Add url shortcuts (#53)

* add github and gitlab shortcut, closes #52

* update version

* update examples and readme

README.md

@@ -2,7 +2,8 @@
 
 # CPM
 
-CPM is a simple dependency manager written in CMake built on top of CMake's built-in [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) module.
+CPM is a CMake script that adds dependency management capabilities to CMake. 
+It's built as an extension of CMake's [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) module that adds version control and simpler usage.
 
 ## Supported projects
 
@@ -10,24 +11,29 @@ Any project that you can add via `add_subdirectory` should already work with CPM
 
 ## Usage
 
-After `CPM.cmake` has been added to your project, you can call `CPMAddPackage` for every dependency of the project with the following named parameters.
+After `CPM.cmake` has been added to your project, the function `CPMAddPackage` can be used to fetch and configure all dependencies.
+Afterwards all targets defined in the dependencies can be used.
+`CPMAddPackage` takes the following named arguments.
 
 ```cmake
 CPMAddPackage(
-  NAME          # The dependency name (usually chosen to match the target name)
+  NAME          # The name of the dependency (should be chosen to match the main target's name)
   VERSION       # The minimum version of the dependency (optional, defaults to 0)
   OPTIONS       # Configuration options passed to the dependency (optional)
   DOWNLOAD_ONLY # If set, the project is downloaded, but not configured (optional)
-  [...]         # Source options, see below
+  [...]         # Origin paramters forwarded to FetchContent_Declare, see below
 )
 ```
 
-The command downloads the project defined by the source options if a newer version hasn't been included before.
-The source is usually a git repository, but svn and direct urls are als supported.
-See the [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) documentation for all available options.
-If a `GIT_TAG` hasn't been explicitly specified it defaults to `v$VERSION` which is a common convention for github projects.
+The origin is usually specified by a `GIT_REPOSITORY`, but [svn revisions and direct URLs are also supported](https://cmake.org/cmake/help/latest/module/FetchContent.html#declaring-content-details).
+If `GIT_TAG` hasn't been explicitly specified it defaults to `v(VERSION)`, a common convention for github projects.
+`GIT_TAG` can also be set to a branch name such as `master` to download the most recent version.
 
-After calling `CPMAddPackage`, the variables `(DEPENDENCY)_SOURCE_DIR` and `(DEPENDENCY)_BINARY_DIR` are set, where `(DEPENDENCY)` is the name of the dependency.
+Besides downloading and to configuring the dependency, the following variables are defined in the local scope, where `(DEPENDENCY)` is the name of the dependency.
+
+- `(DEPENDENCY)_SOURCE_DIR` is the path to the source of the dependency.
+- `(DEPENDENCY)_BINARY_DIR` is the path to the build directory of the dependency.
+- `(DEPENDENCY)_ADDED` is set to `YES` if the dependency has not been added before, otherwise it is set to `NO`.
 
 ## Full Example
 
@@ -70,28 +76,31 @@ To update CPM to the newest version, simply update the script in the project's c
 
 ## Snipplets
 
-These are some small snipplets demonstrating how to include some projects used with CPM.
+These examples demonstrate how to include some well-known projects with CPM.
 
-### Catch2
+### [Catch2](https://github.com/catchorg/Catch2.git)
 
 Has a CMakeLists.txt that supports `add_subdirectory`.
 
 ```cmake
 CPMAddPackage(
   NAME Catch2
-  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GITHUB_REPOSITORY catchorg/Catch2
   VERSION 2.5.0
 )
 ```
 
-### google/benchmark
+See [here](https://github.com/TheLartians/CPM/blob/master/examples/doctest/CMakeLists.txt) for doctest example.
+Note that we can shorten Github and Gitlab URLs by using `GITHUB_REPOSITORY` or `GITLAB_REPOSITORY`, respectively.
+
+### [google/benchmark](https://github.com/google/benchmark.git)
 
 Has a CMakeLists.txt that supports `add_subdirectory`, but needs some configuring to work without external dependencies.
 
 ```cmake
 CPMAddPackage(
   NAME benchmark
-  GIT_REPOSITORY https://github.com/google/benchmark.git
+  GITHUB_REPOSITORY google/benchmark
   VERSION 1.4.1
   OPTIONS
     "BENCHMARK_ENABLE_TESTING Off"
@@ -101,19 +110,40 @@ CPMAddPackage(
 set_target_properties(benchmark PROPERTIES CXX_STANDARD 17)
 ```
 
-### Lua
+### [nlohmann/json](https://github.com/nlohmann/json)
 
