Index: clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp =================================================================== --- clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp +++ clang-tools-extra/clang-tidy/readability/ElseAfterReturnCheck.cpp @@ -26,12 +26,14 @@ compoundStmt(forEach( ifStmt(unless(isConstexpr()), // FIXME: Explore alternatives for the - // `if (T x = ...) {... return; } else { }` - // pattern: + // `if (T x = ...) {... return; } else { }` and + // 'if (T x = ...; cond) {... return; } else { use }' + // patterns: // * warn, but don't fix; // * fix by pulling out the variable declaration out of // the condition. unless(hasConditionVariableStatement(anything())), + unless(hasInitStatement(declStmt())), hasThen(stmt(anyOf(InterruptsControlFlow, compoundStmt(has(InterruptsControlFlow))))), hasElse(stmt().bind("else"))) Index: clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp =================================================================== --- clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp +++ clang-tools-extra/test/clang-tidy/checkers/readability-else-after-return.cpp @@ -1,4 +1,4 @@ -// RUN: %check_clang_tidy %s readability-else-after-return %t -- -- -fexceptions +// RUN: %check_clang_tidy %s readability-else-after-return %t -- -- -fexceptions -std=c++17 namespace std { struct string { @@ -117,3 +117,24 @@ return x; } } + +int *varInitAndCondition() { + if (int *X = g(); X != nullptr) { + return X; + } else { + h(&X); + return X; + } +} + +int *initAndCondition() { + int *X; + if (X = g(); X != nullptr) { + return X; + } else { // comment-11 + // CHECK-MESSAGES: :[[@LINE-1]]:5: warning: do not use 'else' after 'return' + // CHECK-FIXES: {{^}} } // comment-11 + h(&X); + return X; + } +} Index: clang/docs/LibASTMatchersReference.html =================================================================== --- clang/docs/LibASTMatchersReference.html +++ clang/docs/LibASTMatchersReference.html @@ -3009,6 +3009,23 @@ +Matcher<Expr>nullPointerConstant +
Matches expressions that resolve to a null pointer constant, such as
+GNU's __null, C++11's nullptr, or C's NULL macro.
+
+Given:
+  void *v1 = NULL;
+  void *v2 = nullptr;
+  void *v3 = __null; // GNU extension
+  char *cp = (char *)0;
+  int *ip = 0;
+  int i = 0;
+expr(nullPointerConstant())
+  matches the initializer for v1, v2, v3, cp, and ip. Does not match the
+  initializer for i.
+
+ + Matcher<FieldDecl>hasBitWidthunsigned Width 
Matches non-static data members that are bit-fields of the specified
 bit width.
@@ -3761,6 +3778,18 @@
 Example matches y (matcher = parmVarDecl(hasDefaultArgument()))
 void x(int val) {}
 void y(int val = 0) {}
+
+Deprecated. Use hasInitializer() instead to be able to
+match on the contents of the default argument.  For example:
+
+void x(int val = 7) {}
+void y(int val = 42) {}
+parmVarDecl(hasInitializer(integerLiteral(equals(42))))
+  matches the parameter of y
+
+A matcher such as
+  parmVarDecl(hasInitializer(anything()))
+is equivalent to parmVarDecl(hasDefaultArgument()).
@@ -4479,23 +4508,6 @@ -Matcher<internal::Matcher<Expr>>nullPointerConstant -
Matches expressions that resolve to a null pointer constant, such as
-GNU's __null, C++11's nullptr, or C's NULL macro.
-
-Given:
-  void *v1 = NULL;
-  void *v2 = nullptr;
-  void *v3 = __null; // GNU extension
-  char *cp = (char *)0;
-  int *ip = 0;
-  int i = 0;
-expr(nullPointerConstant())
-  matches the initializer for v1, v2, v3, cp, and ip. Does not match the
-  initializer for i.
-
- - Matcher<internal::Matcher<NamedDecl>>hasAnyNameStringRef, ..., StringRef 
Matches NamedDecl nodes that have any of the specified names.
 
