hash table allocation failure
Eric Blake <[email protected]>
| Newsgroups | gmane.comp.gnu.m4.patches |
|---|---|
| Message-ID | <[email protected]> |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Thanks to Jim's recent work on the gnulib hash module, I audited the code for cases where allocation failure could cause assertion failures instead of expected xalloc_die behavior (either way, the program ends, but I want it to be obvious from the stderr output that the user was short on memory, and not that they triggered an internal error in m4). I have a pending patch that aims to clean up a memory leak in gnulib's hash_rehash (admittedly a corner case, since there's not much you can do to recover from an allocation failure on a rehash); but until that is reviewed and applied, I'm using a gnulib local override to avoid a gcc warning. Only branch-1.6 is affected. - -- Don't work too hard, make some time for fun as well! Eric Blake [email protected] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAko3EKgACgkQ84KuGfSFAYDvswCdEaAIsTgH5+wpq+GLfeJMhJVr 4AAAn0L/JxW1cOX/5/jGZAC6qmmN7nRS =yIHW -----END PGP SIGNATURE----- _______________________________________________ M4-patches mailing list [email protected] http://lists.gnu.org/mailman/listinfo/m4-patches
m4.patch419
(text/plain, 3.8 KB)
From 5165ce08a8784648f4fa0fafe2d3005569f16bdd Mon Sep 17 00:00:00 2001 From: Eric Blake <[email protected]> Date: Mon, 15 Jun 2009 09:17:41 -0600 Subject: [PATCH] Properly manage hash return values. * src/symtab.c (symtab_init, lookup_symbol): React to allocation failure. * local/lib/hash.c.diff: New file to silence gcc warning, until such time as upstream gnulib hash module is patched to avoid memory leak. * .gitattributes: Ignore spacing in diff. Signed-off-by: Eric Blake <[email protected]> --- .gitattributes | 3 +++ ChangeLog | 10 ++++++++++ local/lib/hash.c.diff | 27 +++++++++++++++++++++++++++ src/symtab.c | 17 ++++++++++++++--- 4 files changed, 54 insertions(+), 3 deletions(-) create mode 100644 local/lib/hash.c.diff diff --git a/.gitattributes b/.gitattributes index 68d2d12..1b29560 100644 --- a/.gitattributes +++ b/.gitattributes @@ -2,3 +2,6 @@ # needed for using these attributes effectively. ChangeLog merge=merge-changelog *.texi* diff=texinfo +# Ignore whitespace in any gnulib local patches. +local/* -whitespace +local/*/* -whitespace diff --git a/ChangeLog b/ChangeLog index 3b3ca90..c9169f4 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2009-06-15 Eric Blake <[email protected]> + + Properly manage hash return values. + * src/symtab.c (symtab_init, lookup_symbol): React to allocation + failure. + * local/lib/hash.c.diff: New file to silence gcc warning, until + such time as upstream gnulib hash module is patched to avoid + memory leak. + * .gitattributes: Ignore spacing in diff. + 2009-06-13 Eric Blake <[email protected]> Fix testsuite failure. diff --git a/local/lib/hash.c.diff b/local/lib/hash.c.diff new file mode 100644 index 0000000..8d27a36 --- /dev/null +++ b/local/lib/hash.c.diff @@ -0,0 +1,27 @@ +diff --git a/lib/hash.c b/lib/hash.c +index 7d76d45..6f3a5c6 100644 +--- a/lib/hash.c ++++ b/lib/hash.c +@@ -1,7 +1,7 @@ + /* hash - hashing table processing. + +- Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007 Free +- Software Foundation, Inc. ++ Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007, ++ 2009 Free Software Foundation, Inc. + + Written by Jim Meyering, 1992. + +@@ -1012,7 +1012,11 @@ hash_delete (Hash_table *table, const void *entry) + : (table->n_buckets * tuning->shrink_factor + * tuning->growth_threshold)); + +- hash_rehash (table, candidate); ++ if (hash_rehash (table, candidate)) ++ { ++ /* Failure to allocate memory in an attempt to ++ shrink the table is not fatal. */ ++ } + } + } + } diff --git a/src/symtab.c b/src/symtab.c index 6631e9c..338bf17 100644 --- a/src/symtab.c +++ b/src/symtab.c @@ -177,6 +177,8 @@ symtab_init (size_t size) { symtab = hash_initialize (size, NULL, symtab_hasher, symtab_comparator, symtab_free_entry); + if (!symtab) + xalloc_die (); #ifdef DEBUG_SYM atexit (show_profile); /* Ignore failure, since this is debug code. */ @@ -277,7 +279,10 @@ lookup_symbol (const char *name, size_t len, symbol_lookup mode) assert (entry == old); sym->stack = sym; entry = (symbol *) hash_insert (symtab, sym); - assert (sym == entry); + if (entry) + assert (sym == entry); + else + xalloc_die (); } else { @@ -319,7 +324,10 @@ lookup_symbol (const char *name, size_t len, symbol_lookup mode) { sym->stack = sym; entry = (symbol *) hash_insert (symtab, sym); - assert (sym == entry); + if (entry) + assert (sym == entry); + else + xalloc_die (); } return sym; @@ -376,7 +384,10 @@ lookup_symbol (const char *name, size_t len, symbol_lookup mode) sym->stack = sym; entry = (symbol *) hash_insert (symtab, sym); - assert (sym == entry); + if (entry) + assert (sym == entry); + else + xalloc_die (); } return result; } -- 1.6.3.rc3.2.g4b51