build: use Semantic Versioning

See https://semver.org for details, but it basically formalizes our
decision to not break API nor ABI in minor releases.

Closes #953

.hooks/pre-commit

@@ -8,4 +8,4 @@ for file in $(git diff-index --cached --name-only HEAD | grep -E '\.(cpp|cc|hpp|
     clang-format --dry-run --Werror "$file" >/dev/null 2>&1 || (echo 'Run ninja clang-format before committing' 1>&2 && false)
 done
 
-grep "VERSION_GIT_DATE        $(date +%Y%m%d)" version.txt || (echo 'Update VERSION_GIT_DATE in version.txt before committing' 1>&2 && false)
+grep "$(date +%Y%m%d)" version.txt || (echo 'Update the commit date in version.txt before committing' 1>&2 && false)

CMakeLists.txt

@@ -12,8 +12,12 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
+file(READ "version.txt" VERSION_FILE_RAW)
+string(STRIP "${VERSION_FILE_RAW}" VERSION_FILE)
+
 project (pistache
-    LANGUAGES C CXX)
+    LANGUAGES C CXX
+    VERSION ${VERSION_FILE})
 
 include(GNUInstallDirs)
 
@@ -42,50 +46,17 @@ if (PISTACHE_USE_SSL)
     find_package(OpenSSL REQUIRED COMPONENTS SSL Crypto)
 endif ()
 
-# Set release version...
-
-    # Retrieve from external file...
-    file(READ "version.txt" VERSION_FILE)
-
-    # Extract version...
-
-        # Major...
-        string(REGEX MATCH "VERSION_MAJOR *([0-9]*)" _ ${VERSION_FILE})
-        set(VERSION_MAJOR ${CMAKE_MATCH_1})
-
-        # Minor...
-        string(REGEX MATCH "VERSION_MINOR *([0-9]+)" _ ${VERSION_FILE})
-        set(VERSION_MINOR ${CMAKE_MATCH_1})
-
-        # Patch...
-        string(REGEX MATCH "VERSION_PATCH *([0-9]+)" _ ${VERSION_FILE})
-        set(VERSION_PATCH ${CMAKE_MATCH_1})
-
-        # Git date...
-        string(REGEX MATCH "VERSION_GIT_DATE *([0-9]+)" _ ${VERSION_FILE})
-        set(VERSION_GIT_DATE ${CMAKE_MATCH_1})
+# Set version numbers in a header file
 
-        # Full version
-        set(VERSION        ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH}-git${VERSION_GIT_DATE})
-
-    # Make available in a header file...
-    configure_file (
+set(VERSION_MAJOR    ${pistache_VERSION_MAJOR})
+set(VERSION_MINOR    ${pistache_VERSION_MINOR})
+set(VERSION_PATCH    ${pistache_VERSION_PATCH})
+set(VERSION_GIT_DATE ${pistache_VERSION_TWEAK})
+configure_file (
     "include/pistache/version.h.in"
     "include/pistache/version.h"
     @ONLY
-    )
-
-# Set public interface version...
-
-    # Major should be incremented every time a non-backward compatible change
-    #  occurs in the ABI...
-    string(REGEX MATCH "SONAME_VERSION_MAJOR *([0-9]*)" _ ${VERSION_FILE})
-    set(SONAME_VERSION_MAJOR ${CMAKE_MATCH_1})
-
-    # Minor should be incremented every time a backward compatible change occurs
-    #  in the ABI...
-    string(REGEX MATCH "SONAME_VERSION_MINOR *([0-9]+)" _ ${VERSION_FILE})
-    set(SONAME_VERSION_MINOR ${CMAKE_MATCH_1})
+)
 
 add_subdirectory (src)
 

README.md

@@ -38,29 +38,25 @@ Pistache was originally created by Mathieu Stefani (`@octal`). He continues to c
 
 The [Launchpad Team](https://launchpad.net/~pistache+team) administers the daily and stable Ubuntu pre-compiled packages.
 
-### Release Versioning
+### Versioning
 
-Please update `version.txt` accordingly with each unstable or stable release.
+The version of the library's public interface (ABI) is not the same as the release version, but we choose to always guarantee that the major release version and the soname version will match. The interface version is primarily associated with the _external_ interface of the library. Different platforms handle this differently, such as AIX, GNU/Linux, and Solaris.
 
-### Interface Versioning
-
-The version of the library's public interface (ABI) is not the same as the release version. The interface version is primarily associated with the _external_ interface of the library. Different platforms handle this differently, such as AIX, GNU/Linux, and Solaris.
-
-GNU Libtool abstracts each platform's idiosyncrasies away because it is more portable than using `ar(1)` or `ranlib(1)` directly. However, it is a pain to integrate with CMake so we made do without it by setting the SONAME directly.
+GNU Libtool abstracts each platform's idiosyncrasies away because it is more portable than using `ar(1)` or `ranlib(1)` directly. However, it is [not supported in Meson](https://mesonbuild.com/FAQ.html#how-do-i-do-the-equivalent-of-libtools-exportsymbol-and-exportregex) so we made do without it by setting the SONAME directly.
 
