From f2159e7758ca1fb721882e1b5e8059ed1b0e9a52 Mon Sep 17 00:00:00 2001
From: em-eight <m8em.eightm8@gmail.com>
Date: Sat, 16 Sep 2023 20:49:28 +0300
Subject: [PATCH] Try using non-legacy protobuf finding method on modern
 protobuf installations

---
 CMakeLists.txt | 61 ++++++++++++++++++++++++++++++++------------------
 README.md      | 40 ---------------------------------
 2 files changed, 39 insertions(+), 62 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index f43539c..53de279 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -46,37 +46,54 @@ CPMAddPackage("gh:fmtlib/fmt#10.0.0")
 # could either specify a static or shared library.  Depending on either,
 # we need to correctly set the link mode before calling find_package.
 # Newer versions of Protobuf depend on Abseil.
-if(DEFINED Protobuf_LIBRARY)
-  if(Protobuf_LIBRARY MATCHES "\.a$")
-    set(Protobuf_USE_STATIC_LIBS ON)
-  else()
-    set(Protobuf_USE_STATIC_LIBS OFF)
-  endif()
-else()
-  set(Protobuf_USE_STATIC_LIBS ON)   # Use static libs by default
+set(Protobuf_USE_STATIC_LIBS ON)
+
+find_package(protobuf CONFIG)
+if(NOT protobuf_FOUND)        # Legacy protobuf support
+  message(STATUS "Trying legacy method of finding protobuf")
+  set(protobuf_MODULE_COMPATIBLE ON)
+  include(FindProtobuf)
+  find_package(Protobuf REQUIRED)
 endif()
-
-include(FindProtobuf)
-find_package(Protobuf REQUIRED)
 include_directories(${Protobuf_INCLUDE_DIRS})
 
 # Generate Protobuf files
 # This is provided by FindProtobuf.cmake
-file(GLOB PROTO_FILES "${CMAKE_CURRENT_SOURCE_DIR}/proto/*.proto")
-protobuf_generate_cpp(PROTO_SRCS PROTO_HDRS ${PROTO_FILES})
+set(PROTO_DIR "${CMAKE_CURRENT_SOURCE_DIR}/proto")
+file(GLOB PROTO_FILES "${PROTO_DIR}/*.proto")
+if(protobuf_MODULE_COMPATIBLE)
+  protobuf_generate_cpp(PROTO_SRCS PROTO_HDRS ${PROTO_FILES})
+endif()
 
 # ppc2cpp core #################################################################
 
 file(GLOB_RECURSE ppc2cpp_core_SRC "src/*.cpp")
-add_library(ppc2cpp_core ${ppc2cpp_core_SRC} ${PROTO_SRCS} ${PROTO_HDRS} )
-target_include_directories(ppc2cpp_core PUBLIC
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:include>  # <prefix>/include
-  ${YAML_CPP_SOURCE_DIR}/include
-  # protobuf_generate_cpp drops .pb.{h.c} files here.
-  ${CMAKE_CURRENT_BINARY_DIR}
-)
-target_link_libraries(ppc2cpp_core PUBLIC dolrel ppcdisasm elfio fmt ${Protobuf_LIBRARIES} yaml-cpp)
+
+if(protobuf_MODULE_COMPATIBLE)
+  add_library(ppc2cpp_core ${ppc2cpp_core_SRC} ${PROTO_SRCS} ${PROTO_HDRS} )
+  target_include_directories(ppc2cpp_core PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>  # <prefix>/include
+    ${YAML_CPP_SOURCE_DIR}/include
+    # protobuf_generate_cpp drops .pb.{h.c} files here.
+    ${CMAKE_CURRENT_BINARY_DIR}
+  )
+  target_link_libraries(ppc2cpp_core PUBLIC dolrel ppcdisasm elfio fmt ${Protobuf_LIBRARIES} yaml-cpp)
+else()
+  add_library(ppc2cpp_core ${ppc2cpp_core_SRC} ${PROTO_FILES})
+  target_include_directories(ppc2cpp_core PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>  # <prefix>/include
+    ${YAML_CPP_SOURCE_DIR}/include
+    # protobuf_generate_cpp drops .pb.{h.c} files here.
+    ${CMAKE_CURRENT_BINARY_DIR}
+  )
+  target_link_libraries(ppc2cpp_core PUBLIC dolrel ppcdisasm elfio fmt protobuf::libprotobuf yaml-cpp)
+  protobuf_generate(
+    TARGET ppc2cpp_core
+    IMPORT_DIRS "${PROTO_DIR}"
+  )
+endif()
 
 # ppc2cpp CLI  #################################################################
 
diff --git a/README.md b/README.md
index e90a6e9..f85e139 100644
--- a/README.md
+++ b/README.md
@@ -22,43 +22,3 @@ Compare the equivalence between the version of a function in two ppc2cpp project
 Import symbol and relocation information from ppcdis
 ### ppc2pp compare (experimental)
 Compare two ppc2cpp programs. This takes a symbol and reference based approach, which allows symbols to be rearranged arbitrarily. This requires symbol name, type and size information, as well as relocations.
-
-## Troubleshooting
-
-### CMake issues
-
-This project uses CMake's builtin FindProtobuf module which is supposed
-to locate your Protobuf library and compiler installation.  Recent
-versions of Protobuf broke the versioning scheme, resulting in a CMake
-error (e.g. Protobuf 23.4 and CMake 3.26.4 won't work together).
-
-If you get an error like this ...
-
-```
-CMake Warning at /opt/homebrew/Cellar/cmake/3.26.4/share/cmake/Modules/FindProtobuf.cmake:524 (message):
-  Protobuf compiler version 23.4 doesn't match library version 4.23.4
-Call Stack (most recent call first):
-  CMakeLists.txt:33 (find_package)
-
-
-CMake Error at /opt/homebrew/Cellar/cmake/3.26.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:230 (message):
-  Could NOT find Protobuf (missing: Protobuf_LIBRARIES) (found version
-  "4.23.4")
-Call Stack (most recent call first):
-  /opt/homebrew/Cellar/cmake/3.26.4/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:600 (_FPHSA_FAILURE_MESSAGE)
-  /opt/homebrew/Cellar/cmake/3.26.4/share/cmake/Modules/FindProtobuf.cmake:650 (FIND_PACKAGE_HANDLE_STANDARD_ARGS)
-  CMakeLists.txt:33 (find_package)
-```
-
-... work around this issue by defining CMake build variables manually
-specifying protoc and Protobuf link flags.  In the example below, we
-use `pkg-config` to gather the correct link flags.
-
-```
-cmake -B build \
-  -DProtobuf_PROTOC_EXECUTABLE="$(which protoc)" \
-  -DProtobuf_LIBRARY="$(pkg-config --libs protobuf)"
-```
-
-If all of the above still doesn't work, sometimes it helps to delete
-your CMake cache.