From cc0ac62d1c03206bc3a1edba4d60f97921b854f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
Date: Fri, 4 Dec 2015 20:45:33 +0100
Subject: [PATCH] llvm-config: Clean up exported values, update for shared
 linking

Gentoo-specific fixup for llvm-config, including:
- wiping build-specific CFLAGS, CXXFLAGS,
- updating library suffixes for shared libs,
- wiping --system-libs for shared linking,
- banning --obj-root and --src-root due to no sources installed.

Thanks to Steven Newbury for the initial patch.

Bug: https://bugs.gentoo.org/565358
Bug: https://bugs.gentoo.org/501684
---
 tools/llvm-config/CMakeLists.txt   |  9 +++++++--
 tools/llvm-config/llvm-config.cpp  | 17 +++++++++++++----
 utils/llvm-build/llvmbuild/main.py |  5 ++++-
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/tools/llvm-config/CMakeLists.txt b/tools/llvm-config/CMakeLists.txt
index 83794bb..21fd845 100644
--- a/tools/llvm-config/CMakeLists.txt
+++ b/tools/llvm-config/CMakeLists.txt
@@ -22,15 +22,20 @@ get_property(COMPILE_FLAGS TARGET llvm-config PROPERTY COMPILE_FLAGS)
 set(LLVM_SRC_ROOT ${LLVM_MAIN_SRC_DIR})
 set(LLVM_OBJ_ROOT ${LLVM_BINARY_DIR})
 set(LLVM_CPPFLAGS "${CMAKE_CPP_FLAGS} ${CMAKE_CPP_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
+# Just use CMAKE_CPP_FLAGS for CFLAGS and CXXFLAGS, otherwise compiler
+# specific flags will be set when we don't know what compiler will be used
+# with external project utilising llvm-config.  C++ Standard is required.
+# TODO: figure out if we can remove -std=c++11 and move it to revdeps.
 set(LLVM_CFLAGS "${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
-set(LLVM_CXXFLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${COMPILE_FLAGS} ${LLVM_DEFINITIONS}")
+set(LLVM_CXXFLAGS "${CMAKE_CPP_FLAGS} -std=c++11 ${CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
 set(LLVM_BUILD_SYSTEM cmake)
 set(LLVM_HAS_RTTI ${LLVM_CONFIG_HAS_RTTI})
 
 # Use the C++ link flags, since they should be a superset of C link flags.
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")
 set(LLVM_BUILDMODE ${CMAKE_BUILD_TYPE})
-set(LLVM_SYSTEM_LIBS ${SYSTEM_LIBS})
+# We don't do static libs, so we don't need to supply any system-libs
+set(LLVM_SYSTEM_LIBS "")
 if(BUILD_SHARED_LIBS)
   set(LLVM_ENABLE_SHARED ON)
 else()
diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
index 80f6279..b16b9a3 100644
--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
@@ -497,10 +497,19 @@ int main(int argc, char **argv) {
         OS << LLVM_HAS_RTTI << '\n';
       } else if (Arg == "--shared-mode") {
         PrintSharedMode = true;
-      } else if (Arg == "--obj-root") {
-        OS << ActivePrefix << '\n';
-      } else if (Arg == "--src-root") {
-        OS << LLVM_SRC_ROOT << '\n';
+      } else if (Arg == "--obj-root" || Arg == "--src-root") {
+        if (IsInDevelopmentTree) {
+          if (Arg == "--obj-root") {
+            OS << ActivePrefix << '\n';
+          } else {
+            OS << LLVM_SRC_ROOT << '\n';
+          }
+        } else {
+          // sources are not installed
+          llvm::errs() << "llvm-config: sources not installed, "
+                       << Arg << " not available\n";
+          exit(1);
+        }
       } else {
         usage();
       }
diff --git a/utils/llvm-build/llvmbuild/main.py b/utils/llvm-build/llvmbuild/main.py
index f2472f6..a29fc83 100644
--- a/utils/llvm-build/llvmbuild/main.py
+++ b/utils/llvm-build/llvmbuild/main.py
@@ -393,6 +393,8 @@ subdirectories = %s
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Config/config.h"
+
 """)
         f.write('struct AvailableComponent {\n')
         f.write('  /// The name of the component.\n')
@@ -413,7 +415,8 @@ subdirectories = %s
             if library_name is None:
                 library_name_as_cstr = 'nullptr'
             else:
-                library_name_as_cstr = '"lib%s.a"' % library_name
+                library_name_as_cstr = '"lib%s" LTDL_SHLIB_EXT' % library_name
+
             if is_installed:
                 is_installed_as_cstr = 'true'
             else:
-- 
2.6.3