gnome: Use raw link arguments with g-ir and gtk-doc

Those tools use our arguments to build a file and execute it to
introspect it at runtime. However, they do not know that you can pass
the full path to the library to use, and ignore the arguments.

The long-term fix for this is to have them output a .c file that Meson
will build for them, which they can then run, but that will require
upstream changes:
https://gitlab.gnome.org/GNOME/gtk-doc/merge_requests/1

Closes mesonbuild#3774

mesonbuild/dependencies/base.py

@@ -101,6 +101,9 @@ def __init__(self, type_name, kwargs):
         self.type_name = type_name
         self.compile_args = []
         self.link_args = []
+        # Raw -L and -l arguments without manual library searching
+        # If None, self.link_args will be used
+        self.raw_link_args = None
         self.sources = []
         self.methods = self._process_method_kw(kwargs)
 
@@ -111,7 +114,9 @@ def __repr__(self):
     def get_compile_args(self):
         return self.compile_args
 
-    def get_link_args(self):
+    def get_link_args(self, raw=False):
+        if raw and self.raw_link_args is not None:
+            return self.raw_link_args
         return self.link_args
 
     def found(self):
@@ -592,9 +597,18 @@ def _set_libs(self):
         if ret != 0:
             raise DependencyException('Could not generate libs for %s:\n\n%s' %
                                       (self.name, out))
+        # Also get the 'raw' output without -Lfoo system paths for usage when
+        # a library can't be found, and also in gnome.generate_gir
+        # + gnome.gtkdoc which need -L -l arguments.
+        ret, out_raw = self._call_pkgbin(libcmd)
+        if ret != 0:
+            raise DependencyException('Could not generate libs for %s:\n\n%s' %
+                                      (self.name, out_raw))
         link_args = []
+        raw_link_args = []
         # Library paths should be safe to de-dup
         libpaths = OrderedSet()
+        raw_libpaths = OrderedSet()
         # Track -lfoo libraries to avoid duplicate work
         libs_found = OrderedSet()
         # Track not-found libraries to know whether to add library paths
@@ -660,12 +674,19 @@ def _set_libs(self):
                 if lib in link_args:
                     continue
             link_args.append(lib)
+        # Also store the raw link arguments, and store raw_libpaths
+        for lib in self._convert_mingw_paths(shlex.split(out_raw)):
+            if lib.startswith('-L') and not lib.startswith(('-L-l', '-L-L')):
+                raw_libpaths.add(lib[2:])
+            raw_link_args.append(lib)
+        # Set everything
         self.link_args = link_args
+        self.raw_link_args = raw_link_args
         # Add all -Lbar args if we have -lfoo args in link_args
         if libs_notfound:
             # Order of -L flags doesn't matter with ld, but it might with other
             # linkers such as MSVC, so prepend them.
-            self.link_args = ['-L' + lp for lp in libpaths] + self.link_args
+            self.link_args = ['-L' + lp for lp in raw_libpaths] + self.link_args
 
     def get_pkgconfig_variable(self, variable_name, kwargs):
         options = ['--variable=' + variable_name, self.name]
@@ -987,7 +1008,7 @@ def __init__(self, name, link_args, environment, language, silent=False):
             else:
                 mlog.log('Library', mlog.bold(name), 'found:', mlog.red('NO'))
 
-    def get_link_args(self, language=None):
+    def get_link_args(self, language=None, **kwargs):
         '''
         External libraries detected using a compiler must only be used with
         compatible code. For instance, Vala libraries (.vapi files) cannot be
@@ -1000,7 +1021,7 @@ def get_link_args(self, language=None):
         if (self.language == 'vala' and language != 'vala') or \
            (language == 'vala' and self.language != 'vala'):
             return []
-        return self.link_args
+        return super().get_link_args(**kwargs)
 
     def get_partial_dependency(self, *, compile_args=False, link_args=False,
                                links=False, includes=False, sources=False):
@@ -1019,6 +1040,8 @@ def __init__(self, name, required, path, env, lang, kwargs):
         self.required = required
         self.detect(name, path)
         if self.found():
+            self.compile_args = ['-I' + os.path.join(self.path, self.name, 'Headers')]
+            self.link_args = ['-F' + self.path, '-framework', self.name.split('.')[0]]
             mlog.log('Dependency', mlog.bold(name), 'found:', mlog.green('YES'),
                      os.path.join(self.path, self.name))
         else:
@@ -1044,16 +1067,6 @@ def detect(self, name, path):
         if not self.found() and self.required:
             raise DependencyException('Framework dependency %s not found.' % (name, ))
 
-    def get_compile_args(self):
-        if self.found():
-            return ['-I' + os.path.join(self.path, self.name, 'Headers')]
-        return []
-
-    def get_link_args(self):
-        if self.found():
-            return ['-F' + self.path, '-framework', self.name.split('.')[0]]
-        return []
-
     def get_version(self):
         return 'unknown'
 

mesonbuild/dependencies/boost.py

@@ -473,10 +473,10 @@ def extra_lib_dirs(self):
             return [os.path.join(self.boost_root, 'lib')]
         return []
 
-    def get_link_args(self):
+    def get_link_args(self, **kwargs):
         args = []
-        for dir in self.extra_lib_dirs():
-            args += self.clib_compiler.get_linker_search_args(dir)
+        for d in self.extra_lib_dirs():
+            args += self.clib_compiler.get_linker_search_args(d)
         for lib in self.requested_modules:
             args += self.lib_modules['boost_' + lib]
         return args

mesonbuild/dependencies/dev.py

@@ -261,5 +261,5 @@ class ValgrindDependency(PkgConfigDependency):
     def __init__(self, env, kwargs):
         super().__init__('valgrind', env, kwargs)
 
-    def get_link_args(self):
+    def get_link_args(self, **kwargs):
         return []

mesonbuild/modules/gnome.py

@@ -349,7 +349,7 @@ def _get_dependencies_flags(self, deps, state, depends, include_rpath=False,
             # This should be any dependency other than an internal one.
             elif isinstance(dep, Dependency):
                 cflags.update(dep.get_compile_args())
-                for lib in dep.get_link_args():
+                for lib in dep.get_link_args(raw=True):
                     if (os.path.isabs(lib) and
                             # For PkgConfigDependency only:
                             getattr(dep, 'is_libtool', False)):