2 files changed, 15 insertions, 1 deletions
diff --git a/llvm/lib/Support/Unix/Host.inc b/llvm/lib/Support/Unix/Host.inc
index 457217125a2..0ba6a25aa19 100644
--- a/llvm/lib/Support/Unix/Host.inc
+++ b/llvm/lib/Support/Unix/Host.inc
@@ -45,5 +45,11 @@ std::string sys::getDefaultTargetTriple() {
     TargetTripleString += getOSVersion();
   }
 
+  // Override the default target with an environment variable named by LLVM_TARGET_TRIPLE_ENV.
+#if defined(LLVM_TARGET_TRIPLE_ENV)
+  if (const char *EnvTriple = std::getenv(LLVM_TARGET_TRIPLE_ENV))
+    TargetTripleString = EnvTriple;
+#endif
+
   return Triple::normalize(TargetTripleString);
 }
diff --git a/llvm/lib/Support/Windows/Host.inc b/llvm/lib/Support/Windows/Host.inc
index fe89fe0aad8..7e196cf0ce1 100644
--- a/llvm/lib/Support/Windows/Host.inc
+++ b/llvm/lib/Support/Windows/Host.inc
@@ -18,5 +18,13 @@
 using namespace llvm;
 
 std::string sys::getDefaultTargetTriple() {
-  return Triple::normalize(LLVM_DEFAULT_TARGET_TRIPLE);
+  const char *Triple = LLVM_DEFAULT_TARGET_TRIPLE;
+
+  // Override the default target with an environment variable named by LLVM_TARGET_TRIPLE_ENV.
+#if defined(LLVM_TARGET_TRIPLE_ENV)
+  if (const char *EnvTriple = std::getenv(LLVM_TARGET_TRIPLE_ENV))
+    Triple = EnvTriple;
+#endif
+
+  return Triple::normalize(Triple);
 }