[clang-tools-extra] [clang-tidy] support query based custom check (PR #131804)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,111 @@
+//===--- QueryCheck.cpp - clang-tidy --------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "QueryCheck.h"
+#include "../../clang-query/Query.h"
+#include "../../clang-query/QueryParser.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/ASTMatchers/Dynamic/VariantValue.h"
+#include "clang/Basic/DiagnosticIDs.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include <string>
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::custom {
+
+static SmallVector<ast_matchers::dynamic::DynTypedMatcher>
+parseQuery(const ClangTidyOptions::CustomCheckValue &V,
+           ClangTidyContext *Context) {
+  SmallVector<ast_matchers::dynamic::DynTypedMatcher> Matchers{};
+  clang::query::QuerySession QS({});
+  llvm::StringRef QueryStringRef{V.Query};
+  while (!QueryStringRef.empty()) {
+    query::QueryRef Q = query::QueryParser::parse(QueryStringRef, QS);
+    switch (Q->Kind) {
+    case query::QK_Match: {
+      const auto &MatchQuery = llvm::cast<query::MatchQuery>(*Q);
+      Matchers.push_back(MatchQuery.Matcher);
+      break;
+    }
+    case query::QK_Let: {
+      const auto &LetQuery = llvm::cast<query::LetQuery>(*Q);
+      LetQuery.run(llvm::errs(), QS);
+      break;
+    }
+    case query::QK_Invalid: {
+      const auto &InvalidQuery = llvm::cast<query::InvalidQuery>(*Q);
+      Context->configurationDiag(InvalidQuery.ErrStr, DiagnosticIDs::Error);
+      return {};
+    }
+    // FIXME: TODO
+    case query::QK_File:
+    case query::QK_DisableOutputKind:
+    case query::QK_EnableOutputKind:
+    case query::QK_SetOutputKind:
+    case query::QK_SetTraversalKind:
+    case query::QK_Help:
+    case query::QK_NoOp:
+    case query::QK_Quit:
+    case query::QK_SetBool: {
+      Context->configurationDiag("unsupported query kind",
+                                 DiagnosticIDs::Error);
+      return {};
+    }
+    }
+    QueryStringRef = Q->RemainingContent;
+  }
+  return Matchers;
+}
+
+QueryCheck::QueryCheck(llvm::StringRef Name,
+                       const ClangTidyOptions::CustomCheckValue &V,
+                       ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context) {
+  for (const ClangTidyOptions::CustomCheckDiag &D : V.Diags) {
+    auto DiagnosticIdIt =
+        Diags
+            .try_emplace(D.Level.value_or(DiagnosticIDs::Warning),
+                         llvm::StringMap<llvm::SmallVector<std::string>>{})
+            .first;
+    auto DiagMessageIt =
+        DiagnosticIdIt->getSecond()
+            .try_emplace(D.BindName, llvm::SmallVector<std::string>{})
+            .first;
+    DiagMessageIt->second.emplace_back(D.Message);
+  }
+  Matchers = parseQuery(V, Context);
+}
+
+void QueryCheck::registerMatchers(MatchFinder *Finder) {
+  for (const ast_matchers::dynamic::DynTypedMatcher &M : Matchers)
+    Finder->addDynamicMatcher(M, this);
+}
+
+void QueryCheck::check(const MatchFinder::MatchResult &Result) {
+  auto Emit = [this](DiagMaps const &DiagMaps, std::string const &BindName,
+                     DynTypedNode const &Node, DiagnosticIDs::Level Level) {
----------------
vbvictor wrote:

```suggestion
  auto Emit = [this](const DiagMaps &DiagMaps, const std::string &BindName,
                     const DynTypedNode &Node, DiagnosticIDs::Level Level) {
```

https://github.com/llvm/llvm-project/pull/131804