[clang] [clang-tools-extra] [clang-tidy] Added new check to detect redundant inline keyword (PR #73069)

[Félix-Antoine Constantin via cfe-commits]

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@@ -0,0 +1,99 @@
+//===--- RedundantInlineSpecifierCheck.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 "RedundantInlineSpecifierCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Basic/SourceManager.h"
+
+#include "../utils/LexerUtils.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::readability {
+
+static std::optional<SourceLocation>
+getInlineTokenLocation(SourceRange RangeLocation, const SourceManager &Sources,
+                       const LangOptions &LangOpts) {
+  SourceLocation CurrentLocation = RangeLocation.getBegin();
+  Token CurrentToken;
+  while (!Lexer::getRawToken(CurrentLocation, CurrentToken, Sources, LangOpts,
+                             true) &&
+         CurrentLocation < RangeLocation.getEnd() &&
+         CurrentToken.isNot(tok::eof)) {
+    if (CurrentToken.is(tok::raw_identifier)) {
+      if (CurrentToken.getRawIdentifier() == "inline") {
+        return CurrentToken.getLocation();
+      }
+    }
+    CurrentLocation = CurrentToken.getEndLoc();
+  }
+  return std::nullopt;
+}
+
+void RedundantInlineSpecifierCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      functionDecl(unless(isExpansionInSystemHeader()), unless(isImplicit()),
+                   unless(hasAncestor(lambdaExpr())), isInline(),
+                   anyOf(isConstexpr(), isDeleted(),
+                         allOf(isDefinition(), hasAncestor(recordDecl()),
+                               unless(hasAncestor(cxxConstructorDecl())))))
+          .bind("fun_decl"),
+      this);
+
+  Finder->addMatcher(
+      varDecl(isInline(), unless(isImplicit()),
+              anyOf(allOf(isConstexpr(), unless(isStaticStorageClass())),
----------------
felix642 wrote:

The description of this matcher says : 

>Matches variable/function declarations that have "static" storage
>class specifier ("static" keyword) written in the source.

>From what I understand, it needs to have the "static" keyword written in the source. 
Is there a better matcher that I could use in that case?  

https://github.com/llvm/llvm-project/pull/73069