[libcxx-commits] [mlir] [llvm] [openmp] [clang] [flang] [clang-tools-extra] [libcxx] [clang-tidy] Replace memcpy with std::copy (PR #74663)

via libcxx-commits libcxx-commits at lists.llvm.org
Fri Dec 8 15:18:21 PST 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: Giovanni Martins (giovannism20)

<details>
<summary>Changes</summary>

#<!-- -->22583 

---
Full diff: https://github.com/llvm/llvm-project/pull/74663.diff


7 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/CMakeLists.txt (+1) 
- (modified) clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp (+3) 
- (added) clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.cpp (+119) 
- (added) clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.h (+49) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+5) 
- (modified) clang-tools-extra/docs/clang-tidy/checks/list.rst (+1) 
- (added) clang-tools-extra/docs/clang-tidy/checks/modernize/modernize-replace-memcpy-with-stdcopy.rst (+47) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
index c40065358d2dc3..d0a996d3be7292 100644
--- a/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/modernize/CMakeLists.txt
@@ -22,6 +22,7 @@ add_clang_library(clangTidyModernizeModule
   RedundantVoidArgCheck.cpp
   ReplaceAutoPtrCheck.cpp
   ReplaceDisallowCopyAndAssignMacroCheck.cpp
+  ReplaceMemcpyWithStdCopy.cpp
   ReplaceRandomShuffleCheck.cpp
   ReturnBracedInitListCheck.cpp
   ShrinkToFitCheck.cpp
diff --git a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
index e994ffd2a75c85..6bb9efa694eb2f 100644
--- a/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/ModernizeTidyModule.cpp
@@ -23,6 +23,7 @@
 #include "RedundantVoidArgCheck.h"
 #include "ReplaceAutoPtrCheck.h"
 #include "ReplaceDisallowCopyAndAssignMacroCheck.h"
+#include "ReplaceMemcpyWithStdCopy.h"
 #include "ReplaceRandomShuffleCheck.h"
 #include "ReturnBracedInitListCheck.h"
 #include "ShrinkToFitCheck.h"
@@ -78,6 +79,8 @@ class ModernizeModule : public ClangTidyModule {
         "modernize-replace-auto-ptr");
     CheckFactories.registerCheck<ReplaceDisallowCopyAndAssignMacroCheck>(
         "modernize-replace-disallow-copy-and-assign-macro");
+    CheckFactories.registerCheck<ReplaceMemcpyWithStdCopy>(
+        "modernize-replace-memcpy-by-stdcopy");
     CheckFactories.registerCheck<ReplaceRandomShuffleCheck>(
         "modernize-replace-random-shuffle");
     CheckFactories.registerCheck<ReturnBracedInitListCheck>(
diff --git a/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.cpp b/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.cpp
new file mode 100644
index 00000000000000..af6b365c162517
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.cpp
@@ -0,0 +1,119 @@
+//===--- ReplaceMemcpyWithStdCopy.cpp - clang-tidy----------------*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "ReplaceMemcpyWithStdCopy.h"
+#include "../utils/OptionsUtils.h"
+#include <array>
+
+using namespace clang;
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+ReplaceMemcpyWithStdCopy::ReplaceMemcpyWithStdCopy(StringRef Name,
+                                                   ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      IncludeInserter(Options.getLocalOrGlobal("IncludeStyle",
+                                               utils::IncludeSorter::IS_LLVM)) {
+}
+
+void ReplaceMemcpyWithStdCopy::registerMatchers(MatchFinder *Finder) {
+  assert(Finder != nullptr);
+
+  if (!getLangOpts().CPlusPlus)
+    return;
+
+  auto MemcpyMatcher =
+      callExpr(hasDeclaration(functionDecl(hasName("memcpy"),
+                                           isExpansionInSystemHeader())),
+               isExpansionInMainFile())
+          .bind("memcpy_function");
+
+  Finder->addMatcher(MemcpyMatcher, this);
+}
+
+void ReplaceMemcpyWithStdCopy::registerPPCallbacks(
+    const SourceManager &SM, Preprocessor *PP, Preprocessor *ModuleExpanderPP) {
+  if (!getLangOpts().CPlusPlus)
+    return;
+
+  Inserter =
+      std::make_unique<utils::IncludeInserter>(SM, getLangOpts(),
+                                                       IncludeStyle);
+  PP->addPPCallbacks(Inserter->CreatePPCallbacks());
+}
+
+void ReplaceMemcpyWithStdCopy::check(const MatchFinder::MatchResult &Result) {
+  const auto *MemcpyNode = Result.Nodes.getNodeAs<CallExpr>("memcpy_function");
+  assert(MemcpyNode != nullptr);
+
+  DiagnosticBuilder Diag =
+      diag(MemcpyNode->getExprLoc(), "use std::copy instead of memcpy");
