[clang-tools-extra] 782392d - [clang-tidy] modernize-use-using work with multi-argument templates

Mitchell Balan via cfe-commits cfe-commits at lists.llvm.org
Fri Nov 15 13:10:41 PST 2019


Author: Mitchell Balan
Date: 2019-11-15T16:09:10-05:00
New Revision: 782392db8122cafb5e0e4ad5fe0c24c46f11b2b7

URL: https://github.com/llvm/llvm-project/commit/782392db8122cafb5e0e4ad5fe0c24c46f11b2b7
DIFF: https://github.com/llvm/llvm-project/commit/782392db8122cafb5e0e4ad5fe0c24c46f11b2b7.diff

LOG: [clang-tidy] modernize-use-using work with multi-argument templates

Summary:
If clang-tidy's modernize-use-using feature finds any commas that are not within parentheses, it won't create a fix. That means it won't change lines like:
  typedef std::pair<int, int> Point;
to
  using Point = std::pair<int, int>;
or even:
  typedef std::map<std::string, Foo> MyMap;
  typedef std::vector<int,MyCustomAllocator<int>> MyVector;

This patch allows the fix to apply to lines with commas if they are within parentheses or angle brackets that were not themselves within parentheses.

Reviewers: alexfh, hokein, aaron.ballman

Patch by: poelmanc

Subscribers: jonathanmeier, cfe-commits

Tags: #clang, #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D67460

Added: 
    

Modified: 
    clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
    clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
index bd234623d9ec..c9ca8a6114a5 100644
--- a/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp
@@ -39,25 +39,46 @@ static bool CheckRemoval(SourceManager &SM, SourceLocation StartLoc,
                   File.begin(), TokenBegin, File.end());
 
   Token Tok;
-  int ParenLevel = 0;
+  int NestingLevel = 0; // Parens, braces, and square brackets
+  int AngleBracketLevel = 0;
   bool FoundTypedef = false;
 
   while (!DeclLexer.LexFromRawLexer(Tok) && !Tok.is(tok::semi)) {
     switch (Tok.getKind()) {
     case tok::l_brace:
-    case tok::r_brace:
-      // This might be the `typedef struct {...} T;` case.
-      return false;
+      if (NestingLevel == 0 && AngleBracketLevel == 0) {
+        // At top level, this might be the `typedef struct {...} T;` case.
+        // Inside parens, square brackets, or angle brackets it's not.
+        return false;
+      }
+      ++NestingLevel;
+      break;
     case tok::l_paren:
-      ParenLevel++;
+    case tok::l_square:
+      ++NestingLevel;
       break;
+    case tok::r_brace:
     case tok::r_paren:
-      ParenLevel--;
+    case tok::r_square:
+      --NestingLevel;
+      break;
+    case tok::less:
+      // If not nested in paren/brace/square bracket, treat as opening angle bracket.
+      if (NestingLevel == 0)
+        ++AngleBracketLevel;
+      break;
+    case tok::greater:
+      // Per C++ 17 Draft N4659, Section 17.2/3
+      //   https://timsong-cpp.github.io/cppwp/n4659/temp.names#3:
+      // "When parsing a template-argument-list, the first non-nested > is
+      // taken as the ending delimiter rather than a greater-than operator."
+      // If not nested in paren/brace/square bracket, treat as closing angle bracket.
+      if (NestingLevel == 0)
+        --AngleBracketLevel;
       break;
     case tok::comma:
-      if (ParenLevel == 0) {
-        // If there is comma and we are not between open parenthesis then it is
-        // two or more declarations in this chain.
+      if (NestingLevel == 0 && AngleBracketLevel == 0) {
+        // If there is a non-nested comma we have two or more declarations in this chain.
         return false;
       }
       break;
@@ -88,8 +109,7 @@ void UseUsingCheck::check(const MatchFinder::MatchResult &Result) {
   if (StartLoc.isMacroID() && IgnoreMacros)
     return;
 
-  auto Diag =
-      diag(StartLoc, "use 'using' instead of 'typedef'");
+  auto Diag = diag(StartLoc, "use 'using' instead of 'typedef'");
 
   // do not fix if there is macro or array
   if (MatchedDecl->getUnderlyingType()->isArrayType() || StartLoc.isMacroID())

diff  --git a/clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp
index efa4030d001e..73fd2701bbdf 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp
@@ -183,3 +183,67 @@ class E : public C<E> {
   void f() override { super::f(); }
 };
 }
+
+template <typename T1, typename T2>
+class TwoArgTemplate {
+  typedef TwoArgTemplate<T1, T2> self;
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: use 'using' instead of 'typedef'
+  // CHECK-FIXES: using self = TwoArgTemplate<T1, T2>;
+};
+
+template <bool B, typename T>
+struct S {};
+
+typedef S<(0 > 0), int> S_t, *S_p;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: typedef S<(0 > 0), int> S_t, *S_p;
+
+typedef S<(0 < 0), int> S2_t, *S2_p;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: typedef S<(0 < 0), int> S2_t, *S2_p;
+
+typedef S<(0 > 0 && (3 > 1) && (1 < 1)), int> S3_t;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using S3_t = S<(0 > 0 && (3 > 1) && (1 < 1)), int>;
+
+template <bool B>
+struct Q {};
+
+constexpr bool b[1] = {true};
+
+typedef Q<b[0 < 0]> Q_t, *Q_p;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: typedef Q<b[0 < 0]> Q_t, *Q_p;
+
+typedef Q<b[0 < 0]> Q2_t;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using Q2_t = Q<b[0 < 0]>;
+
+struct T {
+  constexpr T(bool) {}
+
+  static constexpr bool b = true;
+};
+
+typedef Q<T{0 < 0}.b> Q3_t, *Q3_p;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: typedef Q<T{0 < 0}.b> Q3_t, *Q3_p;
+
+typedef Q<T{0 < 0}.b> Q3_t;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using Q3_t = Q<T{0 < 0}.b>;
+
+typedef TwoArgTemplate<TwoArgTemplate<int, Q<T{0 < 0}.b> >, S<(0 < 0), Q<b[0 < 0]> > > Nested_t;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using Nested_t = TwoArgTemplate<TwoArgTemplate<int, Q<T{0 < 0}.b> >, S<(0 < 0), Q<b[0 < 0]> > >;
+
+template <typename... Args>
+class Variadic {};
+
+typedef Variadic<Variadic<int, bool, Q<T{0 < 0}.b> >, S<(0 < 0), Variadic<Q<b[0 < 0]> > > > Variadic_t;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: using Variadic_t = Variadic<Variadic<int, bool, Q<T{0 < 0}.b> >, S<(0 < 0), Variadic<Q<b[0 < 0]> > > >
+
+typedef Variadic<Variadic<int, bool, Q<T{0 < 0}.b> >, S<(0 < 0), Variadic<Q<b[0 < 0]> > > > Variadic_t, *Variadic_p;
+// CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef'
+// CHECK-FIXES: typedef Variadic<Variadic<int, bool, Q<T{0 < 0}.b> >, S<(0 < 0), Variadic<Q<b[0 < 0]> > > > Variadic_t, *Variadic_p;


        


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