Add getenv() wrapper that works on multibyte environment variable.

On Windows, character encoding of multibyte environment variable varies
depending on settings. The only reliable way to handle it I think is to use
GetEnvironmentVariableW().

GetEnvironmentVariableW() works on wchar_t string, which is on Windows UTF16
string. That's not ideal because we use UTF-8 as the internal encoding in LLVM.
This patch defines a wrapper function which takes and returns UTF-8 string for
GetEnvironmentVariableW().

The wrapper function does not do any conversion and just forwards the argument
to getenv() on Unix.

Differential Revision: http://llvm-reviews.chandlerc.com/D1612

llvm-svn: 190423

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
index 47d0a3c794d..7d8f6250136 100644
--- a/llvm/lib/Support/Unix/Process.inc
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -13,6 +13,7 @@
 
 #include "Unix.h"
 #include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Mutex.h"
 #include "llvm/Support/MutexGuard.h"
 #include "llvm/Support/TimeValue.h"
@@ -181,6 +182,14 @@ void Process::PreventCoreFiles() {
 #endif
 }
 
+Optional<std::string> Process::GetEnv(StringRef Name) {
+  std::string NameStr = Name.str();
+  const char *Val = ::getenv(NameStr.c_str());
+  if (!Val)
+    return None;
+  return std::string(Val);
+}
+
 bool Process::StandardInIsUserInput() {
   return FileDescriptorIsDisplayed(STDIN_FILENO);
 }