Add submodule dependency filesHEADmaster

Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec

1 files changed, 201 insertions, 0 deletions

diff --git a/meson/mesonbuild/scripts/depscan.py b/meson/mesonbuild/scripts/depscan.py
new file mode 100644
index 000000000..9fc435b5d
--- /dev/null
+++ b/meson/mesonbuild/scripts/depscan.py
@@ -0,0 +1,201 @@
+# Copyright 2020 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.
+
+import pathlib
+import pickle
+import re
+import os
+import sys
+import typing as T
+
+from ..backend.ninjabackend import TargetDependencyScannerInfo, ninja_quote
+from ..compilers.compilers import lang_suffixes
+
+CPP_IMPORT_RE = re.compile(r'\w*import ([a-zA-Z0-9]+);')
+CPP_EXPORT_RE = re.compile(r'\w*export module ([a-zA-Z0-9]+);')
+
+FORTRAN_INCLUDE_PAT = r"^\s*include\s*['\"](\w+\.\w+)['\"]"
+FORTRAN_MODULE_PAT = r"^\s*\bmodule\b\s+(\w+)\s*(?:!+.*)*$"
+FORTRAN_SUBMOD_PAT = r"^\s*\bsubmodule\b\s*\((\w+:?\w+)\)\s*(\w+)"
+FORTRAN_USE_PAT = r"^\s*use,?\s*(?:non_intrinsic)?\s*(?:::)?\s*(\w+)"
+
+FORTRAN_MODULE_RE = re.compile(FORTRAN_MODULE_PAT, re.IGNORECASE)
+FORTRAN_SUBMOD_RE = re.compile(FORTRAN_SUBMOD_PAT, re.IGNORECASE)
+FORTRAN_USE_RE = re.compile(FORTRAN_USE_PAT, re.IGNORECASE)
+
+class DependencyScanner:
+    def __init__(self, pickle_file: str, outfile: str, sources: T.List[str]):
+        with open(pickle_file, 'rb') as pf:
+            self.target_data = pickle.load(pf) # type: TargetDependencyScannerInfo
+        self.outfile = outfile
+        self.sources = sources
+        self.provided_by = {} # type: T.Dict[str, str]
+        self.exports = {} # type: T.Dict[str, str]
+        self.needs = {} # type: T.Dict[str, T.List[str]]
+        self.sources_with_exports = [] # type: T.List[str]
+
+    def scan_file(self, fname: str) -> None:
+        suffix = os.path.splitext(fname)[1][1:].lower()
+        if suffix in lang_suffixes['fortran']:
+            self.scan_fortran_file(fname)
+        elif suffix in lang_suffixes['cpp']:
+            self.scan_cpp_file(fname)
+        else:
+            sys.exit(f'Can not scan files with suffix .{suffix}.')
+
+    def scan_fortran_file(self, fname: str) -> None:
+        fpath = pathlib.Path(fname)
+        modules_in_this_file = set()
+        for line in fpath.read_text(encoding='utf-8').split('\n'):
+            import_match = FORTRAN_USE_RE.match(line)
+            export_match = FORTRAN_MODULE_RE.match(line)
+            submodule_export_match = FORTRAN_SUBMOD_RE.match(line)
+            if import_match:
+                needed = import_match.group(1).lower()
+                # In Fortran you have an using declaration also for the module
+                # you define in the same file. Prevent circular dependencies.
+                if needed not in modules_in_this_file:
+                    if fname in self.needs:
+                        self.needs[fname].append(needed)
+                    else:
+                        self.needs[fname] = [needed]
+            if export_match:
+                exported_module = export_match.group(1).lower()
+                assert(exported_module not in modules_in_this_file)
+                modules_in_this_file.add(exported_module)
+                if exported_module in self.provided_by:
+                    raise RuntimeError(f'Multiple files provide module {exported_module}.')
+                self.sources_with_exports.append(fname)
+                self.provided_by[exported_module] = fname
+                self.exports[fname] = exported_module
+            if submodule_export_match:
+                # Store submodule "Foo" "Bar" as "foo:bar".
+                # A submodule declaration can be both an import and an export declaration:
+                #
+                # submodule (a1:a2) a3
+                #  - requires a1@a2.smod
+                #  - produces a1@a3.smod
+                parent_module_name_full = submodule_export_match.group(1).lower()
+                parent_module_name = parent_module_name_full.split(':')[0]
+                submodule_name = submodule_export_match.group(2).lower()
+                concat_name = f'{parent_module_name}:{submodule_name}'
+                self.sources_with_exports.append(fname)
+                self.provided_by[concat_name] = fname
+                self.exports[fname] = concat_name
+                # Fortran requires that the immediate parent module must be built
+                # before the current one. Thus:
+                #
+                # submodule (parent) parent   <- requires parent.mod (really parent.smod, but they are created at the same time)
+                # submodule (a1:a2) a3        <- requires a1@a2.smod
+                #
