Make CMake find_package(Clang) work. Fixes upstream bug https://bugs.llvm.org/show_bug.cgi?id=37128

* Make CMake find_package(Clang) work. Fixes upstream bug
  https://bugs.llvm.org/show_bug.cgi?id=37128
  - Move Clang*.cmake back to /usr/lib/llvm-X.Y/lib/cmake/clang and install a
    symlink in /usr/lib/cmake/clang-X.Y.
  - Ensure that the LLVM installation prefix is correctly discovered despire
    symlinks (replaces fix-cmake-config-prefix.diff).
  - Create /usr/lib/llvm-X.Y/bin/clang-X.Y symlink as required by
    ClangTargets-relwithdebinfo.cmake.
  - Remove useless LLVM_CMAKE_DIR sed command that did not match anything.
  - Ignore missing binaries in ClangTargets-relwithdebinfo.cmake.

debian/changelog

@@ -2,6 +2,18 @@ llvm-toolchain-6.0 (1:6.0.1~+rc1-1~exp2) experimental; urgency=medium
 
   * Add python-yaml as dep for clang-tidy (Closes: #890514)
 
+  [ Peter Wu ]
+  * Make CMake find_package(Clang) work. Fixes upstream bug
+    https://bugs.llvm.org/show_bug.cgi?id=37128
+    - Move Clang*.cmake back to /usr/lib/llvm-X.Y/lib/cmake/clang and install a
+      symlink in /usr/lib/cmake/clang-X.Y.
+    - Ensure that the LLVM installation prefix is correctly discovered despire
+      symlinks (replaces fix-cmake-config-prefix.diff).
+    - Create /usr/lib/llvm-X.Y/bin/clang-X.Y symlink as required by
+      ClangTargets-relwithdebinfo.cmake.
+    - Remove useless LLVM_CMAKE_DIR sed command that did not match anything.
+    - Ignore missing binaries in ClangTargets-relwithdebinfo.cmake.
+
  -- Sylvestre Ledru <sylvestre@debian.org>  Mon, 07 May 2018 23:27:26 +0200
 
 llvm-toolchain-6.0 (1:6.0.1~+rc1-1~exp1) experimental; urgency=medium

debian/clang-X.Y.install.in

@@ -3,7 +3,7 @@ usr/lib/llvm-@LLVM_VERSION@/bin/clang++
 usr/lib/llvm-@LLVM_VERSION@/bin/clang-cpp
 
 #usr/share/man/man1/clang.1     usr/share/man/man1/
-usr/lib/llvm-@LLVM_VERSION@/lib/cmake/clang/*.cmake usr/share/llvm-@LLVM_VERSION@/cmake/
+usr/lib/llvm-@LLVM_VERSION@/lib/cmake/clang/*.cmake
 usr/lib/llvm-@LLVM_VERSION@/share/clang/bash-autocomplete.sh
 
 usr/bin/clang-@LLVM_VERSION@

debian/clang-X.Y.links.in

@@ -0,0 +1,2 @@
+usr/lib/llvm-@LLVM_VERSION@/bin/clang usr/lib/llvm-@LLVM_VERSION@/bin/clang-@LLVM_VERSION@
+usr/lib/llvm-@LLVM_VERSION@/lib/cmake/clang usr/lib/cmake/clang-@LLVM_VERSION@

debian/patches/0001-llvm-cmake-resolve-symlinks-in-LLVMConfig.cmake.patch

@@ -0,0 +1,34 @@
+From d0d969074f6e0f975ad53d21e7ce6c7b40cf2957 Mon Sep 17 00:00:00 2001
+From: Peter Wu <peter@lekensteyn.nl>
+Date: Fri, 4 May 2018 15:43:06 +0200
+Subject: [PATCH] [llvm] cmake: resolve symlinks in LLVMConfig.cmake
+
+Ensure that symlinks such as /usr/lib/llvm-X.Y/cmake (pointing to
+lib/cmake/llvm) are resolved. This ensures that LLVM_INSTALL_PREFIX
+becomes /usr/lib/llvm-X.Y instead of /usr.
+
+Partially addresses PR37128
+---
+ cmake/modules/CMakeLists.txt | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index 6074e835859..1cf4569b884 100644
+--- a/cmake/modules/CMakeLists.txt
++++ b/cmake/modules/CMakeLists.txt
+@@ -76,10 +76,10 @@ file(COPY .
+ # Generate LLVMConfig.cmake for the install tree.
+ set(LLVM_CONFIG_CODE "
+ # Compute the installation prefix from this LLVMConfig.cmake file location.
+-get_filename_component(LLVM_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" PATH)")
++get_filename_component(LLVM_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" REALPATH)")
+ # Construct the proper number of get_filename_component(... PATH)
+ # calls to compute the installation prefix.
+-string(REGEX REPLACE "/" ";" _count "${LLVM_INSTALL_PACKAGE_DIR}")
++string(REGEX REPLACE "/" ";" _count "prefix/${LLVM_INSTALL_PACKAGE_DIR}")
+ foreach(p ${_count})
+   set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
+ get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
+-- 
+2.17.0
+

