Fix version filename for find_package redirects (#630)

Co-authored-by: Lars Melchior <TheLartians@users.noreply.github.com>

.github/workflows/test.yaml

@@ -19,7 +19,7 @@ jobs:
         os: [ubuntu-latest, windows-2022, macos-latest]
         # we want to ensure compatibility with a recent CMake version as well as the lowest officially supported
         # legacy version that we define as the default version of the second-latest Ubuntu LTS release currently available
-        cmake_version: ['3.16.3', '3.27.5']
+        cmake_version: ['3.16.3', '3.27.5', '3.30.0']
         exclude:
           # there seems to be an issue with CMake 3.16 not finding a C++ compiler on windows-2022 
           - os: windows-2022

README.md

@@ -67,6 +67,7 @@ Afterwards, any targets defined in the dependency can be used directly.
 CPMAddPackage(
   NAME          # The unique name of the dependency (should be the exported target's name)
   VERSION       # The minimum version of the dependency (optional, defaults to 0)
+  PATCHES       # Patch files to be applied sequentially using patch and PATCH_OPTIONS (optional)
   OPTIONS       # Configuration options passed to the dependency (optional)
   DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
   [...]         # Origin parameters forwarded to FetchContent_Declare, see below
@@ -78,6 +79,9 @@ If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a com
 On the other hand, if `VERSION` hasn't been explicitly specified, CPM can automatically identify the version from the git tag in some common cases.
 `GIT_TAG` can also be set to a specific commit or a branch name such as `master`, however this isn't recommended, as such packages will only be updated when the cache is cleared.
 
+`PATCHES` takes a list of patch files to apply sequentially. For a basic example, see [Highway](examples/highway/CMakeLists.txt).
+We recommend that if you use `PATCHES`, you also set `CPM_SOURCE_CACHE`. See [issue 577](https://github.com/cpm-cmake/CPM.cmake/issues/577).
+
 If an additional optional parameter `EXCLUDE_FROM_ALL` is set to a truthy value, then any targets defined inside the dependency won't be built by default. See the [CMake docs](https://cmake.org/cmake/help/latest/prop_tgt/EXCLUDE_FROM_ALL.html) for details.
 
 If an additional optional parameter `SYSTEM` is set to a truthy value, the SYSTEM directory property of the subdirectory added will be set to true.
@@ -211,6 +215,13 @@ In the case that `find_package` requires additional arguments, the parameter `FI
 
 Note that this does not apply to dependencies that have been defined with a truthy `FORCE` parameter. These will be added as defined.
 
+### CPM_DONT_UPDATE_MODULE_PATH
+
+By default, CPM will override any `find_package` commands to use the CPM downloaded version.
+This is equivalent to the `OVERRIDE_FIND_PACKAGE` FetchContent option, which has no effect in CPM.
+To disable this behaviour set the `CPM_DONT_UPDATE_MODULE_PATH` option.
+This will not work for `find_package(CONFIG)` in CMake versions before 3.24.
+
 ### CPM_USE_NAMED_CACHE_DIRECTORIES
 
 If set, CPM use additional directory level in cache to improve readability of packages names in IDEs like CLion. It changes cache structure, so all dependencies are downloaded again. There is no problem to mix both structures in one cache directory but then there may be 2 copies of some dependencies.

cmake/.cmake-format-additional_commands-cpm

@@ -31,6 +31,7 @@ parse:
         EXCLUDE_FROM_ALL: 1
         SYSTEM: 1
         SOURCE_SUBDIR: 1
+        PATCHES: +
         OPTIONS: +
     cpmfindpackage:
       pargs:

cmake/CPM.cmake

@@ -162,7 +162,7 @@ set(CPM_SOURCE_CACHE
     CACHE PATH "Directory to download CPM dependencies"
 )
 
