Merge pull request chapel-lang#17804 from dlongnecke-cray/next-add-while

next: Parse While and DoWhile loops This is for `compiler/next`. Add nodes for `While` and `DoWhile` loops, and wire up the parser actions for them. Reviewed by @lydia-duncan and @mppf. Thanks! TESTING: - [x] All `compiler/next` tests pass Signed-off-by: David Longnecker <[email protected]>
dlongnecke-cray · May 26, 2021 · 7e877bf · 7e877bf
2 parents 34cded4 + 99372f0
commit 7e877bf
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diff --git a/compiler/next/include/chpl/uast/Builder.h b/compiler/next/include/chpl/uast/Builder.h
@@ -122,13 +122,26 @@ class Builder final {
   // Builder methods are actually type methods on the individual AST
   // elements. This prevents the Builder API from growing unreasonably large.
 
+  /// \cond DO_NOT_DOCUMENT
+
   // Use this in the parser to get a mutable view of a node's children so
   // that the node can be modified in place. Later we can also add a method
   // such as 'swapChildren' if we need it.
-  /// \cond DO_NOT_DOCUMENT
   ASTList& mutableRefToChildren(ASTNode* ast) {
     return ast->children_;
   }
+
+  // Use this to take the children of an AST node. The AST node is marked
+  // as owned because it is consumed.
+  ASTList takeChildren(owned<ASTNode> ast) {
+    auto ret = std::move(ast->children_);
+    assert(ast->children_.size() == 0);
+    return ret;
+  }
+
+  // Use this to flatten top level blocks within an ASTList.
+  ASTList flattenTopLevelBlocks(ASTList lst);
+
   /// \endcond
 };
 

diff --git a/compiler/next/include/chpl/uast/DoWhile.h b/compiler/next/include/chpl/uast/DoWhile.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright 2021 Hewlett Packard Enterprise Development LP
+ * Other additional copyright holders may be indicated within.
+ *
+ * The entirety of this work is licensed under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CHPL_UAST_DOWHILE_H
+#define CHPL_UAST_DOWHILE_H
+
+#include "chpl/queries/Location.h"
+#include "chpl/uast/Loop.h"
+
+namespace chpl {
+namespace uast {
+
+
+/**
+  This class represents a do-while loop. For example:
+
+  \rst
+  .. code-block:: chapel
+
+      // Example 1:
+      var i = 0;
+      do {
+        writeln(i);
+        i += 1;
+      } while i < 5;
+
+  \endrst
+
+ */
+class DoWhile final : public Loop {
+ private:
+  DoWhile(ASTList children, int loopBodyChildNum, int numLoopBodyStmts,
+          int conditionChildNum,
+          bool isBodyBlock)
+    : Loop(asttags::DoWhile, std::move(children),
+           loopBodyChildNum,
+           numLoopBodyStmts,
+           /*usesDo*/ true),
+      conditionChildNum_(conditionChildNum),
+      isBodyBlock_(isBodyBlock) {
+    assert(isExpressionASTList(children_));
+    assert(condition());
+  }
+
+  bool contentsMatchInner(const ASTNode* other) const override;
+
+  void markUniqueStringsInner(Context* context) const override {
+    loopMarkUniqueStringsInner(context);
+  }
+
+  int conditionChildNum_;
+  bool isBodyBlock_;
+
+ public:
+  ~DoWhile() override = default;
+
+  /**
+    Create and return a do-while loop. 
+  */
+  static owned<DoWhile> build(Builder* builder, Location loc,
+                              ASTList stmts,
+                              owned<Expression> condition,
+                              bool isBodyBlock);
+
+  /**
+    Return the condition of this do-while loop.
+  */
+  const Expression* condition() const {
+    auto ret = child(conditionChildNum_);
+    assert(ret->isExpression());
+    return (const Expression*)ret;
+  }
+
+  /**
+    Returns true if this do-while loop body is a block.
+  */
+  bool isBodyBlock() const {
+    return isBodyBlock_;
+  }
+
+};
+
+
+} // end namespace uast
+} // end namespace chpl
+
+#endif
diff --git a/compiler/next/include/chpl/uast/While.h b/compiler/next/include/chpl/uast/While.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2021 Hewlett Packard Enterprise Development LP
+ * Other additional copyright holders may be indicated within.
+ *
+ * The entirety of this work is licensed under the Apache License,
+ * Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CHPL_UAST_WHILE_H
+#define CHPL_UAST_WHILE_H
+
+#include "chpl/queries/Location.h"
+#include "chpl/uast/Loop.h"
+
+namespace chpl {
+namespace uast {
+
+
+/**
+  This class represents a while loop. For example:
+
+  \rst
+  .. code-block:: chapel
+
+      // Example 1:
+      var i = 0;
+      while i < 5 {
+        writeln(i);
+        i += 1;
+      }
+
+  \endrst
+
+ */
+class While final : public Loop {
+ private:
+  While(ASTList children,  int8_t conditionChildNum,
+        int loopBodyChildNum,
+        int numLoopBodyStmts,
+        bool usesDo)
+    : Loop(asttags::While, std::move(children), loopBodyChildNum,
+           numLoopBodyStmts,
+           usesDo),
+      conditionChildNum_(conditionChildNum) {
+    assert(isExpressionASTList(children_));
+    assert(condition());
+  }
+
+  bool contentsMatchInner(const ASTNode* other) const override;
+
+  void markUniqueStringsInner(Context* context) const override {
+    loopMarkUniqueStringsInner(context);
+  }
+
+  int8_t conditionChildNum_;
+
+ public:
+  ~While() override = default;
+
+  /**
+    Create and return a while loop. 
+  */
+  static owned<While> build(Builder* builder, Location loc,
+                            owned<Expression> condition,
+                            ASTList stmts,
+                            bool usesDo);
+
+  /**
+    Return the condition of this while loop.
+  */
+  const Expression* condition() const {
+    auto ret = child(conditionChildNum_);
+    assert(ret->isExpression());
+    return (const Expression*)ret;
+  }
+
+};
+
+
+} // end namespace uast
+} // end namespace chpl
+
+#endif
diff --git a/compiler/next/lib/frontend/Parser/ParserContextImpl.h b/compiler/next/lib/frontend/Parser/ParserContextImpl.h
@@ -267,6 +267,8 @@ ParserContext::gatherCommentsFromList(ParserExprList* lst,
 
