SERVER-7252 Introduce and test function for building a Windows comman…

…d line from an argument vector.

src/mongo/SConscript

@@ -41,6 +41,8 @@ env.StaticLibrary('foundation',
                            '$BUILD_DIR/third_party/shim_allocator',
                            '$BUILD_DIR/third_party/shim_boost'])
 
+env.CppUnitTest('text_test', 'util/text_test.cpp', LIBDEPS=['foundation'])
+
 env.StaticLibrary('stringutils', ['util/stringutils.cpp', 'util/base64.cpp',])
 
 env.StaticLibrary('md5', [

src/mongo/util/text.cpp

@@ -18,6 +18,8 @@
 #include "pch.h"
 
 #include <boost/smart_ptr/scoped_array.hpp>
+#include <sstream>
+
 #ifdef _WIN32
 #include <io.h>
 #endif
@@ -299,5 +301,51 @@ namespace mongo {
 
 #endif // #if defined(_WIN32)
 
+    // See "Parsing C++ Command-Line Arguments (C++)"
+    // http://msdn.microsoft.com/en-us/library/windows/desktop/17w5ykft(v=vs.85).aspx
+    static void quoteForWindowsCommandLine(const std::string& arg, std::ostream& os) {
+        if (arg.find_first_of(" \t\"") == std::string::npos) {
+            os << arg;
+        }
+        else {
+            os << '"';
+            std::string backslashes = "";
+            for (std::string::const_iterator iter = arg.begin(), end = arg.end();
+                 iter != end; ++iter) {
+
+                switch (*iter) {
+                case '\\':
+                    backslashes.push_back(*iter);
+                    if (iter + 1 == end)
+                        os << backslashes << backslashes;
+                    break;
+                case '"':
+                    os << backslashes << backslashes << "\\\"";
+                    break;
+                default:
+                    os << backslashes << *iter;
+                    backslashes.clear();
+                    break;
+                }
+            }
+            os << '"';
+        }
+    }
+
+    std::string constructUtf8WindowsCommandLine(const std::vector<std::string>& argv) {
+        if (argv.empty())
+            return "";
+
+        std::ostringstream commandLine;
+        std::vector<std::string>::const_iterator iter = argv.begin();
+        std::vector<std::string>::const_iterator end = argv.end();
+        quoteForWindowsCommandLine(*iter, commandLine);
+        ++iter;
+        for (; iter != end; ++iter) {
+            commandLine << ' ';
+            quoteForWindowsCommandLine(*iter, commandLine);
+        }
+        return commandLine.str();
+    }
 }
 

src/mongo/util/text.h

@@ -89,4 +89,13 @@ namespace mongo {
 
 #endif // #if defined(_WIN32)
 
+    /**
+     * Construct a Windows command line string, UTF-8 encoded, from a vector of
+     * UTF-8 arguments, "argv".
+     *
+     * See "Parsing C++ Command-Line Arguments (C++)"
+     * http://msdn.microsoft.com/en-us/library/windows/desktop/17w5ykft(v=vs.85).aspx
+     */
+    std::string constructUtf8WindowsCommandLine(const std::vector<std::string>& argv);
+
 } // namespace mongo

src/mongo/util/text_test.cpp

@@ -0,0 +1,59 @@
+/*
+ *    Copyright 2012 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (the "License");
+ *    you may not use this file except in compliance with the License.
+ *    You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#include <cstdarg>
+#include <string>
+#include <vector>
+
+#include "mongo/unittest/unittest.h"
+#include "mongo/util/text.h"
+
+using namespace mongo;
+
+static std::vector<std::string> svec(const char* first, ...) {
+    std::vector<std::string> result;
+    if (first) {
+        result.push_back(first);
+        va_list ap;
+        va_start(ap, first);
+        const char* curr;
+        while (NULL != (curr = va_arg(ap, const char*))) {
+            result.push_back(curr);
+        }
+        va_end(ap);
+    }
+    return result;
+}
+
+TEST(WindowsCommandLineConstruction, EmptyCommandLine) {
+    ASSERT_EQUALS("", constructUtf8WindowsCommandLine(svec(NULL)));
+}
+
+TEST(WindowsCommandLineConstruction, NothingToQuote) {
+    ASSERT_EQUALS("abc d e",
+                  constructUtf8WindowsCommandLine(svec("abc", "d", "e", NULL)));
+}
+
+TEST(WindowsCommandLineConstruction, ThingsToQuote) {
+    ASSERT_EQUALS("a\\\\\\b \"de fg\" h",
+                  constructUtf8WindowsCommandLine(svec("a\\\\\\b", "de fg", "h", NULL)));
+    ASSERT_EQUALS("\"a\\\\b c\" d e",
+                  constructUtf8WindowsCommandLine(svec("a\\\\b c", "d" , "e", NULL)));
+    ASSERT_EQUALS("\"a \\\\\" \\",
+                  constructUtf8WindowsCommandLine(svec("a \\", "\\", NULL)));
+    ASSERT_EQUALS("\"\\\\\\\\\\\"\"",
+                  constructUtf8WindowsCommandLine(svec("\\\\\"", NULL)));
+}