-Has no CMakeLists.txt, so a target must be created manually.
+Header-only library with a huge git repositoy.
+Instead of downloading the whole repositoy, we fetch the zip included with the release and create our own target.
+
+```cmake
+CPMAddPackage(
+  NAME nlohmann_json
+  VERSION 3.6.1  
+  URL https://github.com/nlohmann/json/releases/download/v3.6.1/include.zip
+  URL_HASH SHA256=69cc88207ce91347ea530b227ff0776db82dcb8de6704e1a3d74f4841bc651cf
+)
+
+if (nlohmann_json_ADDED)
+  add_library(nlohmann_json INTERFACE)
+  target_include_directories(nlohmann_json INTERFACE ${nlohmann_json_SOURCE_DIR})
+endif()
+```
+
+Adding large repos works as well, but takes a while for the initial clone.
+
+### [Lua](https://www.lua.org)
+
+Lua does not oficially support CMake, so we query the sources and create our own target.
 
 ```cmake
 CPMAddPackage(
   NAME lua
   GIT_REPOSITORY https://github.com/lua/lua.git
   VERSION 5-3-4
-  GIT_SHALLOW YES
   DOWNLOAD_ONLY YES
 )
 
+if (lua_ADDED)
   FILE(GLOB lua_sources ${lua_SOURCE_DIR}/*.c)
   add_library(lua STATIC ${lua_sources})
 
@@ -121,6 +151,7 @@ target_include_directories(lua
     PUBLIC
       $<BUILD_INTERFACE:${lua_SOURCE_DIR}>
   )
+endif()
 ```
 
 ## Local packages
@@ -130,12 +161,13 @@ If `CPM_LOCAL_PACKAGES_ONLY` is set, CPM will error when dependency is not found
 
 ## Advantages
 
-- **Small repos** CPM takes care of project dependencies, allowing you to focus on creating small, well-tested frameworks.
+- **Small and reusable projects** CPM takes care of project dependencies, allowing developers to focus on creating small, well-tested frameworks.
 - **Cross-Plattform** CPM adds projects via `add_subdirectory`, which is compatible with all cmake toolchains and generators.
 - **Reproducable builds** By using versioning via git tags it is ensured that a project will always be in the same state everywhere.
+- **Recursive dependencies** Ensures that no dependency is added twice and is added in the minimum required version.
 - **No installation required** No need to install anything. Just add the script to your project and you're good to go.
 - **No Setup required** There is a good chance your existing projects already work as CPM dependencies.
-- **Simple source distribution** CPM makes including projects with source files easy, reducing the need for monolithic header files.
+- **Simple source distribution** CPM makes including projects with source files and dependencies easy, reducing the need for monolithic header files.
 
 ## Limitations
 
@@ -143,4 +175,4 @@ If `CPM_LOCAL_PACKAGES_ONLY` is set, CPM will error when dependency is not found
 - **No auto-update** To update a dependency, version must be adapted manually and there is no way for CPM to figure out the most recent version.
 - **No pre-built binaries** Unless they are installed or included in the linked repository. 
 
-For projects with more complex needs and an extra setup step doesn't matter, it is worth to check out fully featured C++ package managers such as [conan](https://conan.io) or [hunter](https://github.com/ruslo/hunter) instead.
+For projects with more complex needs and where an extra setup step doesn't matter, it is worth to check out fully featured C++ package managers such as [conan](https://conan.io) or [hunter](https://github.com/ruslo/hunter).

cmake/CPM.cmake

@@ -28,23 +28,18 @@
 
 cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
 
-set(CURRENT_CPM_VERSION 0.9) 
+set(CURRENT_CPM_VERSION 0.11) 
 
 if(CPM_DIRECTORY)
   if(NOT ${CPM_DIRECTORY} MATCHES ${CMAKE_CURRENT_LIST_DIR})
     if (${CPM_VERSION} VERSION_LESS ${CURRENT_CPM_VERSION})
-      message(AUTHOR_WARNING "${CPM_INDENT} \
-A dependency is using a more recent CPM (${CURRENT_CPM_VERSION}) than the current project (${CPM_VERSION}). \
-It is recommended to upgrade CPM to the most recent version. \
-See https://github.com/TheLartians/CPM for more information.\
-")  
+      CPM_HANDLE_OLD_VERSION(${CURRENT_CPM_VERSION})  
     endif()
     return()
   endif()
 endif()
 
 set(CPM_VERSION ${CURRENT_CPM_VERSION} CACHE INTERNAL "")
-
 set(CPM_DIRECTORY ${CMAKE_CURRENT_LIST_DIR} CACHE INTERNAL "")
 set(CPM_PACKAGES "" CACHE INTERNAL "")
 
