cmake: Add CMake file API support

The file API will automatically be used when CMake >= 3.14
is detected. This new API is meant as a replacement for the
now deprecated CMake server API.

The new API (mostly) provides the same information in a
different format. Thus only a slight bit of refactoring was
necessary to implement this new backend

1 files changed, 318 insertions, 0 deletions

diff --git a/mesonbuild/cmake/fileapi.py b/mesonbuild/cmake/fileapi.py
new file mode 100644
index 0000000..df7c73a
--- /dev/null
+++ b/mesonbuild/cmake/fileapi.py
@@ -0,0 +1,318 @@
+# Copyright 2019 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .common import CMakeException, CMakeBuildFile, CMakeConfiguration
+from typing import Any, List, Tuple
+import os
+import json
+import re
+
+STRIP_KEYS = ['cmake', 'reply', 'backtrace', 'backtraceGraph', 'version']
+
+class CMakeFileAPI:
+    def __init__(self, build_dir: str):
+        self.build_dir = build_dir
+        self.api_base_dir = os.path.join(self.build_dir, '.cmake', 'api', 'v1')
+        self.request_dir = os.path.join(self.api_base_dir, 'query', 'client-meson')
+        self.reply_dir = os.path.join(self.api_base_dir, 'reply')
+        self.cmake_sources = []
+        self.cmake_configurations = []
+        self.kind_resolver_map = {
+            'codemodel': self._parse_codemodel,
+            'cmakeFiles': self._parse_cmakeFiles,
+        }
+
+    def get_cmake_sources(self) -> List[CMakeBuildFile]:
+        return self.cmake_sources
+
+    def get_cmake_configurations(self) -> List[CMakeConfiguration]:
+        return self.cmake_configurations
+
+    def setup_request(self) -> None:
+        os.makedirs(self.request_dir, exist_ok=True)
+
+        query = {
+            'requests': [
+                {'kind': 'codemodel', 'version': {'major': 2, 'minor': 0}},
+                {'kind': 'cmakeFiles', 'version': {'major': 1, 'minor': 0}},
+            ]
+        }
+
+        with open(os.path.join(self.request_dir, 'query.json'), 'w') as fp:
+            json.dump(query, fp, indent=2)
+
+    def load_reply(self) -> None:
+        if not os.path.isdir(self.reply_dir):
+            raise CMakeException('No response from the CMake file API')
+
+        files = os.listdir(self.reply_dir)
+        root = None
+        reg_index = re.compile(r'^index-.*\.json$')
+        for i in files:
+            if reg_index.match(i):
+                root = i
+                break
+
+        if not root:
+            raise CMakeException('Failed to find the CMake file API index')
+
+        index = self._reply_file_content(root)   # Load the root index
+        index = self._strip_data(index)          # Avoid loading duplicate files
+        index = self._resolve_references(index)  # Load everything
+        index = self._strip_data(index)          # Strip unused data (again for loaded files)
+
+        # Debug output
+        debug_json = os.path.normpath(os.path.join(self.build_dir, '..', 'fileAPI.json'))
+        with open(debug_json, 'w') as fp:
+            json.dump(index, fp, indent=2)
+
+        # parse the JSON
+        for i in index['objects']:
+            assert(isinstance(i, dict))
+            assert('kind' in i)
+            assert(i['kind'] in self.kind_resolver_map)
+
+            self.kind_resolver_map[i['kind']](i)
+
+    def _parse_codemodel(self, data: dict) -> None:
+        assert('configurations' in data)
+        assert('paths' in data)
+
+        source_dir = data['paths']['source']
+        build_dir = data['paths']['build']
+
+        # The file API output differs quite a bit from the server
+        # output. It is more flat than the server output and makes
+        # heavy use of references. Here these references are
+        # resolved and the resulting data structure is identical
+        # to the CMake serve output.
+
+        def helper_parse_dir(dir_entry: dict) -> Tuple[str, str]:
+            src_dir = dir_entry.get('source', '.')
+            bld_dir = dir_entry.get('build', '.')
