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

[via cfe-commits]

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@@ -0,0 +1,102 @@
+//===--- 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 {
+
+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);
+  }
+
+  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 &MatchQuerry = llvm::cast<query::MatchQuery>(*Q);
+      Matchers.push_back(MatchQuerry.Matcher);
+      break;
+    }
+    case query::QK_Let: {
+      const auto &LetQuerry = llvm::cast<query::LetQuery>(*Q);
+      LetQuerry.run(llvm::errs(), QS);
+      break;
+    }
+    case query::QK_Invalid: {
+      const auto &InvalidQuerry = llvm::cast<query::InvalidQuery>(*Q);
+      Context->configurationDiag(InvalidQuerry.ErrStr);
+      break;
+    }
+    // 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 querry kind");
+    }
+    }
+    QueryStringRef = Q->RemainingContent;
+  }
+}
+
+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) {
+    if (!DiagMaps.contains(Level))
+      return;
+    auto &DiagMap = DiagMaps.at(Level);
+    if (!DiagMap.contains(BindName))
+      return;
+    for (const std::string &Message : DiagMap.at(BindName)) {
+      diag(Node.getSourceRange().getBegin(), Message, Level);
+    }
+  };
+  for (auto &[Name, Node] : Result.Nodes.getMap())
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EugeneZelenko wrote:

`const`? Same below.

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