https://github.com/libsdl-org/autoconf/commit/08b6f99cef7fffd47083341e464e45ee971ddee1
From 08b6f99cef7fffd47083341e464e45ee971ddee1 Mon Sep 17 00:00:00 2001
From: Zack Weinberg <[EMAIL REDACTED]>
Date: Sun, 26 Sep 2021 12:04:28 -0400
Subject: [PATCH] log_environment: Make version probes more robust.
---
BuildCommon.pm | 65 +++++++++++++++++++++++++++++++++++++++++++++----
log_environment | 23 ++++++++++++++---
2 files changed, 80 insertions(+), 8 deletions(-)
diff --git a/BuildCommon.pm b/BuildCommon.pm
index 321442ce..137dc38f 100644
--- a/BuildCommon.pm
+++ b/BuildCommon.pm
@@ -32,7 +32,9 @@ use Exporter qw(import);
BEGIN {
@EXPORT_OK = qw(
ensure_C_locale
+ ensure_empty_stdin
error
+ get_status
get_status_and_output
popen
run
@@ -72,7 +74,7 @@ sub subprocess_error { ## no critic (Subroutines::RequireArgUnpacking)
my $status = $?;
my $cmd = join q{ }, @_;
if ($syserr) {
- error("system error with pipe to $cmd: $syserr");
+ error("system error with $cmd: $syserr");
} elsif ($status == 0) {
return;
@@ -157,11 +159,21 @@ sub run { ## no critic (Subroutines::RequireArgUnpacking)
die 'run: no command to execute'
if scalar(@_) == 0;
log_execution(@_);
- my $status = system { $_[0] } @_;
- return if $status == 0;
- invocation_error($_[0]) if $status == -1;
- subprocess_error(@_);
+ my $pid = fork
+ // invocation_error($_[0]);
+
+ if ($pid == 0) {
+ # child
+ { exec {$_[0]} @_; };
+ print {*STDERR} "exec $_[0] failed: $!\n";
+ exit(127);
+ }
+
+ # parent
+ waitpid $pid, 0;
+ undef $!;
+ subprocess_error(@_) if $?;
}
# Run, and log execution of, a subprocess. @_ should be one of the
@@ -182,6 +194,39 @@ sub popen {
return $fh;
}
+# Run, and log execution of, a subprocess. @_ should be an argument vector.
+# If the subprocess exits normally (successful or unsuccessful),
+# returns the exit status.
+# If the subprocess could not be started because there is no such command,
+# returns -1.
+# Otherwise invocation_error/subprocess_error are called as appropriate.
+sub get_status {
+ die 'run: no command to execute'
+ if scalar(@_) == 0;
+ log_execution(@_);
+
+ my $pid = fork
+ // invocation_error($_[0]);
+
+ if ($pid == 0) {
+ # child
+ { exec {$_[0]} @_; };
+ exit(126) if $!{ENOENT};
+ print {*STDERR} "exec $_[0] failed: $!\n";
+ exit(127);
+ }
+
+ # parent
+ waitpid $pid, 0;
+ undef $!;
+ if ($? == 0x7F00 || ($? & 0x7F) != 0) {
+ subprocess_error(@_);
+ }
+ my $status = $? >> 8;
+ return -1 if $status == 126;
+ return $status;
+}
+
# Run, and log execution of, a subprocess. Capture all of its output,
# including both stdout and stderr.
# @_ should be an argument vector.
@@ -252,6 +297,16 @@ sub ensure_C_locale {
return;
}
+# Close standard input at the OS level and reopen it on /dev/null.
+# This ensures that no subprocesses will get stuck trying to read from
+# standard input.
+sub ensure_empty_stdin {
+ use POSIX qw(open close dup2 O_RDONLY);
+ my $fd = open('/dev/null', O_RDONLY) // die "open('/dev/null'): $!\n";
+ dup2($fd, 0) // die("dup2($fd, 0): $!\n");
+ close($fd);
+}
+
# Clean up $ENV{PATH}, and return the cleaned path as a list.
sub clean_PATH {
state @path;
diff --git a/log_environment b/log_environment
index 5aa13db1..80388ec3 100755
--- a/log_environment
+++ b/log_environment
@@ -31,7 +31,9 @@ use POSIX ();
use lib $FindBin::Bin;
use BuildCommon qw(
ensure_C_locale
+ ensure_empty_stdin
error
+ get_status
get_status_and_output
run
sh_quote
@@ -152,7 +154,21 @@ sub report_programs {
my ($absprog) = which($prog);
if ($absprog) {
print sh_quote($prog), ' is ', sh_quote($absprog), "\n";
- run($absprog, '--version');
+
+ # Try various options that might get a program to print its
+ # version number, in order of likelihood.
+ # mawk only recognizes -Wversion
+ # -qversion is in AC_PROG_CC's list of things to try
+ for my $vopt (qw(--version -V -v -Wversion -qversion)) {
+ my $status = get_status($absprog, $vopt);
+ last if $status == 0;
+ if ($status == -1) {
+ # 'no such file or directory' doesn't make sense here
+ print "$absprog $vopt: exit 126\n";
+ } else {
+ print "$absprog $vopt: exit $status\n";
+ }
+ }
} else {
print "WARNING: $prog not found in \$PATH\n";
}
@@ -163,10 +179,11 @@ sub report_programs {
sub main {
my %orig_env = %ENV;
ensure_C_locale();
+ ensure_empty_stdin();
print "# CI environment report\n";
- report_machine();
- report_ENV(\%orig_env);
+ #report_machine();
+ #report_ENV(\%orig_env);
report_programs(@_) if scalar(@_);
};