From cff4e7d29904250ff95feda85d8baa9da93652de Mon Sep 17 00:00:00 2001
From: Jussi Pakkanen <jpakkane@gmail.com>
Date: Sun, 29 May 2016 03:15:16 +0300
Subject: [PATCH] Can query version strings of dependencies.

---
 mesonbuild/build.py                            |  3 ++-
 mesonbuild/dependencies.py                     |  9 ++++++++-
 mesonbuild/interpreter.py                      | 18 +++++++++++++++---
 .../common/87 declare dep/entity/meson.build   |  3 +++
 test cases/linuxlike/1 pkg-config/meson.build  |  2 ++
 5 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index fcf1ac6f6..105230331 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -497,7 +497,8 @@ class BuildTarget():
                 for l in dep.libraries:
                     self.link(l)
                 # Those parts that are external.
-                extpart = dependencies.InternalDependency([],
+                extpart = dependencies.InternalDependency('undefined',
+                                                          [],
                                                           dep.compile_args,
                                                           dep.link_args,
                                                           [], [], [])
diff --git a/mesonbuild/dependencies.py b/mesonbuild/dependencies.py
index d8081b0ef..7462bd8c0 100644
--- a/mesonbuild/dependencies.py
+++ b/mesonbuild/dependencies.py
@@ -59,8 +59,9 @@ class Dependency():
         return False
 
 class InternalDependency(Dependency):
-    def __init__(self, incdirs, compile_args, link_args, libraries, sources, ext_deps):
+    def __init__(self, version, incdirs, compile_args, link_args, libraries, sources, ext_deps):
         super().__init__()
+        self.version = version
         self.include_directories = incdirs
         self.compile_args = compile_args
         self.link_args = link_args
@@ -74,6 +75,9 @@ class InternalDependency(Dependency):
     def get_link_args(self):
         return self.link_args
 
+    def get_version(self):
+        return self.version
+
 class PkgConfigDependency(Dependency):
     pkgconfig_found = None
 
@@ -188,6 +192,9 @@ class PkgConfigDependency(Dependency):
     def get_modversion(self):
         return self.modversion
 
+    def get_version(self):
+        return self.get_modversion()
+
     def get_compile_args(self):
         return self.cargs
 
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index aac021ac5..3b9226a0d 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -225,20 +225,29 @@ class DependencyHolder(InterpreterObject):
     def __init__(self, dep):
         InterpreterObject.__init__(self)
         self.held_object = dep
-        self.methods.update({'found' : self.found_method})
+        self.methods.update({'found' : self.found_method,
+                             'version': self.version_method})
 
     def found_method(self, args, kwargs):
         return self.held_object.found()
 
+    def version_method(self, args, kwargs):
+        return self.held_object.get_version()
+
 class InternalDependencyHolder(InterpreterObject):
     def __init__(self, dep):
         InterpreterObject.__init__(self)
         self.held_object = dep
-        self.methods.update({'found' : self.found_method})
+        self.methods.update({'found' : self.found_method,
+                             'version': self.version_method,
+                             })
 
     def found_method(self, args, kwargs):
         return True
 
+    def version_method(self, args, kwargs):
+        return self.held_object.get_version()
+
 class ExternalProgramHolder(InterpreterObject):
     def __init__(self, ep):
         InterpreterObject.__init__(self)
@@ -1175,6 +1184,9 @@ class Interpreter():
 
     @noPosargs
     def func_declare_dependency(self, node, args, kwargs):
+        version = kwargs.get('version', 'undefined')
+        if not isinstance(version, str):
+            raise InterpreterException('Version must be a string.')
         incs = kwargs.get('include_directories', [])
         if not isinstance(incs, list):
             incs = [incs]
@@ -1199,7 +1211,7 @@ class Interpreter():
             if not isinstance(d, (dependencies.Dependency, dependencies.ExternalLibrary, dependencies.InternalDependency)):
                 raise InterpreterException('Dependencies must be external deps')
             final_deps.append(d)
-        dep = dependencies.InternalDependency(incs, compile_args, link_args, libs, sources, final_deps)
+        dep = dependencies.InternalDependency(version, incs, compile_args, link_args, libs, sources, final_deps)
         return InternalDependencyHolder(dep)
 
     @noKwargs
diff --git a/test cases/common/87 declare dep/entity/meson.build b/test cases/common/87 declare dep/entity/meson.build
index 12050b5a2..80bbf36fa 100644
--- a/test cases/common/87 declare dep/entity/meson.build	
+++ b/test cases/common/87 declare dep/entity/meson.build	
@@ -4,4 +4,7 @@ entity_dep = declare_dependency(link_with : entity_lib,
   include_directories : include_directories('.'),
   sources : 'entity2.c',
   compile_args : ['-DUSING_ENT=1'],
+  version : '1.2.3',
   link_args : []) # No simple way of testing linker flags :(.
+
+assert(entity_dep.version().version_compare('==1.2.3'), 'Declare_dep has incorrect version string.')
diff --git a/test cases/linuxlike/1 pkg-config/meson.build b/test cases/linuxlike/1 pkg-config/meson.build
index b7f40db9c..a18acc5ce 100644
--- a/test cases/linuxlike/1 pkg-config/meson.build	
+++ b/test cases/linuxlike/1 pkg-config/meson.build	
@@ -5,6 +5,8 @@ project('external dependency', 'c')
 dep = dependency('zlib', version : '>=1.2.8')
 exe = executable('zlibprog', 'prog.c', dependencies : dep)
 
+assert(dep.version().version_compare('>=1.2.8'), 'Pkg-config version numbers exposed incorrectly.')
+
 test('zlibtest', exe)
 
 # Test that dependencies of dependencies work.