Timestamps for URL downloads match the download time (#372)

* Timestamps for URL downloads match the download time

By enabling CMake policy 135 we ensure that extracted files
timestamp match that of the download time, instead of when the
archive is created. This makes sure that if the URL changes to
an older version we still rebuild everything as the timestamp
stays newer.

* Introduce CPM_SET_RECOMMENDED_CMAKE_POLICIES

Enabling CPM_SET_RECOMMENDED_CMAKE_POLICIES will establish defaults
for all CMake policies so that both CPM and added projects
operate inline with CPM recommended best practices.

* Fix style issues found by ci

* Update README.md

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

* Update cmake/CPM.cmake

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

* Set policies when CPM.cmake is included

* CPM_SET_RECOMMENDED_CMAKE_POLICIES default is ON

* Correct failing CI tests

* CPM.cmake always sets policies to on

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

README.md

@@ -227,6 +227,22 @@ cmake --build build --target cpm-update-package-lock
 
 See the [wiki](https://github.com/cpm-cmake/CPM.cmake/wiki/Package-lock) for more info.
 
+## Private repositories and CI
+
+When using CPM.cmake with private repositories, there may be a need to provide an [access token](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token) to be able to clone other projects. Instead of providing the token in CMake, we recommend to provide the regular URL and use [git-config](https://git-scm.com/docs/git-config) to rewrite the URLs to include the token.
+
+As an example, you could include one of the following in your CI script.
+
+```bash
+# Github
+git config --global url."https://${USERNAME}:${TOKEN}@github.com".insteadOf "https://github.com"
+```
+
+```bash
+# GitLab
+git config --global url."https://gitlab-ci-token:${CI_JOB_TOKEN}@gitlab.com".insteadOf "https://gitlab.com"
+```
+
 ## Built with CPM.cmake
 
 Some amazing projects that are built using the CPM.cmake package manager.
@@ -258,6 +274,8 @@ If you know others, feel free to add them here through a PR.
         <p align="center"><b>ModernCppStarter</b></p>
       </a>
     </td>
+  </tr>
+  <tr>
     <td>
       <a href="https://git.io/liblava">
         <p align="center">
@@ -266,6 +284,22 @@ If you know others, feel free to add them here through a PR.
         <p align="center"><b>liblava - Modern Vulkan library</b></p>
       </a>
     </td>
+    <td>
+      <a href="https://github.com/variar/klogg">
+        <p align="center">
+          <img src="https://github.com/variar/klogg/blob/master/src/app/images/hicolor/scalable/klogg.svg" alt="klogg" width="100pt" />
+        </p>
+        <p align="center"><b>klogg - fast advanced log explorer</b></p>
+      </a>
+    </td>
+    <td>
+      <a href="https://github.com/MethanePowered/MethaneKit">
+        <p align="center">
+          <img src="https://github.com/MethanePowered/MethaneKit/raw/master/Docs/Images/Logo/MethaneLogoSmall.png" alt="MethaneKit" width="100pt" />
+        </p>
+        <p align="center"><b>Methane Kit - modern 3D graphics rendering framework</b></p>
+      </a>
+    </td>
   </tr>
 </table>
 
@@ -283,7 +317,7 @@ CPMAddPackage("gh:catchorg/Catch2@2.5.0")
 ### [Range-v3](https://github.com/ericniebler/range-v3)
 
 ```Cmake
-CPMAddPackage("gh:ericniebler/range-v3#0.11.0")
+CPMAddPackage("gh:ericniebler/range-v3#0.12.0")
 ```
 
 ### [Yaml-cpp](https://github.com/jbeder/yaml-cpp)

cmake/CPM.cmake

@@ -28,10 +28,28 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
+# the policy allows us to change options without caching
+cmake_policy(SET CMP0077 NEW)
+set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
+
+# the policy allows us to change set(CACHE) without caching
+if(POLICY CMP0126)
+  cmake_policy(SET CMP0126 NEW)
+  set(CMAKE_POLICY_DEFAULT_CMP0126 NEW)
+endif()
+
+# The policy uses the download time for timestamp, instead of the timestamp in the archive. This
+# allows for proper rebuilds when a projects url changes
+if(POLICY CMP0135)
+  cmake_policy(SET CMP0135 NEW)
+  set(CMAKE_POLICY_DEFAULT_CMP0135 NEW)
+endif()
+
 set(CURRENT_CPM_VERSION 1.0.0-development-version)
 