+                # a3 does not depend on the a1 parent module directly, only transitively.
+                if fname in self.needs:
+                    self.needs[fname].append(parent_module_name_full)
+                else:
+                    self.needs[fname] = [parent_module_name_full]
+
+
+    def scan_cpp_file(self, fname: str) -> None:
+        fpath = pathlib.Path(fname)
+        for line in fpath.read_text(encoding='utf-8').split('\n'):
+            import_match = CPP_IMPORT_RE.match(line)
+            export_match = CPP_EXPORT_RE.match(line)
+            if import_match:
+                needed = import_match.group(1)
+                if fname in self.needs:
+                    self.needs[fname].append(needed)
+                else:
+                    self.needs[fname] = [needed]
+            if export_match:
+                exported_module = export_match.group(1)
+                if exported_module in self.provided_by:
+                    raise RuntimeError(f'Multiple files provide module {exported_module}.')
+                self.sources_with_exports.append(fname)
+                self.provided_by[exported_module] = fname
+                self.exports[fname] = exported_module
+
+    def objname_for(self, src: str) -> str:
+        objname = self.target_data.source2object[src]
+        assert(isinstance(objname, str))
+        return objname
+
+    def module_name_for(self, src: str) -> str:
+        suffix = os.path.splitext(src)[1][1:].lower()
+        if suffix in lang_suffixes['fortran']:
+            exported = self.exports[src]
+            # Module foo:bar goes to a file name foo@bar.smod
+            # Module Foo goes to a file name foo.mod
+            namebase = exported.replace(':', '@')
+            if ':' in exported:
+                extension = 'smod'
+            else:
+                extension = 'mod'
+            return os.path.join(self.target_data.private_dir, f'{namebase}.{extension}')
+        elif suffix in lang_suffixes['cpp']:
+            return '{}.ifc'.format(self.exports[src])
+        else:
+            raise RuntimeError('Unreachable code.')
+
+    def scan(self) -> int:
+        for s in self.sources:
+            self.scan_file(s)
+        with open(self.outfile, 'w', encoding='utf-8') as ofile:
+            ofile.write('ninja_dyndep_version = 1\n')
+            for src in self.sources:
+                objfilename = self.objname_for(src)
+                mods_and_submods_needed = []
+                module_files_generated = []
+                module_files_needed = []
+                if src in self.sources_with_exports:
+                    module_files_generated.append(self.module_name_for(src))
+                if src in self.needs:
+                    for modname in self.needs[src]:
+                        if modname not in self.provided_by:
+                            # Nothing provides this module, we assume that it
+                            # comes from a dependency library somewhere and is
+                            # already built by the time this compilation starts.
+                            pass
+                        else:
+                            mods_and_submods_needed.append(modname)
+
+                for modname in mods_and_submods_needed:
+                    provider_src = self.provided_by[modname]
+                    provider_modfile = self.module_name_for(provider_src)
+                    # Prune self-dependencies
+                    if provider_src != src:
+                        module_files_needed.append(provider_modfile)
+
+                quoted_objfilename = ninja_quote(objfilename, True)
+                quoted_module_files_generated = [ninja_quote(x, True) for x in module_files_generated]
+                quoted_module_files_needed = [ninja_quote(x, True) for x in module_files_needed]
+                if quoted_module_files_generated:
+                    mod_gen = '| ' + ' '.join(quoted_module_files_generated)
+                else:
+                    mod_gen = ''
+                if quoted_module_files_needed:
+                    mod_dep = '| '  + ' '.join(quoted_module_files_needed)
+                else:
+                    mod_dep = ''
+                build_line = 'build {} {}: dyndep {}'.format(quoted_objfilename,
+                                                             mod_gen,
+                                                             mod_dep)
+                ofile.write(build_line + '\n')
+        return 0
+
+def run(args: T.List[str]) -> int:
+    pickle_file = args[0]
+    outfile = args[1]
+    sources = args[2:]
+    scanner = DependencyScanner(pickle_file, outfile, sources)
+    return scanner.scan()