+
+  renameFunction(Diag, MemcpyNode);
+  reorderArgs(Diag, MemcpyNode);
+  insertHeader(Diag, MemcpyNode, Result.SourceManager);
+}
+
+void ReplaceMemcpyWithStdCopy::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+  Options.store(Opts, "IncludeStyle",
+                utils::IncludeSorter::toString(IncludeStyle));
+}
+
+void ReplaceMemcpyWithStdCopy::renameFunction(DiagnosticBuilder &Diag,
+                                              const CallExpr *MemcpyNode) {
+  const CharSourceRange FunctionNameSourceRange = CharSourceRange::getCharRange(
+      MemcpyNode->getBeginLoc(), MemcpyNode->getArg(0)->getBeginLoc());
+
+  Diag << FixItHint::CreateReplacement(FunctionNameSourceRange, "std::copy(");
+}
+
+void ReplaceMemcpyWithStdCopy::reorderArgs(DiagnosticBuilder &Diag,
+                                           const CallExpr *MemcpyNode) {
+  std::array<std::string, 3> arg;
+
+  LangOptions LangOpts;
+  LangOpts.CPlusPlus = true;
+  PrintingPolicy Policy(LangOpts);
+
+  // Retrieve all the arguments
+  for (uint8_t i = 0; i < arg.size(); i++) {
+    llvm::raw_string_ostream s(arg[i]);
+    MemcpyNode->getArg(i)->printPretty(s, nullptr, Policy);
+  }
+
+  // Create lambda that return SourceRange of an argument
+  auto getSourceRange = [MemcpyNode](uint8_t ArgCount) -> SourceRange {
+    return SourceRange(MemcpyNode->getArg(ArgCount)->getBeginLoc(),
+                       MemcpyNode->getArg(ArgCount)->getEndLoc());
+  };
+
+  // Reorder the arguments
+  Diag << FixItHint::CreateReplacement(getSourceRange(0), arg[1]);
+
+  arg[2] = arg[1] + " + ((" + arg[2] + ") / sizeof(*(" + arg[1] + ")))";
+  Diag << FixItHint::CreateReplacement(getSourceRange(1), arg[2]);
+
+  Diag << FixItHint::CreateReplacement(getSourceRange(2), arg[0]);
+}
+
+void ReplaceMemcpyWithStdCopy::insertHeader(DiagnosticBuilder &Diag,
+                                            const CallExpr *MemcpyNode,
+                                            SourceManager *const SM) {
+  Optional<FixItHint> FixInclude = Inserter->CreateIncludeInsertion(
+      /*FileID=*/SM->getMainFileID(), /*Header=*/"algorithm",
+      /*IsAngled=*/true);
+  if (FixInclude)
+    Diag << *FixInclude;
+}
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
diff --git a/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.h b/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.h
new file mode 100644
index 00000000000000..0f262bf839af24
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/modernize/ReplaceMemcpyWithStdCopy.h
@@ -0,0 +1,49 @@
+//===--- ReplaceMemcpyWithStdCopy.h - clang-tidy------------------*- 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_CLANG_TIDY_MODERNIZE_REPLACE_MEMCPY_WITH_STDCOPY_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_REPLACE_MEMCPY_WITH_STDCOPY_H
+
+#include "../ClangTidyCheck.h"
+#include "../utils/IncludeInserter.h"
+#include <memory>
+#include <string>
+#include <vector>
+
+namespace clang {
+namespace tidy {
+namespace modernize {
+
+// Replace the C memcpy function with std::copy
+class ReplaceMemcpyWithStdCopy : public ClangTidyCheck {
+public:
+  ReplaceMemcpyWithStdCopy(StringRef Name, ClangTidyContext *Context);
+  ~ReplaceMemcpyWithStdCopy() override = default;
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void registerPPCallbacks(const SourceManager &SM, Preprocessor *PP,
+                           Preprocessor *ModuleExpanderPP) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+  void storeOptions(ClangTidyOptions::OptionMap &Options) override;
+
+private:
+  void renameFunction(DiagnosticBuilder &Diag, const CallExpr *MemcpyNode);
+  void reorderArgs(DiagnosticBuilder &Diag, const CallExpr *MemcpyNode);
+  void insertHeader(DiagnosticBuilder &Diag, const CallExpr *MemcpyNode,
+                    SourceManager *const SM);
+
+private:
+  std::unique_ptr<utils::IncludeInserter> Inserter;
+  utils::IncludeInserter IncludeInserter;
+  const utils::IncludeSorter::IncludeStyle IncludeStyle;
+};
+
+} // namespace modernize
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MODERNIZE_REPLACE_MEMCPY_WITH_STDCOPY_H
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 4ff4494cef5624..2191e418cead24 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -377,6 +377,11 @@ Changes in existing checks
   <clang-tidy/checks/modernize/use-nullptr>` check by adding option
   `IgnoredTypes` that can be used to exclude some pointer types.
 
