[clang-tools-extra] [clangd] [C++20] [Modules] Introduce initial support for C++20 Modules (PR #66462)

[kadir çetinkaya via cfe-commits]

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@@ -0,0 +1,106 @@
+//===-------------- ModuleDependencyScanner.h --------------------*- C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_MODULEDEPENDENCYSCANNER_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_MODULEDEPENDENCYSCANNER_H
+
+#include "GlobalCompilationDatabase.h"
+#include "support/Path.h"
+#include "support/ThreadsafeFS.h"
+
+#include "clang/Tooling/DependencyScanning/DependencyScanningService.h"
+#include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringMap.h"
+
+namespace clang {
+namespace clangd {
+
+/// A scanner to query the dependency information for C++20 Modules.
+///
+/// The scanner can scan a single file with `scan(PathRef)` member function
+/// or scan the whole project with `globalScan(PathRef)` member function. See
+/// the comments of `globalScan` to see the details.
+///
+/// ModuleDependencyScanner should only be used via ScanningAllProjectModules.
+///
+/// The ModuleDependencyScanner can get the directly required module name for a
+/// specific source file. Also the ModuleDependencyScanner can get the source
+/// file declaring a specific module name.
+///
+/// IMPORTANT NOTE: we assume that every module unit is only declared once in a
+/// source file in the project. But the assumption is not strictly true even
+/// besides the invalid projects. The language specification requires that every
+/// module unit should be unique in a valid program. But a project can contain
+/// multiple programs. Then it is valid that we can have multiple source files
+/// declaring the same module in a project as long as these source files don't
+/// interere with each other.`
----------------
kadircet wrote:

s/interere/interfere/

https://github.com/llvm/llvm-project/pull/66462