[PATCH] D16526: Add hasRetValue narrowing matcher for returnStmt

[Richard via cfe-commits]

LegalizeAdulthood created this revision.
LegalizeAdulthood added a reviewer: klimek.
LegalizeAdulthood added a subscriber: cfe-commits.
Herald added a subscriber: klimek.

Add `hasRetValue` narrowing matcher for `returnStmt` so that you can match on the expression returned by a return stmt (or lack thereof).

Currently you can only match the type of a return value on a `functionDecl` with `returns`.

An example:

clanger> cat /tmp/a.cpp
void g() {
  return;
}

void f() {
  return (void) g();
}

int h() {
  return 1;
}

int j() {
  return h();
}

bool k() {
  return true;
}
~/dev/build
clanger> bin/clang-query /tmp/a.cpp -- -std=c++11
clang-query> match functionDecl(returns(voidType()))

Match #1:

/tmp/a.cpp:1:1: note: "root" binds here
void g() {
^~~~~~~~~~

Match #2:

/tmp/a.cpp:5:1: note: "root" binds here
void f() {
^~~~~~~~~~
2 matches.
clang-query> match returnStmt(unless(hasRetValue(expr())))

Match #1:

/tmp/a.cpp:2:3: note: "root" binds here
  return;
  ^~~~~~
1 match.
clang-query> ^D


http://reviews.llvm.org/D16526

Files:
  docs/LibASTMatchersReference.html
  include/clang/ASTMatchers/ASTMatchers.h
  lib/ASTMatchers/Dynamic/Registry.cpp
  unittests/ASTMatchers/ASTMatchersTest.cpp

Index: unittests/ASTMatchers/ASTMatchersTest.cpp
===================================================================
--- unittests/ASTMatchers/ASTMatchersTest.cpp
+++ unittests/ASTMatchers/ASTMatchersTest.cpp
@@ -1807,6 +1807,11 @@
                           recordDecl(hasName("Y")))))));
 }
 
+TEST(HasRetValue, MatchesReturnExpressions) {
+  
+  EXPECT_TRUE(matches("bool f() { return true; }", returnStmt(hasRetValue(expr()))));
+}
+
 TEST(IsExternC, MatchesExternCFunctionDeclarations) {
   EXPECT_TRUE(matches("extern \"C\" void f() {}", functionDecl(isExternC())));
   EXPECT_TRUE(matches("extern \"C\" { void f() {} }",
Index: lib/ASTMatchers/Dynamic/Registry.cpp
===================================================================
--- lib/ASTMatchers/Dynamic/Registry.cpp
+++ lib/ASTMatchers/Dynamic/Registry.cpp
@@ -235,6 +235,7 @@
   REGISTER_MATCHER(hasQualifier);
   REGISTER_MATCHER(hasRangeInit);
   REGISTER_MATCHER(hasReceiverType);
+  REGISTER_MATCHER(hasRetValue);
   REGISTER_MATCHER(hasRHS);
   REGISTER_MATCHER(hasSelector);
   REGISTER_MATCHER(hasSingleDecl);
Index: include/clang/ASTMatchers/ASTMatchers.h
===================================================================
--- include/clang/ASTMatchers/ASTMatchers.h
+++ include/clang/ASTMatchers/ASTMatchers.h
@@ -2977,6 +2977,14 @@
   return InnerMatcher.matches(Node.getReturnType(), Finder, Builder);
 }
 
+/// \brief Matches the return expression of a return statement.
+///
+AST_MATCHER_P(ReturnStmt, hasRetValue,
+              internal::Matcher<Expr>, InnerMatcher) {
+  const Expr *const RetValue = Node.getRetValue();
+  return RetValue != nullptr && InnerMatcher.matches(*RetValue, Finder, Builder);
+}
+
 /// \brief Matches extern "C" function declarations.
 ///
 /// Given:
Index: docs/LibASTMatchersReference.html
===================================================================
--- docs/LibASTMatchersReference.html
+++ docs/LibASTMatchersReference.html
@@ -4607,6 +4607,12 @@
 </pre></td></tr>
 
 
+<tr><td>Matcher<<a href="http://clang.llvm.org/doxygen/classclang_1_1ReturnStmt.html">ReturnStmt</a>></td><td class="name" onclick="toggle('hasRetValue0')"><a name="hasRetValue0Anchor">hasRetValue</a></td><td>Matcher<<a href="http://clang.llvm.org/doxygen/classclang_1_1Expr.html">Expr</a>> InnerMatcher</td></tr>
+<tr><td colspan="4" class="doc" id="hasRetValue0"><pre>Matches the return expression of a return statement.
+
+</pre></td></tr>
+
+
 <tr><td>Matcher<<a href="http://clang.llvm.org/doxygen/classclang_1_1Stmt.html">Stmt</a>></td><td class="name" onclick="toggle('alignOfExpr0')"><a name="alignOfExpr0Anchor">alignOfExpr</a></td><td>Matcher<<a href="http://clang.llvm.org/doxygen/classclang_1_1UnaryExprOrTypeTraitExpr.html">UnaryExprOrTypeTraitExpr</a>>  InnerMatcher</td></tr>
 <tr><td colspan="4" class="doc" id="alignOfExpr0"><pre>Same as unaryExprOrTypeTraitExpr, but only matching
 alignof.


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