-if(NOT CPM_DONT_UPDATE_MODULE_PATH)
+if(NOT CPM_DONT_UPDATE_MODULE_PATH AND NOT DEFINED CMAKE_FIND_PACKAGE_REDIRECTS_DIR)
   set(CPM_MODULE_PATH
       "${CMAKE_BINARY_DIR}/CPM_modules"
       CACHE INTERNAL ""
@@ -269,10 +269,25 @@ endfunction()
 # finding the system library
 function(cpm_create_module_file Name)
   if(NOT CPM_DONT_UPDATE_MODULE_PATH)
-    # erase any previous modules
-    file(WRITE ${CPM_MODULE_PATH}/Find${Name}.cmake
-         "include(\"${CPM_FILE}\")\n${ARGN}\nset(${Name}_FOUND TRUE)"
-    )
+    if(DEFINED CMAKE_FIND_PACKAGE_REDIRECTS_DIR)
+      # Redirect find_package calls to the CPM package. This is what FetchContent does when you set
+      # OVERRIDE_FIND_PACKAGE. The CMAKE_FIND_PACKAGE_REDIRECTS_DIR works for find_package in CONFIG
+      # mode, unlike the Find${Name}.cmake fallback. CMAKE_FIND_PACKAGE_REDIRECTS_DIR is not defined
+      # in script mode, or in CMake < 3.24.
+      # https://cmake.org/cmake/help/latest/module/FetchContent.html#fetchcontent-find-package-integration-examples
+      string(TOLOWER ${Name} NameLower)
+      file(WRITE ${CMAKE_FIND_PACKAGE_REDIRECTS_DIR}/${NameLower}-config.cmake
+           "include(\"\${CMAKE_CURRENT_LIST_DIR}/${NameLower}-extra.cmake\" OPTIONAL)\n"
+           "include(\"\${CMAKE_CURRENT_LIST_DIR}/${Name}Extra.cmake\" OPTIONAL)\n"
+      )
+      file(WRITE ${CMAKE_FIND_PACKAGE_REDIRECTS_DIR}/${NameLower}-config-version.cmake
+           "set(PACKAGE_VERSION_COMPATIBLE TRUE)\n" "set(PACKAGE_VERSION_EXACT TRUE)\n"
+      )
+    else()
+      file(WRITE ${CPM_MODULE_PATH}/Find${Name}.cmake
+           "include(\"${CPM_FILE}\")\n${ARGN}\nset(${Name}_FOUND TRUE)"
+      )
+    endif()
   endif()
 endfunction()
 
@@ -391,8 +406,8 @@ function(cpm_parse_add_package_single_arg arg outArgs)
     # We don't try to parse the version if it's not provided explicitly. cpm_get_version_from_url
     # should do this at a later point
   else()
-    # We should never get here. This is an assertion and hitting it means there's a bug in the code
-    # above. A packageType was set, but not handled by this if-else.
+    # We should never get here. This is an assertion and hitting it means there's a problem with the
+    # code above. A packageType was set, but not handled by this if-else.
     message(FATAL_ERROR "${CPM_INDENT} Unsupported package type '${packageType}' of '${arg}'")
   endif()
 
@@ -464,6 +479,72 @@ function(cpm_check_git_working_dir_is_clean repoPath gitTag isClean)
 
 endfunction()
 
