Make use of unholder

We have a lot of cases of code like:
```python
if hasattr(var, 'held_object'):
    var = var.held_object`
```

replace that with the unholder function.

1 files changed, 17 insertions, 50 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index fcd1622..12fa6bd 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -534,9 +534,7 @@ class BuildTarget(Target):
 
     def process_objectlist(self, objects):
         assert(isinstance(objects, list))
-        for s in objects:
-            if hasattr(s, 'held_object'):
-                s = s.held_object
+        for s in unholder(objects):
             if isinstance(s, (str, File, ExtractedObjects)):
                 self.objects.append(s)
             elif isinstance(s, (GeneratedList, CustomTarget)):
@@ -552,10 +550,7 @@ class BuildTarget(Target):
     def process_sourcelist(self, sources):
         sources = listify(sources)
         added_sources = {} # If the same source is defined multiple times, use it only once.
-        for s in sources:
-            # Holder unpacking. Ugly.
-            if hasattr(s, 'held_object'):
-                s = s.held_object
+        for s in unholder(sources):
             if isinstance(s, File):
                 if s not in added_sources:
                     self.sources.append(s)
@@ -632,9 +627,7 @@ class BuildTarget(Target):
                 # which is what we need.
                 if not is_object(s):
                     sources.append(s)
-        for d in self.external_deps:
-            if hasattr(d, 'held_object'):
-                d = d.held_object
+        for d in unholder(self.external_deps):
             for s in d.sources:
                 if isinstance(s, (str, File)):
                     sources.append(s)
@@ -696,10 +689,7 @@ class BuildTarget(Target):
         link_depends.
         """
         sources = listify(sources)
-        for s in sources:
-            if hasattr(s, 'held_object'):
-                s = s.held_object
-
+        for s in unholder(sources):
             if isinstance(s, File):
                 self.link_depends.append(s)
             elif isinstance(s, str):
@@ -810,11 +800,7 @@ class BuildTarget(Target):
         kwargs.get('modules', [])
         self.need_install = kwargs.get('install', self.need_install)
         llist = extract_as_list(kwargs, 'link_with')
-        for linktarget in llist:
-            # Sorry for this hack. Keyword targets are kept in holders
-            # in kwargs. Unpack here without looking at the exact type.
-            if hasattr(linktarget, "held_object"):
-                linktarget = linktarget.held_object
+        for linktarget in unholder(llist):
             if isinstance(linktarget, dependencies.ExternalLibrary):
                 raise MesonException('''An external library was used in link_with keyword argument, which
 is reserved for libraries built as part of this project. External
@@ -1033,9 +1019,7 @@ This will become a hard error in a future Meson release.''')
 
     def add_deps(self, deps):
         deps = listify(deps)
-        for dep in deps:
-            if hasattr(dep, 'held_object'):
-                dep = dep.held_object
+        for dep in unholder(deps):
             if isinstance(dep, dependencies.InternalDependency):
                 # Those parts that are internal.
                 self.process_sourcelist(dep.sources)
@@ -1170,10 +1154,7 @@ You probably should put it in link_with instead.''')
 
     def add_include_dirs(self, args, set_is_system: T.Optional[str] = None):
         ids = []
-        for a in args:
-            # FIXME same hack, forcibly unpack from holder.
-            if hasattr(a, 'held_object'):
-                a = a.held_object
+        for a in unholder(args):
             if not isinstance(a, IncludeDirs):
                 raise InvalidArguments('Include directory to be added is not an include directory object.')
             ids.append(a)
@@ -1313,9 +1294,7 @@ class Generator:
     def __init__(self, args, kwargs):
         if len(args) != 1:
             raise InvalidArguments('Generator requires exactly one positional argument: the executable')
-        exe = args[0]
-        if hasattr(exe, 'held_object'):
-            exe = exe.held_object
+        exe = unholder(args[0])
         if not isinstance(exe, (Executable, dependencies.ExternalProgram)):
             raise InvalidArguments('First generator argument must be an executable.')
         self.exe = exe
@@ -1416,9 +1395,7 @@ class Generator:
 
 class GeneratedList:
     def __init__(self, generator, subdir, preserve_path_from=None, extra_args=None):
-        if hasattr(generator, 'held_object'):
-            generator = generator.held_object
-        self.generator = generator
+        self.generator = unholder(generator)
         self.name = self.generator.exe
         self.subdir = subdir
         self.infilelist = []
@@ -1428,10 +1405,10 @@ class GeneratedList:
         self.depend_files = []
         self.preserve_path_from = preserve_path_from
         self.extra_args = extra_args if extra_args is not None else []
-        if isinstance(generator.exe, dependencies.ExternalProgram):
-            if not generator.exe.found():
+        if isinstance(self.generator.exe, dependencies.ExternalProgram):
+            if not self.generator.exe.found():
                 raise InvalidArguments('Tried to use not-found external program as generator')
-            path = generator.exe.get_path()
+            path = self.generator.exe.get_path()
             if os.path.isabs(path):
                 # Can only add a dependency on an external program which we
                 # know the absolute path of
@@ -1873,9 +1850,7 @@ class SharedLibrary(BuildTarget):
 
         # Visual Studio module-definitions file
         if 'vs_module_defs' in kwargs:
-            path = kwargs['vs_module_defs']
-            if hasattr(path, 'held_object'):
-                path = path.held_object
+            path = unholder(kwargs['vs_module_defs'])
             if isinstance(path, str):
                 if os.path.isabs(path):
                     self.vs_module_defs = File.from_absolute_file(path)
@@ -2027,9 +2002,7 @@ class CustomTarget(Target):
     def get_target_dependencies(self):
         deps = self.dependencies[:]
         deps += self.extra_depends
-        for c in self.sources:
-            if hasattr(c, 'held_object'):
-                c = c.held_object
+        for c in unholder(self.sources):
             if isinstance(c, (BuildTarget, CustomTarget)):
                 deps.append(c)
         return deps
@@ -2161,9 +2134,7 @@ class CustomTarget(Target):
         if not isinstance(self.build_always_stale, bool):
             raise InvalidArguments('Argument build_always_stale must be a boolean.')
         extra_deps, depend_files = [extract_as_list(kwargs, c, pop=False) for c in ['depends', 'depend_files']]
-        for ed in extra_deps:
-            while hasattr(ed, 'held_object'):
-                ed = ed.held_object
+        for ed in unholder(extra_deps):
             if not isinstance(ed, (CustomTarget, BuildTarget)):
                 raise InvalidArguments('Can only depend on toplevel targets: custom_target or build_target (executable or a library) got: {}({})'
                                       .format(type(ed), ed))
@@ -2198,9 +2169,7 @@ class CustomTarget(Target):
 
     def get_generated_lists(self):
         genlists = []
-        for c in self.sources:
-            if hasattr(c, 'held_object'):
-                c = c.held_object
+        for c in unholder(self.sources):
             if isinstance(c, GeneratedList):
                 genlists.append(c)
         return genlists
@@ -2463,9 +2432,7 @@ def get_sources_string_names(sources, backend):
     get all the output basenames.
     '''
     names = []
-    for s in sources:
-        if hasattr(s, 'held_object'):
-            s = s.held_object
+    for s in unholder(sources):
         if isinstance(s, str):
             names.append(s)
         elif isinstance(s, (BuildTarget, CustomTarget, CustomTargetIndex, GeneratedList)):