From f4c68951804088424793d38e69903e2af9c82614 Mon Sep 17 00:00:00 2001
From: Isuru Fernando <isuruf@gmail.com>
Date: Fri, 7 Aug 2020 21:09:39 +0000
Subject: [PATCH] Use llvm-tblgen from build

---
 recipe/build.sh                   | 14 +++++---------
 recipe/meta.yaml                  |  3 ++-
 recipe/patches/cross-compile.diff | 18 ++++++++++++------
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/recipe/build.sh b/recipe/build.sh
index c99fad1b..7c97d46b 100644
--- a/recipe/build.sh
+++ b/recipe/build.sh
@@ -4,9 +4,6 @@ IFS='.' read -r -a PKG_VER_ARRAY <<< "${PKG_VERSION}"
 
 sed -i.bak "s/libLTO.dylib/libLTO.${PKG_VER_ARRAY[0]}.dylib/g" lib/Driver/ToolChains/Darwin.cpp
 
-mkdir build
-cd build
-
 if [[ "$variant" == "hcc" ]]; then
   CMAKE_ARGS="$CMAKE_ARGS -DKALMAR_BACKEND=HCC_BACKEND_AMDGPU -DHCC_VERSION_STRING=2.7-19365-24e69cd8-24e69cd8-24e69cd8"
   CMAKE_ARGS="$CMAKE_ARGS -DHCC_VERSION_MAJOR=2 -DHCC_VERSION_MINOR=7 -DHCC_VERSION_PATCH=19365"
@@ -14,14 +11,13 @@ if [[ "$variant" == "hcc" ]]; then
 fi
 
 if [[ "$CC_FOR_BUILD" != "" && "$CC_FOR_BUILD" != "$CC" ]]; then
-  # This is a really convoluted way to cross compile.
-  # We are going to ask clang to build the native tools with host compiler
-  # and since we have QEMU, it's going to work.
-  # Correct way would be to build `llvm-tblgen` and `clang-tblgen` for the
-  # native platform and use them, but who has time?
-  CMAKE_ARGS="${CMAKE_ARGS} -DLLVM_USE_HOST_TOOLS=ON"
+  CMAKE_ARGS="${CMAKE_ARGS} -DLLVM_TABLEGEN_EXE=$BUILD_PREFIX/bin/llvm-tblgen -DNATIVE_LLVM_DIR=$BUILD_PREFIX/lib/cmake/llvm"
+  CMAKE_ARGS="${CMAKE_ARGS} -DCROSS_TOOLCHAIN_FLAGS_NATIVE=-DCMAKE_C_COMPILER=$CC_FOR_BUILD;-DCMAKE_CXX_COMPILER=$CXX_FOR_BUILD;-DCMAKE_C_FLAGS=-O2;-DCMAKE_CXX_FLAGS=-O2;-DCMAKE_EXE_LINKER_FLAGS=;-DCMAKE_MODULE_LINKER_FLAGS=;-DCMAKE_SHARED_LINKER_FLAGS=;-DCMAKE_STATIC_LINKER_FLAGS=;"
 fi
 
+mkdir build
+cd build
+
 cmake \
   -DCMAKE_INSTALL_PREFIX=$PREFIX \
   -DCMAKE_PREFIX_PATH=$PREFIX \
diff --git a/recipe/meta.yaml b/recipe/meta.yaml
index a56b3d2d..acb9e583 100644
--- a/recipe/meta.yaml
+++ b/recipe/meta.yaml
@@ -15,7 +15,7 @@ source:
       - patches/0002-clang-add-conda-specific-env-var-CONDA_BUILD_SYSROOT.patch
       - patches/0003-clang-Fix-normalizeProgramName-s-handling-of-dots-ou.patch
       - patches/0001-Set-VERSION-in-osx-as-well.patch
-      - patches/cross-compile.patch
+      - patches/cross-compile.diff
       #- patches/amd-roc-2.7.0.diff   # [variant != "hcc"]
       #- patches/amd-roc-hcc-2.7.0.diff  # [variant == "hcc"]
     folder: .
@@ -38,6 +38,7 @@ requirements:
     # Building with ninja on windows for parallel builds
     - ninja  # [win]
     - make   # [unix]
+    - llvmdev =={{ version }}    # [build_platform != target_platform]
   host:
     - libcxx {{ cxx_compiler_version }}  # [osx]
     - llvmdev =={{ version }}
diff --git a/recipe/patches/cross-compile.diff b/recipe/patches/cross-compile.diff
index 37cb5e81..b7963cc8 100644
--- a/recipe/patches/cross-compile.diff
+++ b/recipe/patches/cross-compile.diff
@@ -1,13 +1,19 @@
---- CMakeLists.txt      2020-08-07 20:15:39.605174899 +0000
-+++ CMakeLists.txt      2020-08-07 20:15:14.288910164 +0000
-@@ -111,6 +111,10 @@
+--- CMakeLists.txt.old  2020-08-07 20:15:39.605174899 +0000
++++ CMakeLists.txt      2020-08-07 20:20:01.383910098 +0000
+@@ -111,6 +111,16 @@
    option(LLVM_ENABLE_LIBXML2 "Use libxml2 if available." ON)
  
    include(AddLLVM)
-+  if(LLVM_USE_HOST_TOOLS)
++  if(CMAKE_CROSSCOMPILING)
++    set(LLVM_USE_HOST_TOOLS ON)
 +    include(CrossCompile)
-+    llvm_create_cross_target(Clang NATIVE "" Release)
-+  endif(LLVM_USE_HOST_TOOLS)
++    if (NOT NATIVE_LLVM_DIR)
++      message(FATAL_ERROR
++       "Crosscompiling standalone requires the variable NATIVE_LLVM_DIR
++       for building the native lldb-tblgen used during the build process.")
++    endif()
++    llvm_create_cross_target(Clang NATIVE "" Release -DLLVM_DIR=${NATIVE_LLVM_DIR})
++  endif()
    include(TableGen)
    include(HandleLLVMOptions)
    include(VersionFromVCS)