+# Add PATCH_COMMAND to CPM_ARGS_UNPARSED_ARGUMENTS. This method consumes a list of files in ARGN
+# then generates a `PATCH_COMMAND` appropriate for `ExternalProject_Add()`. This command is appended
+# to the parent scope's `CPM_ARGS_UNPARSED_ARGUMENTS`.
+function(cpm_add_patches)
+  # Return if no patch files are supplied.
+  if(NOT ARGN)
+    return()
+  endif()
+
+  # Find the patch program.
+  find_program(PATCH_EXECUTABLE patch)
+  if(CMAKE_HOST_WIN32 AND NOT PATCH_EXECUTABLE)
+    # The Windows git executable is distributed with patch.exe. Find the path to the executable, if
+    # it exists, then search `../usr/bin` and `../../usr/bin` for patch.exe.
+    find_package(Git QUIET)
+    if(GIT_EXECUTABLE)
+      get_filename_component(extra_search_path ${GIT_EXECUTABLE} DIRECTORY)
+      get_filename_component(extra_search_path_1up ${extra_search_path} DIRECTORY)
+      get_filename_component(extra_search_path_2up ${extra_search_path_1up} DIRECTORY)
+      find_program(
+        PATCH_EXECUTABLE patch HINTS "${extra_search_path_1up}/usr/bin"
+                                     "${extra_search_path_2up}/usr/bin"
+      )
+    endif()
+  endif()
+  if(NOT PATCH_EXECUTABLE)
+    message(FATAL_ERROR "Couldn't find `patch` executable to use with PATCHES keyword.")
+  endif()
+
+  # Create a temporary
+  set(temp_list ${CPM_ARGS_UNPARSED_ARGUMENTS})
+
+  # Ensure each file exists (or error out) and add it to the list.
+  set(first_item True)
+  foreach(PATCH_FILE ${ARGN})
+    # Make sure the patch file exists, if we can't find it, try again in the current directory.
+    if(NOT EXISTS "${PATCH_FILE}")
+      if(NOT EXISTS "${CMAKE_CURRENT_LIST_DIR}/${PATCH_FILE}")
+        message(FATAL_ERROR "Couldn't find patch file: '${PATCH_FILE}'")
+      endif()
+      set(PATCH_FILE "${CMAKE_CURRENT_LIST_DIR}/${PATCH_FILE}")
+    endif()
+
+    # Convert to absolute path for use with patch file command.
+    get_filename_component(PATCH_FILE "${PATCH_FILE}" ABSOLUTE)
+
+    # The first patch entry must be preceded by "PATCH_COMMAND" while the following items are
+    # preceded by "&&".
+    if(first_item)
+      set(first_item False)
+      list(APPEND temp_list "PATCH_COMMAND")
+    else()
+      list(APPEND temp_list "&&")
+    endif()
+    # Add the patch command to the list
+    list(APPEND temp_list "${PATCH_EXECUTABLE}" "-p1" "<" "${PATCH_FILE}")
+  endforeach()
+
+  # Move temp out into parent scope.
+  set(CPM_ARGS_UNPARSED_ARGUMENTS
+      ${temp_list}
+      PARENT_SCOPE
+  )
+
+endfunction()
+
 # method to overwrite internal FetchContent properties, to allow using CPM.cmake to overload
 # FetchContent calls. As these are internal cmake properties, this method should be used carefully
 # and may need modification in future CMake versions. Source:
@@ -537,7 +618,7 @@ function(CPMAddPackage)
       CUSTOM_CACHE_KEY
   )
 
-  set(multiValueArgs URL OPTIONS DOWNLOAD_COMMAND)
+  set(multiValueArgs URL OPTIONS DOWNLOAD_COMMAND PATCHES)
 
   cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
 
@@ -628,6 +709,7 @@ function(CPMAddPackage)
       SOURCE_DIR "${PACKAGE_SOURCE}"
       EXCLUDE_FROM_ALL "${CPM_ARGS_EXCLUDE_FROM_ALL}"
       SYSTEM "${CPM_ARGS_SYSTEM}"
+      PATCHES "${CPM_ARGS_PATCHES}"
       OPTIONS "${CPM_ARGS_OPTIONS}"
       SOURCE_SUBDIR "${CPM_ARGS_SOURCE_SUBDIR}"
       DOWNLOAD_ONLY "${DOWNLOAD_ONLY}"
@@ -683,6 +765,8 @@ function(CPMAddPackage)
     set(CPM_FETCHCONTENT_BASE_DIR ${CMAKE_BINARY_DIR}/_deps)
   endif()
 
