[ASTMatchers] Add cxxNoexceptExpr AST matcher

[njames93]

Summary

Adds a cxxNoexceptExpr matcher that matches the noexcept operator.

[merge_guards_bot]

Unit tests: pass. 62196 tests passed, 0 failed and 815 were skipped.

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[njames93]

• Fix typo in documentation

[merge_guards_bot]

Unit tests: pass. 62196 tests passed, 0 failed and 815 were skipped.

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[aaron.ballman]

LGTM aside from some minor nits.

clang/include/clang/ASTMatchers/ASTMatchers.h

1831

typo -- noexcept

1835

Can you also add this as an example:

void func() noexcept(noexcept(1 + 1));

to make it clear that this matches noexcept(1 + 1) but not noexcept(noexcept(...))?

[njames93]

• Tweak documentation

[merge_guards_bot]

Unit tests: pass. 62196 tests passed, 0 failed and 815 were skipped.

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

clang/docs/LibASTMatchersReference.html

 
 Given
   new X;
 cxxNewExpr()
   matches 'new X'.
 </pre></td></tr>
 
 
+<tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('cxxNoexceptExpr0')"><a name="cxxNoexceptExpr0Anchor">cxxNoexceptExpr</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXNoexceptExpr.html">CXXNoexceptExpr</a>&gt;...</td></tr>
+<tr><td colspan="4" class="doc" id="cxxNoexceptExpr0"><pre>Matches noexcept expressions.
+
+Given
+  bool a() noexcept;
+  bool b() noexcept(true);
+  bool c() noexcept(false);
+  bool d() noexcept(noexcept(a()));
+  bool e = noexcept(b()) || noexcept(c());
+cxxNoexceptExpr()
+  matches `noexcept(a())`, `noexcept(b())` and `noexcept(c())`.
+  doesn't match the noexcept specifier in the declarations a, b, c or d.
+</pre></td></tr>
+
+
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('cxxNullPtrLiteralExpr0')"><a name="cxxNullPtrLiteralExpr0Anchor">cxxNullPtrLiteralExpr</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXNullPtrLiteralExpr.html">CXXNullPtrLiteralExpr</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="cxxNullPtrLiteralExpr0"><pre>Matches nullptr literal.
 </pre></td></tr>
 
 
 <tr><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>&gt;</td><td class="name" onclick="toggle('cxxOperatorCallExpr0')"><a name="cxxOperatorCallExpr0Anchor">cxxOperatorCallExpr</a></td><td>Matcher&lt;<a href="https://clang.llvm.org/doxygen/classclang_1_1CXXOperatorCallExpr.html">CXXOperatorCallExpr</a>&gt;...</td></tr>
 <tr><td colspan="4" class="doc" id="cxxOperatorCallExpr0"><pre>Matches overloaded operator calls.
 

clang/include/clang/ASTMatchers/ASTMatchers.h

 /// \code
 ///   delete X;
 /// \endcode
 /// cxxDeleteExpr()
 ///   matches 'delete X'.
 extern const internal::VariadicDynCastAllOfMatcher<Stmt, CXXDeleteExpr>
     cxxDeleteExpr;
 
+/// Matches noexcept expressions.
+///
+/// Given
+/// \code
+///   bool a() noexcept;
+///   bool b() noexcept(true);
+///   bool c() noexcept(false);
+///   bool d() noexcept(noexcept(a()));
+///   bool e = noexcept(b()) || noexcept(c());
+/// \endcode
+/// cxxNoexceptExpr()
+///   matches `noexcept(a())`, `noexcept(b())` and `noexcept(c())`.
+///   doesn't match the noexcept specifier in the declarations a, b, c or d.
+extern const internal::VariadicDynCastAllOfMatcher<Stmt, CXXNoexceptExpr>
+    cxxNoexceptExpr;
+
 /// Matches array subscript expressions.
 ///
 /// Given
 /// \code
 ///   int i = a[1];
 /// \endcode
 /// arraySubscriptExpr()
 ///   matches "a[1]"

