[PATCH] D72414: Implement new AST matchers `hasAnyCapture` and `capturesThis`.These matchers match on LambdaExpr:hasAnyCapture - matches if any child VarDecl matcher matches one of the captured vars.capturesThis - matches if `this` is captured by the LambdaExpr.

[Reid via Phabricator via cfe-commits]

rhiro created this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Add new AST matchers `hasAnyCapture` and `capturesThis` as LambdaExpr matchers.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D72414

Files:
  clang/include/clang/ASTMatchers/ASTMatchers.h
  clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp


Index: clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
+++ clang/unittests/ASTMatchers/ASTMatchersTraversalTest.cpp
@@ -454,6 +454,26 @@
       objcMessageExpr(hasReceiver(declRefExpr(to(varDecl(hasName("x"))))))));
 }
 
+TEST(Matcher, HasAnyCapture) {
+  auto HasCaptureX = lambdaExpr(hasAnyCapture(varDecl(hasName("x"))));
+  EXPECT_TRUE(matches("void f() { int x = 3; [x](){}; }", HasCaptureX));
+  EXPECT_TRUE(matches("void f() { int x = 3; [&x](){}; }", HasCaptureX));
+  EXPECT_TRUE(notMatches("void f() { [](){}; }", HasCaptureX));
+  EXPECT_TRUE(notMatches("void f() { int z = 3; [&z](){}; }", HasCaptureX));
+  EXPECT_TRUE(
+      notMatches("struct a { void f() { [this](){}; }; };", HasCaptureX));
+}
+
+TEST(Matcher, CapturesThis) {
+  auto HasCaptureThis = lambdaExpr(capturesThis());
+  EXPECT_TRUE(
+      matches("struct a { void f() { [this](){}; }; };", HasCaptureThis));
+  EXPECT_TRUE(notMatches("void f() { [](){}; }", HasCaptureThis));
+  EXPECT_TRUE(notMatches("void f() { int x = 3; [x](){}; }", HasCaptureThis));
+  EXPECT_TRUE(notMatches("void f() { int x = 3; [&x](){}; }", HasCaptureThis));
+  EXPECT_TRUE(notMatches("void f() { int z = 3; [&z](){}; }", HasCaptureThis));
+}
+
 TEST(Matcher, isClassMessage) {
   EXPECT_TRUE(matchesObjC(
       "@interface NSString +(NSString *) stringWithFormat; @end "
Index: clang/include/clang/ASTMatchers/ASTMatchers.h
===================================================================
--- clang/include/clang/ASTMatchers/ASTMatchers.h
+++ clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -55,6 +55,7 @@
 #include "clang/AST/Expr.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
+#include "clang/AST/LambdaCapture.h"
 #include "clang/AST/NestedNameSpecifier.h"
 #include "clang/AST/OpenMPClause.h"
 #include "clang/AST/OperationKinds.h"
@@ -4014,6 +4015,53 @@
   return false;
 }
 
+/// Matches any capture of a lambda expression.
+///
+/// Given
+/// \code
+///   void foo() {
+///     int x;
+///     auto f = [x](){};
+///   }
+/// \endcode
+/// lambdaExpr(hasAnyCapture(anything()))
+///   matches [x](){};
+AST_MATCHER_P(LambdaExpr, hasAnyCapture, internal::Matcher<VarDecl>,
+              InnerMatcher) {
+  for (const LambdaCapture &Capture : Node.captures()) {
+    if (Capture.capturesThis()) {
+      continue;
+    }
+    BoundNodesTreeBuilder Result(*Builder);
+    if (InnerMatcher.matches(*Capture.getCapturedVar(), Finder, &Result)) {
+      *Builder = std::move(Result);
+      return true;
+    }
+  }
+  return false;
+}
+
+/// Matches any capture of 'this' in a lambda expression.
+///
+/// Given
+/// \code
+///   struct foo {
+///     void bar() {
+///       auto f = [this](){};
+///     }
+///   }
+/// \endcode
+/// lambdaExpr(capturesThis())
+///   matches [this](){};
+AST_MATCHER(LambdaExpr, capturesThis) {
+  for (const LambdaCapture &Capture : Node.captures()) {
+    if (Capture.capturesThis()) {
+      return true;
+    }
+  }
+  return false;
+}
+
 /// Matches a constructor call expression which uses list initialization.
 AST_MATCHER(CXXConstructExpr, isListInitialization) {
   return Node.isListInitialization();


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D72414.236901.patch
Type: text/x-patch
Size: 3277 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200108/57ed6532/attachment-0001.bin>