+  cpm_add_patches(${CPM_ARGS_PATCHES})
+
   if(DEFINED CPM_ARGS_DOWNLOAD_COMMAND)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS DOWNLOAD_COMMAND ${CPM_ARGS_DOWNLOAD_COMMAND})
   elseif(DEFINED CPM_ARGS_SOURCE_DIR)
@@ -796,14 +880,39 @@ function(CPMAddPackage)
   )
 
   if(NOT CPM_SKIP_FETCH)
+    # CMake 3.28 added EXCLUDE, SYSTEM (3.25), and SOURCE_SUBDIR (3.18) to FetchContent_Declare.
+    # Calling FetchContent_MakeAvailable will then internally forward these options to
+    # add_subdirectory. Up until these changes, we had to call FetchContent_Populate and
+    # add_subdirectory separately, which is no longer necessary and has been deprecated as of 3.30.
+    # A Bug in CMake prevents us to use the non-deprecated functions until 3.30.3.
+    set(fetchContentDeclareExtraArgs "")
+    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.30.3")
+      if(${CPM_ARGS_EXCLUDE_FROM_ALL})
+        list(APPEND fetchContentDeclareExtraArgs EXCLUDE_FROM_ALL)
+      endif()
+      if(${CPM_ARGS_SYSTEM})
+        list(APPEND fetchContentDeclareExtraArgs SYSTEM)
+      endif()
+      if(DEFINED CPM_ARGS_SOURCE_SUBDIR)
+        list(APPEND fetchContentDeclareExtraArgs SOURCE_SUBDIR ${CPM_ARGS_SOURCE_SUBDIR})
+      endif()
+      # For CMake version <3.28 OPTIONS are parsed in cpm_add_subdirectory
+      if(CPM_ARGS_OPTIONS AND NOT DOWNLOAD_ONLY)
+        foreach(OPTION ${CPM_ARGS_OPTIONS})
+          cpm_parse_option("${OPTION}")
+          set(${OPTION_KEY} "${OPTION_VALUE}")
+        endforeach()
+      endif()
+    endif()
     cpm_declare_fetch(
-      "${CPM_ARGS_NAME}" "${CPM_ARGS_VERSION}" "${PACKAGE_INFO}" "${CPM_ARGS_UNPARSED_ARGUMENTS}"
+      "${CPM_ARGS_NAME}" ${fetchContentDeclareExtraArgs} "${CPM_ARGS_UNPARSED_ARGUMENTS}"
     )
-    cpm_fetch_package("${CPM_ARGS_NAME}" populated)
+
+    cpm_fetch_package("${CPM_ARGS_NAME}" ${DOWNLOAD_ONLY} populated ${CPM_ARGS_UNPARSED_ARGUMENTS})
     if(CPM_SOURCE_CACHE AND download_directory)
       file(LOCK ${download_directory}/../cmake.lock RELEASE)
     endif()
-    if(${populated})
+    if(${populated} AND ${CMAKE_VERSION} VERSION_LESS "3.30.3")
       cpm_add_subdirectory(
         "${CPM_ARGS_NAME}"
         "${DOWNLOAD_ONLY}"
@@ -914,7 +1023,7 @@ function(CPMGetPackageVersion PACKAGE OUTPUT)
 endfunction()
 
 # declares a package in FetchContent_Declare
-function(cpm_declare_fetch PACKAGE VERSION INFO)
+function(cpm_declare_fetch PACKAGE)
   if(${CPM_DRY_RUN})
     cpm_message(STATUS "${CPM_INDENT} Package not declared (dry run)")
     return()
@@ -990,7 +1099,7 @@ endfunction()
 
