[flang-commits] [flang] [flang] Legacy ASSIGN statement target processing (PR #133737)

[via flang-commits]

https://github.com/vdonaldson created https://github.com/llvm/llvm-project/pull/133737

Like other target statements, the statement associated with the label in a legacy ASSIGN statement could be inside a construct. Constructs containing such a target must therefore be marked as unstructured, fairly similar to how targets are processed in `markBranchTarget`.

>From e5c41f70fc42715fdb720b91daa9ffd458a736a4 Mon Sep 17 00:00:00 2001
From: V Donaldson <vdonaldson at nvidia.com>
Date: Mon, 31 Mar 2025 07:59:04 -0700
Subject: [PATCH] [flang] Legacy ASSIGN statement target processing

Like other target statements, the statement associated with the label
in a legacy ASSIGN statement could be inside a construct. Constructs
containing such a target must therefore be marked as unstructured,
fairly similar to how targets are processed in `markBranchTarget`.
---
 flang/lib/Lower/PFTBuilder.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/flang/lib/Lower/PFTBuilder.cpp b/flang/lib/Lower/PFTBuilder.cpp
index 41bdff4dca471..2cc458cb6130d 100644
--- a/flang/lib/Lower/PFTBuilder.cpp
+++ b/flang/lib/Lower/PFTBuilder.cpp
@@ -878,8 +878,18 @@ class PFTBuilder {
             lower::pft::Evaluation *target{
                 labelEvaluationMap->find(label)->second};
             assert(target && "missing branch target evaluation");
-            if (!target->isA<parser::FormatStmt>())
+            if (!target->isA<parser::FormatStmt>()) {
               target->isNewBlock = true;
+              for (lower::pft::Evaluation *parent = target->parentConstruct;
+                   parent; parent = parent->parentConstruct) {
+                parent->isUnstructured = true;
+                // The exit of an enclosing DO or IF construct is a new block.
+                if (parent->constructExit &&
+                    (parent->isA<parser::DoConstruct>() ||
+                     parent->isA<parser::IfConstruct>()))
+                  parent->constructExit->isNewBlock = true;
+              }
+            }
             auto iter = assignSymbolLabelMap->find(*sym);
             if (iter == assignSymbolLabelMap->end()) {
               lower::pft::LabelSet labelSet{};