[PATCH] Use strwinerror in gdb/windows-nat.c

[Tom Tromey <tromey@adacore.com>]

When working on windows-nat.c, it's useful to see an error message in
addition to the error number given by GetLastError.  This patch moves
strwinerror from gdbserver to gdbsupport, and then updates
windows-nat.c to use it.  A couple of minor changes to strwinerror
(constify the return type and use the ARRAY_SIZE macro) are also
included.
---
 gdb/nat/windows-nat.c  | 22 ++++++++++------
 gdb/windows-nat.c      | 51 ++++++++++++++++++++++++------------
 gdbserver/win32-low.cc | 59 ------------------------------------------
 gdbserver/win32-low.h  | 11 --------
 gdbsupport/errors.cc   | 54 ++++++++++++++++++++++++++++++++++++++
 gdbsupport/errors.h    | 16 ++++++++++++
 6 files changed, 119 insertions(+), 94 deletions(-)

diff --git a/gdb/nat/windows-nat.c b/gdb/nat/windows-nat.c
index ea6e2980f59..ba60b585e85 100644
--- a/gdb/nat/windows-nat.c
+++ b/gdb/nat/windows-nat.c
@@ -95,8 +95,8 @@ windows_thread_info::suspend ()
 	 We can get Invalid Handle (6) if the main thread
 	 has exited.  */
       if (err != ERROR_INVALID_HANDLE && err != ERROR_ACCESS_DENIED)
-	warning (_("SuspendThread (tid=0x%x) failed. (winerr %u)"),
-		 (unsigned) tid, (unsigned) err);
+	warning (_("SuspendThread (tid=0x%x) failed. (winerr %u: %s)"),
+		 (unsigned) tid, (unsigned) err, strwinerror (err));
       suspended = -1;
     }
   else
@@ -113,8 +113,8 @@ windows_thread_info::resume ()
       if (ResumeThread (h) == (DWORD) -1)
 	{
 	  DWORD err = GetLastError ();
-	  warning (_("warning: ResumeThread (tid=0x%x) failed. (winerr %u)"),
-		   (unsigned) tid, (unsigned) err);
+	  warning (_("warning: ResumeThread (tid=0x%x) failed. (winerr %u: %s)"),
+		   (unsigned) tid, (unsigned) err, strwinerror (err));
 	}
     }
   suspended = 0;
@@ -204,8 +204,11 @@ windows_process_info::get_exec_module_filename (char *exe_name_ret,
     len = GetModuleFileNameEx (handle,
 			       dh_buf, pathbuf, exe_name_max_len);
     if (len == 0)
-      error (_("Error getting executable filename: %u."),
-	     (unsigned) GetLastError ());
+      {
+	unsigned err = (unsigned) GetLastError ();
+	error (_("Error getting executable filename (error %u): %s"),
+	       err, strwinerror (err));
+      }
     if (cygwin_conv_path (CCP_WIN_W_TO_POSIX, pathbuf, exe_name_ret,
 			  exe_name_max_len) < 0)
       error (_("Error converting executable filename to POSIX: %d."), errno);
@@ -214,8 +217,11 @@ windows_process_info::get_exec_module_filename (char *exe_name_ret,
   len = GetModuleFileNameEx (handle,
 			     dh_buf, exe_name_ret, exe_name_max_len);
   if (len == 0)
-    error (_("Error getting executable filename: %u."),
-	   (unsigned) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      error (_("Error getting executable filename (error %u): %s"),
+	     err, strwinerror (err));
+    }
 #endif
 
     return 1;	/* success */
diff --git a/gdb/windows-nat.c b/gdb/windows-nat.c
index 9265ed9e632..1e310371e47 100644
--- a/gdb/windows-nat.c
+++ b/gdb/windows-nat.c
@@ -325,8 +325,11 @@ static void
 check (BOOL ok, const char *file, int line)
 {
   if (!ok)
-    gdb_printf ("error return %s:%d was %u\n", file, line,
-		(unsigned) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      gdb_printf ("error return %s:%d was %u: %s\n", file, line,
+		  err, strwinerror (err));
+    }
 }
 
