Norihiro Tanaka wrote:
Perhaps, I may run accross it in order to use old GCC (4.1.2 on CentOS 5.10).
Thanks, it's lucky you did, so that we won't be inundated by other people reporting similar problems. I see now that we were passing -Wno-pointer-sign to GCC, and that this suppressed useful diagnostics on newer GCC instances (but not on your older one). I installed the attached patch to fix both the signedness problem, and the diagnostic-suppression problem.
From 5f7911e016a31a8d9de260e86103b1c2d286b3fa Mon Sep 17 00:00:00 2001 From: Paul Eggert <[email protected]> Date: Fri, 18 Apr 2014 23:17:41 -0700 Subject: [PATCH] dfa: fix pointer type conversion bug The code converted between size_t * and ptrdiff_t *, which wasn't diagnosed by modern x86-64 GCC but isn't portable. Problem reported by Norihiro Tanaka in <http://bugs.gnu.org/17136#31>. * configure.ac (WERROR_CFLAGS): Don't add -Wno-pointer-sign. We want GCC to diagnose pointer signedness problems, as they violate the C standard and other compilers no doubt complain too. * src/dfa.c (struct dfa): Change type of salloc to size_t. (realloc_trans_if_necessary): Convert signed value to size_t before passing its address to x2nrealloc. Changing the type of tralloc to size_t might have led to problems elsewhere. --- configure.ac | 1 - src/dfa.c | 10 +++++----- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/configure.ac b/configure.ac index 886449b..17a8920 100644 --- a/configure.ac +++ b/configure.ac @@ -145,7 +145,6 @@ if test "$gl_gcc_warnings" = yes; then done gl_WARN_ADD([-Wno-missing-field-initializers]) # We need this one gl_WARN_ADD([-Wno-sign-compare]) # Too many warnings for now - gl_WARN_ADD([-Wno-pointer-sign]) # Too many warnings for now gl_WARN_ADD([-Wno-unused-parameter]) # Too many warnings for now # In spite of excluding -Wlogical-op above, it is enabled, as of diff --git a/src/dfa.c b/src/dfa.c index eeca257..90cf4a9 100644 --- a/src/dfa.c +++ b/src/dfa.c @@ -378,7 +378,7 @@ struct dfa /* Fields filled by the state builder. */ dfa_state *states; /* States of the dfa. */ state_num sindex; /* Index for adding new states. */ - state_num salloc; /* Number of states currently allocated. */ + size_t salloc; /* Number of states currently allocated. */ /* Fields filled by the parse tree->NFA conversion. */ position_set *follows; /* Array of follow sets, indexed by position @@ -2780,12 +2780,12 @@ realloc_trans_if_necessary (struct dfa *d, state_num new_state) if (oldalloc <= new_state) { state_num **realtrans = d->trans ? d->trans - 1 : NULL; - size_t newalloc; - d->tralloc = new_state + 1; - realtrans = x2nrealloc (realtrans, &d->tralloc, sizeof *realtrans); + size_t newalloc, newalloc1; + newalloc1 = new_state + 1; + realtrans = x2nrealloc (realtrans, &newalloc1, sizeof *realtrans); realtrans[0] = NULL; d->trans = realtrans + 1; - newalloc = --d->tralloc; + d->tralloc = newalloc = newalloc1 - 1; d->fails = xnrealloc (d->fails, newalloc, sizeof *d->fails); d->success = xnrealloc (d->success, newalloc, sizeof *d->success); d->newlines = xnrealloc (d->newlines, newalloc, sizeof *d->newlines); -- 1.9.0
