/bin/sh on 32-bit Cygwin

[Bruno Haible]

Hi,

In a 64-bit Cygwin environment, one can compile 32-bit Cygwin binaries.
These binaries run fine as long as they don't have to manipulate files
in the Cygwin64 root. Apparently the 32-bit Cygwin runtime does not
find files whose file name starts with /home, /usr, /bin etc.

For most files, this is easy to achieve: Just build outside the
Cygwin64 root. One notable exception is /bin/sh. The use of this
absolute file name in the test-posix_spawn1 and test-posix_spawn2 tests
fails. The fix is to reference the shell through $PATH.


2018-10-04  Bruno Haible  <address@hidden>

        sh-filename: New module.
        * m4/sh-filename.m4: New file.
        * modules/sh-filename: New file.
        * lib/spawni.c (_PATH_BSHELL): Use BOURNE_SHELL instead of hardcoding
        "/bin/sh".
        * tests/test-posix_spawn1.c (main): Likewise.
        * tests/test-posix_spawn2.c (main): Likewise.
        * lib/javacomp.c (compile_using_envjavac, is_envjavac_gcj,
        is_envjavac_gcj43): Likewise.
        * lib/javaexec.c (execute_java_class): Likewise.
        * modules/posix_spawn-internal (Depends-on): Add sh-filename.
        * modules/posix_spawnp-tests (Depends-on): Likewise.
        * modules/javacomp (Depends-on): Likewise.
        * modules/javaexec (Depends-on): Likewise.

diff --git a/m4/sh-filename.m4 b/m4/sh-filename.m4
new file mode 100644
index 0000000..53148f4
--- /dev/null
+++ b/m4/sh-filename.m4
@@ -0,0 +1,20 @@
+# sh-filename.m4 serial 1
+dnl Copyright (C) 2018 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+AC_DEFUN([gl_SH_FILENAME],
+[
+  AH_VERBATIM([SH_FILENAME],
+[/* File name of the Bourne shell.  */
+#if defined __CYGWIN__
+/* Omit the directory part because for 32-bit Cygwin programs in a
+   64-bit Cygwin environment, the Cygwin mounts are not visible.  */
+# define BOURNE_SHELL "sh"
+#else
+# define BOURNE_SHELL "/bin/sh"
+#endif])
+])
diff --git a/modules/sh-filename b/modules/sh-filename
new file mode 100644
index 0000000..7043fc1
--- /dev/null
+++ b/modules/sh-filename
@@ -0,0 +1,20 @@
+Description:
+Provide BOURNE_SHELL, the file name of the standard Bourne shell.
+
+Files:
+m4/sh-filename.m4
+
+Depends-on:
+
+configure.ac:
+gl_SH_FILENAME
+
+Makefile.am:
+
+Include:
+
+License:
+LGPLv2+
+
+Maintainer:
+all
diff --git a/lib/spawni.c b/lib/spawni.c
index bd49cc8..05dc8b4 100644
--- a/lib/spawni.c
+++ b/lib/spawni.c
@@ -32,7 +32,7 @@
 #if _LIBC || HAVE_PATHS_H
 # include <paths.h>
 #else
-# define _PATH_BSHELL "/bin/sh"
+# define _PATH_BSHELL BOURNE_SHELL
 #endif
 
 #include <signal.h>
diff --git a/tests/test-posix_spawn1.c b/tests/test-posix_spawn1.c
index 6b6c864..c6b59dd 100644
--- a/tests/test-posix_spawn1.c
+++ b/tests/test-posix_spawn1.c
@@ -73,7 +73,7 @@ fd_safer (int fd)
 int
 main ()
 {
-  char *argv[3] = { (char *) "/bin/sh", (char *) CHILD_PROGRAM_FILENAME, NULL 
};
+  char *argv[3] = { (char *) BOURNE_SHELL, (char *) CHILD_PROGRAM_FILENAME, 
NULL };
   int ifd[2];
   sigset_t blocked_signals;
   sigset_t fatal_signal_set;
@@ -113,7 +113,7 @@ main ()
           || (attrs_allocated = true,
               (err = posix_spawnattr_setsigmask (&attrs, &blocked_signals)) != 0
               || (err = posix_spawnattr_setflags (&attrs, 
POSIX_SPAWN_SETSIGMASK)) != 0)
-          || (err = posix_spawnp (&child, "/bin/sh", &actions, &attrs, argv, 
environ)) != 0))
+          || (err = posix_spawnp (&child, BOURNE_SHELL, &actions, &attrs, 
argv, environ)) != 0))
     {
       if (actions_allocated)
         posix_spawn_file_actions_destroy (&actions);
diff --git a/tests/test-posix_spawn2.c b/tests/test-posix_spawn2.c
index d9f29a1..1311951 100644
--- a/tests/test-posix_spawn2.c
+++ b/tests/test-posix_spawn2.c
@@ -51,7 +51,7 @@ fd_safer (int fd)
 int
 main ()
 {
-  char *argv[3] = { (char *) "/bin/sh", (char *) CHILD_PROGRAM_FILENAME, NULL 
};
+  char *argv[3] = { (char *) BOURNE_SHELL, (char *) CHILD_PROGRAM_FILENAME, 
NULL };
   int ofd[2];
   sigset_t blocked_signals;
   sigset_t fatal_signal_set;
@@ -90,7 +90,7 @@ main ()
           || (attrs_allocated = true,
               (err = posix_spawnattr_setsigmask (&attrs, &blocked_signals)) != 0
               || (err = posix_spawnattr_setflags (&attrs, 
POSIX_SPAWN_SETSIGMASK)) != 0)
-          || (err = posix_spawnp (&child, "/bin/sh", &actions, &attrs, argv, 
environ)) != 0))
+          || (err = posix_spawnp (&child, BOURNE_SHELL, &actions, &attrs, 
argv, environ)) != 0))
     {
       if (actions_allocated)
         posix_spawn_file_actions_destroy (&actions);
diff --git a/lib/javacomp.c b/lib/javacomp.c
index 9d5b249..779d5ec 100644
--- a/lib/javacomp.c
+++ b/lib/javacomp.c
@@ -339,11 +339,11 @@ compile_using_envjavac (const char *javac,
   if (verbose)
     printf ("%s\n", command);
 
