[clang-tools-extra] f325b5b - [clang-tidy] Support std::string_view in readability-redundant-string-cstr

[Tamas Berghammer via cfe-commits]

Author: Tamas Berghammer
Date: 2023-01-02T06:24:00-05:00
New Revision: f325b5b8cb1d6c16dd04c88380caea7b0a7750eb

URL: https://github.com/llvm/llvm-project/commit/f325b5b8cb1d6c16dd04c88380caea7b0a7750eb
DIFF: https://github.com/llvm/llvm-project/commit/f325b5b8cb1d6c16dd04c88380caea7b0a7750eb.diff

LOG: [clang-tidy] Support std::string_view in readability-redundant-string-cstr

Previously we were matching constructor calls for std::string and
llvm::StringRef and this change extends this set with including
std::string_view as well.

Reviewed By: njames93, carlosgalvezp

Differential Revision: https://reviews.llvm.org/D140018

Added: 
    

Modified: 
    clang-tools-extra/clang-tidy/readability/RedundantStringCStrCheck.cpp
    clang-tools-extra/docs/ReleaseNotes.rst
    clang-tools-extra/test/clang-tidy/checkers/readability/redundant-string-cstr.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clang-tidy/readability/RedundantStringCStrCheck.cpp b/clang-tools-extra/clang-tidy/readability/RedundantStringCStrCheck.cpp
index 79211731ff7be..9ecd6d612e0c8 100644
--- a/clang-tools-extra/clang-tidy/readability/RedundantStringCStrCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/RedundantStringCStrCheck.cpp
@@ -86,6 +86,11 @@ void RedundantStringCStrCheck::registerMatchers(
           // be present explicitly.
           hasArgument(1, cxxDefaultArgExpr()))));
 
+  // Match string constructor.
+  const auto StringViewConstructorExpr = cxxConstructExpr(
+      argumentCountIs(1),
+      hasDeclaration(cxxMethodDecl(hasName("basic_string_view"))));
+
   // Match a call to the string 'c_str()' method.
   const auto StringCStrCallExpr =
       cxxMemberCallExpr(on(StringExpr.bind("arg")),
@@ -101,7 +106,8 @@ void RedundantStringCStrCheck::registerMatchers(
       traverse(
           TK_AsIs,
           cxxConstructExpr(
-              StringConstructorExpr, hasArgument(0, StringCStrCallExpr),
+              anyOf(StringConstructorExpr, StringViewConstructorExpr),
+              hasArgument(0, StringCStrCallExpr),
               unless(anyOf(HasRValueTempParent, hasParent(cxxBindTemporaryExpr(
                                                     HasRValueTempParent)))))),
       this);

diff  --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 2135dd1e01be0..580776b76fd14 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -204,6 +204,10 @@ Changes in existing checks
   The check now skips concept definitions since redundant expressions still make sense
   inside them.
 
+- Support removing ``c_str`` calls from ``std::string_view`` constructor calls in
+  :doc: `readability-redundant-string-cstr <clang-tidy/checks/readability/redundant-string-cstr>`
+  check.
+
 Removed checks
 ^^^^^^^^^^^^^^
 

diff  --git a/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-string-cstr.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-string-cstr.cpp
index e1df8cccc10b3..ed50ad16f2423 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-string-cstr.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/redundant-string-cstr.cpp
@@ -48,6 +48,15 @@ typedef basic_string<char, std::char_traits<char>, std::allocator<char>> string;
 typedef basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t>> wstring;
 typedef basic_string<char16, std::char_traits<char16>, std::allocator<char16>> u16string;
 typedef basic_string<char32, std::char_traits<char32>, std::allocator<char32>> u32string;
+
+template <typename C, typename T>
+struct basic_string_view {
+  basic_string_view(const C* s);
+};
+typedef basic_string_view<char, std::char_traits<char>> string_view;
+typedef basic_string_view<wchar_t, std::char_traits<wchar_t>> wstring_view;
+typedef basic_string_view<char16, std::char_traits<char16>> u16string_view;
+typedef basic_string_view<char32, std::char_traits<char32>> u32string_view;
 }
 
 std::string operator+(const std::string&, const std::string&);
@@ -169,6 +178,15 @@ void f6(const std::string &s) {
   tmp.insert(1, s);
   tmp.insert(1, s.c_str(), 2);
 }
+void f7(std::string_view sv) {
+  std::string s;
+  f7(s.c_str());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}f7(s);{{$}}
+  f7(s.data());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'data' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}f7(s);{{$}}
+}
 
 // Tests for std::wstring.
 
@@ -177,6 +195,15 @@ void g1(const std::wstring &s) {
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
   // CHECK-FIXES: {{^  }}g1(s);{{$}}
 }
+void g2(std::wstring_view sv) {
+  std::wstring s;
+  g2(s.c_str());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}g2(s);{{$}}
+  g2(s.data());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'data' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}g2(s);{{$}}
+}
 
 // Tests for std::u16string.
 
@@ -185,6 +212,15 @@ void h1(const std::u16string &s) {
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
   // CHECK-FIXES: {{^  }}h1(s);{{$}}
 }
+void h2(std::u16string_view sv) {
+  std::u16string s;
+  h2(s.c_str());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}h2(s);{{$}}
+  h2(s.data());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'data' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}h2(s);{{$}}
+}
 
 // Tests for std::u32string.
 
@@ -193,6 +229,15 @@ void k1(const std::u32string &s) {
   // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
   // CHECK-FIXES: {{^  }}k1(s);{{$}}
 }
+void k2(std::u32string_view sv) {
+  std::u32string s;
+  k2(s.c_str());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'c_str' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}k2(s);{{$}}
+  k2(s.data());
+  // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: redundant call to 'data' [readability-redundant-string-cstr]
+  // CHECK-FIXES: {{^  }}k2(s);{{$}}
+}
 
 // Tests on similar classes that aren't good candidates for this checker.