[flang] Debugging, and resolve another TODO in unparse.cc.

Original-commit: flang-compiler/f18@edeb283cd5
Reviewed-on: https://github.com/flang-compiler/f18/pull/37
Tree-same-pre-rewrite: false

flang/lib/parser/grammar.h

@@ -1651,16 +1651,8 @@ constexpr auto percentOrDot = "%"_tok ||
     // legacy VAX extension for RECORD field access
     extension("."_tok / lookAhead(structureComponentName));
 
-// TODO - why is this not a TYPE_PARSER?
-template<>
-std::optional<DataReference> Parser<DataReference>::Parse(ParseState *state) {
-  static constexpr auto partRefs =
-      nonemptySeparated(Parser<PartRef>{}, percentOrDot);
-  if (auto parts = partRefs.Parse(state)) {
-    return {DataReference(std::move(*parts))};
-  }
-  return {};
-}
+TYPE_PARSER(construct<DataReference>{}(
+    nonemptySeparated(Parser<PartRef>{}, percentOrDot)))
 
 // R912 part-ref -> part-name [( section-subscript-list )] [image-selector]
 TYPE_PARSER(construct<PartRef>{}(name,
@@ -3386,7 +3378,7 @@ TYPE_PARSER(construct<ProcedureStmt>{}("MODULE PROCEDURE"_sptok >>
 //         READ ( FORMATTED ) | READ ( UNFORMATTED ) |
 //         WRITE ( FORMATTED ) | WRITE ( UNFORMATTED )
 TYPE_PARSER(construct<GenericSpec>{}(
-                "OPERATOR" >> parenthesized(definedOperator)) ||
+                "OPERATOR" >> parenthesized(Parser<DefinedOperator>{})) ||
     construct<GenericSpec>{}(
         "ASSIGNMENT ( = )" >> construct<GenericSpec::Assignment>{}) ||
     construct<GenericSpec>{}(
@@ -3663,8 +3655,7 @@ constexpr struct StructureComponents {
   }
 } structureComponents;
 
-TYPE_PARSER(
-    construct<StructureField>{}(statement(structureComponents)) ||
+TYPE_PARSER(construct<StructureField>{}(statement(structureComponents)) ||
     construct<StructureField>{}(indirect(Parser<Union>{})) ||
     construct<StructureField>{}(indirect(Parser<StructureDef>{})))
 

flang/lib/parser/unparse.cc

@@ -10,6 +10,7 @@
 #include <algorithm>
 #include <cinttypes>
 #include <cstddef>
+#include <set>
 