 # downloads a previously declared package via FetchContent and exports the variables
 # `${PACKAGE}_SOURCE_DIR` and `${PACKAGE}_BINARY_DIR` to the parent scope
-function(cpm_fetch_package PACKAGE populated)
+function(cpm_fetch_package PACKAGE DOWNLOAD_ONLY populated)
   set(${populated}
       FALSE
       PARENT_SCOPE
@@ -1005,7 +1114,24 @@ function(cpm_fetch_package PACKAGE populated)
   string(TOLOWER "${PACKAGE}" lower_case_name)
 
   if(NOT ${lower_case_name}_POPULATED)
-    FetchContent_Populate(${PACKAGE})
+    if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.30.3")
+      if(DOWNLOAD_ONLY)
+        # MakeAvailable will call add_subdirectory internally which is not what we want when
+        # DOWNLOAD_ONLY is set. Populate will only download the dependency without adding it to the
+        # build
+        FetchContent_Populate(
+          ${PACKAGE}
+          SOURCE_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-src"
+          BINARY_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-build"
+          SUBBUILD_DIR "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-subbuild"
+          ${ARGN}
+        )
+      else()
+        FetchContent_MakeAvailable(${PACKAGE})
+      endif()
+    else()
+      FetchContent_Populate(${PACKAGE})
+    endif()
     set(${populated}
         TRUE
         PARENT_SCOPE

examples/boost/CMakeLists.txt

@@ -13,10 +13,12 @@ include(../../cmake/CPM.cmake)
 
 CPMAddPackage(
   NAME Boost
-  VERSION 1.84.0
-  URL https://github.com/boostorg/boost/releases/download/boost-1.84.0/boost-1.84.0.tar.xz
-  URL_HASH SHA256=2e64e5d79a738d0fa6fb546c6e5c2bd28f88d268a2a080546f74e5ff98f29d0e
-  OPTIONS "BOOST_ENABLE_CMAKE ON" "BOOST_INCLUDE_LIBRARIES container\\\;asio" # Note the escapes!
+  VERSION 1.86.0 # Versions less than 1.85.0 may need patches for installation targets.
+  URL https://github.com/boostorg/boost/releases/download/boost-1.86.0/boost-1.86.0-cmake.tar.xz
+  URL_HASH SHA256=2c5ec5edcdff47ff55e27ed9560b0a0b94b07bd07ed9928b476150e16b0efc57
+  OPTIONS "BOOST_ENABLE_CMAKE ON" "BOOST_SKIP_INSTALL_RULES ON" # Set `OFF` for installation
+          "BUILD_SHARED_LIBS OFF" "BOOST_INCLUDE_LIBRARIES container\\\;asio" # Note the escapes!
 )
 
+# `Boost::headers` is also valid
 target_link_libraries(CPMExampleBoost PRIVATE Boost::asio Boost::container)

examples/highway/CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMExamplePatchHighway)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+# Google's highway Includes a SIMD sorting function that is faster than x86-simd-sort for larger
+# arrays. See: https://github.com/google/highway/blob/master/g3doc/quick_reference.md
+CPMAddPackage(
+  NAME highway
+  URL https://github.com/google/highway/archive/refs/tags/1.1.0.tar.gz
+  URL_HASH SHA256=354a8b4539b588e70b98ec70844273e3f2741302c4c377bcc4e81b3d1866f7c9
+  PATCHES "highway.patch" # This adds SYSTEM to the includes.
+  OPTIONS "HWY_ENABLE_EXAMPLES OFF" "HWY_ENABLE_INSTALL OFF" "HWY_ENABLE_TESTS OFF"
+)
+
+# ---- Executable ----
+
+if(LINUX)
+  # This would cause a float compare error inside the highway header code if the patch is NOT
+  # applied.
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wfloat-equal")
+endif()
+
+add_executable(CPMExamplePatchHighway "main.cpp")
+target_link_libraries(CPMExamplePatchHighway hwy hwy_contrib)

