[PATCH 0/6] Two -Wclobbered fixes, plus other cleanup

[PATCH 0/6] Two -Wclobbered fixes, plus other cleanup

[Richard Henderson]

As reported by Stefan, and reproduced on Ubuntu 22.04.


r~

Richard Henderson (6):
  disas/nanomips: Move setjmp into nanomips_dis
  disas/nanomips: Merge insn{1,2,3} into words[3]
  disas/nanomips: Split out read_u16
  disas/nanomips: Tidy read for 48-bit opcodes
  tcg: Move TCG_TARGET_HAS_direct_jump init to tb_gen_code
  accel/tcg: Split out setjmp_gen_code

 accel/tcg/translate-all.c |  68 ++++++++++++------------
 disas/nanomips.c          | 106 ++++++++++++++++----------------------
 tcg/tcg.c                 |  12 +++++
 3 files changed, 90 insertions(+), 96 deletions(-)

-- 
2.34.1

[PATCH 1/6] disas/nanomips: Move setjmp into nanomips_dis

[Richard Henderson]

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]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 disas/nanomips.c | 44 ++++++++++++++++++++------------------------
 1 file changed, 20 insertions(+), 24 deletions(-)

diff --git a/disas/nanomips.c b/disas/nanomips.c
index 9647f1a8e3..9a69e6880a 100644
--- a/disas/nanomips.c
+++ b/disas/nanomips.c
@@ -21905,22 +21905,27 @@ 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;
+    int ret;
+
+    ret = sigsetjmp(info->buf, 0);
+    if (ret != 0) {
+        return false;
+    }
+
+    ret = Disassemble(bits, buf, &type, MAJOR, 2, info);
+    return ret >= 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;
@@ -21950,6 +21955,7 @@ 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.  */
@@ -21965,6 +21971,7 @@ 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, "     ");
@@ -21982,27 +21989,16 @@ 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;
+    if (nanomips_dis(&buf, &disassm_info, insn1, insn2, insn3)) {
+        (*info->fprintf_func) (info->stream, "%s", buf);
     }
 
-    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;
-    }
-
-    info->insn_type = dis_noninsn;
-
-    return insn3 ? 6 : insn2 ? 4 : 2;
+    return length;
 }
-- 
2.34.1