On 8/1/19 4:41 PM, Jakub Jelinek wrote:
> On Thu, Aug 01, 2019 at 04:34:09PM +0200, Martin Liška wrote:
>> Ok, after deeper discussion with Honza, I would like to suggest the original
>> patch that was about proper detection of jobserver.
>>
>> Can you please Jakub test the patch in your environment?
>
> Isn't this done too late (as in, doesn't the driver at that moment already
> have some files newly openend, like e.g. the @ option files?
You are right, I've reworked that. Good observation.
>
>> + = ((sscanf (n, "--jobserver-auth=%d,%d", &rfd, &wfd) == 2)
>
> No need to wrap sscanf (...) == 2 into ()s. Also, you've already done
> a strstr, what is the point in verifying it once again that it starts with
> --jobserver-auth= string?
> And in the lto-writer.c code there is no space between sscanf and (.
Yep, I simplified that.
Martin
>
> Jakub
>
>From 9f96e16a7798fd3b60fa9ec5b7a66748212146c4 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Thu, 1 Aug 2019 16:30:01 +0200
Subject: [PATCH] Properly detect working jobserver in gcc driver.
gcc/ChangeLog:
2019-08-02 Martin Liska <mli...@suse.cz>
* gcc.c (driver::main): Call detect_jobserver right
at the very start of the function.
(driver::detect_jobserver): Test whether jobserver
is active from GCC driver. That will prevent situation where
GCC is invoked from a LD plugin and the linker already uses
file descriptors suggested by make. That leads to a wrong
detection.
* gcc.h (driver): Add detect_jobserver.
* lto-wrapper.c (jobserver_active_p): Simplify sscanf by
not scanning for --jobserver-auth prefix.
---
gcc/gcc.c | 41 +++++++++++++++++++++++++++++++++++++++++
gcc/gcc.h | 1 +
gcc/lto-wrapper.c | 2 +-
3 files changed, 43 insertions(+), 1 deletion(-)
diff --git a/gcc/gcc.c b/gcc/gcc.c
index a4323eb146e..c8753b9671f 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -7354,6 +7354,7 @@ driver::main (int argc, char **argv)
{
bool early_exit;
+ detect_jobserver ();
set_progname (argv[0]);
expand_at_files (&argc, &argv);
decode_argv (argc, const_cast <const char **> (argv));
@@ -8357,6 +8358,46 @@ driver::final_actions () const
}
}
+/* Detect whether jobserver is active and working. If not drop
+ --jobserver-auth from MAKEFLAGS. */
+
+void
+driver::detect_jobserver () const
+{
+ /* Detect jobserver and drop it if it's not working. */
+ const char *makeflags = env.get ("MAKEFLAGS");
+ if (makeflags != NULL)
+ {
+ const char *needle = "--jobserver-auth=";
+ const char *n = strstr (makeflags, needle);
+ if (n != NULL)
+ {
+ int rfd = -1;
+ int wfd = -1;
+
+ bool jobserver
+ = (sscanf (n + strlen (needle), "%d,%d", &rfd, &wfd) == 2
+ && rfd > 0
+ && wfd > 0
+ && fcntl (rfd, F_GETFD) >= 0
+ && fcntl (wfd, F_GETFD) >= 0);
+
+ /* Drop the jobserver if it's not working now. */
+ if (!jobserver)
+ {
+ unsigned offset = n - makeflags;
+ char *dup = xstrdup (makeflags);
+ dup[offset] = '\0';
+
+ const char *space = strchr (makeflags + offset, ' ');
+ if (space != NULL)
+ strcpy (dup + offset, space);
+ xputenv (concat ("MAKEFLAGS=", dup, NULL));
+ }
+ }
+ }
+}
+
/* Determine what the exit code of the driver should be. */
int
diff --git a/gcc/gcc.h b/gcc/gcc.h
index a0a1d94c6e6..dc77dba67fb 100644
--- a/gcc/gcc.h
+++ b/gcc/gcc.h
@@ -51,6 +51,7 @@ class driver
void do_spec_on_infiles () const;
void maybe_run_linker (const char *argv0) const;
void final_actions () const;
+ void detect_jobserver () const;
int get_exit_code () const;
private:
diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
index 353187c6043..3414adedd26 100644
--- a/gcc/lto-wrapper.c
+++ b/gcc/lto-wrapper.c
@@ -1234,7 +1234,7 @@ jobserver_active_p (void)
int rfd = -1;
int wfd = -1;
- return ((sscanf(n, "--jobserver-auth=%d,%d", &rfd, &wfd) == 2)
+ return (sscanf (n + strlen (needle), "%d,%d", &rfd, &wfd) == 2
&& rfd > 0
&& wfd > 0
&& fcntl (rfd, F_GETFD) >= 0
--
2.22.0
