Re: [PATCH] tests: fix unportable assumption on sys/wait.h

[Bruno Haible]

Hi Eric,

Eric Blake wrote on 2010-09-17:
> * tests/test-sys_wait.c (main): Relax test.
> * tests/test-stdlib.c (main): Likewise.

I have another change to make to this test. But I don't want to do it in two
files. So first let's reduce the code duplication.


2010-09-26  Bruno Haible  <address@hidden>

        stdlib tests: Avoid code duplication.
        * modules/stdlib-tests (Files): Add tests/test-sys_wait.h.
        * modules/sys_wait-tests (Files): Likewise.
        * tests/test-sys_wait.h: New file, extracted from tests/test-stdlib.c.
        * tests/test-stdlib.c: Include test-sys_wait.h.
        (main): Invoke test_sys_wait_macros.
        * tests/test-sys_wait.c: Include test-sys_wait.h.
        (main): Invoke test_sys_wait_macros.

============================ tests/test-sys_wait.h ============================
/* Test of macros shared between <sys/wait.h> and <stdlib.h>.
   Copyright (C) 2010 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Eric Blake <address@hidden>, 2010.  */

static int
test_sys_wait_macros (void)
{
  /* Check subset of <sys/wait.h> macros that must be visible here.
     Note that some of these macros are only portable when operating
     on an lvalue.  */
  int i;
  for (i = 0; i < 0x8000; i = (i ? i << 1 : 1))
    {
      /* POSIX requires that for all valid process statuses, that
         exactly one of these three macros is true.  But not all
         possible 16-bit values map to valid process status.
         Traditionally, 8 of the bits are for WIFEXITED, 7 of the bits
         to tell between WIFSIGNALED and WIFSTOPPED, and either 0x80
         or 0x8000 to flag that core was also dumped.  Since we don't
         know which byte is WIFEXITED, we skip the both possible bits
         that can signal core dump.  */
      if (i == 0x80)
        continue;
      if (!!WIFSIGNALED (i) + !!WIFEXITED (i) + !!WIFSTOPPED (i) != 1)
        return 1;
    }
  i = WEXITSTATUS (i) + WSTOPSIG (i) + WTERMSIG (i);

  switch (i)
    {
#if 0
  /* Gnulib doesn't guarantee these, yet.  */
    case WNOHANG:
    case WUNTRACED:
#endif
      break;
    }
  return 0;
}
===============================================================================
--- modules/stdlib-tests.orig   Sun Sep 26 14:17:56 2010
+++ modules/stdlib-tests        Sun Sep 26 14:13:56 2010
@@ -1,5 +1,6 @@
 Files:
 tests/test-stdlib.c
+tests/test-sys_wait.h
 
 Depends-on:
 verify
--- modules/sys_wait-tests.orig Sun Sep 26 14:17:56 2010
+++ modules/sys_wait-tests      Sun Sep 26 14:14:01 2010
@@ -1,5 +1,6 @@
 Files:
 tests/test-sys_wait.c
+tests/test-sys_wait.h
 
 Depends-on:
 
--- tests/test-stdlib.c.orig    Sun Sep 26 14:17:56 2010
+++ tests/test-stdlib.c Sun Sep 26 14:14:36 2010
@@ -38,38 +38,13 @@
    per POSIX 2008.  */
 verify (sizeof NULL == sizeof (void *));
 
+#include "test-sys_wait.h"
+
 int
 main (void)
 {
-  /* Check subset of <sys/wait.h> macros that must be visible here.
-     Note that some of these macros are only portable when operating
-     on an lvalue.  */
-  int i;
-  for (i = 0; i < 0x8000; i = (i ? i << 1 : 1))
-    {
-      /* POSIX requires that for all valid process statuses, that
-         exactly one of these three macros is true.  But not all
-         possible 16-bit values map to valid process status.
-         Traditionally, 8 of the bits are for WIFEXITED, 7 of the bits
-         to tell between WIFSIGNALED and WIFSTOPPED, and either 0x80
-         or 0x8000 to flag that core was also dumped.  Since we don't
-         know which byte is WIFEXITED, we skip the both possible bits
-         that can signal core dump.  */
-      if (i == 0x80)
-        continue;
-      if (!!WIFSIGNALED (i) + !!WIFEXITED (i) + !!WIFSTOPPED (i) != 1)
-        return 1;
-    }
-  i = WEXITSTATUS (i) + WSTOPSIG (i) + WTERMSIG (i);
+  if (test_sys_wait_macros ())
+    return 1;
 
-  switch (i)
-    {
-#if 0
-  /* Gnulib doesn't guarantee these, yet.  */
-    case WNOHANG:
-    case WUNTRACED:
-#endif
-      break;
-    }
   return exitcode;
 }
--- tests/test-sys_wait.c.orig  Sun Sep 26 14:17:56 2010
+++ tests/test-sys_wait.c       Sun Sep 26 14:14:23 2010
@@ -23,41 +23,25 @@
 /* Check for existence of required types.  */
 static pid_t a;
 
+#include "test-sys_wait.h"
+
 int
 main (void)
 {
-  /* Check for existence of required macros.  Note that we document
-     that these are safe only on lvalues.  */
-  int i;
-  for (i = 0; i < 0x10000; i = (i ? i << 1 : 1))
-    {
-      /* POSIX requires that for all valid process statuses, that
-         exactly one of these three macros is true.  But not all
-         possible 16-bit values map to valid process status.
-         Traditionally, 8 of the bits are for WIFEXITED, 7 of the bits
-         to tell between WIFSIGNALED and WIFSTOPPED, and either 0x80
-         or 0x8000 to flag that core was also dumped.  Since we don't
-         know which byte is WIFEXITED, we skip the both possible bits
-         that can signal core dump.  */
-      if (i == 0x80)
-        continue;
-      if (!!WIFSIGNALED (i) + !!WIFEXITED (i) + !!WIFSTOPPED (i) != 1)
-        return 1;
-    }
-  i = WEXITSTATUS (i) + WSTOPSIG (i) + WTERMSIG (i);
+  if (test_sys_wait_macros ())
+    return 1;
 
-  switch (i)
+  switch (0)
     {
 #if 0
   /* Gnulib doesn't guarantee these, yet.  */
     case WCONTINUED:
-    case WNOHANG:
-    case WUNTRACED:
     case WEXITED:
     case WNOWAIT:
     case WSTOPPED:
 #endif
       break;
     }
-  return a ? i : 0;
+
+  return a ? 1 : 0;
 }