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| author | Tom de Vries <tdevries@suse.de> | 2020-07-29 09:03:20 +0200 |
|---|---|---|
| committer | Tom de Vries <tdevries@suse.de> | 2020-07-29 09:03:20 +0200 |
| commit | 8ba83e9109a1a02f54f1c4793c8f231bb9256acd (patch) | |
| tree | 3b9b22b97b8449bc7ab65af3a67494d658aa523f /gdb/s390-tdep.c | |
| parent | f5c79e97fecb9333c150bfaa84bfee66c41a93bc (diff) | |
| download | fsf-binutils-gdb-8ba83e9109a1a02f54f1c4793c8f231bb9256acd.zip fsf-binutils-gdb-8ba83e9109a1a02f54f1c4793c8f231bb9256acd.tar.gz fsf-binutils-gdb-8ba83e9109a1a02f54f1c4793c8f231bb9256acd.tar.bz2 | |
[tdep/s390] Fix Wmaybe-uninitialized in s390_displaced_step_fixup
When building gdb with CFLAGS/CXXFLAGS="-O2 -g -Wall", I see:
...
src/gdb/s390-tdep.c: In function 'void s390_displaced_step_fixup(gdbarch*, \
displaced_step_closure*, CORE_ADDR, CORE_ADDR, regcache*)':
src/gdb/s390-tdep.c:528:30: warning: 'r2' may be used uninitialized in this \
function [-Wmaybe-uninitialized]
528 | if (insn[0] == op_basr && r2 == 0)
| ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
...
The problem is that the compiler is unaware that
'is_rr (insn, op_basr, &r1, &r2) == 1' ensures that 'insn[0] == op_basr':
...
if (is_rr (insn, op_basr, &r1, &r2)
|| is_rx (insn, op_bas, &r1, &d2, &x2, &b2))
{
/* Recompute saved return address in R1. */
regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1,
amode | (from + insnlen));
/* Update PC iff the instruction doesn't actually branch. */
if (insn[0] == op_basr && r2 == 0)
regcache_write_pc (regs, from + insnlen);
}
...
Fix this by storing the result of the call, and using it instead of
'insn[0] ==op_basr'.
Build on x86_64-linux with --enable-targets=s390-suse-linux,s390x-suse-linux.
gdb/ChangeLog:
2020-07-29 Tom de Vries <tdevries@suse.de>
PR tdep/26280
* s390-tdep.c (s390_displaced_step_fixup): Fix Wmaybe-uninitialized.
Diffstat (limited to 'gdb/s390-tdep.c')
| -rw-r--r-- | gdb/s390-tdep.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c index 0ee7a37..65cb237 100644 --- a/gdb/s390-tdep.c +++ b/gdb/s390-tdep.c @@ -518,14 +518,15 @@ s390_displaced_step_fixup (struct gdbarch *gdbarch, paddress (gdbarch, pc), insnlen, (int) amode); /* Handle absolute branch and save instructions. */ - if (is_rr (insn, op_basr, &r1, &r2) + int op_basr_p = is_rr (insn, op_basr, &r1, &r2); + if (op_basr_p || is_rx (insn, op_bas, &r1, &d2, &x2, &b2)) { /* Recompute saved return address in R1. */ regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1, amode | (from + insnlen)); /* Update PC iff the instruction doesn't actually branch. */ - if (insn[0] == op_basr && r2 == 0) + if (op_basr_p && r2 == 0) regcache_write_pc (regs, from + insnlen); } |