = 4;
         (*info->fprintf_func)(info->stream, "%04x ", insn2);
     } else {
         (*info->fprintf_func)(info->stream, "     ");
@@ -21984,27 +21988,15 @@ int print_insn_nanomips(bfd_vma memaddr, struct disassemble_info *info)
         } else {
             insn3 = bfd_getl16(buffer);
         }
+        length = 6;
         (*info->fprintf_func)(info->stream, "%04x ", insn3);
     } else {
         (*info->fprintf_func)(info->stream, "     ");
     }
 
-    /* Handle runtime errors. */
-    if (sigsetjmp(disassm_info.buf, 0) != 0) {
-        info->insn_type = dis_noninsn;
-        return insn3 ? 6 : insn2 ? 4 : 2;
-    }
-
-    int length = nanomips_dis(&buf, &disassm_info, insn1, insn2, insn3);
-
-    /* FIXME: Should probably use a hash table on the major opcode here.  */
-
-    (*info->fprintf_func) (info->stream, "%s", buf);
-    if (length > 0) {
-        return length / 8;
+    if (nanomips_dis(&buf, &disassm_info, insn1, insn2, insn3)) {
+        (*info->fprintf_func) (info->stream, "%s", buf);
     }
 
-    info->insn_type = dis_noninsn;
-
-    return insn3 ? 6 : insn2 ? 4 : 2;
+    return length;
 }
-- 
2.11.0