From e22491c83265200f518e9fb4deff54e3c2823b68 Mon Sep 17 00:00:00 2001
From: Karol Herbst <kherbst@redhat.com>
Date: Tue, 22 Nov 2022 11:48:08 +0100
Subject: [PATCH] clc: fetch clang resource dir at runtime

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19617>
---
 src/compiler/clc/clc_helpers.cpp | 15 +++++++++++++--
 src/compiler/clc/meson.build     |  4 ++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/compiler/clc/clc_helpers.cpp b/src/compiler/clc/clc_helpers.cpp
index 5827d066338..fe30b6aac0f 100644
--- a/src/compiler/clc/clc_helpers.cpp
+++ b/src/compiler/clc/clc_helpers.cpp
@@ -23,6 +23,7 @@
 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 // OTHER DEALINGS IN THE SOFTWARE.
 
+#include <filesystem>
 #include <sstream>
 #include <mutex>
 
@@ -38,6 +39,7 @@
 #include <llvm-c/Target.h>
 #include <LLVMSPIRVLib/LLVMSPIRVLib.h>
 
+#include <clang/Driver/Driver.h>
 #include <clang/CodeGen/CodeGenAction.h>
 #include <clang/Lex/PreprocessorOptions.h>
 #include <clang/Frontend/CompilerInstance.h>
@@ -63,6 +65,8 @@
 
 #include "clc_helpers.h"
 
+namespace fs = std::filesystem;
+
 /* Use the highest version of SPIRV supported by SPIRV-Tools. */
 constexpr spv_target_env spirv_target = SPV_ENV_UNIVERSAL_1_5;
 
@@ -853,12 +857,19 @@ clc_compile_to_llvm_module(LLVMContext &llvm_ctx,
          ::llvm::MemoryBuffer::getMemBuffer(llvm::StringRef(opencl_c_base_source, ARRAY_SIZE(opencl_c_base_source) - 1)).release());
    }
 #else
+   // GetResourcePath is a way to retrive the actual libclang resource dir based on a given binary
+   // or library. The path doesn't even need to exist, we just have to put something in there,
+   // because we might have linked clang statically.
+   auto libclang_path = fs::path(LLVM_LIB_DIR) / "libclang.so";
+   auto clang_res_path =
+      fs::path(clang::driver::Driver::GetResourcesPath(libclang_path.string())) / "include";
+
    c->getHeaderSearchOpts().UseBuiltinIncludes = true;
    c->getHeaderSearchOpts().UseStandardSystemIncludes = true;
-   c->getHeaderSearchOpts().ResourceDir = CLANG_RESOURCE_DIR;
+   c->getHeaderSearchOpts().ResourceDir = clang_res_path.string();
 
    // Add opencl-c generic search path
-   c->getHeaderSearchOpts().AddPath(CLANG_RESOURCE_DIR,
+   c->getHeaderSearchOpts().AddPath(clang_res_path.string(),
                                     clang::frontend::Angled,
                                     false, false);
    // Add opencl include
diff --git a/src/compiler/clc/meson.build b/src/compiler/clc/meson.build
index 4fd4a220f6a..caae07e26dd 100644
--- a/src/compiler/clc/meson.build
+++ b/src/compiler/clc/meson.build
@@ -19,17 +19,17 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 # IN THE SOFTWARE.
 
-clang_resource_dir = join_paths(llvm_libdir, 'clang', dep_llvm.version(), 'include')
 
 files_libclc = files(
   'clc.c',
   'clc_helpers.cpp',
 )
 
-_libclc_cpp_args = ['-DCLANG_RESOURCE_DIR="@0@"'.format(clang_resource_dir)]
+_libclc_cpp_args = ['-DLLVM_LIB_DIR="@0@"'.format(llvm_libdir)]
 _libclc_sources = []
 
 if with_microsoft_clc
+  clang_resource_dir = join_paths(llvm_libdir, 'clang', dep_llvm.version(), 'include')
   if dep_llvm.version().version_compare('< 15.0')
     opencl_c_h = custom_target(
       'opencl-c.h',