 /* See nat/windows-nat.h.  */
@@ -1160,9 +1163,12 @@ windows_continue (DWORD continue_status, int id, int killed)
   res = continue_last_debug_event (continue_status, debug_events);
 
   if (!res)
-    error (_("Failed to resume program execution"
-	     " (ContinueDebugEvent failed, error %u)"),
-	   (unsigned int) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      error (_("Failed to resume program execution"
+	       " (ContinueDebugEvent failed, error %u: %s)"),
+	     err, strwinerror (err));
+    }
 
   return res;
 }
@@ -1179,8 +1185,9 @@ windows_nat_target::fake_create_process ()
     windows_process.open_process_used = 1;
   else
     {
-      error (_("OpenProcess call failed, GetLastError = %u"),
-       (unsigned) GetLastError ());
+      unsigned err = (unsigned) GetLastError ();
+      error (_("OpenProcess call failed, GetLastError = %u: %s"),
+	     err, strwinerror (err));
       /*  We can not debug anything in that case.  */
     }
   add_thread (ptid_t (windows_process.current_event.dwProcessId, 0,
@@ -1887,8 +1894,11 @@ windows_nat_target::attach (const char *args, int from_tty)
 #endif
 
   if (!ok)
-    error (_("Can't attach to process %u (error %u)"),
-	   (unsigned) pid, (unsigned) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      error (_("Can't attach to process %u (error %u: %s)"),
+	     (unsigned) pid, err, strwinerror (err));
+    }
 
   DebugSetProcessKillOnExit (FALSE);
 
@@ -1916,9 +1926,12 @@ windows_nat_target::detach (inferior *inf, int from_tty)
   resume (ptid, 0, GDB_SIGNAL_0);
 
   if (!DebugActiveProcessStop (windows_process.current_event.dwProcessId))
-    error (_("Can't detach process %u (error %u)"),
-	   (unsigned) windows_process.current_event.dwProcessId,
-	   (unsigned) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      error (_("Can't detach process %u (error %u: %s)"),
+	     (unsigned) windows_process.current_event.dwProcessId,
+	     err, strwinerror (err));
+    }
   DebugSetProcessKillOnExit (FALSE);
 
   target_announce_detach (from_tty);
@@ -2526,8 +2539,11 @@ windows_nat_target::create_inferior (const char *exec_file,
       tty = CreateFileA (inferior_tty.c_str (), GENERIC_READ | GENERIC_WRITE,
 			 0, &sa, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
       if (tty == INVALID_HANDLE_VALUE)
-	warning (_("Warning: Failed to open TTY %s, error %#x."),
-		 inferior_tty.c_str (), (unsigned) GetLastError ());
+	{
+	  unsigned err = (unsigned) GetLastError ();
+	  warning (_("Warning: Failed to open TTY %s, error %#x: %s"),
+		   inferior_tty.c_str (), err, strwinerror (err));
+	}
     }
   if (redirected || tty != INVALID_HANDLE_VALUE)
     {
@@ -2608,8 +2624,11 @@ windows_nat_target::create_inferior (const char *exec_file,
 #endif	/* !__CYGWIN__ */
 
   if (!ret)
-    error (_("Error creating process %s, (error %u)."),
-	   exec_file, (unsigned) GetLastError ());
+    {
+      unsigned err = (unsigned) GetLastError ();
+      error (_("Error creating process %s, (error %u: %s)"),
+	     exec_file, err, strwinerror (err));
+    }
 
 #ifdef __x86_64__
   BOOL wow64;
diff --git a/gdbserver/win32-low.cc b/gdbserver/win32-low.cc
index 27224077cea..5e2c028d683 100644
--- a/gdbserver/win32-low.cc
+++ b/gdbserver/win32-low.cc
@@ -61,10 +61,6 @@ gdbserver_windows_process windows_process;
 #define _T(x) TEXT (x)
 #endif
 
-#ifndef COUNTOF
-#define COUNTOF(STR) (sizeof (STR) / sizeof ((STR)[0]))
-#endif
-
 int using_threads = 1;
 
 const struct target_desc *win32_tdesc;
@@ -483,61 +479,6 @@ child_store_inferior_registers (struct regcache *regcache, int r)
       (*the_low_target.store_inferior_register) (regcache, th, regno);
 }
 
