[PATCH] D81493: [flang] Fix bug resolving type in type definition

[Tim Keith via Phabricator via llvm-commits]

tskeith created this revision.
Herald added a reviewer: DavidTruby.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

When we encountered a type name in a derived type definition, we were
sometimes finding a component of that name rather than the type from
the enclosing scope. Fix this by introducing `NonDerivedTypeScope()` to
start the search in the right scope.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D81493

Files:
  flang/lib/Semantics/resolve-names.cpp
  flang/test/Semantics/resolve92.f90


Index: flang/test/Semantics/resolve92.f90
===================================================================
--- /dev/null
+++ flang/test/Semantics/resolve92.f90
@@ -0,0 +1,16 @@
+! RUN: %S/test_errors.sh %s %t %f18
+
+module m
+  implicit none
+  type t
+    integer :: n
+  end type
+  type t2
+    ! t and t2 must be resolved to types in m, not components in t2
+    type(t) :: t(10) = t(1)
+    type(t) :: x = t(1)
+    integer :: t2
+    type(t2), pointer :: p
+  end type
+end
+
Index: flang/lib/Semantics/resolve-names.cpp
===================================================================
--- flang/lib/Semantics/resolve-names.cpp
+++ flang/lib/Semantics/resolve-names.cpp
@@ -455,6 +455,8 @@
   // TODO: Will return the scope of a FORALL or implied DO loop; is this ok?
   // If not, should call FindProgramUnitContaining() instead.
   Scope &InclusiveScope();
+  // The enclosing scope, skipping derived types.
+  Scope &NonDerivedTypeScope();
 
   // Create a new scope and push it on the scope stack.
   void PushScope(Scope::Kind kind, Symbol *symbol);
@@ -1999,6 +2001,10 @@
   DIE("inclusive scope not found");
 }
 
+Scope &ScopeHandler::NonDerivedTypeScope() {
+  return currScope_->IsDerivedType() ? currScope_->parent() : *currScope_;
+}
+
 void ScopeHandler::PushScope(Scope::Kind kind, Symbol *symbol) {
   PushScope(currScope().MakeScope(kind, symbol));
 }
@@ -3294,9 +3300,7 @@
 
 bool DeclarationVisitor::Pre(const parser::AccessSpec &x) {
   Attr attr{AccessSpecToAttr(x)};
-  const Scope &scope{
-      currScope().IsDerivedType() ? currScope().parent() : currScope()};
-  if (!scope.IsModule()) { // C817
+  if (!NonDerivedTypeScope().IsModule()) { // C817
     Say(currStmtSource().value(),
         "%s attribute may only appear in the specification part of a module"_err_en_US,
         EnumToString(attr));
@@ -4725,7 +4729,7 @@
 
 std::optional<DerivedTypeSpec> DeclarationVisitor::ResolveDerivedType(
     const parser::Name &name) {
-  Symbol *symbol{FindSymbol(name)};
+  Symbol *symbol{FindSymbol(NonDerivedTypeScope(), name)};
   if (!symbol || symbol->has<UnknownDetails>()) {
     if (allowForwardReferenceToDerivedType()) {
       if (!symbol) {
@@ -5769,7 +5773,7 @@
 void ResolveNamesVisitor::HandleProcedureName(
     Symbol::Flag flag, const parser::Name &name) {
   CHECK(flag == Symbol::Flag::Function || flag == Symbol::Flag::Subroutine);
-  auto *symbol{FindSymbol(name)};
+  auto *symbol{FindSymbol(NonDerivedTypeScope(), name)};
   if (!symbol) {
     if (context().intrinsics().IsIntrinsic(name.source.ToString())) {
       symbol =


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D81493.269619.patch
Type: text/x-patch
Size: 2585 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200609/baf58bf5/attachment.bin>