clang/lib/ASTMatchers/ASTMatchersInternal.cpp

const internal::VariadicDynCastAllOfMatcher<Stmt, CXXUnresolvedConstructExpr>
     cxxUnresolvedConstructExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXThisExpr> cxxThisExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXBindTemporaryExpr>
     cxxBindTemporaryExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, MaterializeTemporaryExpr>
     materializeTemporaryExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXNewExpr> cxxNewExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXDeleteExpr> cxxDeleteExpr;
+const internal::VariadicDynCastAllOfMatcher<Stmt, CXXNoexceptExpr>
+    cxxNoexceptExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, ArraySubscriptExpr>
     arraySubscriptExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXDefaultArgExpr>
     cxxDefaultArgExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, CXXOperatorCallExpr>
     cxxOperatorCallExpr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, Expr> expr;
 const internal::VariadicDynCastAllOfMatcher<Stmt, DeclRefExpr> declRefExpr;

clang/lib/ASTMatchers/Dynamic/Registry.cpp

RegistryMaps::RegistryMaps() {
   REGISTER_MATCHER(cxxDependentScopeMemberExpr);
   REGISTER_MATCHER(cxxDestructorDecl);
   REGISTER_MATCHER(cxxDynamicCastExpr);
   REGISTER_MATCHER(cxxForRangeStmt);
   REGISTER_MATCHER(cxxFunctionalCastExpr);
   REGISTER_MATCHER(cxxMemberCallExpr);
   REGISTER_MATCHER(cxxMethodDecl);
   REGISTER_MATCHER(cxxNewExpr);
+  REGISTER_MATCHER(cxxNoexceptExpr);
   REGISTER_MATCHER(cxxNullPtrLiteralExpr);
   REGISTER_MATCHER(cxxOperatorCallExpr);
   REGISTER_MATCHER(cxxRecordDecl);
   REGISTER_MATCHER(cxxReinterpretCastExpr);
   REGISTER_MATCHER(cxxStaticCastExpr);
   REGISTER_MATCHER(cxxStdInitializerListExpr);
   REGISTER_MATCHER(cxxTemporaryObjectExpr);
   REGISTER_MATCHER(cxxThisExpr);

clang/lib/Analysis/ExprMutationAnalyzer.cpp

 
 const ast_matchers::internal::VariadicDynCastAllOfMatcher<Stmt, CXXTypeidExpr>
     cxxTypeidExpr;
 
 AST_MATCHER(CXXTypeidExpr, isPotentiallyEvaluated) {
   return Node.isPotentiallyEvaluated();
 }
 
-const ast_matchers::internal::VariadicDynCastAllOfMatcher<Stmt, CXXNoexceptExpr>
-    cxxNoexceptExpr;
-
 const ast_matchers::internal::VariadicDynCastAllOfMatcher<Stmt,
                                                           GenericSelectionExpr>
     genericSelectionExpr;
 
 AST_MATCHER_P(GenericSelectionExpr, hasControllingExpr,
               ast_matchers::internal::Matcher<Expr>, InnerMatcher) {
   return InnerMatcher.matches(*Node.getControllingExpr(), Finder, Builder);
 }

clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp

TEST(Matcher, NewExpression) {
   EXPECT_TRUE(matches("class X {}; void x(int) { new X; }", New));
 }
 
 TEST(Matcher, DeleteExpression) {
   EXPECT_TRUE(matches("struct A {}; void f(A* a) { delete a; }",
                       cxxDeleteExpr()));
 }
 
+TEST(Matcher, NoexceptExpression) {
+  StatementMatcher NoExcept = cxxNoexceptExpr();
+  EXPECT_TRUE(matches("void foo(); bool bar = noexcept(foo());", NoExcept));
+  EXPECT_TRUE(
+      matches("void foo() noexcept; bool bar = noexcept(foo());", NoExcept));
+  EXPECT_TRUE(notMatches("void foo() noexcept;", NoExcept));
+  EXPECT_TRUE(notMatches("void foo() noexcept(1+1);", NoExcept));
+  EXPECT_TRUE(matches("void foo() noexcept(noexcept(1+1));", NoExcept));
+}
+
 TEST(Matcher, DefaultArgument) {
   StatementMatcher Arg = cxxDefaultArgExpr();
 
   EXPECT_TRUE(matches("void x(int, int = 0) { int y; x(y); }", Arg));
   EXPECT_TRUE(
     matches("class X { void x(int, int = 0) { int y; x(y); } };", Arg));
   EXPECT_TRUE(notMatches("void x(int, int = 0) { int y; x(y, 0); }", Arg));
 }