Adding PATCHES keyword. (#558)

* Adding PATCHES keyword.

* Formatting fix.

* Move cpm_add_patches() outside if/else scopes.

* cmake-format: add PATCHES to CPMAddPackage.

* Integration tests for PATCHES command.

* Use get_filename_component() in place of cmake_path() for use with all cmake versions 3.14 and above.

* Added an example and improved comment for cpm_add_patches.

Author: ScottBailey

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 +79,8 @@ 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).
+
 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.

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

@@ -464,6 +464,69 @@ 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(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` 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 ${extra_search_path} DIRECTORY)
+      get_filename_component(extra_search_path ${extra_search_path} DIRECTORY)
+      find_program(PATCH_EXECUTABLE patch HINTS "${extra_search_path}/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 +600,7 @@ 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 +691,7 @@ 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 +747,8 @@ 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)

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;
+}

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;
+}