From 8a51e9673859eb3fb819f0d1dad5e2a60d1a3c0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
Date: Wed, 2 Dec 2015 16:04:56 +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    |  11 ++++++++---
 tools/llvm-config/llvm-config.cpp   |  22 ++++++++++++++++------
 utils/llvm-build/llvmbuild/main.py  |   4 +++-
 4 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/tools/llvm-config/CMakeLists.txt b/tools/llvm-config/CMakeLists.txt
index edbd8c9..9a801bd 100644
--- a/tools/llvm-config/CMakeLists.txt
+++ b/tools/llvm-config/CMakeLists.txt
@@ -22,12 +22,17 @@ 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}} ${LLVM_DEFINITIONS}")
-set(LLVM_CFLAGS "${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} ${LLVM_DEFINITIONS}")
+# Just use CMAKE_CPP_FLAGS for CFLAGS and CXXFLAGS, otherwise compiler
+# specific flags will be set when we don't know what compiler will be used
+# with external project utilising llvm-config.  C++ Standard is required.
+# TODO: figure out if we can remove -std=c++11 and move it to revdeps.
+set(LLVM_CFLAGS "${CMAKE_CPP_FLAGS} ${CMAKE_C_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
+set(LLVM_CXXFLAGS "${CMAKE_CPP_FLAGS} -std=c++11 ${CMAKE_CXX_FLAGS_${uppercase_CMAKE_BUILD_TYPE}} ${LLVM_DEFINITIONS}")
 # Use the C++ link flags, since they should be a superset of C link flags.
 set(LLVM_LDFLAGS "${CMAKE_CXX_LINK_FLAGS}")
 set(LLVM_BUILDMODE ${CMAKE_BUILD_TYPE})
-set(LLVM_SYSTEM_LIBS ${SYSTEM_LIBS})
+# We don't do static libs, so we don't need to supply any system-libs
+set(LLVM_SYSTEM_LIBS "")
 string(REPLACE ";" " " LLVM_TARGETS_BUILT "${LLVM_TARGETS_TO_BUILD}")
 configure_file(${BUILDVARIABLES_SRCPATH} ${BUILDVARIABLES_OBJPATH} @ONLY)
 
diff --git a/tools/llvm-config/llvm-config.cpp b/tools/llvm-config/llvm-config.cpp
index 879b9ab..d2c43fa 100644
--- a/tools/llvm-config/llvm-config.cpp
+++ b/tools/llvm-config/llvm-config.cpp
@@ -323,10 +323,19 @@ int main(int argc, char **argv) {
 #else
         OS << "ON\n";
 #endif
-      } 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();
       }
@@ -360,8 +369,9 @@ int main(int argc, char **argv) {
           OS << ActiveLibDir << '/' << Lib;
         } else if (PrintLibs) {
           // If this is a typical library name, include it using -l.
-          if (Lib.startswith("lib") && Lib.endswith(".a")) {
-            OS << "-l" << Lib.slice(3, Lib.size()-2);
+          if (Lib.startswith("lib") && Lib.endswith(LTDL_SHLIB_EXT)) {
+            // sizeof counts trailing NUL
+            OS << "-l" << Lib.slice(3, Lib.size()-sizeof(LTDL_SHLIB_EXT)+1);
             continue;
           }
 
diff --git a/utils/llvm-build/llvmbuild/main.py b/utils/llvm-build/llvmbuild/main.py
index 353741f..4ba5e91 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 +415,7 @@ subdirectories = %s
             if library_name is None:
                 library_name_as_cstr = '0'
             else:
-                library_name_as_cstr = '"lib%s.a"' % library_name
+                library_name_as_cstr = '"lib%s" LTDL_SHLIB_EXT' % library_name
             f.write('  { "%s", %s, %d, { %s } },\n' % (
                 name, library_name_as_cstr, is_installed,
                 ', '.join('"%s"' % dep

-- 
2.6.3