 namespace Fortran {
 namespace parser {
@@ -804,7 +805,14 @@ public:
     return false;
   }
   bool Pre(const StructureComponent &x) {  // R913
-    Walk(x.base), Put(percentOrDot_), Walk(x.component);
+    Walk(x.base);
+    if (structureComponents_.find(x.component.source) !=
+        structureComponents_.end()) {
+      Put('.');
+    } else {
+      Put('%');
+    }
+    Walk(x.component);
     return false;
   }
   bool Pre(const ArrayElement &x) {  // R917
@@ -1007,8 +1015,7 @@ public:
     return false;
   }
   bool Pre(const ProcComponentRef &x) {  // R1039
-    Walk(std::get<Scalar<Variable>>(x.t)), Put(percentOrDot_);
-    Walk(std::get<Name>(x.t));
+    Walk(std::get<Scalar<Variable>>(x.t)), Put('%'), Walk(std::get<Name>(x.t));
     return false;
   }
   bool Pre(const WhereStmt &x) {  // R1041, R1045, R1046
@@ -1710,7 +1717,8 @@ public:
     return true;
   }
   bool Pre(const EndProgramStmt &x) {  // R1403
-    Outdent(), Word("END PROGRAM"), Walk(" ", x.v);
+    Word("END PROGRAM"), Walk(" ", x.v);
+    EndSubprogram();
     return false;
   }
   bool Pre(const ModuleStmt &) {  // R1405
@@ -1889,7 +1897,8 @@ public:
     return false;
   }
   bool Pre(const EndFunctionStmt &x) {  // R1533
-    Outdent(), Word("END FUNCTION"), Walk(" ", x.v);
+    Word("END FUNCTION"), Walk(" ", x.v);
+    EndSubprogram();
     return false;
   }
   bool Pre(const SubroutineStmt &x) {  // R1535
@@ -1907,7 +1916,8 @@ public:
     return false;
   }
   bool Pre(const EndSubroutineStmt &x) {  // R1537
-    Outdent(), Word("END SUBROUTINE"), Walk(" ", x.v);
+    Word("END SUBROUTINE"), Walk(" ", x.v);
+    EndSubprogram();
     return false;
   }
   bool Pre(const MpSubprogramStmt &) {  // R1539
@@ -1915,7 +1925,8 @@ public:
     return true;
   }
   bool Pre(const EndMpSubprogramStmt &x) {  // R1540
-    Outdent(), Word("END PROCEDURE"), Walk(" ", x.v);
+    Word("END PROCEDURE"), Walk(" ", x.v);
+    EndSubprogram();
     return false;
   }
   bool Pre(const EntryStmt &x) {  // R1541
@@ -1971,6 +1982,14 @@ public:
     Walk("(", std::get<std::optional<ArraySpec>>(x.t), ")"), Put(')');
     return false;
   }
+  void Post(const StructureField &x) {
+    if (const auto *def = std::get_if<Statement<DataComponentDefStmt>>(&x.u)) {
+      for (const auto &decl :
+          std::get<std::list<ComponentDecl>>(def->statement.t)) {
+        structureComponents_.insert(std::get<Name>(decl.t).source);
+      }
+    }
+  }
   bool Pre(const StructureStmt &x) {
     Word("STRUCTURE ");
     if (std::get<bool>(x.t)) {  // slashes around name
@@ -1981,7 +2000,6 @@ public:
       Walk(std::get<Name>(x.t));
     }
     Indent();
-    percentOrDot_ = '.';  // TODO: this is so lame
     return false;
   }
   void Post(const Union::UnionStmt &) { Word("UNION"), Indent(); }
@@ -2106,12 +2124,17 @@ private:
     WalkTupleElements(tuple, separator);
   }
 
+  void EndSubprogram() {
+    Outdent();
+    structureComponents_.clear();
+  }
+
   std::ostream &out_;
   int indent_{0};
   const int indentationAmount_{1};
   int column_{1};
   const int maxColumns_{80};
-  char percentOrDot_{'%'};
+  std::set<CharBlock> structureComponents_;
   Encoding encoding_{Encoding::UTF8};
   bool capitalizeKeywords_{true};
 };

flang/lib/parser/user-state.h

@@ -16,6 +16,12 @@ namespace parser {
 
 class UserState {
 public:
+  void NewSubprogram() {
+    doLabels_.clear();
+    nonlabelDoConstructNestingDepth_ = 0;
+    structureComponents_.clear();
+  }
+
   using Label = std::uint64_t;
   bool IsDoLabel(Label label) const {
     return doLabels_.find(label) != doLabels_.end();
@@ -24,11 +30,6 @@ public:
     return nonlabelDoConstructNestingDepth_ > 0;
   }
   void NewDoLabel(Label label) { doLabels_.insert(label); }
-  void NewSubprogram() {
-    doLabels_.clear();
-    nonlabelDoConstructNestingDepth_ = 0;
-    structureComponents_.clear();
-  }
   void EnterNonlabelDoConstruct() { ++nonlabelDoConstructNestingDepth_; }
   void LeaveDoConstruct() {
     if (nonlabelDoConstructNestingDepth_ > 0) {
@@ -46,7 +47,6 @@ public:
 private:
   std::unordered_set<Label> doLabels_;
   int nonlabelDoConstructNestingDepth_{0};
-
   std::set<CharBlock> structureComponents_;
 };
 }  // namespace parser