+get_filename_component(CPM_CURRENT_DIRECTORY "${CMAKE_CURRENT_LIST_DIR}" REALPATH)
 if(CPM_DIRECTORY)
-  if(NOT CPM_DIRECTORY STREQUAL CMAKE_CURRENT_LIST_DIR)
+  if(NOT CPM_DIRECTORY STREQUAL CPM_CURRENT_DIRECTORY)
     if(CPM_VERSION VERSION_LESS CURRENT_CPM_VERSION)
       message(
         AUTHOR_WARNING
@@ -93,7 +111,7 @@ set(CPM_VERSION
     CACHE INTERNAL ""
 )
 set(CPM_DIRECTORY
-    ${CMAKE_CURRENT_LIST_DIR}
+    ${CPM_CURRENT_DIRECTORY}
     CACHE INTERNAL ""
 )
 set(CPM_FILE
@@ -476,6 +494,7 @@ endfunction()
 
 # Download and add a package from source
 function(CPMAddPackage)
+
   list(LENGTH ARGN argnLength)
   if(argnLength EQUAL 1)
     cpm_parse_add_package_single_arg("${ARGN}" ARGN)
@@ -650,6 +669,20 @@ function(CPMAddPackage)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS DOWNLOAD_COMMAND ${CPM_ARGS_DOWNLOAD_COMMAND})
   elseif(DEFINED CPM_ARGS_SOURCE_DIR)
     list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS SOURCE_DIR ${CPM_ARGS_SOURCE_DIR})
+    if(NOT IS_ABSOLUTE ${CPM_ARGS_SOURCE_DIR})
+      # Expand `CPM_ARGS_SOURCE_DIR` relative path. This is important because EXISTS doesn't work
+      # for relative paths.
+      get_filename_component(
+        source_directory ${CPM_ARGS_SOURCE_DIR} REALPATH BASE_DIR ${CMAKE_CURRENT_BINARY_DIR}
+      )
+    else()
+      set(source_directory ${CPM_ARGS_SOURCE_DIR})
+    endif()
+    if(NOT EXISTS ${source_directory})
+      string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
+      # remove timestamps so CMake will re-download the dependency
+      file(REMOVE_RECURSE "${CPM_FETCHCONTENT_BASE_DIR}/${lower_case_name}-subbuild")
+    endif()
   elseif(CPM_SOURCE_CACHE AND NOT CPM_ARGS_NO_CACHE)
     string(TOLOWER ${CPM_ARGS_NAME} lower_case_name)
     set(origin_parameters ${CPM_ARGS_UNPARSED_ARGUMENTS})
@@ -891,16 +924,6 @@ function(
       set(addSubdirectoryExtraArgs "")
     endif()
     if(OPTIONS)
-      # the policy allows us to change options without caching
-      cmake_policy(SET CMP0077 NEW)
-      set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
-
-      # the policy allows us to change set(CACHE) without caching
-      if(POLICY CMP0126)
-        cmake_policy(SET CMP0126 NEW)
-        set(CMAKE_POLICY_DEFAULT_CMP0126 NEW)
-      endif()
-
       foreach(OPTION ${OPTIONS})
         cpm_parse_option("${OPTION}")
         set(${OPTION_KEY} "${OPTION_VALUE}")

examples/range-v3/CMakeLists.txt

@@ -6,7 +6,7 @@ project(CPMRangev3Example)
 
 include(../../cmake/CPM.cmake)
 
-CPMAddPackage("gh:ericniebler/range-v3#0.11.0")
+CPMAddPackage("gh:ericniebler/range-v3#0.12.0")
 
 # ---- Executable ----
 

test/integration/test_remove_source_dir.rb

@@ -0,0 +1,36 @@
+require_relative './lib'
+
+class RemoveSourceDir < IntegrationTest
+  def test_remove_source_dir
+    prj = make_project 'using-adder'
+    
+    prj.create_lists_from_default_template package: <<~PACK
+      CPMAddPackage(
+        NAME testpack-adder
+        GITHUB_REPOSITORY cpm-cmake/testpack-adder
+        VERSION 1.0.0
+        OPTIONS "ADDER_BUILD_TESTS OFF"
+        SOURCE_DIR testpack-adder
+      )
+    PACK
+
+    # configure and build
+    assert_success prj.configure
+    assert_success prj.build
+
+    # source_dir is populated
+    assert_true File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+
+    # source_dir is deleted by user
+    FileUtils.remove_dir(File.join(prj.bin_dir, 'testpack-adder'), true)
+    assert_false File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+
+    # configure and build with missing source_dir to fetch new content
+    assert_success prj.configure
+    assert_success prj.build
+
+    # source_dir is populated
+    assert_true File.exist?(File.join(prj.bin_dir, 'testpack-adder'))
+  end
+
+end