Print meaningfull error text for abonormal process exit on Win32, rather

than hex codes, using FormatMessage().

src/backend/postmaster/postmaster.c

@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.510 2007/01/22 19:38:05 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.511 2007/01/23 01:45:11 momjian Exp $
  *
  * NOTES
  *
@@ -2430,14 +2430,30 @@ LogChildExit(int lev, const char *procname, int pid, int exitstatus)
 				(errmsg("%s (PID %d) was terminated by signal %d",
 						procname, pid, WTERMSIG(exitstatus))));
 #else
-		ereport(lev,
+	{
+		static char last_system_error[512];
+
+		if (WERRORCODE(exitstatus) == 0 ||
+			FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
+						  FORMAT_MESSAGE_FROM_SYSTEM,
+						  NULL,
+						  WERRORCODE(exitstatus),
+						  MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
+						  last_system_error,
+						  sizeof(last_system_error) - 1,
+						  NULL) == 0)
+			snprintf(last_system_error, sizeof(last_system_error) - 1,
+					 "Unknown error %X.", WEXITSTATUS(exitstatus));
 
+		ereport(lev,
+	
 		/*------
 		  translator: %s is a noun phrase describing a child process, such as
 		  "server process" */
-				(errmsg("%s (PID %d) was terminated by exception %X",
-						procname, pid, WTERMSIG(exitstatus)),
-				 errhint("See http://source.winehq.org/source/include/ntstatus.h for a description of the hex value.")));
+				(errmsg("%s (PID %d) was terminated by the operating system",
+						procname, pid),
+				 errdetail("%s", last_system_error)));
+	}
 #endif
 	else
 		ereport(lev,

src/include/port/win32.h

-/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.67 2007/01/22 18:32:57 momjian Exp $ */
+/* $PostgreSQL: pgsql/src/include/port/win32.h,v 1.68 2007/01/23 01:45:11 momjian Exp $ */
 
 #if defined(_MSC_VER) || defined(__BORLANDC__)
 #define WIN32_ONLY_COMPILER
@@ -140,13 +140,26 @@ int			semop(int semId, struct sembuf * sops, int flag);
  *		Descriptions - http://www.comp.nus.edu.sg/~wuyongzh/my_doc/ntstatus.txt
  *		MS SDK - http://www.nologs.com/ntstatus.html
  *
- *	Some day we might want to print descriptions for the most common
- *	exceptions, rather than printing a URL.
+ *	Because FormatMessage only handles NT_ERROR strings, and assumes they
+ *	do not have the 0xC prefix, we strip it to match this list:
+ *		http://msdn2.microsoft.com/en-us/library/ms681381.aspx
+ *
+ *	When using FormatMessage():
+ *
+ *	On MinGW, system() returns STATUS_* values.  MSVC might be
+ *	different.  To test, create a binary that does *(NULL), and
+ *	then create a second binary that calls it via system(),
+ *	and check the return value of system().  On MinGW, it is
+ *	0xC0000005 == STATUS_ACCESS_VIOLATION, and 0x5 is a value
+ *	FormatMessage() can look up.  GetLastError() does not work;
+ *	always zero.
  */
-#define WIFEXITED(w)    (((w) & 0XFFFFFF00) == 0)
-#define WIFSIGNALED(w)  (!WIFEXITED(w))
-#define WEXITSTATUS(w)  (w)
-#define WTERMSIG(w)     (w)
+#define STATUS_ERROR_MASK	0xC0000000
+#define WIFEXITED(w)		(((w) & 0XFFFFFF00) == 0)
+#define WIFSIGNALED(w)		(!WIFEXITED(w))
+#define WEXITSTATUS(w)		(w)
+#define WERRORCODE(w)		((((w) & STATUS_ERROR_MASK) == STATUS_ERROR_MASK) ? \
+							((w) & ~STATUS_ERROR_MASK) : 0)
 
 #define sigmask(sig) ( 1 << ((sig)-1) )
 

src/port/exec.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/port/exec.c,v 1.45 2007/01/22 18:31:51 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/port/exec.c,v 1.46 2007/01/23 01:45:11 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -586,8 +586,24 @@ pclose_check(FILE *stream)
 		log_error(_("child process was terminated by signal %d"),
 				  WTERMSIG(exitstatus));
 #else
-		log_error(_("child process was terminated by exception %X\nSee http://source.winehq.org/source/include/ntstatus.h for a description\nof the hex value."),
-				  WTERMSIG(exitstatus));
+	{
+		static char last_system_error[512];
+
+		if (WERRORCODE(exitstatus) == 0 ||
+			FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS |
+						  FORMAT_MESSAGE_FROM_SYSTEM,
+						  NULL,
+						  WERRORCODE(exitstatus),
+						  MAKELANGID(LANG_ENGLISH, SUBLANG_DEFAULT),
+						  last_system_error,
+						  sizeof(last_system_error) - 1,
+						  NULL) == 0)
+			snprintf(last_system_error, sizeof(last_system_error) - 1,
+					 "Unknown error %X.", WEXITSTATUS(exitstatus));
+
+		log_error(_("child process was terminated by the operating system\n%s"),
+				  last_system_error);
+	}
 #endif
 	else
 		log_error(_("child process exited with unrecognized status %d"),