[clang-tools-extra] r353327 - [clang-tidy] modernize-avoid-c-arrays: avoid main function (PR40604)

[Roman Lebedev via cfe-commits]

Author: lebedevri
Date: Wed Feb  6 11:17:30 2019
New Revision: 353327

URL: http://llvm.org/viewvc/llvm-project?rev=353327&view=rev
Log:
[clang-tidy] modernize-avoid-c-arrays: avoid main function (PR40604)

Summary:
The check should ignore the main function, the program entry point.
It is not possible to use `std::array<>` for the `argv`.
The alternative is to use `char** argv`.

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=40604 | PR40604 ]]

Reviewers: JonasToth, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: xazax.hun, hans, cfe-commits

Tags: #clang-tools-extra, #clang

Differential Revision: https://reviews.llvm.org/D57787

Added:
    clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-main.cpp
    clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-three-arg-main.cpp
Modified:
    clang-tools-extra/trunk/clang-tidy/modernize/AvoidCArraysCheck.cpp
    clang-tools-extra/trunk/docs/clang-tidy/checks/modernize-avoid-c-arrays.rst

Modified: clang-tools-extra/trunk/clang-tidy/modernize/AvoidCArraysCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/modernize/AvoidCArraysCheck.cpp?rev=353327&r1=353326&r2=353327&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/AvoidCArraysCheck.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/modernize/AvoidCArraysCheck.cpp Wed Feb  6 11:17:30 2019
@@ -30,6 +30,12 @@ AST_MATCHER(clang::RecordDecl, isExternC
   return Node.isExternCContext();
 }
 
+AST_MATCHER(clang::ParmVarDecl, isArgvOfMain) {
+  const clang::DeclContext *DC = Node.getDeclContext();
+  const auto *FD = llvm::dyn_cast<clang::FunctionDecl>(DC);
+  return FD ? FD->isMain() : false;
+}
+
 } // namespace
 
 namespace clang {
@@ -43,7 +49,8 @@ void AvoidCArraysCheck::registerMatchers
 
   Finder->addMatcher(
       typeLoc(hasValidBeginLoc(), hasType(arrayType()),
-              unless(anyOf(hasParent(varDecl(isExternC())),
+              unless(anyOf(hasParent(parmVarDecl(isArgvOfMain())),
+                           hasParent(varDecl(isExternC())),
                            hasParent(fieldDecl(
                                hasParent(recordDecl(isExternCContext())))),
                            hasAncestor(functionDecl(isExternC())))))

Modified: clang-tools-extra/trunk/docs/clang-tidy/checks/modernize-avoid-c-arrays.rst
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/docs/clang-tidy/checks/modernize-avoid-c-arrays.rst?rev=353327&r1=353326&r2=353327&view=diff
==============================================================================
--- clang-tools-extra/trunk/docs/clang-tidy/checks/modernize-avoid-c-arrays.rst (original)
+++ clang-tools-extra/trunk/docs/clang-tidy/checks/modernize-avoid-c-arrays.rst Wed Feb  6 11:17:30 2019
@@ -54,3 +54,7 @@ such headers between C code, and C++ cod
   }
 
   }
+
+Similarly, the ``main()`` function is ignored. Its second and third parameters
+can be either ``char* argv[]`` or ``char** argv``, but can not be
+``std::array<>``.

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-main.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-main.cpp?rev=353327&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-main.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-main.cpp Wed Feb  6 11:17:30 2019
@@ -0,0 +1,18 @@
+// RUN: %check_clang_tidy %s modernize-avoid-c-arrays %t
+
+int not_main(int argc, char *argv[]) {
+  // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: do not declare C-style arrays, use std::array<> instead
+  int f4[] = {1, 2};
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not declare C-style arrays, use std::array<> instead
+}
+
+int main(int argc, char *argv[]) {
+  int f5[] = {1, 2};
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not declare C-style arrays, use std::array<> instead
+
+  auto not_main = [](int argc, char *argv[]) {
+    // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: do not declare C-style arrays, use std::array<> instead
+    int f6[] = {1, 2};
+    // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not declare C-style arrays, use std::array<> instead
+  };
+}

Added: clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-three-arg-main.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-three-arg-main.cpp?rev=353327&view=auto
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-three-arg-main.cpp (added)
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-avoid-c-arrays-ignores-three-arg-main.cpp Wed Feb  6 11:17:30 2019
@@ -0,0 +1,20 @@
+// RUN: %check_clang_tidy %s modernize-avoid-c-arrays %t
+
+int not_main(int argc, char *argv[], char *argw[]) {
+  // CHECK-MESSAGES: :[[@LINE-1]]:24: warning: do not declare C-style arrays, use std::array<> instead
+  // CHECK-MESSAGES: :[[@LINE-2]]:38: warning: do not declare C-style arrays, use std::array<> instead
+  int f4[] = {1, 2};
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not declare C-style arrays, use std::array<> instead
+}
+
+int main(int argc, char *argv[], char *argw[]) {
+  int f5[] = {1, 2};
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: do not declare C-style arrays, use std::array<> instead
+
+  auto not_main = [](int argc, char *argv[], char *argw[]) {
+    // CHECK-MESSAGES: :[[@LINE-1]]:32: warning: do not declare C-style arrays, use std::array<> instead
+    // CHECK-MESSAGES: :[[@LINE-2]]:46: warning: do not declare C-style arrays, use std::array<> instead
+    int f6[] = {1, 2};
+    // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not declare C-style arrays, use std::array<> instead
+  };
+}