[clang-tools-extra] [clang-tidy] Add deprecated-posix-functions check (PR #195641)

[Yanzuo Liu via cfe-commits]

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@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 "DeprecatedPosixFunctionsCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "llvm/ADT/StringSwitch.h"
+
+using namespace clang::ast_matchers;
+using namespace llvm;
+
+namespace clang::tidy::portability {
+
+static constexpr StringRef DeprecatedFunctionId = "DeprecatedFunctions";
+static constexpr StringRef DeclRefId = "DRE";
+
+static StringRef getReplacementFor(StringRef FunctionName) {
+  // TODO: Suggest Annex K replacements when available.
+  return StringSwitch<StringRef>(FunctionName)
+      .Case("bcmp", "memcmp")
+      .Case("bcopy", "memmove")
+      .Case("bzero", "memset")
+      .Case("getpw", "getpwuid")
+      .Case("vfork", "posix_spawn")
+      .Default({});
+}
+
+void DeprecatedPosixFunctionsCheck::registerMatchers(MatchFinder *Finder) {
+  const auto FunctionNamesMatcher =
+      hasAnyName("::bcmp", "::bcopy", "::bzero", "::getpw", "::vfork");
+  Finder->addMatcher(
+      declRefExpr(
+          to(functionDecl(FunctionNamesMatcher).bind(DeprecatedFunctionId)))
+          .bind(DeclRefId),
+      this);
+}
+
+void DeprecatedPosixFunctionsCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const auto *SourceExpr = Result.Nodes.getNodeAs<DeclRefExpr>(DeclRefId);
+  const auto *FuncDecl =
+      Result.Nodes.getNodeAs<FunctionDecl>(DeprecatedFunctionId);
+  if (!SourceExpr || !FuncDecl)
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zwuis wrote:

Use `assert` :)

https://github.com/llvm/llvm-project/pull/195641