Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>

From 61b00e1e051e367f5483d7b5253b6c85a9e8a90f Mon Sep 17 00:00:00 2001
From: Martin Kelly <mkelly@xevo.com>
Date: Fri, 19 May 2017 00:22:57 -0700
Subject: [PATCH] llvm: allow env override of exe path

When using a native llvm-config from inside a sysroot, we need llvm-config to
return the libraries, include directories, etc. from inside the sysroot rather
than from the native sysroot. Thus provide an env override for calling
llvm-config from a target sysroot.

Signed-off-by: Martin Kelly <mkelly@xevo.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
 llvm/tools/llvm-config/llvm-config.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/llvm/tools/llvm-config/llvm-config.cpp b/llvm/tools/llvm-config/llvm-config.cpp
index 7ef7c46a262..a4f7ed82c7b 100644
--- a/llvm/tools/llvm-config/llvm-config.cpp
+++ b/llvm/tools/llvm-config/llvm-config.cpp
@@ -225,6 +225,13 @@ Typical components:\n\
 
 /// Compute the path to the main executable.
 std::string GetExecutablePath(const char *Argv0) {
+  // Hack for Yocto: we need to override the root path when we are using
+  // llvm-config from within a target sysroot.
+  const char *Sysroot = std::getenv("YOCTO_ALTERNATE_EXE_PATH");
+  if (Sysroot != nullptr) {
+    return Sysroot;
+  }
+
   // This just needs to be some symbol in the binary; C++ doesn't
   // allow taking the address of ::main however.
   void *P = (void *)(intptr_t)GetExecutablePath;