+            src_dir = src_dir if os.path.isabs(src_dir) else os.path.join(source_dir, src_dir)
+            bld_dir = bld_dir if os.path.isabs(bld_dir) else os.path.join(source_dir, bld_dir)
+            src_dir = os.path.normpath(src_dir)
+            bld_dir = os.path.normpath(bld_dir)
+
+            return src_dir, bld_dir
+
+        def parse_sources(comp_group: dict, tgt: dict) -> Tuple[List[str], List[str], List[int]]:
+            gen = []
+            src = []
+            idx = []
+
+            src_list_raw = tgt.get('sources', [])
+            for i in comp_group.get('sourceIndexes', []):
+                if i >= len(src_list_raw) or 'path' not in src_list_raw[i]:
+                    continue
+                if src_list_raw[i].get('isGenerated', False):
+                    gen += [src_list_raw[i]['path']]
+                else:
+                    src += [src_list_raw[i]['path']]
+                idx += [i]
+
+            return src, gen, idx
+
+        def parse_target(tgt: dict) -> dict:
+            src_dir, bld_dir = helper_parse_dir(cnf.get('paths', {}))
+
+            # Parse install paths (if present)
+            install_paths = []
+            if 'install' in tgt:
+                prefix = tgt['install']['prefix']['path']
+                install_paths = [os.path.join(prefix, x['path']) for x in tgt['install']['destinations']]
+                install_paths = list(set(install_paths))
+
+            # On the first look, it looks really nice that the CMake devs have
+            # decided to use arrays for the linker flags. However, this feeling
+            # soon turns into despair when you realize that there only one entry
+            # per type in most cases, and we still have to do manual string splitting.
+            link_flags = []
+            link_libs = []
+            for i in tgt.get('link', {}).get('commandFragments', []):
+                if i['role'] == 'flags':
+                    link_flags += [i['fragment']]
+                elif i['role'] == 'libraries':
+                    link_libs += [i['fragment']]
+                elif i['role'] == 'libraryPath':
+                    link_flags += ['-L{}'.format(i['fragment'])]
+                elif i['role'] == 'frameworkPath':
+                    link_flags += ['-F{}'.format(i['fragment'])]
+            for i in tgt.get('archive', {}).get('commandFragments', []):
+                if i['role'] == 'flags':
+                    link_flags += [i['fragment']]
+
+            # TODO The `dependencies` entry is new in the file API.
+            #      maybe we can make use of that in addtion to the
+            #      implicit dependency detection
+            tgt_data = {
+                'artifacts': [x.get('path', '') for x in tgt.get('artifacts', [])],
+                'sourceDirectory': src_dir,
+                'buildDirectory': bld_dir,
+                'name': tgt.get('name', ''),
+                'fullName': tgt.get('nameOnDisk', ''),
+                'hasInstallRule': 'install' in tgt,
+                'installPaths': install_paths,
+                'linkerLanguage': tgt.get('link', {}).get('language', 'CXX'),
+                'linkLibraries': ' '.join(link_libs),  # See previous comment block why we join the array
+                'linkFlags': ' '.join(link_flags),     # See previous comment block why we join the array
+                'type': tgt.get('type', 'EXECUTABLE'),
+                'fileGroups': [],
+            }
+
+            processed_src_idx = []
+            for cg in tgt.get('compileGroups', []):
+                # Again, why an array, when there is usually only one element
+                # and arguments are seperated with spaces...
+                flags = []
+                for i in cg.get('compileCommandFragments', []):
+                    flags += [i['fragment']]
+
+                cg_data = {
+                    'defines': [x.get('define', '') for x in cg.get('defines', [])],
+                    'compileFlags': ' '.join(flags),
+                    'language': cg.get('language', 'C'),
+                    'isGenerated': None,  # Set later, flag is stored per source file
+                    'sources': [],
+
+                    # TODO handle isSystem
+                    'includePath': [x.get('path', '') for x in cg.get('includes', [])],
+                }
+
+                normal_src, generated_src, src_idx = parse_sources(cg, tgt)
+                if normal_src:
+                    cg_data = dict(cg_data)
+                    cg_data['isGenerated'] = False
+                    cg_data['sources'] = normal_src
+                    tgt_data['fileGroups'] += [cg_data]
+                if generated_src:
+                    cg_data = dict(cg_data)
+                    cg_data['isGenerated'] = True
+                    cg_data['sources'] = generated_src
+                    tgt_data['fileGroups'] += [cg_data]
+                processed_src_idx += src_idx
+
+            # Object libraries have no compile groups, only source groups.
