add support for cups dependencies (#2255)

* add support for cups dependencies

libcups has its own cups-config tool rather than using pkg-config.
This adds support for cups-config, based on pcap-config and
sdl2-config implementations.

This change also includes the unit test case and documentation for
cups dependency object implementation, and libcups2 dep to CI image.

ciimage/Dockerfile

@@ -10,7 +10,7 @@ RUN apt-get -y update && apt-get -y upgrade \
 && apt-get -y install python3-pip libxml2-dev libxslt1-dev cmake libyaml-dev \
 && apt-get -y install openmpi-bin libopenmpi-dev \
 && apt-get -y install libboost-log-dev \
-&& apt-get -y install libvulkan-dev libpcap-dev \
+&& apt-get -y install libvulkan-dev libpcap-dev libcups2-dev \
 && apt-get -y install gcovr lcov \
 && apt-get -y install gtk-sharp2 gtk-sharp2-gapi libglib2.0-cil-dev \
 && python3 -m pip install hotdoc codecov

docs/markdown/Dependencies.md

@@ -132,6 +132,16 @@ automatically:
 pcap_dep = dependency('pcap', version : '>=1.0')
 ```
 
+## CUPS
+
+The cups library does not ship with pkg-config at the time or writing
+but instead it has its own `cups-config` util. Meson will use it
+automatically:
+
+```meson
+cups_dep = dependency('cups', version : '>=1.4')
+```
+
 ## Declaring your own
 
 You can declare your own dependency objects that can be used

mesonbuild/dependencies/__init__.py

@@ -17,7 +17,7 @@ from .base import (  # noqa: F401
     ExternalDependency, ExternalLibrary, ExtraFrameworkDependency, InternalDependency,
     PkgConfigDependency, find_external_dependency, get_dep_identifier, packages, _packages_accept_language)
 from .dev import GMockDependency, GTestDependency, LLVMDependency, ValgrindDependency
-from .misc import (BoostDependency, MPIDependency, Python3Dependency, ThreadDependency, PcapDependency)
+from .misc import (BoostDependency, MPIDependency, Python3Dependency, ThreadDependency, PcapDependency, CupsDependency)
 from .platform import AppleFrameworks
 from .ui import GLDependency, GnuStepDependency, Qt4Dependency, Qt5Dependency, SDL2Dependency, WxDependency, VulkanDependency
 
@@ -35,6 +35,7 @@ packages.update({
     'python3': Python3Dependency,
     'threads': ThreadDependency,
     'pcap': PcapDependency,
+    'cups': CupsDependency,
 
     # From platform:
     'appleframeworks': AppleFrameworks,

mesonbuild/dependencies/base.py

@@ -46,6 +46,8 @@ class DependencyMethods(Enum):
     SDLCONFIG = 'sdlconfig'
     # Detect using pcap-config
     PCAPCONFIG = 'pcap-config'
+    # Detect using cups-config
+    CUPSCONFIG = 'cups-config'
     # This is only supported on OSX - search the frameworks directory by name.
     EXTRAFRAMEWORK = 'extraframework'
     # Detect using the sysconfig module.

mesonbuild/dependencies/misc.py

@@ -623,3 +623,51 @@ class PcapDependency(ExternalDependency):
             return [DependencyMethods.PKGCONFIG, DependencyMethods.PCAPCONFIG, DependencyMethods.EXTRAFRAMEWORK]
         else:
             return [DependencyMethods.PKGCONFIG, DependencyMethods.PCAPCONFIG]
+
+class CupsDependency(ExternalDependency):
+    def __init__(self, environment, kwargs):
+        super().__init__('cups', environment, None, kwargs)
+        if DependencyMethods.PKGCONFIG in self.methods:
+            try:
+                kwargs['required'] = False
+                pcdep = PkgConfigDependency('cups', environment, kwargs)
+                if pcdep.found():
+                    self.type_name = 'pkgconfig'
+                    self.is_found = True
+                    self.compile_args = pcdep.get_compile_args()
+                    self.link_args = pcdep.get_link_args()
+                    self.version = pcdep.get_version()
+                    return
+            except Exception as e:
+                mlog.debug('cups not found via pkgconfig. Trying next, error was:', str(e))
+        if DependencyMethods.CUPSCONFIG in self.methods:
+            cupsconf = shutil.which('cups-config')
+            if cupsconf:
+                stdo = Popen_safe(['cups-config', '--cflags'])[1]
+                self.compile_args = stdo.strip().split()
+                stdo = Popen_safe(['cups-config', '--libs'])[1]
+                self.link_args = stdo.strip().split()
+                stdo = Popen_safe(['cups-config', '--version'])[1]
+                self.version = stdo.strip().split()
+                self.is_found = True
+                mlog.log('Dependency', mlog.bold('cups'), 'found:',
+                         mlog.green('YES'), '(%s)' % cupsconf)
+                return
+            mlog.debug('Could not find cups-config binary, trying next.')
+        if DependencyMethods.EXTRAFRAMEWORK in self.methods:
+            if mesonlib.is_osx():
+                fwdep = ExtraFrameworkDependency('cups', False, None, self.env,
+                                                 self.language, kwargs)
+                if fwdep.found():
+                    self.is_found = True
+                    self.compile_args = fwdep.get_compile_args()
+                    self.link_args = fwdep.get_link_args()
+                    self.version = fwdep.get_version()
+                    return
+            mlog.log('Dependency', mlog.bold('cups'), 'found:', mlog.red('NO'))
+
+    def get_methods(self):
+        if mesonlib.is_osx():
+            return [DependencyMethods.PKGCONFIG, DependencyMethods.CUPSCONFIG, DependencyMethods.EXTRAFRAMEWORK]
+        else:
+            return [DependencyMethods.PKGCONFIG, DependencyMethods.CUPSCONFIG]

test cases/frameworks/20 cups/cups_prog.c

@@ -0,0 +1,8 @@
+#include <cups/cups.h>
+
+int
+main()
+{
+    cupsGetDefault();
+    return 0;
+}

test cases/frameworks/20 cups/meson.build

@@ -0,0 +1,7 @@
+project('cups test', 'c')
+
+cups_dep = dependency('cups', version : '>=1.4')
+
+e = executable('cups_prog', 'cups_prog.c', dependencies : cups_dep)
+
+test('cupstest', e)