 When Pistache is installed it will normally ship:
 
-- `libpistache-<release>.so.X.Y`: This is the actual shared-library binary file. The _X_ and _Y_ values are the major and minor interface versions respectively.
+- `libpistache.so.X.Y.Z`: This is the actual shared-library binary file. The _X_, _Y_ and _Z_ values are the major, minor and patch interface versions respectively.
 
-- `libpistache-<release>.so.X`: This is the _soname_ soft link that points to the binary file. It is what other programs and other libraries reference internally. You should never need to directly reference this file in your build environment.
+- `libpistache.so.X`: This is the _soname_ soft link that points to the binary file. It is what other programs and other libraries reference internally. You should never need to directly reference this file in your build environment.
 
-- `libpistache-<release>.so`: This is the _linker name_ entry. This is also a soft link that refers to the soname with the highest major interface version. This linker name is what is referred to on the linker command line. This file is created by the installation process.
+- `libpistache.so`: This is the _linker name_ entry. This is also a soft link that refers to the soname with the highest major interface version. This linker name is what is referred to on the linker command line.
 
-- `libpistache-<release>.a`: This is the _static archive_ form of the library. Since when using a static library all of its symbols are normally resolved before runtime, an interface version in the filename is unnecessary.
+- `libpistache.a`: This is the _static archive_ form of the library. Since when using a static library all of its symbols are normally resolved before runtime, an interface version in the filename is unnecessary.
 
 If your contribution has modified the interface, you may need to update the major or minor interface versions. Otherwise user applications and build environments will eventually break. This is because they will attempt to link against an incorrect version of the library -- or worse, link correctly but with undefined runtime behaviour.
 
-The major version should be incremented every time a non-backward compatible change occured in the ABI. The minor version should be incremented every time a backward compatible change occurs. This can be done by modifying `version.txt` accordingly.
+The major version should be incremented when you make incompatible API or ABI changes. The minor version should be incremented when you add functionality in a backwards compatible manner. The patch version should be incremented when you make backwards compatible bug fixes. This can be done by modifying `version.txt` accordingly. Also remember to always update the commit date in the aformentioned file.
 
 ## Precompiled Packages
 
@@ -87,7 +83,7 @@ Currently Pistache is built and tested on a number of [architectures](https://wi
 
 The project builds [daily unstable snapshots](https://launchpad.net/~pistache+team/+archive/ubuntu/unstable) in a separate unstable PPA. To use it, run the following:
 
-```console
+```sh
 $ sudo add-apt-repository ppa:pistache+team/unstable
 $ sudo apt update
 $ sudo apt install libpistache-dev
@@ -97,7 +93,7 @@ $ sudo apt install libpistache-dev
 
 Currently there are no stable release of Pistache published into the [stable](https://launchpad.net/~pistache+team/+archive/ubuntu/stable) PPA. However, when that time comes, run the following to install a stable package:
 
-```console
+```sh
 $ sudo add-apt-repository ppa:pistache+team/stable
 $ sudo apt update
 $ sudo apt install libpistache-dev
@@ -145,19 +141,19 @@ executable(
 If you want to build the library from source in case the dependency is not found on the system, you can add this repository as a submodule in the `subprojects` directory of your project, and edit the `dependency()` call as follows:
 
 ```meson
-dependencies: dependency('libpistache', fallback: 'pistache')
+dependency('libpistache', fallback: 'pistache')
 ```
 
 If you're using a Meson version older than 0.55.0 you'll have to use the "older" syntax for `dependency()`:
 
 ```meson
-dependencies: dependency('libpistache', fallback: ['pistache', 'pistache_dep'])
+dependency('libpistache', fallback: ['pistache', 'pistache_dep'])
 ```
 
 Lastly, if you'd like to build the fallback as a static library you can specify it with the `default_options` keyword:
 
 ```meson
-dependencies: dependency('libpistache', fallback: 'pistache', default_options: 'default_library=static')
+dependency('libpistache', fallback: 'pistache', default_options: 'default_library=static')
 ```
 
