Move AlterEnvironment to base/environment.h, implement on Windows.

base/process/launch_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/process/launch.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
@@ skipping 252 matching lines @@
     // own use and will complain if we try to close them.  All of
     // these FDs are >= |max_fds|, so we can check against that here
     // before closing.  See https://bugs.kde.org/show_bug.cgi?id=191758
     if (fd < static_cast<int>(max_fds)) {
       int ret = HANDLE_EINTR(close(fd));
       DPCHECK(ret == 0);
     }
   }
 }
 
-char** AlterEnvironment(const EnvironmentVector& changes,
-                        const char* const* const env) {
-  unsigned count = 0;
-  unsigned size = 0;
-
-  // First assume that all of the current environment will be included.
-  for (unsigned i = 0; env[i]; i++) {
-    const char *const pair = env[i];
-    count++;
-    size += strlen(pair) + 1 /* terminating NUL */;
-  }
-
-  for (EnvironmentVector::const_iterator j = changes.begin();
-       j != changes.end();
-       ++j) {
-    bool found = false;
-    const char *pair;
-
-    for (unsigned i = 0; env[i]; i++) {
-      pair = env[i];
-      const char *const equals = strchr(pair, '=');
-      if (!equals)
-        continue;
-      const unsigned keylen = equals - pair;
-      if (keylen == j->first.size() &&
-          memcmp(pair, j->first.data(), keylen) == 0) {
-        found = true;
-        break;
-      }
-    }
-
-    // if found, we'll either be deleting or replacing this element.
-    if (found) {
-      count--;
-      size -= strlen(pair) + 1;
-      if (j->second.size())
-        found = false;
-    }
-
-    // if !found, then we have a new element to add.
-    if (!found && !j->second.empty()) {
-      count++;
-      size += j->first.size() + 1 /* '=' */ + j->second.size() + 1 /* NUL */;
-    }
-  }
-
-  count++;  // for the final NULL
-  uint8_t *buffer = new uint8_t[sizeof(char*) * count + size];
-  char **const ret = reinterpret_cast<char**>(buffer);
-  unsigned k = 0;
-  char *scratch = reinterpret_cast<char*>(buffer + sizeof(char*) * count);
-
-  for (unsigned i = 0; env[i]; i++) {
-    const char *const pair = env[i];
-    const char *const equals = strchr(pair, '=');
-    if (!equals) {
-      const unsigned len = strlen(pair);
-      ret[k++] = scratch;
-      memcpy(scratch, pair, len + 1);
-      scratch += len + 1;
-      continue;
-    }
-    const unsigned keylen = equals - pair;
-    bool handled = false;
-    for (EnvironmentVector::const_iterator
-         j = changes.begin(); j != changes.end(); j++) {
-      if (j->first.size() == keylen &&
-          memcmp(j->first.data(), pair, keylen) == 0) {
-        if (!j->second.empty()) {
-          ret[k++] = scratch;
-          memcpy(scratch, pair, keylen + 1);
-          scratch += keylen + 1;
-          memcpy(scratch, j->second.c_str(), j->second.size() + 1);
-          scratch += j->second.size() + 1;
-        }
-        handled = true;
-        break;
-      }
-    }
-
-    if (!handled) {
-      const unsigned len = strlen(pair);
-      ret[k++] = scratch;
-      memcpy(scratch, pair, len + 1);
-      scratch += len + 1;
-    }
-  }
-
-  // Now handle new elements
-  for (EnvironmentVector::const_iterator
-       j = changes.begin(); j != changes.end(); j++) {
-    if (j->second.empty())
-      continue;
-
-    bool found = false;
-    for (unsigned i = 0; env[i]; i++) {
-      const char *const pair = env[i];
-      const char *const equals = strchr(pair, '=');
-      if (!equals)
-        continue;
-      const unsigned keylen = equals - pair;
-      if (keylen == j->first.size() &&
-          memcmp(pair, j->first.data(), keylen) == 0) {
-        found = true;
-        break;
-      }
-    }
-
-    if (!found) {
-      ret[k++] = scratch;
-      memcpy(scratch, j->first.data(), j->first.size());
-      scratch += j->first.size();
-      *scratch++ = '=';
-      memcpy(scratch, j->second.c_str(), j->second.size() + 1);
-      scratch += j->second.size() + 1;
-     }
-  }
-
-  ret[k] = NULL;
-  return ret;
-}
-
 bool LaunchProcess(const std::vector<std::string>& argv,
                    const LaunchOptions& options,
                    ProcessHandle* process_handle) {
   size_t fd_shuffle_size = 0;
   if (options.fds_to_remap) {
     fd_shuffle_size = options.fds_to_remap->size();
   }
 
   InjectiveMultimap fd_shuffle1;
   InjectiveMultimap fd_shuffle2;
   fd_shuffle1.reserve(fd_shuffle_size);
   fd_shuffle2.reserve(fd_shuffle_size);
 
   scoped_ptr<char*[]> argv_cstr(new char*[argv.size() + 1]);
   scoped_ptr<char*[]> new_environ;
-  if (options.environ)
-    new_environ.reset(AlterEnvironment(*options.environ, GetEnvironment()));
+  if (!options.environ.empty())
+    new_environ = AlterEnvironment(GetEnvironment(), options.environ);
 
   sigset_t full_sigset;
   sigfillset(&full_sigset);
   const sigset_t orig_sigmask = SetSignalMask(full_sigset);
 
   pid_t pid;
 #if defined(OS_LINUX)
   if (options.clone_flags) {
     // Signal handling in this function assumes the creation of a new
     // process, so we check that a thread is not being created by mistake
@@ skipping 107 matching lines @@
 
     if (options.fds_to_remap) {
       for (FileHandleMappingVector::const_iterator
                it = options.fds_to_remap->begin();
            it != options.fds_to_remap->end(); ++it) {
         fd_shuffle1.push_back(InjectionArc(it->first, it->second, false));
         fd_shuffle2.push_back(InjectionArc(it->first, it->second, false));
       }
     }
 
-    if (options.environ)
+    if (!options.environ.empty())
       SetEnvironment(new_environ.get());
 
     // fd_shuffle1 is mutated by this call because it cannot malloc.
     if (!ShuffleFileDescriptors(&fd_shuffle1))
       _exit(127);
 
     CloseSuperfluousFds(fd_shuffle2);
 
     for (size_t i = 0; i < argv.size(); i++)
       argv_cstr[i] = const_cast<char*>(argv[i].c_str());
@@ skipping 201 matching lines @@
                               std::string* output,
                               int* exit_code) {
   // Run |execve()| with the current environment and store "unlimited" data.
   GetAppOutputInternalResult result = GetAppOutputInternal(
       cl.argv(), NULL, output, std::numeric_limits<std::size_t>::max(), true,
       exit_code);
   return result == EXECUTE_SUCCESS;
 }
 
 }  // namespace base