[clang-tidy] Avoid C arrays check

Summary:
[[ https://bugs.llvm.org/show_bug.cgi?id=39224 | PR39224 ]]
As discussed, we can't always do the transform automatically due to that array-to-pointer decay of C array.
In order to detect whether we can do said transform, we'd need to be able to see all usages of said array,
which is, i would say, rather impossible if e.g. it is in the header.
Thus right now no fixit exists.

Exceptions: `extern "C"` code.

References:
* [[ https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es27-use-stdarray-or-stack_array-for-arrays-on-the-stack | CPPCG ES.27: Use std::array or stack_array for arrays on the stack ]]
* [[ https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#slcon1-prefer-using-stl-array-or-vector-instead-of-a-c-array | CPPCG SL.con.1: Prefer using STL array or vector instead of a C array ]]
* HICPP `4.1.1 Ensure that a function argument does not undergo an array-to-pointer conversion`
* MISRA `5-2-12 An identifier with array type passed as a function argument shall not decay to a pointer`

Reviewers: aaron.ballman, JonasToth, alexfh, hokein, xazax.hun

Reviewed By: JonasToth

Subscribers: Eugene.Zelenko, mgorny, rnkovacs, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D53771

llvm-svn: 346835

2 files changed, 4 insertions, 0 deletions

diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt b/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
index 70f6c33c31b..a36f95716a0 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/CMakeLists.txt
@@ -28,6 +28,7 @@ add_clang_library(clangTidyCppCoreGuidelinesModule
   clangLex
   clangTidy
   clangTidyMiscModule
+  clangTidyModernizeModule
   clangTidyReadabilityModule
   clangTidyUtils
   clangTooling
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
index 590ec6df10e..0870f1ee68d 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/CppCoreGuidelinesTidyModule.cpp
@@ -12,6 +12,7 @@
 #include "../ClangTidyModuleRegistry.h"
 #include "../misc/NonPrivateMemberVariablesInClassesCheck.h"
 #include "../misc/UnconventionalAssignOperatorCheck.h"
+#include "../modernize/AvoidCArraysCheck.h"
 #include "../readability/MagicNumbersCheck.h"
 #include "AvoidGotoCheck.h"
 #include "InterfacesGlobalInitCheck.h"
@@ -40,6 +41,8 @@ namespace cppcoreguidelines {
 class CppCoreGuidelinesModule : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+    CheckFactories.registerCheck<modernize::AvoidCArraysCheck>(
+        "cppcoreguidelines-avoid-c-arrays");
     CheckFactories.registerCheck<AvoidGotoCheck>(
         "cppcoreguidelines-avoid-goto");
     CheckFactories.registerCheck<readability::MagicNumbersCheck>(