dependnecies: generalize version suffix stripping code

This replaces calls to .rstrip('git'), .rstrip('svn') with a regex that
takes the leading numbers and dots, and throws away the rest. This also
moves the code up to the ConfigToolDepdency level, since these config
tools are of various quality and some of them are good, and some are
not. This shouldn't affect well behaved tools.

This should future proof LLVM against future suffixes (like someone
doing something strange like using Mercurial as a VCS).

mesonbuild/dependencies/base.py

@@ -207,6 +207,7 @@ class ConfigToolDependency(ExternalDependency):
 
     tools = None
     tool_name = None
+    __strip_version = re.compile(r'^[0-9.]*')
 
     def __init__(self, name, environment, language, kwargs):
         super().__init__('config-tool', environment, language, kwargs)
@@ -222,6 +223,15 @@ class ConfigToolDependency(ExternalDependency):
             return
         self.version = version
 
+    def _sanitize_version(self, version):
+        """Remove any non-numeric, non-point version suffixes."""
+        m = self.__strip_version.match(version)
+        if m:
+            # Ensure that there isn't a trailing '.', such as an input like
+            # `1.2.3.git-1234`
+            return m.group(0).rstrip('.')
+        return version
+
     @classmethod
     def factory(cls, name, environment, language, kwargs, tools, tool_name):
         """Constructor for use in dependencies that can be found multiple ways.
@@ -259,7 +269,7 @@ class ConfigToolDependency(ExternalDependency):
             if p.returncode != 0:
                 continue
 
-            out = out.strip()
+            out = self._sanitize_version(out.strip())
             # Some tools, like pcap-config don't supply a version, but also
             # dont fail with --version, in that case just assume that there is
             # only one verison and return it.

mesonbuild/dependencies/dev.py

@@ -146,16 +146,6 @@ class LLVMDependency(ConfigToolDependency):
             return
         self.static = kwargs.get('static', False)
 
-        # Currently meson doesn't really attempt to handle pre-release versions,
-        # so strip the 'svn' off the end, since it will probably cuase problems
-        # for users who want the patch version.
-        #
-        # If LLVM is built from svn then "svn" will be appended to the version
-        # string, if it's built from a git mirror then "git-<very short sha>"
-        # will be appended instead.
-        self.version = self.version.rstrip('svn')
-        self.version = self.version.split('git')[0]
-
         self.provided_modules = self.get_config_value(['--components'], 'modules')
         modules = stringlistify(extract_as_list(kwargs, 'modules'))
         self.check_components(modules)