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| author | Paul Eggert <eggert@cs.ucla.edu> | 2023-04-01 16:44:03 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2023-04-01 16:44:28 -0700 |
| commit | 713d9822bbfb2923115065efaefed34a0113f8a1 (patch) | |
| tree | 9c919574a18f3c9c90a1fdda625d36dcb49df328 | |
| parent | 05e295b60cfdf378b7ed8c1f8563a5644d5d4689 (diff) | |
| download | autoconf-713d9822bbfb2923115065efaefed34a0113f8a1.tar.gz | |
Fix timing bug on high-speed builds
Problem reported by Bogdan via Jacob Bachmeyer in:
https://lists.gnu.org/r/autoconf/2023-04/msg00002.html
* bin/autom4te.in: If a file timestamp equals a dependency’s
timestamp, consider the file to be out of date. Although this may
result in extra work, it fixes some rare timing bugs.
| -rw-r--r-- | bin/autom4te.in | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/bin/autom4te.in b/bin/autom4te.in index 4b61f0a8..71d7e6a6 100644 --- a/bin/autom4te.in +++ b/bin/autom4te.in @@ -910,10 +910,8 @@ sub up_to_date ($) return 0 if ! -f $tfile || ! -f $ofile; - # The youngest of the cache files must be older than the oldest of + # The younger of the cache files must be older than the oldest of # the dependencies. - # FIXME: These timestamps have only 1-second resolution. - # Time::HiRes fixes this, but assumes Perl 5.8 or later. my $tmtime = mtime ($tfile); my $omtime = mtime ($ofile); my ($file, $mtime) = ($tmtime < $omtime @@ -926,7 +924,7 @@ sub up_to_date ($) # We depend at least upon the arguments. foreach my $dep (@ARGV) { - if ($mtime < mtime ($dep)) + if ($mtime <= mtime ($dep)) { verb "up_to_date ($file): outdated: $dep"; return 0; @@ -949,7 +947,7 @@ sub up_to_date ($) # timestamp of that missing file was newer). return 0 if ! $dep; - if ($mtime < mtime ($dep)) + if ($mtime <= mtime ($dep)) { verb "up_to_date ($file): outdated: $dep"; return 0; @@ -1038,7 +1036,7 @@ $icache_file = new Autom4te::XFile $icache, O_RDWR|O_CREAT; $icache_file->lock (LOCK_EX) if ($flock_implemented eq "yes"); -# Read the cache index if available and older than autom4te itself. +# Read the cache index if available and younger than autom4te itself. # If autom4te is younger, then some structures such as C4che might # have changed, which would corrupt its processing. Autom4te::C4che->load ($icache_file) @@ -1105,7 +1103,7 @@ else # Actual M4 expansion, if the user wants it, or if $output is old # (STDOUT is pretty old). handle_output ($req, $output) - if $force || mtime ($output) < mtime ($ocache . $req->id); + if $force || mtime ($output) <= mtime ($ocache . $req->id); } # If we ran up to here, the cache is valid. |