Make I/O redirection handling in sys::Program a bit more consistent. No

functional changes. Win32 code is untested, but should work fine.

In the unix variant, rename RedirectFD to RedirectIO and let that function
handle empty and null paths instead of doing that in the caller 3 times. This
is the same as win32 already does it.

In the win32 variant, use Path::isEmpty() instead of checking the resulting
c_str() manually. This is the same as unix already does it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52230 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 18 insertions, 24 deletions

diff --git a/lib/System/Unix/Program.inc b/lib/System/Unix/Program.inc
index d0dade1f8c..6ff69ca133 100644
--- a/lib/System/Unix/Program.inc
+++ b/lib/System/Unix/Program.inc
@@ -84,8 +84,16 @@ Program::FindProgramByName(const std::string& progName) {
   return Path();
 }
 
-static bool RedirectFD(const std::string &File, int FD, std::string* ErrMsg) {
-  if (File.empty()) return false;  // Noop
+static bool RedirectIO(const Path *Path, int FD, std::string* ErrMsg) {
+  if (Path == 0)
+    // Noop
+    return false;
+  std::string File;
+  if (Path->isEmpty())
+    // Redirect empty paths to /dev/null
+    File = "/dev/null";
+  else
+    File = Path->toString();
 
   // Open the file
   int InFD = open(File.c_str(), FD == 0 ? O_RDONLY : O_WRONLY|O_CREAT, 0666);
@@ -162,27 +170,11 @@ Program::ExecuteAndWait(const Path& path,
     case 0: {
       // Redirect file descriptors...
       if (redirects) {
-        if (redirects[0]) {
-          if (redirects[0]->isEmpty()) {
-            if (RedirectFD("/dev/null",0,ErrMsg)) { return -1; }
-          } else {
-            if (RedirectFD(redirects[0]->toString(), 0,ErrMsg)) { return -1; }
-          }
-        }
-        if (redirects[1]) {
-          if (redirects[1]->isEmpty()) {
-            if (RedirectFD("/dev/null",1,ErrMsg)) { return -1; }
-          } else {
-            if (RedirectFD(redirects[1]->toString(),1,ErrMsg)) { return -1; }
-          }
-        }
+        if (RedirectIO(redirects[0], 0, ErrMsg)) { return -1; }
+        if (RedirectIO(redirects[1], 1, ErrMsg)) { return -1; }
         if (redirects[1] && redirects[2] && 
             *(redirects[1]) != *(redirects[2])) {
-          if (redirects[2]->isEmpty()) {
-            if (RedirectFD("/dev/null",2,ErrMsg)) { return -1; }
-          } else {
-            if (RedirectFD(redirects[2]->toString(), 2,ErrMsg)) { return -1; }
-          }
+          if (RedirectIO(redirects[2], 2, ErrMsg)) { return -1; }
         } else if (-1 == dup2(1,2)) {
           MakeErrMsg(ErrMsg, "Can't redirect");
           return -1;
diff --git a/lib/System/Win32/Program.inc b/lib/System/Win32/Program.inc
index cb002132bf..52eb9677ff 100644
--- a/lib/System/Win32/Program.inc
+++ b/lib/System/Win32/Program.inc
@@ -77,10 +77,12 @@ static HANDLE RedirectIO(const Path *path, int fd, std::string* ErrMsg) {
                     0, TRUE, DUPLICATE_SAME_ACCESS);
     return h;
   }
-
-  const char *fname = path->toString().c_str();
-  if (*fname == 0)
+  
+  const char *fname;
+  if (path->isEmpty())
     fname = "NUL";
+  else
+    fname = path->toString().c_str();
 
   SECURITY_ATTRIBUTES sa;
   sa.nLength = sizeof(sa);