remove "no warnings 'once'" in a few places

[public-inbox.git] / lib / PublicInbox / Spawn.pm

diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index 7b0f3bdde6637f356e14be70790b77914c44a060..c64812ddf4a3fb01e6bb13f3c1489316a78693c1 100644 (file)
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2016-2018 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2019 all contributors <meta@public-inbox.org>
 # License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
 #
 # This allows vfork to be used for spawning subprocesses if
@@ -26,22 +26,35 @@ my $vfork_spawn = <<'VFORK_SPAWN';
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>
-#include <alloca.h>
-#include <signal.h>
-#include <assert.h>
+#include <stdlib.h>
 
-#define AV_ALLOCA(av, max) alloca((max = (av_len((av)) + 1)) * sizeof(char *))
+/* some platforms need alloca.h, but some don't */
+#if defined(__GNUC__) && !defined(alloca)
+#  define alloca(sz) __builtin_alloca(sz)
+#endif
 
-static void av2c_copy(char **dst, AV *src, I32 max)
-{
-       I32 i;
+#include <signal.h>
+#include <assert.h>
 
-       for (i = 0; i < max; i++) {
-               SV **sv = av_fetch(src, i, 0);
-               dst[i] = sv ? SvPV_nolen(*sv) : 0;
-       }
-       dst[max] = 0;
-}
+/*
+ * From the av_len apidoc:
+ *   Note that, unlike what the name implies, it returns
+ *   the highest index in the array, so to get the size of
+ *   the array you need to use "av_len(av) + 1".
+ *   This is unlike "sv_len", which returns what you would expect.
+ */
+#define AV2C_COPY(dst, src) do { \
+       I32 i; \
+       I32 top_index = av_len(src); \
+       I32 real_len = top_index + 1; \
+       I32 capa = real_len + 1; \
+       dst = alloca(capa * sizeof(char *)); \
+       for (i = 0; i < real_len; i++) { \
+               SV **sv = av_fetch(src, i, 0); \
+               dst[i] = SvPV_nolen(*sv); \
+       } \
+       dst[real_len] = 0; \
+} while (0)
 
 static void *deconst(const char *s)
 {
@@ -86,15 +99,11 @@ int pi_fork_exec(int in, int out, int err,
        const char *filename = SvPV_nolen(file);
        pid_t pid;
        char **argv, **envp;
-       I32 max;
        sigset_t set, old;
        int ret, errnum;
 
-       argv = AV_ALLOCA(cmd, max);
-       av2c_copy(argv, cmd, max);
-
-       envp = AV_ALLOCA(env, max);
-       av2c_copy(envp, env, max);
+       AV2C_COPY(argv, cmd);
+       AV2C_COPY(envp, env);
 
        ret = sigfillset(&set);
        assert(ret == 0 && "BUG calling sigfillset");
@@ -163,13 +172,12 @@ if (defined $vfork_spawn) {
 
 unless (defined $vfork_spawn) {
        require PublicInbox::SpawnPP;
-       no warnings 'once';
-       *pi_fork_exec = *PublicInbox::SpawnPP::pi_fork_exec
+       *pi_fork_exec = \&PublicInbox::SpawnPP::pi_fork_exec
 }
 
 sub which ($) {
        my ($file) = @_;
-       return $file if index($file, '/') == 0;
+       return $file if index($file, '/') >= 0;
        foreach my $p (split(':', $ENV{PATH})) {
                $p .= "/$file";
                return $p if -x $p;
@@ -184,17 +192,7 @@ sub spawn ($;$$) {
        my @env;
        $opts ||= {};
 
-       my %env = $opts->{-env} ? () : %ENV;
-       if ($env) {
-               foreach my $k (keys %$env) {
-                       my $v = $env->{$k};
-                       if (defined $v) {
-                               $env{$k} = $v;
-                       } else {
-                               delete $env{$k};
-                       }
-               }
-       }
+       my %env = $env ? (%ENV, %$env) : %ENV;
        while (my ($k, $v) = each %env) {
                push @env, "$k=$v";
        }
@@ -220,8 +218,6 @@ sub popen_rd {
        my ($cmd, $env, $opts) = @_;
        pipe(my ($r, $w)) or die "pipe: $!\n";
        $opts ||= {};
-       my $blocking = $opts->{Blocking};
-       IO::Handle::blocking($r, $blocking) if defined $blocking;
        $opts->{1} = fileno($w);
        my $pid = spawn($cmd, $env, $opts);
        return unless defined $pid;