Fix offline cache support (#110)

* use cmake -E true as empty command

* use cmake without arguments as valid empty command

.github/workflows/macos.yml

@@ -1,11 +1,17 @@
 name: MacOS
 
-on: [push]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
 
 jobs:
   build:
 
-    runs-on: macOS-10.14
+    runs-on: macos-latest
     
     steps:
     - uses: actions/checkout@v1

.github/workflows/publish.yaml

@@ -0,0 +1,21 @@
+name: Publish
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build:
+    name: Publish CPM.cmake
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - name: Upload CPM.cmake to release
+        uses: svenstaro/upload-release-action@v1-release
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          file: cmake/CPM.cmake
+          asset_name: CPM.cmake
+          tag: ${{ github.ref }}
+          overwrite: true

.github/workflows/ubuntu.yml

@@ -1,11 +1,17 @@
 name: Ubuntu
 
-on: [push]
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
 
 jobs:
   build:
 
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-latest
     
     steps:
     - uses: actions/checkout@v1

.github/workflows/windows.yml

@@ -1,11 +1,17 @@
 name: Windows
 
-on: [push]
+on:
+  push:
+    branches:
+    - master
+  pull_request:
+    branches:
+    - master
 
 jobs:
   build:
 
-    runs-on: windows-2019
+    runs-on: windows-latest
     
     steps:
     - uses: actions/checkout@v1

README.md

@@ -36,6 +36,7 @@ CPMAddPackage(
 
 The origin may be specified by a `GIT_REPOSITORY`, but other sources, such as direct URLs, are [also supported](https://cmake.org/cmake/help/v3.11/module/ExternalProject.html#external-project-definition).
 If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a common convention for git projects.
+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` to always download the most recent version.
 The optional argument `FIND_PACKAGE_ARGUMENTS` can be specified to a string of parameters that will be passed to `find_package` if enabled (see below).
 
@@ -80,7 +81,7 @@ To add CPM to your current project, simply add `cmake/CPM.cmake` to your project
 
 ```bash
 mkdir -p cmake
-wget -O cmake/CPM.cmake https://raw.githubusercontent.com/TheLartians/CPM.cmake/master/cmake/CPM.cmake
+wget -O cmake/CPM.cmake https://github.com/TheLartians/CPM.cmake/releases/latest/download/CPM.cmake
 ```
 
 You can also use CMake to download CPM for you. See the [wiki](https://github.com/TheLartians/CPM/wiki/Adding-CPM) for more details.

cmake/CPM.cmake

@@ -28,7 +28,7 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-set(CURRENT_CPM_VERSION 0.17)
+set(CURRENT_CPM_VERSION 0.20)
 
 if(CPM_DIRECTORY)
   if(NOT ${CPM_DIRECTORY} MATCHES ${CMAKE_CURRENT_LIST_DIR})
@@ -70,7 +70,7 @@ endif()
 
 function(cpm_find_package NAME VERSION)
   string(REPLACE " " ";" EXTRA_ARGS "${ARGN}")
-  find_package(${NAME} ${VERSION} ${EXTRA_ARGS})
+  find_package(${NAME} ${VERSION} ${EXTRA_ARGS} QUIET)
   if(${CPM_ARGS_NAME}_FOUND)
     message(STATUS "${CPM_INDENT} using local package ${CPM_ARGS_NAME}@${${CPM_ARGS_NAME}_VERSION}")
     CPMRegisterPackage(${CPM_ARGS_NAME} "${${CPM_ARGS_NAME}_VERSION}")
@@ -124,7 +124,7 @@ function(CPMAddPackage)
     OPTIONS
   )
 
-  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+  cmake_parse_arguments(CPM_ARGS "" "${oneValueArgs}" "${multiValueArgs}" "${ARGN}")
 
   if(CPM_USE_LOCAL_PACKAGES OR CPM_LOCAL_PACKAGES_ONLY)
     cpm_find_package(${CPM_ARGS_NAME} "${CPM_ARGS_VERSION}" ${CPM_ARGS_FIND_PACKAGE_ARGUMENTS})
@@ -218,7 +218,8 @@ function(CPMAddPackage)
     set(download_directory ${CPM_SOURCE_CACHE}/${lower_case_name}/${origin_hash})
     list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS SOURCE_DIR ${download_directory})
     if (EXISTS ${download_directory})
-      list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS DOWNLOAD_COMMAND ":")
+      # disable the download command to allow offline builds
+      list(APPEND FETCH_CONTENT_DECLARE_EXTRA_OPTS DOWNLOAD_COMMAND "${CMAKE_COMMAND}")
       set(PACKAGE_INFO "${download_directory}")
     else()
       # remove timestamps so CMake will re-download the dependency

examples/catch2/CMakeLists.txt

@@ -2,10 +2,6 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
 project(CPMExampleCatch2)
 
-# ---- Options ----
-
-option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
-
 # ---- Dependencies ----
 
 include(../../cmake/CPM.cmake)
@@ -26,16 +22,9 @@ CPMAddPackage(
 
 add_executable(CPMExampleCatch2 main.cpp)
 target_link_libraries(CPMExampleCatch2 fibonacci Catch2)
-set_target_properties(CPMExampleCatch2 PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-Wall -pedantic -Wextra -Werror")
+set_target_properties(CPMExampleCatch2 PROPERTIES CXX_STANDARD 17)
 