debian/patches/0001-tools-clang-cmake-resolve-symlinks-in-ClangConfig.cmake.patch

@@ -0,0 +1,34 @@
+From c830d84bc802ca1e9219415a5784c4ad97a34819 Mon Sep 17 00:00:00 2001
+From: Peter Wu <peter@lekensteyn.nl>
+Date: Fri, 4 May 2018 15:55:26 +0200
+Subject: [PATCH] [clang] cmake: resolve symlinks in ClangConfig.cmake
+
+Ensure that symlinks such as /usr/lib/cmake/clang-X.Y (pointing to
+/usr/lib/llvm-X.Y/lib/cmake/llvm) are resolved. This ensures that
+CLANG_INSTALL_PREFIX ends up to be /usr/lib/llvm-X.Y instead of /usr.
+
+Partially addresses PR37128
+---
+ cmake/modules/CMakeLists.txt | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/cmake/modules/CMakeLists.txt b/cmake/modules/CMakeLists.txt
+index be6d1d7257..bcb61f6cc8 100644
+--- a/clang/cmake/modules/CMakeLists.txt
++++ b/clang/cmake/modules/CMakeLists.txt
+@@ -30,10 +30,10 @@ set(CLANG_CONFIG_EXPORTS_FILE)
+ # Generate ClangConfig.cmake for the install tree.
+ set(CLANG_CONFIG_CODE "
+ # Compute the installation prefix from this LLVMConfig.cmake file location.
+-get_filename_component(CLANG_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" PATH)")
++get_filename_component(CLANG_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" REALPATH)")
+ # Construct the proper number of get_filename_component(... PATH)
+ # calls to compute the installation prefix.
+-string(REGEX REPLACE "/" ";" _count "${CLANG_INSTALL_PACKAGE_DIR}")
++string(REGEX REPLACE "/" ";" _count "prefix/${CLANG_INSTALL_PACKAGE_DIR}")
+ foreach(p ${_count})
+   set(CLANG_CONFIG_CODE "${CLANG_CONFIG_CODE}
+ get_filename_component(CLANG_INSTALL_PREFIX \"\${CLANG_INSTALL_PREFIX}\" PATH)")
+-- 
+2.17.0
+

debian/patches/fix-cmake-config-prefix.diff

@@ -1,27 +0,0 @@
-## Description: add some description
-## Origin/Author: add some origin or author
-## Bug: bug URL
----
-# cmake/modules/CMakeLists.txt |   11 +----------
-# 1 file changed, 1 insertion(+), 10 deletions(-)
-#
---- a/cmake/modules/CMakeLists.txt
-+++ b/cmake/modules/CMakeLists.txt
-@@ -74,16 +74,7 @@ file(COPY .
-   )
- 
- # Generate LLVMConfig.cmake for the install tree.
--set(LLVM_CONFIG_CODE "
--# Compute the installation prefix from this LLVMConfig.cmake file location.
--get_filename_component(LLVM_INSTALL_PREFIX \"\${CMAKE_CURRENT_LIST_FILE}\" PATH)")
--# Construct the proper number of get_filename_component(... PATH)
--# calls to compute the installation prefix.
--string(REGEX REPLACE "/" ";" _count "${LLVM_INSTALL_PACKAGE_DIR}")
--foreach(p ${_count})
--  set(LLVM_CONFIG_CODE "${LLVM_CONFIG_CODE}
--get_filename_component(LLVM_INSTALL_PREFIX \"\${LLVM_INSTALL_PREFIX}\" PATH)")
--endforeach(p)
-+set(LLVM_CONFIG_CODE "set(LLVM_INSTALL_PREFIX \"${CMAKE_INSTALL_PREFIX}\")")
- set(LLVM_CONFIG_INCLUDE_DIRS "\${LLVM_INSTALL_PREFIX}/include")
- set(LLVM_CONFIG_LIBRARY_DIRS "\${LLVM_INSTALL_PREFIX}/lib\${LLVM_LIBDIR_SUFFIX}")
- set(LLVM_CONFIG_CMAKE_DIR "\${LLVM_INSTALL_PREFIX}/${LLVM_INSTALL_PACKAGE_DIR}")