@@ -54,35 +49,21 @@ option(CPM_LOCAL_PACKAGES_ONLY "Use only locally installed packages" OFF)
 include(FetchContent)
 include(CMakeParseArguments)
 
+# Initialize logging prefix
 if(NOT CPM_INDENT)
   set(CPM_INDENT "CPM:")
 endif()
 
-function(CPMRegisterPackage PACKAGE VERSION)
-  list(APPEND CPM_PACKAGES ${PACKAGE})
-  set(CPM_PACKAGES ${CPM_PACKAGES} CACHE INTERNAL "")
-  set("CPM_PACKAGE_${PACKAGE}_VERSION" ${VERSION} CACHE INTERNAL "")
-endfunction()
-
-function(CPM_GET_PACKAGE_VERSION PACKAGE)
-  set(CPM_PACKAGE_VERSION "${CPM_PACKAGE_${PACKAGE}_VERSION}" PARENT_SCOPE)
-endfunction()
-
-function(CPM_PARSE_OPTION OPTION)
-  string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
-  string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
-  math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
-  string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
-  set(OPTION_KEY "${OPTION_KEY}" PARENT_SCOPE)
-  set(OPTION_VALUE "${OPTION_VALUE}" PARENT_SCOPE)
-endfunction()
-
+# The main workhorse of CPM
 function(CPMAddPackage)
+
   set(oneValueArgs
     NAME
     VERSION
     GIT_TAG
     DOWNLOAD_ONLY
+    GITHUB_REPOSITORY
+    GITLAB_REPOSITORY
   )
 
   set(multiValueArgs
@@ -116,12 +97,22 @@ function(CPMAddPackage)
     set(CPM_ARGS_GIT_TAG v${CPM_ARGS_VERSION})
   endif()
 
+  list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_TAG ${CPM_ARGS_GIT_TAG})
+
   if(CPM_ARGS_DOWNLOAD_ONLY)
     set(DOWNLOAD_ONLY ${CPM_ARGS_DOWNLOAD_ONLY})
   else()
     set(DOWNLOAD_ONLY NO)
   endif()
 
+  if (CPM_ARGS_GITHUB_REPOSITORY)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_REPOSITORY "https://github.com/${CPM_ARGS_GITHUB_REPOSITORY}.git")
+  endif()
+
+  if (CPM_ARGS_GITLAB_REPOSITORY)
+    list(APPEND CPM_ARGS_UNPARSED_ARGUMENTS GIT_REPOSITORY "https://gitlab.com/${CPM_ARGS_GITHUB_REPOSITORY}.git")
+  endif()
+
   if (${CPM_ARGS_NAME} IN_LIST CPM_PACKAGES)
     CPM_GET_PACKAGE_VERSION(${CPM_ARGS_NAME})
     if(${CPM_PACKAGE_VERSION} VERSION_LESS ${CPM_ARGS_VERSION})
@@ -139,6 +130,7 @@ function(CPMAddPackage)
     CPMGetProperties(${CPM_ARGS_NAME})
     SET(${CPM_ARGS_NAME}_SOURCE_DIR "${${CPM_ARGS_NAME}_SOURCE_DIR}" PARENT_SCOPE)
     SET(${CPM_ARGS_NAME}_BINARY_DIR "${${CPM_ARGS_NAME}_BINARY_DIR}" PARENT_SCOPE)  
+    SET(${CPM_ARGS_NAME}_ADDED NO PARENT_SCOPE)  
     return()
   endif()
 
@@ -156,6 +148,7 @@ function(CPMAddPackage)
   CPMGetProperties(${CPM_ARGS_NAME})
   SET(${CPM_ARGS_NAME}_SOURCE_DIR "${${CPM_ARGS_NAME}_SOURCE_DIR}" PARENT_SCOPE)
   SET(${CPM_ARGS_NAME}_BINARY_DIR "${${CPM_ARGS_NAME}_BINARY_DIR}" PARENT_SCOPE)
+  SET(${CPM_ARGS_NAME}_ADDED YES PARENT_SCOPE)  
 endfunction()
 
 function (CPM_DECLARE_PACKAGE PACKAGE VERSION GIT_TAG)
@@ -163,7 +156,6 @@ function (CPM_DECLARE_PACKAGE PACKAGE VERSION GIT_TAG)
 
