[bug #43887] shell function blocks for x64 builds with MSVC compiler

[Christian Boos]

URL:
  <http://savannah.gnu.org/bugs/?43887>

                 Summary: shell function blocks for x64 builds with MSVC
compiler
                 Project: make
            Submitted by: cboos
            Submitted on: Thu 25 Dec 2014 05:55:11 PM GMT
                Severity: 3 - Normal
              Item Group: Bug
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
       Component Version: 4.1
        Operating System: MS Windows
           Fixed Release: None
           Triage Status: None

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Details:

Season's greetings!

I've recently built Make 4.1 using Visual Studio 2012, for the x64 platform
(i.e. a 64-bits build).
The build went well, but using this make.exe for my usual build hanged.
Debugging it, I saw that the hang happened in a $(shell ...) function call,
never returning and stuck in reap_children().

I figured out that the "pid == shell_function_pid" comparison that needs to
succeed for setting the shell_function_completed flag and exiting
reap_children() could actually never succeed:
 - "pid" is obtained from process_wait_for_any() and is actually a pointer,
cast from sub_process* to HANDLE to pid_t
 - "shell_function_pid" got its value from process_init_fd() via
windows32_openpipe(), but here the cast chain is sub_process* to HANDLE to
int!
For that specific compiler/platform combination, pointers and pid_t are
64-bits values, while ints are 32-bits values 

Using pid_t when declaring shell_function_pid fixed the problem. Patch
attached.

I've looked for other potential problems in the code, but all the other
int/pid_t mismatches seem to happen for platforms where it shouldn't be a
problem (EMX, Amiga).

Nearly forgot to say: everything else seems to work like a charm after that!
Thanks!




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File Attachments:


-------------------------------------------------------
Date: Thu 25 Dec 2014 05:55:11 PM GMT  Name:
0001-Use-correct-pid_t-type-for-shell_function_pid.patch  Size: 1kB   By:
cboos
fix for this issue, on top of 4.1
<http://savannah.gnu.org/bugs/download.php?file_id=32711>

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