examples/highway/highway.patch

@@ -0,0 +1,28 @@
+Common subdirectories: a/.bcr and b/.bcr
+Common subdirectories: a/.github and b/.github
+diff -u a/CMakeLists.txt b/CMakeLists.txt
+--- a/CMakeLists.txt	2024-05-21 12:50:37.738318520 -0500
++++ b/CMakeLists.txt	2024-05-21 12:49:59.914226871 -0500
+@@ -350,7 +350,7 @@
+ target_compile_options(hwy PRIVATE ${HWY_FLAGS})
+ set_property(TARGET hwy PROPERTY POSITION_INDEPENDENT_CODE ON)
+ set_target_properties(hwy PROPERTIES VERSION ${LIBRARY_VERSION} SOVERSION ${LIBRARY_SOVERSION})
+-target_include_directories(hwy PUBLIC
++target_include_directories(hwy SYSTEM PUBLIC
+     $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+     $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+ target_compile_features(hwy PUBLIC cxx_std_11)
+@@ -370,7 +370,7 @@
+ target_compile_options(hwy_contrib PRIVATE ${HWY_FLAGS})
+ set_property(TARGET hwy_contrib PROPERTY POSITION_INDEPENDENT_CODE ON)
+ set_target_properties(hwy_contrib PROPERTIES VERSION ${LIBRARY_VERSION} SOVERSION ${LIBRARY_SOVERSION})
+-target_include_directories(hwy_contrib PUBLIC
++target_include_directories(hwy_contrib SYSTEM PUBLIC
+     $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}>
+     $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+ target_compile_features(hwy_contrib PUBLIC cxx_std_11)
+Common subdirectories: a/cmake and b/cmake
+Common subdirectories: a/debian and b/debian
+Common subdirectories: a/docs and b/docs
+Common subdirectories: a/g3doc and b/g3doc
+Common subdirectories: a/hwy and b/hwy

examples/highway/main.cpp

@@ -0,0 +1,27 @@
+#include <hwy/contrib/sort/vqsort.h>  // hwy::VQSort() for large data sets
+
+#include <cstdint>
+#include <random>
+#include <vector>
+
+// Use hwy::VQSort to sort larger vectors
+inline void sort_large(std::vector<double>& v) {
+  hwy::VQSort(v.data(), v.size(), hwy::SortAscending{});
+}
+
+int main(int, char**) {
+  std::random_device random_device;
+  std::default_random_engine random_engine(random_device());
+  std::uniform_real_distribution<double> uniform_dist(0.0, 100.0);
+
+  const std::size_t sz = 100000;
+  std::vector<double> v;
+  v.reserve(sz);
+  for (std::size_t i = 0; i < sz; ++i) {
+    v.push_back(uniform_dist(random_engine));
+  }
+
+  sort_large(v);
+
+  return 0;
+}

examples/sol2/CMakeLists.txt

@@ -8,7 +8,7 @@ include(../../cmake/CPM.cmake)
 
 CPMAddPackage(
   NAME lua
-  GIT_REPOSITORY https://github.com/lua/lua.git
+  GITHUB_REPOSITORY lua/lua
   VERSION 5.3.5
   DOWNLOAD_ONLY YES
 )
@@ -21,7 +21,13 @@ if(lua_ADDED)
   target_include_directories(lua SYSTEM PUBLIC $<BUILD_INTERFACE:${lua_SOURCE_DIR}>)
 endif()
 
-CPMAddPackage("gh:ThePhD/sol2@3.3.0")
+CPMAddPackage(
+  NAME sol2
+  GITHUB_REPOSITORY ThePhD/sol2
+  VERSION 3.3.0
+  # fix for clang 18.1.0, see https://github.com/ThePhD/sol2/issues/1581#issuecomment-2103463524
+  PATCHES fix_for_clang.patch
+)
 
