[flang-commits] [PATCH] D159040: [flang] Allow GOTO to containing END IF after ELSE

[Peter Klausler via Phabricator via flang-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG48a8262cb8dc: [flang] Allow GOTO to containing END IF after ELSE (authored by klausler).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D159040/new/

https://reviews.llvm.org/D159040

Files:
  flang/lib/Semantics/resolve-labels.cpp
  flang/test/Semantics/label18.f90


Index: flang/test/Semantics/label18.f90
===================================================================
--- /dev/null
+++ flang/test/Semantics/label18.f90
@@ -0,0 +1,18 @@
+! RUN: %python %S/test_errors.py %s %flang_fc1 -Werror
+program main
+  if (.true.) then
+    do j = 1, 2
+      goto 1 ! ok; used to cause looping in label resolution
+    end do
+  else
+    goto 1 ! ok
+1 end if
+  if (.true.) then
+    do j = 1, 2
+      !WARNING: Label '1' is in a construct that should not be used as a branch target here
+      goto 1
+    end do
+  end if
+  !WARNING: Label '1' is in a construct that should not be used as a branch target here
+  goto 1
+end
Index: flang/lib/Semantics/resolve-labels.cpp
===================================================================
--- flang/lib/Semantics/resolve-labels.cpp
+++ flang/lib/Semantics/resolve-labels.cpp
@@ -239,8 +239,9 @@
     auto targetFlags{ConstructBranchTargetFlags(statement)};
     if constexpr (common::HasMember<A, LabeledConstructStmts>) {
       AddTargetLabelDefinition(label.value(), targetFlags, ParentScope());
-    } else if constexpr (std::is_same_v<A, parser::EndSelectStmt>) {
-      // the label on an END SELECT is not in the last case
+    } else if constexpr (std::is_same_v<A, parser::EndIfStmt> ||
+        std::is_same_v<A, parser::EndSelectStmt>) {
+      // the label on an END IF/SELECT is not in the last part/case
       AddTargetLabelDefinition(label.value(), targetFlags, ParentScope(), true);
     } else if constexpr (common::HasMember<A, LabeledConstructEndStmts>) {
       constexpr bool isExecutableConstructEndStmt{true};
@@ -279,12 +280,17 @@
   bool Pre(const parser::IfConstruct &ifConstruct) {
     return PushConstructName(ifConstruct);
   }
+  void Post(const parser::IfThenStmt &) { PushScope(); }
   bool Pre(const parser::IfConstruct::ElseIfBlock &) {
     return SwitchToNewScope();
   }
   bool Pre(const parser::IfConstruct::ElseBlock &) {
     return SwitchToNewScope();
   }
+  bool Pre(const parser::EndIfStmt &) {
+    PopScope();
+    return true;
+  }
   bool Pre(const parser::CaseConstruct &caseConstruct) {
     return PushConstructName(caseConstruct);
   }
@@ -1008,15 +1014,18 @@
       }
       bool isFatal{false};
       ProxyForScope fromScope{scope};
-      for (ProxyForScope toScope{target.proxyForScope}; fromScope != toScope;
+      for (ProxyForScope toScope{target.proxyForScope}; HasScope(toScope);
            toScope = scopes[toScope].parent) {
+        while (scopes[fromScope].depth > scopes[toScope].depth) {
+          fromScope = scopes[fromScope].parent;
+        }
+        if (toScope == fromScope) {
+          break;
+        }
         if (scopes[toScope].isExteriorGotoFatal) {
           isFatal = true;
           break;
         }
-        if (scopes[toScope].depth == scopes[fromScope].depth) {
-          fromScope = scopes[fromScope].parent;
-        }
       }
       context.Say(position,
           isFatal


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