+- New :doc:`modernize-replace-memcpy-with-stdcopy
+  <clang-tidy/checks/modernize-replace-memcpy-by-stdcopy>` check.
+
+  Replaces all occurrences of the C ``memcpy`` function by ``std::copy``.
+
 - Improved :doc:`modernize-use-std-print
   <clang-tidy/checks/modernize/use-std-print>` check to accurately generate
   fixes for reordering arguments.
diff --git a/clang-tools-extra/docs/clang-tidy/checks/list.rst b/clang-tools-extra/docs/clang-tidy/checks/list.rst
index df2d5d15238d63..57d13aacb81890 100644
--- a/clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ b/clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -275,6 +275,7 @@ Clang-Tidy Checks
    :doc:`modernize-raw-string-literal <modernize/raw-string-literal>`, "Yes"
    :doc:`modernize-redundant-void-arg <modernize/redundant-void-arg>`, "Yes"
    :doc:`modernize-replace-auto-ptr <modernize/replace-auto-ptr>`, "Yes"
+   :doc:`modernize-replace-memcpy-with-std-copy <modernize/replace-auto-ptr>`, "Yes"
    :doc:`modernize-replace-disallow-copy-and-assign-macro <modernize/replace-disallow-copy-and-assign-macro>`, "Yes"
    :doc:`modernize-replace-random-shuffle <modernize/replace-random-shuffle>`, "Yes"
    :doc:`modernize-return-braced-init-list <modernize/return-braced-init-list>`, "Yes"
diff --git a/clang-tools-extra/docs/clang-tidy/checks/modernize/modernize-replace-memcpy-with-stdcopy.rst b/clang-tools-extra/docs/clang-tidy/checks/modernize/modernize-replace-memcpy-with-stdcopy.rst
new file mode 100644
index 00000000000000..922a7f36e7e078
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/checks/modernize/modernize-replace-memcpy-with-stdcopy.rst
@@ -0,0 +1,47 @@
+.. title:: clang-tidy - modernize-replace-memcpy-with-stdcopy
+
+modernize-replace-memcpy-with-stdcopy
+===================================
+
+Replaces all occurrences of the C ``memcpy`` function with ``std::copy``
+
+Example:
+
+.. code-block:: c++
+
+  /*!
+   * \param destination Pointer to the destination array where the content is to be copied
+   * \param source Pointer to the source of data to be copied
+   * \param num Number of bytes to copy
+   */
+  memcpy(destination, source, num);
+
+becomes
+
+.. code-block:: c++
+
+  /*!
+   * \param destination Pointer to the destination array where the content is to be copied
+   * \param source Pointer to the source of data to be copied
+   * \param num Number of bytes to copy
+   */
+  std::copy(source, source + (num / sizeof *source), destination);
+
+Bytes to iterator conversion
+----------------------------
+
+Unlike ``std::copy`` that take an iterator on the last element of the source array, ``memcpy`` request the number of bytes to copy.
+In order to make the check working, it will convert the size parameter to an iterator by replacing it by ``source + (num / sizeof *source)``
+
+Header inclusion
+----------------
+
+``std::copy`` being provided by the ``algorithm`` header file, this check will include it if needed.
+
+Options
+-------
+
+.. option:: IncludeStyle
+
+   A string specifying which include-style is used, `llvm` or `google`. Default
+   is `llvm`.

``````````

</details>


https://github.com/llvm/llvm-project/pull/74663


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