 void ParserContext::appendComments(CommentsAndStmt*cs,
                                    std::vector<ParserComment>* comments) {
+  if (comments == nullptr) return;
+
   if (cs->comments == nullptr) {
     cs->comments = comments;
     return;

diff --git a/compiler/next/lib/frontend/Parser/chapel.ypp b/compiler/next/lib/frontend/Parser/chapel.ypp
@@ -1300,17 +1300,37 @@ extern_block_stmt:
 
 loop_stmt:
   TDO stmt TWHILE expr TSEMI
-    {
-      $$ = TODOSTMT(@$);
-    }
+  {
+    const bool isBodyBlock = $2.stmt->isBlock();
+    auto exprLst = context->makeList($2);
+    auto comments = context->gatherCommentsFromList(exprLst, @1);
+
+    // Append any comment appearing before 'while' into the exprs of $2.
+    exprLst = context->appendList(exprLst, context->gatherComments(@3));
+
+    auto astLst = context->consumeList(exprLst);
+    auto statements = BUILDER->flattenTopLevelBlocks(std::move(astLst));
+    auto node = DoWhile::build(BUILDER, LOC(@1), std::move(statements),
+                               toOwned($4),
+                               isBodyBlock);
+    $$ = { .comments=comments, .stmt=node.release() };
+  }
 | TWHILE expr do_stmt
-    {
-      $$ = TODOSTMT(@$);
-    }
+  {
+    auto comments = context->gatherCommentsFromList($3.exprList, @1);
+    auto node = While::build(BUILDER, LOC(@1), toOwned($2),
+                             context->consumeList($3.exprList),
+                             $3.usesDo);
+    $$ = { .comments=comments, .stmt=node.release() };
+  }
 | TWHILE ifvar do_stmt
-    {
-      $$ = TODOSTMT(@$);
-    }
+  {
+    auto comments = context->gatherCommentsFromList($3.exprList, @1);
+    auto node = While::build(BUILDER, LOC(@1), toOwned($2),
+                             context->consumeList($3.exprList),
+                             $3.usesDo);
+    $$ = { .comments=comments, .stmt=node.release() };
+  }
 | TCOFORALL expr TIN expr opt_task_intent_ls do_stmt
     {
       $$ = TODOSTMT(@$);

diff --git a/compiler/next/lib/frontend/Parser/parser-dependencies.h b/compiler/next/lib/frontend/Parser/parser-dependencies.h
@@ -30,6 +30,7 @@
 #include "chpl/uast/Call.h"
 #include "chpl/uast/Comment.h"
 #include "chpl/uast/Dot.h"
+#include "chpl/uast/DoWhile.h"
 #include "chpl/uast/Enum.h"
 #include "chpl/uast/EnumElement.h"
 #include "chpl/uast/ErroneousExpression.h"
@@ -49,6 +50,7 @@
 #include "chpl/uast/Serial.h"
 #include "chpl/uast/TaskVar.h"
 #include "chpl/uast/Variable.h"
+#include "chpl/uast/While.h"
 #include "chpl/uast/Zip.h"
 
 #include <cstdint>

diff --git a/compiler/next/lib/uast/Builder.cpp b/compiler/next/lib/uast/Builder.cpp
@@ -270,6 +270,24 @@ void Builder::Result::updateFilePaths(Context* context, const Result& keep) {
   }
 }
 
+ASTList Builder::flattenTopLevelBlocks(ASTList lst) {
+  ASTList ret;
+
+  for (auto& ast : lst) {
+    if (ast->isBlock()) {
+      for (auto& child : takeChildren(std::move(ast))) {
+        ret.push_back(std::move(child));
+      }
+    } else {
+      ret.push_back(std::move(ast));
+    }
+  }
+
+  lst.clear();
+
+  return ret;
+}
+
 
 } // namespace uast
 } // namespace chpl
diff --git a/compiler/next/lib/uast/CMakeLists.txt b/compiler/next/lib/uast/CMakeLists.txt
@@ -28,6 +28,7 @@ target_sources(libchplcomp-obj
                ControlFlow.cpp
                Decl.cpp
                Dot.cpp
+               DoWhile.cpp
                Enum.cpp
                EnumElement.cpp
                ErroneousExpression.cpp
@@ -53,6 +54,7 @@ target_sources(libchplcomp-obj
                Variable.cpp
                VarLikeDecl.cpp
                Visitor.cpp
+               While.cpp
                WithClause.cpp
                Zip.cpp