More long path name support on Windows, this time in program execution.

Allows long paths for the executable and redirected stdin/stdout/stderr.
Addresses PR21563.

llvm-svn: 222671

3 files changed, 24 insertions, 9 deletions

diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index 365031cf150..adb9a60857f 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -44,6 +44,7 @@ using namespace llvm;
 
 using llvm::sys::windows::UTF8ToUTF16;
 using llvm::sys::windows::UTF16ToUTF8;
+using llvm::sys::path::widenPath;
 
 static std::error_code windows_error(DWORD E) {
   return mapWindowsError(E);
@@ -59,11 +60,15 @@ static bool is_separator(const wchar_t value) {
   }
 }
 
+namespace llvm {
+namespace sys  {
+namespace path {
+
 // Convert a UTF-8 path to UTF-16.  Also, if the absolute equivalent of the
 // path is longer than CreateDirectory can tolerate, make it absolute and
 // prefixed by '\\?\'.
-static std::error_code widenPath(const Twine &Path8,
-                                 SmallVectorImpl<wchar_t> &Path16) {
+std::error_code widenPath(const Twine &Path8,
+                          SmallVectorImpl<wchar_t> &Path16) {
   const size_t MaxDirLen = MAX_PATH - 12; // Must leave room for 8.3 filename.
 
   // Several operations would convert Path8 to SmallString; more efficient to
@@ -111,9 +116,8 @@ static std::error_code widenPath(const Twine &Path8,
   // Just use the caller's original path.
   return UTF8ToUTF16(Path8Str, Path16);
 }
+} // end namespace path
 
-namespace llvm {
-namespace sys  {
 namespace fs {
 
 std::string getMainExecutable(const char *argv0, void *MainExecAddr) {
diff --git a/llvm/lib/Support/Windows/Program.inc b/llvm/lib/Support/Windows/Program.inc
index 72c2a58688d..6467dddb3da 100644
--- a/llvm/lib/Support/Windows/Program.inc
+++ b/llvm/lib/Support/Windows/Program.inc
@@ -117,14 +117,19 @@ static HANDLE RedirectIO(const StringRef *path, int fd, std::string* ErrMsg) {
   sa.bInheritHandle = TRUE;
 
   SmallVector<wchar_t, 128> fnameUnicode;
-  if (windows::UTF8ToUTF16(fname, fnameUnicode))
-    return INVALID_HANDLE_VALUE;
-
+  if (path->empty()) {
+    // Don't play long-path tricks on "NUL".
+    if (windows::UTF8ToUTF16(fname, fnameUnicode))
+      return INVALID_HANDLE_VALUE;
+  } else {
+    if (path::widenPath(fname, fnameUnicode))
+      return INVALID_HANDLE_VALUE;
+  }
   h = CreateFileW(fnameUnicode.data(), fd ? GENERIC_WRITE : GENERIC_READ,
                   FILE_SHARE_READ, &sa, fd == 0 ? OPEN_EXISTING : CREATE_ALWAYS,
                   FILE_ATTRIBUTE_NORMAL, NULL);
   if (h == INVALID_HANDLE_VALUE) {
-    MakeErrMsg(ErrMsg, std::string(fname) + ": Can't open file for " +
+    MakeErrMsg(ErrMsg, fname + ": Can't open file for " +
         (fd ? "input: " : "output: "));
   }
 
@@ -322,7 +327,7 @@ static bool Execute(ProcessInfo &PI, StringRef Program, const char **args,
   fflush(stderr);
 
   SmallVector<wchar_t, MAX_PATH> ProgramUtf16;
-  if (std::error_code ec = windows::UTF8ToUTF16(Program, ProgramUtf16)) {
+  if (std::error_code ec = path::widenPath(Program, ProgramUtf16)) {
     SetLastError(ec.value());
     MakeErrMsg(ErrMsg,
                std::string("Unable to convert application name to UTF-16"));
diff --git a/llvm/lib/Support/Windows/WindowsSupport.h b/llvm/lib/Support/Windows/WindowsSupport.h
index 6d9c5fb24ff..1d1cedcce29 100644
--- a/llvm/lib/Support/Windows/WindowsSupport.h
+++ b/llvm/lib/Support/Windows/WindowsSupport.h
@@ -30,6 +30,7 @@
 
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/Config/config.h" // Get build system configuration settings
 #include "llvm/Support/Compiler.h"
 #include <system_error>
@@ -162,6 +163,11 @@ c_str(SmallVectorImpl<T> &str) {
 }
 
 namespace sys {
+namespace path {
+std::error_code widenPath(const Twine &Path8,
+                          SmallVectorImpl<wchar_t> &Path16);
+} // end namespace path
+
 namespace windows {
 std::error_code UTF8ToUTF16(StringRef utf8, SmallVectorImpl<wchar_t> &utf16);
 std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,