From 25955bc845f3680632b6230148f1a39d6a5c1e88 Mon Sep 17 00:00:00 2001
From: sof <unknown>
Date: Thu, 10 Jul 2003 19:25:59 +0000
Subject: [PATCH] [project @ 2003-07-10 19:25:58 by sof] For
 System.Directory.renameFile on Win32 platforms, implement
 the Haskell98 semantics of replacing the target file if it
 already exists (i.e., file/directory renaming is now done
 by dirUtils.c:__hscore_renameFile().)

Document that System.Directory.renameDirectory will fail on Win32 boxes should
the target directory exist.

Merge to STABLE, I suppose.
---
 System/Directory.hs       |    3 ++
 System/Posix/Internals.hs |    2 +-
 cbits/dirUtils.c          |   70 +++++++++++++++++++++++++++++++++++++++++++++
 include/dirUtils.h        |    1 +
 4 files changed, 75 insertions(+), 1 deletion(-)

diff --git a/System/Directory.hs b/System/Directory.hs
index d37a364..17672c5 100644
--- a/System/Directory.hs
+++ b/System/Directory.hs
@@ -292,6 +292,9 @@ renaming directories in all situations (e.g. renaming to an existing
 directory, or across different physical devices), but the constraints
 must be documented.
 
+On Win32 platforms, @renameDirectory@ fails if the /new/ directory already
+exists.
+
 The operation may fail with:
 
 * 'HardwareFault'
diff --git a/System/Posix/Internals.hs b/System/Posix/Internals.hs
index 47362ed..575ec66 100644
--- a/System/Posix/Internals.hs
+++ b/System/Posix/Internals.hs
@@ -354,7 +354,7 @@ foreign import ccall unsafe "HsBase.h read"
 foreign import ccall unsafe "HsBase.h readdir" 
    c_readdir :: Ptr CDir -> IO (Ptr CDirent)
 
-foreign import ccall unsafe "HsBase.h rename"
+foreign import ccall unsafe "dirUtils.h __hscore_renameFile"
    c_rename :: CString -> CString -> IO CInt
 		     
 foreign import ccall unsafe "HsBase.h rewinddir"
diff --git a/cbits/dirUtils.c b/cbits/dirUtils.c
index 8d94a45..316a689 100644
--- a/cbits/dirUtils.c
+++ b/cbits/dirUtils.c
@@ -65,3 +65,73 @@ __hscore_readdir( HsAddr dirPtr, HsAddr pDirEnt )
   }  
 #endif
 }
+
+/*
+ * Function: __hscore_renameFile()
+ *
+ * Provide Haskell98's semantics for renaming files and directories.
+ * It mirrors that of POSIX.1's behaviour for rename() by overwriting
+ * the target if it exists (the MS CRT implementation of rename() returns
+ * an error
+ *
+ */
+HsInt
+__hscore_renameFile( HsAddr src,
+		     HsAddr dest)
+{
+#if defined(_MSC_VER) || defined(_WIN32)
+    static int forNT = -1;
+    DWORD rc;
+    
+    /* ToDo: propagate error codes back */
+    if (MoveFileA(src, dest)) {
+	return 0;
+    } else {
+	rc = GetLastError();
+    }
+    
+    /* Failed...it could be because the target already existed. */
+    if ( !GetFileAttributes(dest) ) {
+	/* No, it's not there - just fail. */
+	errno = 0;
+	return (-1);
+    }
+
+    if (forNT == -1) {
+	OSVERSIONINFO ovi;
+	ovi.dwOSVersionInfoSize = sizeof(ovi);
+	if ( !GetVersionEx(&ovi) ) {
+	    errno = 0; 
+	    return (-1);
+	}
+	forNT = ((ovi.dwPlatformId & VER_PLATFORM_WIN32_NT) != 0);
+    }
+    
+    if (forNT) {
+	/* Easy, go for MoveFileEx() */
+	if ( MoveFileExA(src, dest, MOVEFILE_REPLACE_EXISTING) ) {
+	    return 0;
+	} else {
+	    errno = 0; 
+	    return (-1);
+	}
+    }
+
+    /* No MoveFileEx() for Win9x, try deleting the target. */
+    /* Similarly, if the MoveFile*() ops didn't work out under NT */
+    if (DeleteFileA(dest)) {
+	if (MoveFileA(src,dest)) {
+	    return 0;
+	} else {
+	    errno = 0;
+	    return (-1);
+	}
+    } else {
+	errno = 0;
+	return (-1);
+    }
+#else
+    return rename(src,dest);
+#endif
+}
+
diff --git a/include/dirUtils.h b/include/dirUtils.h
index fb91ba1..ce11b08 100644
--- a/include/dirUtils.h
+++ b/include/dirUtils.h
@@ -7,5 +7,6 @@
 #define __DIRUTILS_H__
 
 extern HsInt __hscore_readdir(HsAddr dirPtr, HsAddr pDirEnt);
+extern HsInt __hscore_renameFile(HsAddr src, HsAddr dest);
 
 #endif /* __DIRUTILS_H__ */
-- 
1.7.10.4