[flang-commits] [flang] [flang] Record the position of a labeled program-unit END statement (PR #217842)

[Eugene Epshteyn via flang-commits]

================
@@ -857,19 +857,25 @@ class ParseTreeAnalyzer {
   }
 
   // 6.2.5., paragraph 2
+  //
+  // `position` is the source position of the labeled statement itself.  It is
+  // passed in rather than read from currentPosition_ because the END statement
+  // of a program unit is visited in advance, before the statement visitor has
+  // moved currentPosition_ onto it.
   void AddTargetLabelDefinition(parser::Label label,
       LabeledStmtClassificationSet labeledStmtClassificationSet,
-      ProxyForScope scope, bool isExecutableConstructEndStmt) {
+      ProxyForScope scope, bool isExecutableConstructEndStmt,
+      parser::CharBlock position) {
     CheckLabelInRange(label);
----------------
eugeneepshteyn wrote:

(Definitely as a separate PR. I can do it, if you like.)

Optional, in-theme completion: `CheckLabelInRange` still reports at `currentPosition_`, so an out-of-range label on a program-unit END stays unlocated even with this PR:

```fortran
subroutine s()
  print *, "body"
100000 end subroutine
```

```console
error: Label '100000' is out of range
```

(no source location, before and after). Since this function now has the position in hand, passing it down to `CheckLabelInRange` (and `currentPosition_` from the four `AddLabelReference*` helpers, which are visited normally) completes the plumbing. Fine as an immediate follow-up if you prefer to keep this PR minimal.


https://github.com/llvm/llvm-project/pull/217842