From fe2e6e796454925ba487a213b3682b15e0f63c3a Mon Sep 17 00:00:00 2001
From: Eric Fiselier <eric@efcs.ca>
Date: Fri, 17 Oct 2014 16:32:06 +0000
Subject: [PATCH] [libcxxabi] Document the standalone build's requirements on
 llvm-config and llvm sources.

The current documentation does not explain that the standalone build requires
the LLVM sources. This patch updates the documentation to reflect this
requirement and explains how to manually specify the location of the required
files.

llvm-svn: 220049
---
 libcxxabi/CMakeLists.txt |  4 +++-
 libcxxabi/www/index.html | 10 ++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/libcxxabi/CMakeLists.txt b/libcxxabi/CMakeLists.txt
index 6815b0d98284..494b18d7b79a 100644
--- a/libcxxabi/CMakeLists.txt
+++ b/libcxxabi/CMakeLists.txt
@@ -46,7 +46,9 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     set(LLVM_CMAKE_PATH "${LLVM_BINARY_DIR}/share/llvm/cmake")
     set(LLVM_LIT_PATH "${LLVM_PATH}/utils/lit/lit.py")
   else()
-    message(FATAL_ERROR "llvm-config not found and LLVM_MAIN_SRC_DIR not defined")
+    message(FATAL_ERROR "llvm-config not found and LLVM_MAIN_SRC_DIR not defined. "
+                        "Reconfigure with -DLLVM_CONFIG=path/to/llvm-config "
+                        "or -DLLVM_PATH=path/to/llvm-source-root.")
   endif()
 
   if(EXISTS ${LLVM_CMAKE_PATH})
diff --git a/libcxxabi/www/index.html b/libcxxabi/www/index.html
index 197e71755e10..b7b66d8c5522 100644
--- a/libcxxabi/www/index.html
+++ b/libcxxabi/www/index.html
@@ -96,6 +96,16 @@
     linux you may need -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++</code></li>
   <li><code>make</code></li>
   </ul>
+  <p> By default CMake uses <code>llvm-config</code> to locate the required
+      LLVM sources. If CMake cannot find <code>llvm-config</code> then you must
+      configure CMake using either of the following options.
+  </p>
+  <ul>
+  <li><code>-DLLVM_CONFIG=path/to/llvm-config</code></li>
+  <li><code>-DLLVM_PATH=path/to/llvm-source-root</code></li>
+  </ul>
+
+  </p>
 
   <p>To run the tests:</p>
   <ul>