Resubmit "[Support] Expose flattenWindowsCommandLine."

There were a few linux compilation failures, but other than that
I think this was just a flake that caused the tests to fail.  I'm
going to resubmit and see if the failures go away, if not I'll
revert again.

llvm-svn: 334355

1 files changed, 4 insertions, 6 deletions

diff --git a/llvm/lib/Support/Unix/Program.inc b/llvm/lib/Support/Unix/Program.inc
index 04840bf..be97155 100644
--- a/llvm/lib/Support/Unix/Program.inc
+++ b/llvm/lib/Support/Unix/Program.inc
@@ -434,7 +434,7 @@ llvm::sys::writeFileWithEncoding(StringRef FileName, StringRef Contents,
 }
 
 bool llvm::sys::commandLineFitsWithinSystemLimits(StringRef Program,
-                                                  ArrayRef<const char *> Args) {
+                                                  ArrayRef<StringRef> Args) {
   static long ArgMax = sysconf(_SC_ARG_MAX);
   // POSIX requires that _POSIX_ARG_MAX is 4096, which is the lowest possible
   // value for ARG_MAX on a POSIX compliant system.
@@ -456,18 +456,16 @@ bool llvm::sys::commandLineFitsWithinSystemLimits(StringRef Program,
   long HalfArgMax = EffectiveArgMax / 2;
 
   size_t ArgLength = Program.size() + 1;
-  for (const char* Arg : Args) {
-    size_t length = strlen(Arg);
-
+  for (StringRef Arg : Args) {
     // Ensure that we do not exceed the MAX_ARG_STRLEN constant on Linux, which
     // does not have a constant unlike what the man pages would have you
     // believe. Since this limit is pretty high, perform the check
     // unconditionally rather than trying to be aggressive and limiting it to
     // Linux only.
-    if (length >= (32 * 4096))
+    if (Arg.size() >= (32 * 4096))
       return false;
 
-    ArgLength += length + 1;
+    ArgLength += Arg.size() + 1;
     if (ArgLength > size_t(HalfArgMax)) {
       return false;
     }