[flang-commits] [PATCH] D143817: [flang] Emit portability warning for extension

[Peter Klausler via Phabricator via flang-commits]

klausler created this revision.
klausler added a reviewer: vdonaldson.
klausler added a project: Flang.
Herald added subscribers: sunshaoce, jdoerfert.
Herald added a reviewer: sscalpone.
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klausler requested review of this revision.

f18 accepts statement labels in fixed form source even if they follow
a semicolon -- i.e., they're not in the fixed form's label field.
Emit a warning for such usage.


https://reviews.llvm.org/D143817

Files:
  flang/docs/Extensions.md
  flang/lib/Parser/prescan.cpp
  flang/test/Parser/bad-label.f


Index: flang/test/Parser/bad-label.f
===================================================================
--- /dev/null
+++ flang/test/Parser/bad-label.f
@@ -0,0 +1,4 @@
+! RUN: %flang_fc1 -fsyntax-only -pedantic %s 2>&1 | FileCheck %s
+!CHECK: portability: Label should be in the label field
+      goto 1;  1 continue
+      end
Index: flang/lib/Parser/prescan.cpp
===================================================================
--- flang/lib/Parser/prescan.cpp
+++ flang/lib/Parser/prescan.cpp
@@ -629,6 +629,12 @@
       EmitCharAndAdvance(tokens, nch);
     } else if (ch == '/') {
       slashInCurrentStatement_ = true;
+    } else if (ch == ';' && InFixedFormSource()) {
+      SkipSpaces();
+      if (IsDecimalDigit(*at_)) {
+        Say(GetProvenanceRange(at_, at_ + 1),
+            "Label should be in the label field"_port_en_US);
+      }
     }
   }
   tokens.CloseToken();
Index: flang/docs/Extensions.md
===================================================================
--- flang/docs/Extensions.md
+++ flang/docs/Extensions.md
@@ -256,6 +256,7 @@
   to apply only to a scalar data-ref, but most compilers don't
   enforce it and the constraint is not necessary for a correct
   implementation.
+* A label may follow a semicolon in fixed form source.
 
 ### Extensions supported when enabled by options
 


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