debian/patches/series

@@ -26,7 +26,8 @@ clang-analyzer-force-version.diff
 install-scan-build-py.diff
 scan-view-fix-path.diff
 mips-fpxx-enable.diff
-fix-cmake-config-prefix.diff
+0001-llvm-cmake-resolve-symlinks-in-LLVMConfig.cmake.patch
+0001-tools-clang-cmake-resolve-symlinks-in-ClangConfig.cmake.patch
 lldb-link-atomic-cmake.patch
 disable-source-interleave.diff
 silent-gold-utils.diff

debian/qualify-clang.sh

@@ -26,18 +26,18 @@ fi
 echo 'int main() {return 0;}' > foo.c
 clang-$VERSION foo.c
 
-echo '#include <stddef.h>' > x.c
-clang-$VERSION -c x.c
+echo '#include <stddef.h>' > foo.c
+clang-$VERSION -c foo.c
 
-echo "#include <fenv.h>" > x.cc
-NBLINES=$(clang++-$VERSION -P -E x.cc|wc -l)
+echo "#include <fenv.h>" > foo.cc
+NBLINES=$(clang++-$VERSION -P -E foo.cc|wc -l)
 if test $NBLINES -lt 100; then
     echo "Error: more than 100 lines should be returned"
     exit 42
 fi
 
-echo '#include <emmintrin.h>' > x.cc
-clang++-$VERSION -c x.cc
+echo '#include <emmintrin.h>' > foo.cc
+clang++-$VERSION -c foo.cc
 
 echo '
 #include <string.h>
@@ -46,16 +46,16 @@ main ()
 {
   (void) strcat;
   return 0;
-}' > x.c
-clang-$VERSION -c x.c
+}' > foo.c
+clang-$VERSION -c foo.c
 
 echo '#include <errno.h>
-int main() {} ' > x.c
-clang-$VERSION x.c
+int main() {} ' > foo.c
+clang-$VERSION foo.c
 
 echo '#include <chrono>
-int main() { }' > x.cpp
-clang++-$VERSION -std=c++11 x.cpp
+int main() { }' > foo.cpp
+clang++-$VERSION -std=c++11 foo.cpp
 
 echo '#include <stdio.h>
 int main() {
@@ -166,20 +166,45 @@ int main (void)
 {  std::vector<int> a;
   a.push_back (0);
 }
-' > o.cpp
-clang++-$VERSION -g -o o o.cpp
-echo 'target create "./o"
+' > foo.cpp
+clang++-$VERSION -g -o foo foo.cpp
+echo 'target create "./foo"
 b main
 r
 n
 p a
 quit' > lldb-cmd.txt
-lldb-$VERSION -s lldb-cmd.txt ./o
+lldb-$VERSION -s lldb-cmd.txt ./foo
 
 echo "int main() { return 1; }" > foo.c
 clang-$VERSION -fsanitize=efficiency-working-set -o foo foo.c
 ./foo > /dev/null || true
 
