Bug 1551842 - Add new clang-tidy checkers from clang 8.0.0. r=sylvestre,froydnj

Differential Revision: https://phabricator.services.mozilla.com/D31229

--HG--
extra : moz-landing-system : lando

tools/clang-tidy/config.yaml

@@ -62,6 +62,8 @@ clang_checkers:
     reliability: high
   - name: bugprone-swapped-arguments
     reliability: high
+  - name: bugprone-too-small-loop-variable
+    reliability: high
   - name: bugprone-unused-raii
     reliability: high
   - name: bugprone-use-after-move
@@ -120,6 +122,8 @@ clang_checkers:
     reliability: high
   - name: clang-analyzer-unix.cstring.NullArg
     reliability: high
+  - name: cppcoreguidelines-narrowing-conversions
+    reliability: high
   - name: misc-non-copyable-objects
     reliability: high
   - name: misc-redundant-expression
@@ -133,6 +137,8 @@ clang_checkers:
       - win32
       - win64
     reliability: medium
+  - name: modernize-deprecated-ios-base-aliases
+    reliability: high
   - name: modernize-loop-convert
     reliability: high
   - name: modernize-raw-string-literal
@@ -191,6 +197,8 @@ clang_checkers:
     reliability: high
   - name: readability-braces-around-statements
     reliability: high
+  - name: readability-const-return-type
+    reliability: high
   # Note: this can be loosened up by using the ShortStatementLines option
   - name: readability-container-size-empty
     reliability: high
@@ -211,6 +219,12 @@ clang_checkers:
         value: 1
   - name: readability-inconsistent-declaration-parameter-name
     reliability: high
+  - name: readability-isolate-declaration
+    reliability: high
+  - name: readability-magic-numbers
+    # Bug 1553495 - we must see first its impact on our code.
+    publish: !!bool no
+    reliability: high
   - name: readability-misleading-indentation
     reliability: high
   - name: readability-non-const-parameter

tools/clang-tidy/test/bugprone-too-small-loop-variable.cpp

@@ -0,0 +1,4 @@
+int main() {
+  long size = 294967296l;
+  for (short i = 0; i < size; ++i) {}
+}

tools/clang-tidy/test/bugprone-too-small-loop-variable.json

@@ -0,0 +1 @@
+[["warning", "loop variable has narrower type 'short' than iteration's upper bound 'long'", "bugprone-too-small-loop-variable"], {"reliability": "high"}]

tools/clang-tidy/test/cppcoreguidelines-narrowing-conversions.cpp

@@ -0,0 +1,4 @@
+class Foo {
+  int f;
+  void a_f(double val) { f = val;}
+};

tools/clang-tidy/test/cppcoreguidelines-narrowing-conversions.json

@@ -0,0 +1 @@
+[["warning", "narrowing conversion from 'double' to 'int'", "cppcoreguidelines-narrowing-conversions"], {"reliability": "high"}]

tools/clang-tidy/test/modernize-deprecated-ios-base-aliases.cpp

@@ -0,0 +1,18 @@
+namespace std {
+class ios_base {
+public:
+  typedef int io_state;
+  typedef int open_mode;
+  typedef int seek_dir;
+
+  typedef int streampos;
+  typedef int streamoff;
+};
+
+template <class CharT>
+class basic_ios : public ios_base {
+};
+} // namespace std
+
+// Test function return values (declaration)
+std::ios_base::io_state f_5();

tools/clang-tidy/test/modernize-deprecated-ios-base-aliases.json

@@ -0,0 +1 @@
+[["warning", "'std::ios_base::io_state' is deprecated; use 'std::ios_base::iostate' instead", "modernize-deprecated-ios-base-aliases"], {"reliability": "high"}]

tools/clang-tidy/test/readability-const-return-type.cpp

@@ -0,0 +1,5 @@
+const int p1() {
+// CHECK-MESSAGES: [[@LINE-1]]:1: warning: return type 'const int' is 'const'-qualified at the top level, which may reduce code readability without improving const correctness
+// CHECK-FIXES: int p1() {
+  return 1;
+}

tools/clang-tidy/test/readability-const-return-type.json

@@ -0,0 +1 @@
+[["warning", "return type 'const int' is 'const'-qualified at the top level, which may reduce code readability without improving const correctness", "readability-const-return-type"], {"reliability": "high"}]

tools/clang-tidy/test/readability-isolate-declaration.cpp

@@ -0,0 +1,7 @@
+void f() {
+  int * pointer = nullptr, value = 42, * const const_ptr = &value;
+  // This declaration will be diagnosed and transformed into:
+  // int * pointer = nullptr;
+  // int value = 42;
+  // int * const const_ptr = &value;
+}

tools/clang-tidy/test/readability-isolate-declaration.json

@@ -0,0 +1 @@
+[["warning", "multiple declarations in a single statement reduces readability", "readability-isolate-declaration"], {"reliability": "high"}]

tools/clang-tidy/test/readability-magic-numbers.cpp

@@ -0,0 +1,4 @@
+void func() {
+  int radius = 2;
+  double circleArea = 3.1415926535 * radius * radius;
+}

tools/clang-tidy/test/readability-magic-numbers.json

@@ -0,0 +1 @@
+[["warning", "3.1415926535 is a magic number; consider replacing it with a named constant", "readability-magic-numbers"], {"reliability": "high"}]