   FetchContent_Declare(
     ${PACKAGE}
-    GIT_TAG ${GIT_TAG}
     ${ARGN}
   )
 endfunction()
@@ -187,3 +179,32 @@ function (CPMGetProperties PACKAGE)
   SET(${PACKAGE}_SOURCE_DIR "${${lpackage}_SOURCE_DIR}" PARENT_SCOPE)
   SET(${PACKAGE}_BINARY_DIR "${${lpackage}_BINARY_DIR}" PARENT_SCOPE)
 endfunction()
+
+function(CPMRegisterPackage PACKAGE VERSION)
+  list(APPEND CPM_PACKAGES ${PACKAGE})
+  set(CPM_PACKAGES ${CPM_PACKAGES} CACHE INTERNAL "")
+  set("CPM_PACKAGE_${PACKAGE}_VERSION" ${VERSION} CACHE INTERNAL "")
+endfunction()
+
+function(CPM_GET_PACKAGE_VERSION PACKAGE)
+  set(CPM_PACKAGE_VERSION "${CPM_PACKAGE_${PACKAGE}_VERSION}" PARENT_SCOPE)
+endfunction()
+
+function(CPM_PARSE_OPTION OPTION)
+  string(REGEX MATCH "^[^ ]+" OPTION_KEY ${OPTION})
+  string(LENGTH ${OPTION_KEY} OPTION_KEY_LENGTH)
+  math(EXPR OPTION_KEY_LENGTH "${OPTION_KEY_LENGTH}+1")
+  string(SUBSTRING ${OPTION} "${OPTION_KEY_LENGTH}" "-1" OPTION_VALUE)
+  set(OPTION_KEY "${OPTION_KEY}" PARENT_SCOPE)
+  set(OPTION_VALUE "${OPTION_VALUE}" PARENT_SCOPE)
+endfunction()
+
+function (CPM_HANDLE_OLD_VERSION NEW_CPM_VERSION)
+  
+  message(AUTHOR_WARNING "${CPM_INDENT} \
+A dependency is using a more recent CPM (${NEW_CPM_VERSION}) than the current project (${CPM_VERSION}). \
+It is recommended to upgrade CPM to the most recent version. \
+See https://github.com/TheLartians/CPM for more information."
+  )
+
+endfunction()

examples/benchmark/CMakeLists.txt

@@ -12,14 +12,16 @@ CPMAddPackage(
 
 CPMAddPackage(
   NAME benchmark
-  GIT_REPOSITORY https://github.com/google/benchmark.git
+  GITHUB_REPOSITORY google/benchmark
   VERSION 1.4.1
   OPTIONS
     "BENCHMARK_ENABLE_TESTING Off"
 )
 
+if (benchmark_ADDED)
   # patch google benchmark target
   set_target_properties(benchmark PROPERTIES CXX_STANDARD 17)
+endif()
 
 # ---- Executable ----
 

examples/catch2/CMakeLists.txt

@@ -16,7 +16,7 @@ CPMAddPackage(
 
 CPMAddPackage(
   NAME Catch2
-  GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+  GITHUB_REPOSITORY catchorg/Catch2
   VERSION 2.5.0
 )
 

examples/doctest/CMakeLists.txt

@@ -16,10 +16,9 @@ CPMAddPackage(
 
 CPMAddPackage(
   NAME doctest
-  GIT_REPOSITORY https://github.com/onqtam/doctest.git
+  GITHUB_REPOSITORY onqtam/doctest
   VERSION 2.3.2
   GIT_TAG 2.3.2
-  GIT_SHALLOW True
 )
 
 # ---- Create binary ----

examples/json/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME nlohmann_json
+  VERSION 3.6.1  
+  # not using the repo as it takes forever to clone
+  URL https://github.com/nlohmann/json/releases/download/v3.6.1/include.zip
+  URL_HASH SHA256=69cc88207ce91347ea530b227ff0776db82dcb8de6704e1a3d74f4841bc651cf
+)
+
+if(nlohmann_json_ADDED)
+  add_library(nlohmann_json INTERFACE)
+  target_include_directories(nlohmann_json INTERFACE ${nlohmann_json_SOURCE_DIR})
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMJSONExample "main.cpp")
+set_target_properties(CPMJSONExample PROPERTIES CXX_STANDARD 17)        
+target_link_libraries(CPMJSONExample nlohmann_json)