+            # So we add all the source files to a dummy source group that were
+            # not found in the previous loop
+            normal_src = []
+            generated_src = []
+            for idx, src in enumerate(tgt.get('sources', [])):
+                if idx in processed_src_idx:
+                    continue
+
+                if src.get('isGenerated', False):
+                    generated_src += [src['path']]
+                else:
+                    normal_src += [src['path']]
+
+            if normal_src:
+                tgt_data['fileGroups'] += [{
+                    'isGenerated': False,
+                    'sources': normal_src,
+                }]
+            if generated_src:
+                tgt_data['fileGroups'] += [{
+                    'isGenerated': True,
+                    'sources': generated_src,
+                }]
+            return tgt_data
+
+        def parse_project(pro: dict) -> dict:
+            # Only look at the first directory specified in directoryIndexes
+            # TODO Figure out what the other indexes are there for
+            p_src_dir = source_dir
+            p_bld_dir = build_dir
+            try:
+                p_src_dir, p_bld_dir = helper_parse_dir(cnf['directories'][pro['directoryIndexes'][0]])
+            except (IndexError, KeyError):
+                pass
+
+            pro_data = {
+                'name': pro.get('name', ''),
+                'sourceDirectory': p_src_dir,
+                'buildDirectory': p_bld_dir,
+                'targets': [],
+            }
+
+            for ref in pro.get('targetIndexes', []):
+                tgt = {}
+                try:
+                    tgt = cnf['targets'][ref]
+                except (IndexError, KeyError):
+                    pass
+                pro_data['targets'] += [parse_target(tgt)]
+
+            return pro_data
+
+        for cnf in data.get('configurations', []):
+            cnf_data = {
+                'name': cnf.get('name', ''),
+                'projects': [],
+            }
+
+            for pro in cnf.get('projects', []):
+                cnf_data['projects'] += [parse_project(pro)]
+
+            self.cmake_configurations += [CMakeConfiguration(cnf_data)]
+
+    def _parse_cmakeFiles(self, data: dict) -> None:
+        assert('inputs' in data)
+        assert('paths' in data)
+
+        src_dir = data['paths']['source']
+
+        for i in data['inputs']:
+            path = i['path']
+            path = path if os.path.isabs(path) else os.path.join(src_dir, path)
+            self.cmake_sources += [CMakeBuildFile(path, i.get('isCMake', False), i.get('isGenerated', False))]
+
+    def _strip_data(self, data: Any) -> Any:
+        if isinstance(data, list):
+            for idx, i in enumerate(data):
+                data[idx] = self._strip_data(i)
+
+        elif isinstance(data, dict):
+            new = {}
+            for key, val in data.items():
+                if key not in STRIP_KEYS:
+                    new[key] = self._strip_data(val)
+            data = new
+
+        return data
+
+    def _resolve_references(self, data: Any) -> Any:
+        if isinstance(data, list):
+            for idx, i in enumerate(data):
+                data[idx] = self._resolve_references(i)
+
+        elif isinstance(data, dict):
+            # Check for the "magic" reference entry and insert
+            # it into the root data dict
+            if 'jsonFile' in data:
+                data.update(self._reply_file_content(data['jsonFile']))
+
+            for key, val in data.items():
+                data[key] = self._resolve_references(val)
+
+        return data
+
+    def _reply_file_content(self, filename: str) -> dict:
+        real_path = os.path.join(self.reply_dir, filename)
+        if not os.path.exists(real_path):
+            raise CMakeException('File "{}" does not exist'.format(real_path))
+
+        with open(real_path, 'r') as fp:
+            return json.load(fp)