-/* Map the Windows error number in ERROR to a locale-dependent error
-   message string and return a pointer to it.  Typically, the values
-   for ERROR come from GetLastError.
-
-   The string pointed to shall not be modified by the application,
-   but may be overwritten by a subsequent call to strwinerror
-
-   The strwinerror function does not change the current setting
-   of GetLastError.  */
-
-char *
-strwinerror (DWORD error)
-{
-  static char buf[1024];
-  TCHAR *msgbuf;
-  DWORD lasterr = GetLastError ();
-  DWORD chars = FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
-			       | FORMAT_MESSAGE_ALLOCATE_BUFFER,
-			       NULL,
-			       error,
-			       0, /* Default language */
-			       (LPTSTR) &msgbuf,
-			       0,
-			       NULL);
-  if (chars != 0)
-    {
-      /* If there is an \r\n appended, zap it.  */
-      if (chars >= 2
-	  && msgbuf[chars - 2] == '\r'
-	  && msgbuf[chars - 1] == '\n')
-	{
-	  chars -= 2;
-	  msgbuf[chars] = 0;
-	}
-
-      if (chars > ((COUNTOF (buf)) - 1))
-	{
-	  chars = COUNTOF (buf) - 1;
-	  msgbuf [chars] = 0;
-	}
-
-#ifdef UNICODE
-      wcstombs (buf, msgbuf, chars + 1);
-#else
-      strncpy (buf, msgbuf, chars + 1);
-#endif
-      LocalFree (msgbuf);
-    }
-  else
-    sprintf (buf, "unknown win32 error (%u)", (unsigned) error);
-
-  SetLastError (lasterr);
-  return buf;
-}
-
 static BOOL
 create_process (const char *program, char *args,
 		DWORD flags, PROCESS_INFORMATION *pi)
diff --git a/gdbserver/win32-low.h b/gdbserver/win32-low.h
index 58bb105b283..d7bb76b6a98 100644
--- a/gdbserver/win32-low.h
+++ b/gdbserver/win32-low.h
@@ -211,15 +211,4 @@ extern gdbserver_windows_process windows_process;
 /* Retrieve the context for this thread, if not already retrieved.  */
 extern void win32_require_context (windows_nat::windows_thread_info *th);
 
-/* Map the Windows error number in ERROR to a locale-dependent error
-   message string and return a pointer to it.  Typically, the values
-   for ERROR come from GetLastError.
-
-   The string pointed to shall not be modified by the application,
-   but may be overwritten by a subsequent call to strwinerror
-
-   The strwinerror function does not change the current setting
-   of GetLastError.  */
-extern char * strwinerror (DWORD error);
-
 #endif /* GDBSERVER_WIN32_LOW_H */
diff --git a/gdbsupport/errors.cc b/gdbsupport/errors.cc
index 703b2213756..b98d0154eb3 100644
--- a/gdbsupport/errors.cc
+++ b/gdbsupport/errors.cc
@@ -19,6 +19,9 @@
 
 #include "common-defs.h"
 #include "errors.h"
+#ifdef USE_WIN32API
+#include <windows.h>
+#endif /* USE_WIN32API */
 
 /* See gdbsupport/errors.h.  */
 
@@ -67,3 +70,54 @@ internal_warning (const char *file, int line, const char *fmt, ...)
   internal_vwarning (file, line, fmt, ap);
   va_end (ap);
 }
+
+#ifdef USE_WIN32API
+
+/* See errors.h.  */
+
+const char *
+strwinerror (ULONGEST error)
+{
+  static char buf[1024];
+  TCHAR *msgbuf;
+  DWORD lasterr = GetLastError ();
+  DWORD chars = FormatMessage (FORMAT_MESSAGE_FROM_SYSTEM
+			       | FORMAT_MESSAGE_ALLOCATE_BUFFER,
+			       NULL,
+			       error,
+			       0, /* Default language */
+			       (LPTSTR) &msgbuf,
+			       0,
+			       NULL);
+  if (chars != 0)
+    {
+      /* If there is an \r\n appended, zap it.  */
+      if (chars >= 2
+	  && msgbuf[chars - 2] == '\r'
+	  && msgbuf[chars - 1] == '\n')
+	{
+	  chars -= 2;
+	  msgbuf[chars] = 0;
+	}
+
+      if (chars > ARRAY_SIZE (buf) - 1)
+	{
+	  chars = ARRAY_SIZE (buf) - 1;
+	  msgbuf [chars] = 0;
+	}
+
+#ifdef UNICODE
+      wcstombs (buf, msgbuf, chars + 1);
+#else
+      strncpy (buf, msgbuf, chars + 1);
+#endif
+      LocalFree (msgbuf);
+    }
+  else
+    sprintf (buf, "unknown win32 error (%u)", (unsigned) error);
+
+  SetLastError (lasterr);
+  return buf;
+}
+
+#endif /* USE_WIN32API */
diff --git a/gdbsupport/errors.h b/gdbsupport/errors.h
index 47965ea8a3c..9a671d3e289 100644
--- a/gdbsupport/errors.h
+++ b/gdbsupport/errors.h
@@ -91,4 +91,20 @@ extern void malloc_failure (long size) ATTRIBUTE_NORETURN;
 
 extern void flush_streams ();
 
+#ifdef USE_WIN32API
+
+/* Map the Windows error number in ERROR to a locale-dependent error
+   message string and return a pointer to it.  Typically, the values
+   for ERROR come from GetLastError.
+
+   The string pointed to shall not be modified by the application,
+   but may be overwritten by a subsequent call to strwinerror
+
+   The strwinerror function does not change the current setting
+   of GetLastError.  */
+
+extern const char *strwinerror (ULONGEST error);
+
+#endif /* USE_WIN32API */
+
 #endif /* COMMON_ERRORS_H */
-- 
2.34.1