examples/json/main.cpp

@@ -0,0 +1,25 @@
+#include <nlohmann/json.hpp>
+#include <iostream>
+#include <iomanip>
+
+int main(){
+  
+  nlohmann::json json = {
+    {"pi", 3.141},
+    {"happy", true},
+    {"name", "Niels"},
+    {"nothing", nullptr},
+    {"answer", {
+      {"everything", 42}
+    }},
+    {"list", {1, 0, 2}},
+    {"object", {
+      {"currency", "USD"},
+      {"value", 42.99}
+    }}
+  };
+
+  std::cout << "declared JSON object: " << std::setw(2) << json << std::endl;
+
+  return 0;
+}

examples/simple_match/CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME simple_match
+  GIT_REPOSITORY https://github.com/jbandela/simple_match.git
+  GIT_TAG a3ab17f3d98db302de68ad85ed399a42ae41889e
+  DOWNLOAD_ONLY True
+)
+
+if(simple_match_ADDED)
+  add_library(simple_match INTERFACE IMPORTED)
+  target_include_directories(simple_match INTERFACE "${simple_match_SOURCE_DIR}/include")
+endif()
+
+# ---- Executable ----
+
+add_executable(CPMSimpleMatchExample "main.cpp")
+set_target_properties(CPMSimpleMatchExample PROPERTIES CXX_STANDARD 17)        
+target_link_libraries(CPMSimpleMatchExample simple_match)
+

examples/simple_match/main.cpp

@@ -0,0 +1,34 @@
+#include <simple_match/simple_match.hpp>
+
+#include <iostream>
+
+int main(int argc, char ** argv){
+  using namespace simple_match;
+  using namespace simple_match::placeholders;
+
+  std::string input;
+  std::cout << "please enter a number or 'quit' to exit" << std::endl;
+
+  while (true) {
+    std::cout << "> ";
+    std::getline(std::cin, input);
+    if (input == "quit") { break; }
+    int x;
+    try {
+      x = std::stoi(input);
+    } catch(std::invalid_argument &) {
+      std::cout << "invalid input" << std::endl;
+      continue;
+    }
+    
+    match(x,
+      1, []() {std::cout << "The answer is one\n"; },
+      2, []() {std::cout << "The answer is two\n"; },
+      _x < 10, [](auto&& a) {std::cout << "The answer " << a << " is less than 10\n"; },
+      10 < _x < 20,	[](auto&& a) {std::cout << "The answer " << a  << " is between 10 and 20 exclusive\n"; },
+      _, []() {std::cout << "Did not match\n"; }
+    );
+  }
+
+  return 0;
+}

examples/yaml/CMakeLists.txt

@@ -0,0 +1,25 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+
+CPMAddPackage(
+  NAME yaml-cpp
+  GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
+  # 0.6.2 uses depricated CMake syntax
+  VERSION 0.6.3                                  
+  # 0.6.3 is not released yet, so use the most recent commit
+  GIT_TAG 012269756149ae99745b6dafefd415843d7420bb 
+  OPTIONS
+    "YAML_CPP_BUILD_TESTS Off"
+    "YAML_CPP_BUILD_CONTRIB Off"
+    "YAML_CPP_BUILD_TOOLS Off"
+)
+
+# ---- Executable ----
+
+add_executable(CPMYamlExample "main.cpp")
+set_target_properties(CPMYamlExample PROPERTIES CXX_STANDARD 17)        
+target_link_libraries(CPMYamlExample yaml-cpp)
+

examples/yaml/main.cpp

@@ -0,0 +1,14 @@
+#include <yaml-cpp/yaml.h>
+#include <iostream>
+
+int main(int argc, char ** argv){
+  if (argc != 2) {
+    std::cout << "usage: " << argv[0] << " <path to yaml file>" << std::endl;
+    return 1;
+  }
+
+  YAML::Node config = YAML::LoadFile(argv[1]);
+  std::cout << "Parsed YAML:\n" << config << std::endl;
+
+  return 0;
+}

examples/yaml/monsters.yaml

@@ -0,0 +1,21 @@
+- name: Ogre
+  position: [0, 5, 0]
+  powers:
+    - name: Club
+      damage: 10
+    - name: Fist
+      damage: 8
+- name: Dragon
+  position: [1, 0, 10]
+  powers:
+    - name: Fire Breath
+      damage: 25
+    - name: Claws
+      damage: 15
+- name: Wizard
+  position: [5, -3, 0]
+  powers:
+    - name: Acid Rain
+      damage: 50
+    - name: Staff
+      damage: 3