-  argv[0] = "/bin/sh";
+  argv[0] = BOURNE_SHELL;
   argv[1] = "-c";
   argv[2] = command;
   argv[3] = NULL;
-  exitstatus = execute (javac, "/bin/sh", argv, false, false, false,
+  exitstatus = execute (javac, BOURNE_SHELL, argv, false, false, false,
                         null_stderr, true, true, NULL);
   err = (exitstatus != 0);
 
@@ -656,11 +656,11 @@ is_envjavac_gcj (const char *javac)
         abort ();
 
       /* Call $JAVAC --version 2>/dev/null.  */
-      argv[0] = "/bin/sh";
+      argv[0] = BOURNE_SHELL;
       argv[1] = "-c";
       argv[2] = command;
       argv[3] = NULL;
-      child = create_pipe_in (javac, "/bin/sh", argv, DEV_NULL, true, true,
+      child = create_pipe_in (javac, BOURNE_SHELL, argv, DEV_NULL, true, true,
                               false, fd);
       if (child == -1)
         goto failed;
@@ -738,11 +738,11 @@ is_envjavac_gcj43 (const char *javac)
         abort ();
 
       /* Call $JAVAC --version 2>/dev/null.  */
-      argv[0] = "/bin/sh";
+      argv[0] = BOURNE_SHELL;
       argv[1] = "-c";
       argv[2] = command;
       argv[3] = NULL;
-      child = create_pipe_in (javac, "/bin/sh", argv, DEV_NULL, true, true,
+      child = create_pipe_in (javac, BOURNE_SHELL, argv, DEV_NULL, true, true,
                               false, fd);
       if (child == -1)
         goto failed;
diff --git a/lib/javaexec.c b/lib/javaexec.c
index b6f2eff..2dd6853 100644
--- a/lib/javaexec.c
+++ b/lib/javaexec.c
@@ -172,11 +172,11 @@ execute_java_class (const char *class_name,
         if (verbose)
           printf ("%s\n", command);
 
-        argv[0] = "/bin/sh";
+        argv[0] = BOURNE_SHELL;
         argv[1] = "-c";
         argv[2] = command;
         argv[3] = NULL;
-        err = executer (java, "/bin/sh", argv, private_data);
+        err = executer (java, BOURNE_SHELL, argv, private_data);
 
         freea (command);
 
diff --git a/modules/posix_spawn-internal b/modules/posix_spawn-internal
index b1ab488..294b3f8 100644
--- a/modules/posix_spawn-internal
+++ b/modules/posix_spawn-internal
@@ -12,6 +12,7 @@ alloca-opt
 dup2
 errno
 open
+sh-filename
 strchrnul
 
 configure.ac:
diff --git a/modules/posix_spawnp-tests b/modules/posix_spawnp-tests
index bce8be7..743c95f 100644
--- a/modules/posix_spawnp-tests
+++ b/modules/posix_spawnp-tests
@@ -20,6 +20,7 @@ unistd
 sys_wait
 dup
 environ
+sh-filename
 sigprocmask
 
 configure.ac:
diff --git a/modules/javacomp b/modules/javacomp
index dcfcae8..2568a9e 100644
--- a/modules/javacomp
+++ b/modules/javacomp
@@ -28,6 +28,7 @@ xvasprintf
 c-strstr
 gettext-h
 javacomp-script
+sh-filename
 
 configure.ac:
 
diff --git a/modules/javaexec b/modules/javaexec
index b66c2fc..879580a 100644
--- a/modules/javaexec
+++ b/modules/javaexec
@@ -17,6 +17,7 @@ xmalloca
 error
 gettext-h
 javaexec-script
+sh-filename
 
 configure.ac: