src/windows/native/java/io/io_util_md.c

rev 1551 : 8057530: (process) Runtime.exec throws garbled message in jp locale
8016579: (process) IOException thrown by ProcessBuilder.start() method is incorrectly encoded
Reviewed-by: alanb

@@ -27,10 +27,11 @@
 #include "jni_util.h"
 #include "jvm.h"
 #include "io_util.h"
 #include "io_util_md.h"
 #include <stdio.h>
+#include <windows.h>
 
 #include <wchar.h>
 #include <io.h>
 #include <fcntl.h>
 #include <errno.h>

@@ -574,5 +575,79 @@
             return -1;
         }
     }
     return (((jlong)highPos) << 32) | lowPos;
 }
+
+size_t
+getLastErrorString(char *utf8_jvmErrorMsg, size_t cbErrorMsg)
+{
+    size_t n = 0;
+    if (cbErrorMsg > 0) {
+        BOOLEAN noError = FALSE;
+        WCHAR *utf16_osErrorMsg = (WCHAR *)malloc(cbErrorMsg*sizeof(WCHAR));
+        if (utf16_osErrorMsg == NULL) {
+            // OOM accident
+            strncpy(utf8_jvmErrorMsg, "Out of memory", cbErrorMsg);
+            // truncate if too long
+            utf8_jvmErrorMsg[cbErrorMsg - 1] = '\0';
+            n = strlen(utf8_jvmErrorMsg);
+        } else {
+            DWORD errval = GetLastError();
+            if (errval != 0) {
+                // WIN32 error
+                n = (size_t)FormatMessageW(
+                    FORMAT_MESSAGE_FROM_SYSTEM|FORMAT_MESSAGE_IGNORE_INSERTS,
+                    NULL,
+                    errval,
+                    0,
+                    utf16_osErrorMsg,
+                    (DWORD)cbErrorMsg,
+                    NULL);
+                if (n > 3) {
+                    // Drop final '.', CR, LF
+                    if (utf16_osErrorMsg[n - 1] == L'\n') --n;
+                    if (utf16_osErrorMsg[n - 1] == L'\r') --n;
+                    if (utf16_osErrorMsg[n - 1] == L'.') --n;
+                    utf16_osErrorMsg[n] = L'\0';
+                }
+            } else if (errno != 0) {
+                // C runtime error that has no corresponding WIN32 error code
+                const WCHAR *rtError = _wcserror(errno);
+                if (rtError != NULL) {
+                    wcsncpy(utf16_osErrorMsg, rtError, cbErrorMsg);
+                    // truncate if too long
+                    utf16_osErrorMsg[cbErrorMsg - 1] = L'\0';
+                    n = wcslen(utf16_osErrorMsg);
+                }
+            } else
+                noError = TRUE; //OS has no error to report
+
+            if (!noError) {
+                if (n > 0) {
+                    n = WideCharToMultiByte(
+                        CP_UTF8,
+                        0,
+                        utf16_osErrorMsg,
+                        n,
+                        utf8_jvmErrorMsg,
+                        cbErrorMsg,
+                        NULL,
+                        NULL);
+
+                    // no way to die
+                    if (n > 0)
+                        utf8_jvmErrorMsg[min(cbErrorMsg - 1, n)] = '\0';
+                }
+
+                if (n <= 0) {
+                    strncpy(utf8_jvmErrorMsg, "Secondary error while OS message extraction", cbErrorMsg);
+                    // truncate if too long
+                    utf8_jvmErrorMsg[cbErrorMsg - 1] = '\0';
+                    n = strlen(utf8_jvmErrorMsg);
+                }
+            }
+            free(utf16_osErrorMsg);
+        }
+    }
+    return n;
+}