Refactor local `execvpe(3)` implementation

The previous code was prone to conflicts with when the platform happens
to expose a `execvpe(3)` implementation in its libc.

This commit renames the internal implementation to `__hsunix_execvpe` as
well as adding an autoconf-detection for the presence of `execvpe(3)`,
in which case `__hsunix_execvpe()` forwards the call to `execvpe(3)`.

Moreover, the code has been cleaned up to remove likely bitrotted CPP
conditionals.

This should fix #22

(This also partially addresses #11 on platforms which have a
libc-provided `execvpe(3)`)

1 files changed, 4 insertions, 20 deletions

diff --git a/include/execvpe.h b/include/execvpe.h
index c3b2dd3..1d49e35 100644
--- a/include/execvpe.h
+++ b/include/execvpe.h
@@ -1,27 +1,11 @@
 /* ----------------------------------------------------------------------------
    (c) The University of Glasgow 2004
 
-   Interface for code in execvpe.c
+   Interface for code in cbits/execvpe.c
    ------------------------------------------------------------------------- */
 
-#include "HsUnixConfig.h"
-// Otherwise these clash with similar definitions from other packages:
-#undef PACKAGE_BUGREPORT
-#undef PACKAGE_NAME
-#undef PACKAGE_STRING
-#undef PACKAGE_TARNAME
-#undef PACKAGE_VERSION
+extern int
+__hsunix_execvpe(const char *name, char *const argv[], char *const envp[]);
 
-#include <errno.h>
-#include <sys/types.h>
-#if HAVE_SYS_WAIT_H
-#include <sys/wait.h>
-#endif
-
-#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(_WIN32)
-#ifndef __QNXNTO__
-extern int execvpe(char *name, char *const argv[], char **envp);
-#endif
+// implemented in cbits/ghcrts.c
 extern void pPrPr_disableITimers (void);
-#endif
-