@@ -5082,6 +5094,29 @@
+Matcher<CXXForRangeStmt>hasInitStatementMatcher<Stmt> InnerMatcher +
Matches selection statements with initializer.
+
+Given:
+ void foo() { 
+   if (int i = foobar(); i > 0) {}
+   switch (int i = foobar(); i) {}
+   for (auto& a = get_range(); auto& x : a) {} 
+ }
+ void bar() { 
+   if (foobar() > 0) {}
+   switch (foobar()) {}
+   for (auto& x : get_range()) {} 
+ }
+ifStmt(hasInitStatement(anything()))
+  matches the if statement in foo but not in bar.
+switchStmt(hasInitStatement(anything()))
+  matches the switch statement in foo but not in bar.
+cxxForRangeStmt(hasInitStatement(anything()))
+  matches the range for statement in foo but not in bar.
+
+ + Matcher<CXXForRangeStmt>hasLoopVariableMatcher<VarDecl> InnerMatcher 
Matches the initialization statement of a for loop.
 
@@ -6206,6 +6241,29 @@
+Matcher<IfStmt>hasInitStatementMatcher<Stmt> InnerMatcher +
Matches selection statements with initializer.
+
+Given:
+ void foo() { 
+   if (int i = foobar(); i > 0) {}
+   switch (int i = foobar(); i) {}
+   for (auto& a = get_range(); auto& x : a) {} 
+ }
+ void bar() { 
+   if (foobar() > 0) {}
+   switch (foobar()) {}
+   for (auto& x : get_range()) {} 
+ }
+ifStmt(hasInitStatement(anything()))
+  matches the if statement in foo but not in bar.
+switchStmt(hasInitStatement(anything()))
+  matches the switch statement in foo but not in bar.
+cxxForRangeStmt(hasInitStatement(anything()))
+  matches the range for statement in foo but not in bar.
+
+ + Matcher<IfStmt>hasThenMatcher<Stmt> InnerMatcher 
Matches the then-statement of an if statement.
 
@@ -6943,6 +7001,29 @@
+Matcher<SwitchStmt>hasInitStatementMatcher<Stmt> InnerMatcher +
Matches selection statements with initializer.
+
+Given:
+ void foo() { 
+   if (int i = foobar(); i > 0) {}
+   switch (int i = foobar(); i) {}
+   for (auto& a = get_range(); auto& x : a) {} 
+ }
+ void bar() { 
+   if (foobar() > 0) {}
+   switch (foobar()) {}
+   for (auto& x : get_range()) {} 
+ }
+ifStmt(hasInitStatement(anything()))
+  matches the if statement in foo but not in bar.
+switchStmt(hasInitStatement(anything()))
+  matches the switch statement in foo but not in bar.
+cxxForRangeStmt(hasInitStatement(anything()))
+  matches the range for statement in foo but not in bar.
+
+ + Matcher<TagType>hasDeclarationconst Matcher<Decl> InnerMatcher 
Matches a node if the declaration associated with that node
 matches the given matcher.
@@ -7170,6 +7251,22 @@
+Matcher<T>traverseast_type_traits::TraversalKind TK, const Matcher<T> InnerMatcher +
Causes all nested matchers to be matched with the specified traversal kind.
+
+Given
+  void foo()
+  {
+      int i = 3.0;
+  }
+The matcher
+  traverse(ast_type_traits::TK_IgnoreImplicitCastsAndParentheses,
+    varDecl(hasInitializer(floatLiteral().bind("init")))
+  )
+matches the variable declaration with "init" bound to the "3.0".
+
+ + Matcher<TypedefNameDecl>hasTypeMatcher<QualType> InnerMatcher 
Matches if the expression's or declaration's type matches a type
 matcher.
Index: clang/include/clang/ASTMatchers/ASTMatchers.h
===================================================================
--- clang/include/clang/ASTMatchers/ASTMatchers.h
+++ clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -4297,6 +4297,35 @@
   return Node.isConstexpr();
 }
 