 # ---- Enable testing ----
 
 ENABLE_TESTING() 
 ADD_TEST(CPMExampleCatch2 CPMExampleCatch2)
-
-# ---- Add code coverage ----
-
-if (${ENABLE_TEST_COVERAGE})
-  set_target_properties(CPMExampleCatch2 PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-O0 -g -fprofile-arcs -ftest-coverage --coverage")
-  target_link_options(CPMExampleCatch2 PUBLIC "--coverage")
-endif()

examples/cxxopts/CMakeLists.txt

@@ -2,10 +2,6 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
 project(CPMExampleCXXOpts)
 
-# ---- Options ----
-
-option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
-
 # ---- Dependencies ----
 
 include(../../cmake/CPM.cmake)
@@ -23,4 +19,4 @@ CPMAddPackage(
 
 add_executable(CPMExampleCXXOpts main.cpp)
 target_link_libraries(CPMExampleCXXOpts cxxopts)
-set_target_properties(CPMExampleCXXOpts PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-Wall -pedantic -Wextra -Werror")
+set_target_properties(CPMExampleCXXOpts PROPERTIES CXX_STANDARD 17)

examples/doctest/CMakeLists.txt

@@ -2,10 +2,6 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
 project(CPMExampleDoctest)
 
-# ---- Options ----
-
-option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
-
 # ---- Dependencies ----
 
 include(../../cmake/CPM.cmake)
@@ -26,16 +22,9 @@ CPMAddPackage(
 
 add_executable(CPMExampleDoctest main.cpp)
 target_link_libraries(CPMExampleDoctest fibonacci doctest)
-set_target_properties(CPMExampleDoctest PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-Wall -pedantic -Wextra -Werror")
+set_target_properties(CPMExampleDoctest PROPERTIES CXX_STANDARD 17)
 
 # ---- Enable testing ----
 
 ENABLE_TESTING() 
 ADD_TEST(CPMExampleDoctest CPMExampleDoctest)
-
-# ---- Add code coverage ----
-
-if (${ENABLE_TEST_COVERAGE})
-  set_target_properties(CPMExampleDoctest PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-O0 -g -fprofile-arcs -ftest-coverage --coverage")
-  target_link_options(CPMExampleDoctest PUBLIC "--coverage")
-endif()

examples/fmt/CMakeLists.txt

@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMJSONExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME fmt
+  GIT_TAG 6.1.2
+  GITHUB_REPOSITORY fmtlib/fmt
+)
+
+# ---- Executable ----
+
+add_executable(CPMFmtExample "main.cpp")
+set_target_properties(CPMFmtExample PROPERTIES CXX_STANDARD 17)        
+target_link_libraries(CPMFmtExample fmt)

examples/fmt/main.cpp

@@ -0,0 +1,6 @@
+#include <fmt/format.h>
+
+int main(){
+  fmt::print("Hello, {}!\n", "world");
+  return 0;
+}

examples/gtest/CMakeLists.txt

@@ -2,10 +2,6 @@ cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
 project(CPMExampleGtest)
 
-# ---- Options ----
-
-option(ENABLE_TEST_COVERAGE "Enable test coverage" OFF)
-
 # ---- Dependencies ----
 
 include(../../cmake/CPM.cmake)
@@ -36,10 +32,3 @@ set_target_properties(CPMExampleGtest PROPERTIES CXX_STANDARD 17)
 
 enable_testing() 
 add_test(CPMExampleGtest CPMExampleGtest)
-
-# ---- Add code coverage ----
-
-if (${ENABLE_TEST_COVERAGE})
-  set_target_properties(CPMExampleGtest PROPERTIES CXX_STANDARD 17 COMPILE_FLAGS "-O0 -g -fprofile-arcs -ftest-coverage --coverage")
-  target_link_options(CPMExampleGtest PUBLIC "--coverage")
-endif()

test/unit/cache.cmake

@@ -8,6 +8,7 @@ set(CPM_SOURCE_CACHE_DIR "${CMAKE_CURRENT_BINARY_DIR}/CPM")
 set(TEST_BUILD_DIR ${CMAKE_CURRENT_BINARY_DIR}/cache)
 
 function(clear_cache)
+  message(STATUS "clearing CPM cache")
   FILE(REMOVE_RECURSE ${CPM_SOURCE_CACHE_DIR})
   
   if (EXISTS "${CPM_SOURCE_CACHE_DIR}")
@@ -104,6 +105,16 @@ if (NOT EXISTS "${CPM_SOURCE_CACHE_DIR}/fibonacci")
   ASSERTION_FAILED("fibonacci not in cache")
 endif()
 
+## Reuse cached packages for other build
+
+execute_process(
+  COMMAND 
+  ${CMAKE_COMMAND} -E env "CPM_SOURCE_CACHE=${CPM_SOURCE_CACHE_DIR}" ${CMAKE_COMMAND} "-H${CMAKE_CURRENT_LIST_DIR}/cache" "-B${TEST_BUILD_DIR}-2"
+  RESULT_VARIABLE ret
+)
+
+ASSERT_EQUAL(${ret} "0")
+
 ## Overwrite CPM_SOURCE_CACHE with argument
 
 reset_test()