 # ---- Executable ----
 

examples/sol2/fix_for_clang.patch

@@ -0,0 +1,18 @@
+diff -u a/include/sol/function_types_stateless.hpp b/include/types/function_types_stateless.hpp
+--- a/include/sol/function_types_stateless.hpp
++++ b/include/sol/function_types_stateless.hpp
+@@ -322,7 +322,13 @@ namespace sol { namespace function_detail {
+ 		}
+ 
+ 		template <bool is_yielding, bool no_trampoline>
+-		static int call(lua_State* L) noexcept(std::is_nothrow_copy_assignable_v<T>) {
++		static int call(lua_State* L)
++#if SOL_IS_ON(SOL_COMPILER_CLANG)
++		// apparent regression in clang 18 - llvm/llvm-project#91362
++#else
++			noexcept(std::is_nothrow_copy_assignable_v<T>)
++#endif
++		{
+ 			int nr;
+ 			if constexpr (no_trampoline) {
+ 				nr = real_call(L);

test/integration/templates/using-patch-adder/lists.in.cmake

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(using-patch-adder)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+
+include("%{cpm_path}")
+
+%{packages}
+
+add_executable(using-patch-adder using-patch-adder.cpp)
+
+target_link_libraries(using-patch-adder adder)

test/integration/templates/using-patch-adder/patches/001-test_patches_command.patch

@@ -0,0 +1,12 @@
+diff --git a/code/adder/adder.hpp b/code/adder/adder.hpp
+index fdb9324..7c2fa00 100644
+--- a/code/adder/adder.hpp
++++ b/code/adder/adder.hpp
+@@ -1,6 +1,6 @@
+ #pragma once
+ 
+-namespace adder
++namespace patched
+ {
+ int add(int a, int b);
+ }

test/integration/templates/using-patch-adder/patches/002-test_patches_command.patch

@@ -0,0 +1,12 @@
+diff --git a/code/adder/adder.cpp b/code/adder/adder.cpp
+index fc6e767..44b1197 100644
+--- a/code/adder/adder.cpp
++++ b/code/adder/adder.cpp
+@@ -1,6 +1,6 @@
+ #include "adder.hpp"
+ 
+-namespace adder
++namespace patched
+ {
+ int add(int a, int b)
+ {

test/integration/templates/using-patch-adder/using-patch-adder.cpp

@@ -0,0 +1,8 @@
+#include <adder/adder.hpp>
+#include <cstdio>
+
+int main() {
+  int sum = patched::add(5, 3);
+  std::printf("%d\n", sum);
+  return 0;
+}

test/integration/test_basics.rb

@@ -31,7 +31,9 @@ class Basics < IntegrationTest
     assert_same_path File.join(prj.bin_dir, 'cpm-package-lock.cmake'), check_and_get('CPM_PACKAGE_LOCK_FILE')
 
     assert_equal 'OFF', check_and_get('CPM_DONT_UPDATE_MODULE_PATH', 'BOOL')
-    assert_same_path File.join(prj.bin_dir, 'CPM_modules'), check_and_get('CPM_MODULE_PATH')
+    if @cache.entries['CMAKE_FIND_PACKAGE_REDIRECTS_DIR'].nil?
+      assert_same_path File.join(prj.bin_dir, 'CPM_modules'), check_and_get('CPM_MODULE_PATH')
+    end
   end
 
   # Test when env CPM_SOURCE_CACHE is set

test/integration/test_patches_command.rb

@@ -0,0 +1,27 @@
+require_relative './lib'
+
+# Tests using a multi-argumenet PATCHES command to fetch and modify a dependency
+
+class DownloadCommand < IntegrationTest
+
+  def test_fetch_dependency_using_download_command
+    prj = make_project from_template: 'using-patch-adder'
+
+    prj.create_lists_from_default_template package: <<~PACK
+      set(DOWNLOAD_DIR ${CMAKE_BINARY_DIR}/_deps/testpack-adder-src)
+      CPMAddPackage(
+        NAME testpack-adder
+        DOWNLOAD_COMMAND git clone --depth 1 --branch v1.0.0 https://github.com/cpm-cmake/testpack-adder.git ${DOWNLOAD_DIR}
+        OPTIONS "ADDER_BUILD_TESTS OFF" "ADDER_BUILD_EXAMPLES OFF"
+        PATCHES
+          patches/001-test_patches_command.patch
+          patches/002-test_patches_command.patch
+      )
+    PACK
+
+    # configure with unpopulated cache
+    assert_success prj.configure
+    assert_success prj.build
+  end
+
+end

