cmake: prefer system llvm library

CMakeLists.txt

@@ -208,6 +208,7 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 find_package(enet 1.3 MODULE)
 find_package(fmt 9 REQUIRED)
 find_package(inih MODULE)
+find_package(LLVM MODULE)
 find_package(lz4 REQUIRED)
 find_package(nlohmann_json 3.8 REQUIRED)
 find_package(Opus 1.3 MODULE)

CMakeModules/FindLLVM.cmake

@@ -0,0 +1,16 @@
+# SPDX-FileCopyrightText: 2023 Alexandre Bouvier <contact@amb.tf>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+find_package(LLVM QUIET CONFIG)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(LLVM CONFIG_MODE)
+
+if (LLVM_FOUND AND NOT TARGET LLVM::Demangle)
+    add_library(LLVM::Demangle INTERFACE IMPORTED)
+    llvm_map_components_to_libnames(LLVM_LIBRARIES demangle)
+    target_compile_definitions(LLVM::Demangle INTERFACE ${LLVM_DEFINITIONS})
+    target_include_directories(LLVM::Demangle INTERFACE ${LLVM_INCLUDE_DIRS})
+    target_link_libraries(LLVM::Demangle INTERFACE ${LLVM_LIBRARIES})
+endif()

externals/CMakeLists.txt

@@ -158,6 +158,9 @@ if (YUZU_USE_EXTERNAL_VULKAN_HEADERS)
     add_subdirectory(Vulkan-Headers EXCLUDE_FROM_ALL)
 endif()
 
-add_library(demangle STATIC)
-target_include_directories(demangle PUBLIC ./demangle)
-target_sources(demangle PRIVATE demangle/ItaniumDemangle.cpp)
+if (NOT TARGET LLVM::Demangle)
+    add_library(demangle STATIC)
+    target_include_directories(demangle PUBLIC ./demangle)
+    target_sources(demangle PRIVATE demangle/ItaniumDemangle.cpp)
+    add_library(LLVM::Demangle ALIAS demangle)
+endif()

externals/demangle/ItaniumDemangle.cpp

@@ -11,8 +11,8 @@
 // file does not yet support:
 //   - C++ modules TS
 
-#include "Demangle.h"
-#include "ItaniumDemangle.h"
+#include "llvm/Demangle/Demangle.h"
+#include "llvm/Demangle/ItaniumDemangle.h"
 
 #include <cassert>
 #include <cctype>

src/common/CMakeLists.txt

@@ -177,7 +177,7 @@ endif()
 create_target_directory_groups(common)
 
 target_link_libraries(common PUBLIC ${Boost_LIBRARIES} fmt::fmt microprofile Threads::Threads)
-target_link_libraries(common PRIVATE lz4::lz4 zstd::zstd demangle)
+target_link_libraries(common PRIVATE lz4::lz4 zstd::zstd LLVM::Demangle)
 
 if (YUZU_USE_PRECOMPILED_HEADERS)
     target_precompile_headers(common PRIVATE precompiled_headers.h)

src/common/demangle.cpp

@@ -1,13 +1,11 @@
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <llvm/Demangle/Demangle.h>
+
 #include "common/demangle.h"
 #include "common/scope_exit.h"
 
-namespace llvm {
-char* itaniumDemangle(const char* mangled_name, char* buf, size_t* n, int* status);
-}
-
 namespace Common {
 
 std::string DemangleSymbol(const std::string& mangled) {