 ### CMake
@@ -205,7 +201,7 @@ $ meson setup build \
     -DPISTACHE_BUILD_EXAMPLES=true \
     -DPISTACHE_BUILD_TESTS=true \
     -DPISTACHE_BUILD_DOCS=false \
-    --prefix=$PWD/prefix
+    --prefix="$PWD/prefix"
 $ meson compile -C build
 $ meson install -C build
 ```
@@ -239,7 +235,7 @@ using namespace Pistache;
 
 struct HelloHandler : public Http::Handler {
   HTTP_PROTOTYPE(HelloHandler)
-  void onRequest(const Http::Request&, Http::ResponseWriter writer) override{
+  void onRequest(const Http::Request&, Http::ResponseWriter writer) override {
     writer.send(Http::Code::Ok, "Hello, World!");
   }
 };

include/pistache/meson.build

@@ -2,9 +2,9 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-configure_file(input: 'version.h.in', output: 'version.h', configuration: version_data_conf, install: get_option('PISTACHE_INSTALL'), install_dir: get_option('includedir')/'pistache')
+configure_file(input: 'version.h.in', output: 'version.h', configuration: version_conf, install: get_option('PISTACHE_INSTALL'), install_dir: get_option('includedir')/'pistache')
 
-install_headers([
+install_headers(
 	'async.h',
 	'base64.h',
 	'client.h',
@@ -41,7 +41,7 @@ install_headers([
 	'type_checkers.h',
 	'typeid.h',
 	'utils.h',
-	'view.h'
-], subdir: 'pistache')
+	'view.h',
+	subdir: 'pistache')
 
 install_subdir('serializer', install_dir: get_option('includedir')/'pistache')

meson.build

@@ -5,7 +5,7 @@
 project(
 	'pistache',
 	'cpp',
-	version: '0.0.003', # TODO: This should be assigned dynamically from version.txt
+	version: '0.0.3', # In Meson 0.57 this can be replaced with files('version.txt')
 	license: 'Apache-2.0',
 	default_options: [
 		'cpp_std=c++17',
@@ -86,26 +86,27 @@ if get_option('PISTACHE_USE_SSL')
 	deps_libpistache += dependency('openssl')
 endif
 
-version_data_raw = ''
+version_array = []
 if meson.version().version_compare('>=0.57.0')
-	fs = import('fs')
-	version_data_raw = fs.read('version.txt').split('\n')
+	version_array = import('fs').read('version.txt').strip().split('.')
 else
 	# Ugly workaround for reading a file
-	version_data_raw = run_command(
+	version_array = run_command(
 		import('python').find_installation(), '-c', 'print(open("version.txt").read())'
-	).stdout().strip().split('\n')
+	).stdout().strip().split('.')
 endif
-version_data_conf = configuration_data()
-foreach _ : version_data_raw
-	if _ != ''
-		__ = _.split(' ')
-		version_data_conf.set(__[0], __[-1])
-	endif
-endforeach
 
-pistache_version_str = '.'.join([version_data_conf.get_unquoted('VERSION_MAJOR'), version_data_conf.get_unquoted('VERSION_MINOR'), version_data_conf.get_unquoted('VERSION_PATCH')])
-pistache_soversion_str = '.'.join([version_data_conf.get_unquoted('SONAME_VERSION_MAJOR'), version_data_conf.get_unquoted('SONAME_VERSION_MINOR')])
+version_major    = version_array[0]
+version_minor    = version_array[1]
+version_patch    = version_array[2]
+version_git_date = version_array[3]
+version_str      = '@0@.@1@.@2@'.format(version_major, version_minor, version_patch)
+
+version_conf = configuration_data()
+version_conf.set('VERSION_MAJOR',    version_major)
+version_conf.set('VERSION_MINOR',    version_minor)
+version_conf.set('VERSION_PATCH',    version_patch)
+version_conf.set('VERSION_GIT_DATE', version_git_date)
 
 incl_pistache = include_directories('include')
 

src/CMakeLists.txt

@@ -71,14 +71,14 @@ if (PISTACHE_USE_SSL)
     endif ()
 endif ()
 
-set(Pistache_OUTPUT_NAME "pistache")
 if (BUILD_SHARED_LIBS)
     set_target_properties(pistache_shared PROPERTIES
-        OUTPUT_NAME ${Pistache_OUTPUT_NAME}-${VERSION}
-        SOVERSION ${SONAME_VERSION_MAJOR}.${SONAME_VERSION_MINOR}
+        OUTPUT_NAME ${PROJECT_NAME}
+        VERSION ${pistache_VERSION}
+        SOVERSION ${pistache_VERSION_MAJOR}
     )
 endif ()
 
 set_target_properties(pistache_static PROPERTIES
-    OUTPUT_NAME ${Pistache_OUTPUT_NAME}
+    OUTPUT_NAME ${PROJECT_NAME}
 )

src/meson.build

@@ -41,8 +41,7 @@ libpistache = library(
 	include_directories: incl_pistache,
 	dependencies: deps_libpistache,
 	install: get_option('PISTACHE_INSTALL'),
-	version: pistache_version_str,
-	soversion: pistache_soversion_str,
+	version: version_str,
 	pic: get_option('b_staticpic')
 )
 
@@ -52,12 +51,11 @@ if meson.version().version_compare('>=0.54.0')
 	meson.override_dependency('libpistache', pistache_dep)
 endif
 
-pkg = import('pkgconfig')
-pkg.generate(
+import('pkgconfig').generate(
    libpistache,
    name: 'Pistache',
-   description: 'An elegant C++ REST framework.',
+   description: 'An elegant C++ REST framework',
    url: 'http://pistache.io',
-   version: pistache_version_str+'-git'+version_data_conf.get_unquoted('VERSION_GIT_DATE'),
+   version: '@0@-git@1@'.format(version_str, version_git_date),
    filebase: 'libpistache'
 )

version.txt

-VERSION_MAJOR           0
-VERSION_MINOR           0
-VERSION_PATCH           003
-VERSION_GIT_DATE        20211020
-
-SONAME_VERSION_MAJOR    1
-SONAME_VERSION_MINOR    0
+0.0.3.20211030