test/unit/local_dependency/ModuleCMakeLists.txt.in

@@ -8,6 +8,10 @@ option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
 
 # ---- Dependencies ----
 
+if (@TEST_FORCE_MODULE_MODE@)
+  unset(CMAKE_FIND_PACKAGE_REDIRECTS_DIR CACHE)
+endif()
+
 include(@CPM_PATH@/CPM.cmake)
 
 CPMAddPackage(
@@ -15,21 +19,23 @@ CPMAddPackage(
   SOURCE_DIR ${CMAKE_CURRENT_LIST_DIR}/dependency
 )
 
-# ---- check if generated modules override find_package ----
-
-if (@test_check_find_package@)
-  find_package(@TEST_DEPENDENCY_NAME@ REQUIRED)
-endif()
-
 # ---- Call dependency method to validate correct addition of directory ----
 
 dependency_function()
 
-# ---- Check parameters ----
-
+# ---- Check newly added ----
 include(@CPM_PATH@/testing.cmake)
-
 ASSERT_TRUTHY(@TEST_DEPENDENCY_NAME@_ADDED)
+
+# ---- Check if generated modules override find_package ----
+
+if (@TEST_FIND_PACKAGE@)
+  find_package(@TEST_DEPENDENCY_NAME@ @TEST_FIND_PACKAGE_CONFIG@ REQUIRED)
+  find_package(@TEST_CANT_FIND_PACKAGE_NAME@ @TEST_FIND_PACKAGE_CONFIG@ QUIET)
+  ASSERT_FALSY(@TEST_CANT_FIND_PACKAGE_NAME@_FOUND)
+endif()
+
+# ---- Check parameters ----
 ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_SOURCE_DIR)
 ASSERT_DEFINED(@TEST_DEPENDENCY_NAME@_BINARY_DIR)
 ASSERT_EQUAL("${CPM_LAST_PACKAGE_NAME}" "@TEST_DEPENDENCY_NAME@")

test/unit/modules.cmake

@@ -3,7 +3,8 @@ include(${CPM_PATH}/testing.cmake)
 
 set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/modules)
 
-function(init_project_with_dependency TEST_DEPENDENCY_NAME)
+function(init_project_with_dependency TEST_DEPENDENCY_NAME TEST_CANT_FIND_PACKAGE_NAME)
+  set(TEST_FIND_PACKAGE ON)
   configure_package_config_file(
     "${CMAKE_CURRENT_LIST_DIR}/local_dependency/ModuleCMakeLists.txt.in"
     "${CMAKE_CURRENT_LIST_DIR}/local_dependency/CMakeLists.txt"
@@ -18,11 +19,17 @@ function(init_project_with_dependency TEST_DEPENDENCY_NAME)
   assert_equal(${ret} "0")
 endfunction()
 
-init_project_with_dependency(A)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
-assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)
+init_project_with_dependency(A B)
+init_project_with_dependency(B A)
 
-init_project_with_dependency(B)
-assert_not_exists(${TEST_BUILD_DIR}/CPM_modules/FindA.cmake)
-assert_exists(${TEST_BUILD_DIR}/CPM_modules/FindB.cmake)
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.24.0")
+  set(TEST_FIND_PACKAGE_CONFIG CONFIG)
+  init_project_with_dependency(A B)
+  init_project_with_dependency(B A)
+
+  # Test the fallback path for CMake <3.24 works
+  set(TEST_FIND_PACKAGE_CONFIG)
+  set(TEST_FORCE_MODULE_MODE ON)
+  init_project_with_dependency(A B)
+  init_project_with_dependency(B A)
+endif()