+/// Matches selection statements with initializer.
+///
+/// Given:
+/// \code
+///  void foo() {
+///    if (int i = foobar(); i > 0) {}
+///    switch (int i = foobar(); i) {}
+///    for (auto& a = get_range(); auto& x : a) {}
+///  }
+///  void bar() {
+///    if (foobar() > 0) {}
+///    switch (foobar()) {}
+///    for (auto& x : get_range()) {}
+///  }
+/// \endcode
+/// ifStmt(hasInitStatement(anything()))
+///   matches the if statement in foo but not in bar.
+/// switchStmt(hasInitStatement(anything()))
+///   matches the switch statement in foo but not in bar.
+/// cxxForRangeStmt(hasInitStatement(anything()))
+///   matches the range for statement in foo but not in bar.
+AST_POLYMORPHIC_MATCHER_P(hasInitStatement,
+                          AST_POLYMORPHIC_SUPPORTED_TYPES(IfStmt, SwitchStmt,
+                                                          CXXForRangeStmt),
+                          internal::Matcher, InnerMatcher) {
+  const Stmt *const Init = Node.getInit();
+  return (Init != nullptr && InnerMatcher.matches(*Init, Finder, Builder));
+}
+
 /// Matches the condition expression of an if statement, for loop,
 /// switch statement or conditional operator.
 ///
Index: clang/lib/ASTMatchers/Dynamic/Registry.cpp
===================================================================
--- clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -279,6 +279,7 @@
   REGISTER_MATCHER(hasIndex);
   REGISTER_MATCHER(hasInit);
   REGISTER_MATCHER(hasInitializer);
+  REGISTER_MATCHER(hasInitStatement);
   REGISTER_MATCHER(hasKeywordSelector);
   REGISTER_MATCHER(hasLHS);
   REGISTER_MATCHER(hasLocalQualifiers);
Index: clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
+++ clang/unittests/ASTMatchers/ASTMatchersNarrowingTest.cpp
@@ -1071,6 +1071,35 @@
                          LanguageMode::Cxx17OrLater));
 }
 
+TEST(hasInitStatement, MatchesSelectionInitializers) {
+  EXPECT_TRUE(matches("void baz() { if (int i = 1; i > 0) {} }",
+                      ifStmt(hasInitStatement(anything())),
+                      LanguageMode::Cxx17OrLater));
+  EXPECT_TRUE(notMatches("void baz() { if (int i = 1) {} }",
+                         ifStmt(hasInitStatement(anything()))));
+  EXPECT_TRUE(notMatches("void baz() { if (1 > 0) {} }",
+                         ifStmt(hasInitStatement(anything()))));
+  EXPECT_TRUE(matches(
+      "void baz(int i) { switch (int j = i; j) { default: break; } }",
+      switchStmt(hasInitStatement(anything())), LanguageMode::Cxx17OrLater));
+  EXPECT_TRUE(notMatches("void baz(int i) { switch (i) { default: break; } }",
+                         switchStmt(hasInitStatement(anything()))));
+}
+
+TEST(hasInitStatement, MatchesRangeForInitializers) {
+  EXPECT_TRUE(matches("void baz() {"
+                      "int items[] = {};"
+                      "for (auto &arr = items; auto &item : arr) {}"
+                      "}",
+                      cxxForRangeStmt(hasInitStatement(anything())),
+                      LanguageMode::Cxx2aOrLater));
+  EXPECT_TRUE(notMatches("void baz() {"
+                         "int items[] = {};"
+                         "for (auto &item : items) {}"
+                         "}",
+                         cxxForRangeStmt(hasInitStatement(anything()))));
+}
+
 TEST(TemplateArgumentCountIs, Matches) {
   EXPECT_TRUE(
     matches("template struct C {}; C c;",