+
+rm -rf cmaketest && mkdir cmaketest
+cat > cmaketest/CMakeLists.txt <<EOF
+cmake_minimum_required(VERSION 2.8.12)
+project(SanityCheck)
+find_package(LLVM $VERSION REQUIRED CONFIG)
+message(STATUS "LLVM_CMAKE_DIR: \${LLVM_CMAKE_DIR}")
+if(NOT EXISTS "\${LLVM_TOOLS_BINARY_DIR}/clang")
+message(FATAL_ERROR "Invalid LLVM_TOOLS_BINARY_DIR: \${LLVM_TOOLS_BINARY_DIR}")
+endif()
+# TODO add version to ClangConfig.cmake and use $VERSION below
+find_package(Clang REQUIRED CONFIG)
+find_file(H clang/AST/ASTConsumer.h PATHS \${CLANG_INCLUDE_DIRS} NO_DEFAULT_PATH)
+message(STATUS "CLANG_INCLUDE_DIRS: \${CLANG_INCLUDE_DIRS}")
+if(NOT H)
+message(FATAL_ERROR "Invalid Clang header path: \${CLANG_INCLUDE_DIRS}")
+endif()
+EOF
+mkdir cmaketest/standard cmaketest/explicit
+echo "Test: CMake find LLVM and Clang in default path"
+(cd cmaketest/standard && CC=clang-$VERSION CXX=clang++-$VERSION cmake ..)
+echo "Test: CMake find LLVM and Clang in explicit prefix path"
+(cd cmaketest/explicit && CC=clang-$VERSION CXX=clang++-$VERSION CMAKE_PREFIX_PATH=/usr/lib/llvm-$VERSION cmake ..)
+rm -rf cmaketest
+
 CLANG=clang-$VERSION
 #command -v "$CLANG" 1>/dev/null 2>/dev/null || { printf "Usage:\n%s CLANGEXE [ARGS]\n" "$0" 1>&2; exit 1; }
 #shift
@@ -214,6 +239,9 @@ int main ()
 }
 EOF
 
+#clean up
+rm a.out bar crash-* foo foo.* lldb-cmd.txt main.c test_fuzzer.cc
+
 # only for AMD64 for now
 # many sanitizers only work on AMD64
 # x32 programs need to be enabled in the kernel bootparams for debian
@@ -222,6 +250,8 @@ EOF
 # SYSTEM should iterate multiple targets (eg. x86_64-unknown-none-gnu for embedded)
 # MARCH should iterate the library architectures via flags
 # LIB should iterate the different libraries
+echo "if it fails, please run"
+echo "apt-get install libc6-dev:i386 libgcc-5-dev:i386 libc6-dev-x32 libx32gcc-5-dev"
 for SYSTEM in ""; do
     for MARCH in -m64 -m32 -mx32 "-m32 -march=i686"; do
         for LIB in --rtlib=compiler-rt -fsanitize=address -fsanitize=thread -fsanitize=memory -fsanitize=undefined -fsanitize=dataflow; do # -fsanitize=efficiency-working-set; do
@@ -246,8 +276,14 @@ for SYSTEM in ""; do
     done
 done
 
+echo "If the following fails, try setting an environment variable such as:"
+echo "OBJC_INCLUDE_PATH=/usr/lib/gcc/x86_64-linux-gnu/5/include"
 echo "#include <objc/objc.h>" > foo.m
 clang-$VERSION -c foo.m
 
-echo "Completed"
+if test ! -f /usr/lib/llvm-$VERSION/lib/libclangBasic.a; then
+    echo "Install libclang-$VERSION-dev"
+    exit 1
+fi
 
+echo "Completed"

debian/rules

@@ -443,12 +443,12 @@ endif
 # Remove some license files
 	rm -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/include/llvm/Support/LICENSE.TXT
 
-# Change CMake module dir
-	sed -i 's|LLVM_CMAKE_DIR "/usr/lib/llvm-$(LLVM_VERSION)/share/llvm/cmake"|LLVM_CMAKE_DIR "/usr/share/llvm-$(LLVM_VERSION)/cmake"|' $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/cmake/llvm/LLVMConfig.cmake
-
 # Disable CMake's package validation checks for target files that we may remove.
 	sed -i '/_IMPORT_CHECK_TARGETS \(Polly\|sancov\)/ {s|^|#|}' $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/cmake/llvm/LLVMExports-*.cmake
 
+# Disable CMake's package validation checks for binaries that may not be installed
+	sed -i 's|.*_IMPORT_CHECK_FILES_FOR_.*/bin/.*)|#&|' $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/cmake/clang/ClangTargets-*.cmake
+
 # Managed in python-lldb-X.Y.links.in
 	rm -f $(DEB_INST)/usr/lib/llvm-$(LLVM_VERSION)/lib/python*/site-packages/lldb/_lldb.so