Un-revert the environ copy in ProgramTest after fixing it on OS X

This was r180041 and r180046, which was reverted in r180066.
Re-committing this should fix the dragonegg bootstrap, which I presume
needs LD_LIBRARY_PATH to be propagated to the child.

Tested on Linux, Windows, and Mac OS 10.6.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180099 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Support/ProgramTest.cpp

@@ -13,6 +13,12 @@
 #include "gtest/gtest.h"
 
 #include <stdlib.h>
+#ifdef __APPLE__
+# include <crt_externs.h>
+#else
+// Forward declare environ in case it's not provided by stdlib.h.
+extern char **environ;
+#endif
 
 namespace {
 
@@ -24,6 +30,21 @@ ProgramTestStringArg1("program-test-string-arg1");
 static cl::opt<std::string>
 ProgramTestStringArg2("program-test-string-arg2");
 
+static void CopyEnvironment(std::vector<const char *> &out) {
+#ifdef __APPLE__
+  // _NSGetEnviron() only works from the main exe on Mac.  Fortunately the test
+  // should be in the executable.
+  char **envp = *_NSGetEnviron();
+#else
+  // environ seems to work for Windows and most other Unices.
+  char **envp = environ;
+#endif
+  while (*envp != 0) {
+    out.push_back(*envp);
+    ++envp;
+  }
+}
+
 TEST(ProgramTest, CreateProcessTrailingSlash) {
   if (getenv("LLVM_PROGRAM_TEST_CHILD")) {
     if (ProgramTestStringArg1 == "has\\\\ trailing\\" &&
@@ -43,7 +64,13 @@ TEST(ProgramTest, CreateProcessTrailingSlash) {
     "-program-test-string-arg2", "has\\\\ trailing\\",
     0
   };
-  const char *envp[] = { "LLVM_PROGRAM_TEST_CHILD=1", 0 };
+
+  // Add LLVM_PROGRAM_TEST_CHILD to the environment of the child.
+  std::vector<const char *> envp;
+  CopyEnvironment(envp);
+  envp.push_back("LLVM_PROGRAM_TEST_CHILD=1");
+  envp.push_back(0);
+
   std::string error;
   bool ExecutionFailed;
   // Redirect stdout and stdin to NUL, but let stderr through.
@@ -53,7 +80,7 @@ TEST(ProgramTest, CreateProcessTrailingSlash) {
   Path nul("/dev/null");
 #endif
   const Path *redirects[] = { &nul, &nul, 0 };
-  int rc = Program::ExecuteAndWait(my_exe, argv, envp, redirects,
+  int rc = Program::ExecuteAndWait(my_exe, argv, &envp[0], redirects,
                                    /*secondsToWait=*/10, /*memoryLimit=*/0,
                                    &error, &ExecutionFailed);
   EXPECT_FALSE(ExecutionFailed) << error;