Commit: 8e848b8b65f5a1f5c6dec8892e3fffa9228d31f0 - mingw-get (git)

The MinGW.org Installation Manager Tool

Commit MetaInfo

• Révision: 8e848b8b65f5a1f5c6dec8892e3fffa9228d31f0 (tree)
• l'heure: 2013-06-15 04:58:21
• Auteur: Keith Marshall <keithmarshall@user...>
• Commiter: Keith Marshall

Message de Log

Handle Microsoft's 32-bit vs. 64-bit time_t ambiguity.

Change Summary

• modified: ChangeLog
• modified: Makefile.in
• add: src/apihook.c
• modified: src/tarproc.cpp

Modification

--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
[phone]  Keith Marshall  <[e-mail]>
+
+	Handle Microsoft's 32-bit vs. 64-bit time_t ambiguity.
+
+	* src/apihook.c: New file; it provides...
+	(have_api): ...this helper; it checks for availability of any specific
+	API function, within a specific system DLL, (MSVCRT.DLL by default).
+
+	* src/tarproc.cpp (have_utime64_api): New inline function; it wraps...
+	(have_api): ...this, to check whether MSVCRT.DLL provides...
+	(commit_saved_entity) [_utime64]: ...this; use if available, else...
+	(commit_saved_entity) [!_utime64]: ...fall back to using...
+	(utime): ...this.
+
+	* Makefile.in (CORE_DLL_OBJECTS): Add apihook.$OBJEXT
+
 2013-06-13  Keith Marshall  <[e-mail]>
 
 	Facilitate package extraction and registration at setup time.

--- a/Makefile.in
+++ b/Makefile.in
@@ -165,7 +165,7 @@ CORE_DLL_OBJECTS  =  climain.$(OBJEXT) pkgshow.$(OBJEXT) dmhcore.$(OBJEXT) \
    pkgdeps.$(OBJEXT) pkgreqs.$(OBJEXT) pkginst.$(OBJEXT) pkgunst.$(OBJEXT) \
    tarproc.$(OBJEXT) xmlfile.$(OBJEXT) keyword.$(OBJEXT) vercmp.$(OBJEXT) \
    tinyxml.$(OBJEXT) tinystr.$(OBJEXT) tinyxmlparser.$(OBJEXT) \
-   mkpath.$(OBJEXT)  tinyxmlerror.$(OBJEXT)
+   apihook.$(OBJEXT) mkpath.$(OBJEXT)  tinyxmlerror.$(OBJEXT)
 
 CLI_EXE_OBJECTS  =   \
    clistub.$(OBJEXT) version.$(OBJEXT) approot.$(OBJEXT) getopt.$(OBJEXT)

--- /dev/null
+++ b/src/apihook.c
@@ -0,0 +1,61 @@
+/*
+ * apihook.c
+ *
+ * $Id$
+ *
+ * Written by Keith Marshall <[e-mail]>
+ * Copyright (C) 2013, MinGW.org Project
+ *
+ *
+ * Implementation of a utility function to check for availabiliity of
+ * a specified API function within a specified DLL.
+ *
+ *
+ * This is free software.  Permission is granted to copy, modify and
+ * redistribute this software, under the provisions of the GNU General
+ * Public License, Version 3, (or, at your option, any later version),
+ * as published by the Free Software Foundation; see the file COPYING
+ * for licensing details.
+ *
+ * Note, in particular, that this software is provided "as is", in the
+ * hope that it may prove useful, but WITHOUT WARRANTY OF ANY KIND; not
+ * even an implied WARRANTY OF MERCHANTABILITY, nor of FITNESS FOR ANY
+ * PARTICULAR PURPOSE.  Under no circumstances will the author, or the
+ * MinGW Project, accept liability for any damages, however caused,
+ * arising from the use of this software.
+ *
+ */
+#define  WIN32_LEAN_AND_MEAN
+
+#include <windows.h>
+
+int have_api( const char *entry, const char *dll )
+{
+  /* Initially assuming that the specified API is "unsupported",
+   * attempt to get a handle for the nominated provider DLL.
+   */
+  HMODULE provider;
+  enum { API_UNSUPPORTED = 0, API_SUPPORTED } status = API_UNSUPPORTED;
+  if( (provider = LoadLibrary( dll == NULL ? "msvcrt.dll" : dll )) != NULL )
+  {
+    /* When we have a valid DLL handle, look up the entry point
+     * address, within it, for the specified API function...
+     */
+    if( GetProcAddress( provider, entry ) != NULL )
+      /*
+       * ...and, provided this returns a valid entry address,
+       * mark the API as "supported".
+       */
+      status = API_SUPPORTED;
+
+    /* Release the handle we acquired above, for the provider DLL,
+     * so that we maintain a balanced reference count.
+     */
+    FreeLibrary( provider );
+  }
+  /* Finally, return the support state for the API, as determined.
+   */
+  return (int)(status);
+}
+
+/* $RCSfile$: end of file */

--- a/src/tarproc.cpp
+++ b/src/tarproc.cpp
@@ -532,16 +532,62 @@ char *pkgTarArchiveProcessor::EntityDataAsString()
  */
 #include <utime.h>
 
-static int commit_saved_entity( const char *pathname, time_t mtime )
+EXTERN_C int have_api( const char *, const char * = NULL );
+
+static inline int have_utime64_api( void )
+{
+  /* Local helper function to check and record the availability of
+   * the _utime64() API function, within the particular version of
+   * MSVCRT.DLL which is installed on the host platform.
+   */
+  enum { API_UNSUPPORTED = 0, API_SUPPORTED, API_UNTESTED };
+
+  /* On first call, we don't know; initialise accordingly.
+   */
+  static int status = (int)(API_UNTESTED);
+
+  return (status == (int)(API_UNTESTED))
+    /*
+     * Must be first time of calling; check, record, and return
+     * the appropriate availability status.
+     */
+    ? status = have_api( "_utime64" )
+    /*
+     * On second and subsequent calls, we've already checked, so
+     * we know the availability status; simply return it.
+     */
+    : status;
+}
+
+static int commit_saved_entity( const char *pathname, __time64_t mtime )
 {
   /* Helper to set the access and modification times for a file,
    * after extraction from an archive, to match the specified "mtime";
    * (typically "mtime" is as recorded within the archive).
    */
-  struct utimbuf timestamp;
+  if( have_utime64_api() )
+  {
+    /* When the _utime64() API function is available...
+     */
+    struct __utimbuf64 timestamp;
 
-  timestamp.actime = timestamp.modtime = mtime;
-  return utime( pathname, &timestamp );
+    /* ...we prefer to use it...
+     */
+    timestamp.actime = timestamp.modtime = mtime;
+    return _utime64( pathname, &timestamp );
+  }
+  else
+  {
+    /* ...otherwise, we assume that this is a legacy system,
+     * and the utime() function is based on 32-bit time_t...
+     */
+    struct __utimbuf32 timestamp;
+
+    /* ...so fall back to using that.
+     */
+    timestamp.actime = timestamp.modtime = mtime;
+    return utime( pathname, (utimbuf *)(&timestamp) );
+  }
 }
 
 pkgTarArchiveExtractor::pkgTarArchiveExtractor( const char *fn, const char *dir )