[gcc r17-2837] cobol: Restore SECTION number warnings.

https://gcc.gnu.org/g:cec7574ff3f1559066b209c1973a383efc341fb0

commit r17-2837-gcec7574ff3f1559066b209c1973a383efc341fb0
Author: James K. Lowden <[email protected]>
Date:   Thu Jul 30 22:26:37 2026 +0000

    cobol: Restore SECTION number warnings.
    
    Lexer recognizes SECTION explicitly and handles it correctly.
    
    gcc/cobol/ChangeLog:
    
            * parse.y (dialect_ok): Enable messages without a quoted tagline.
            * scan.l: Add SECTION pattern so it is not handled by general NAME pattern.

Diff:
---
 gcc/cobol/parse.y | 46 +++++++++++++++++++++-------------------------
 gcc/cobol/scan.l  |  1 +
 2 files changed, 22 insertions(+), 25 deletions(-)

diff --git a/gcc/cobol/parse.y b/gcc/cobol/parse.y
index eef000a7ee60..ae0371ae886a 100644
--- a/gcc/cobol/parse.y
+++ b/gcc/cobol/parse.y
@@ -8032,31 +8032,27 @@ section_name:	NAME section_kw '.'
                 ;
 
 section_kw:     SECTION
-/* Dubner commented out this code on 2026-06-28 as part of getting the
-   compiler working on the IBM S390. It was failing in an off-by-one way;
-   the $1 parameter, on the S390, wasn't the section number, but rather the
-   section name.  */
-//                {
-//                  if( $1 && dialect_ok(@1, IbmSectionSegmentW, "SECTION segment") ) {
-//		    cbl_message(@1, IbmSectionSegmentW,
-//                                "SECTION segment %qs was ignored", $1);
-//		    if( *$1 == '-' ) {
-//                      cbl_message(@1, IbmSectionNegE,
-//                                  "SECTION segment %qs is negative", $1);
-//                    } else {
-//                      int sectno;
-//                      sscanf($1, "%d", &sectno);
-//                      if( ! (0 <= sectno && sectno <= 99) ) {
-//                        cbl_message(@1, IbmSectionRangeE,
-//                                     "SECTION segment %qs must be 0-99", $1);
-//		      } 
-//                    }
-//		  }
-//                }
-//        |       SECTION error
-//                {
-//                  error_msg(@1, "unknown section qualifier");
-//                }
+               {
+                 if( $1 && dialect_ok(@1, IbmSectionSegmentW, "SECTION segment") ) {
+		    cbl_message(@1, IbmSectionSegmentW,
+                               "SECTION segment %qs was ignored", $1);
+		    if( *$1 == '-' ) {
+                     cbl_message(@1, IbmSectionNegE,
+                                 "SECTION segment %qs is negative", $1);
+                   } else {
+                     int sectno;
+                     sscanf($1, "%d", &sectno);
+                     if( ! (0 <= sectno && sectno <= 99) ) {
+                       cbl_message(@1, IbmSectionRangeE,
+                                    "SECTION segment %qs must be 0-99", $1);
+		      } 
+                   }
+		  }
+               }
+       |       SECTION error
+               {
+                 error_msg(@1, "unknown section qualifier");
+               }
                 ;
 
 stop:           STOP RUN exit_with
diff --git a/gcc/cobol/scan.l b/gcc/cobol/scan.l
index 278cad8b1545..85603117e92d 100644
--- a/gcc/cobol/scan.l
+++ b/gcc/cobol/scan.l
@@ -1987,6 +1987,7 @@ USE({SPC}FOR)?		{ return USE; }
 
   FUNCTION 			{ yy_push_state(function); return FUNCTION; }
 
+  SECTION{OSPC}/{DOTSEP} { yylval.string = NULL; return SECTION; }
   SECTION{OSPC}[.]+{SPC}/USE[[:space:]]	{ yylval.string = NULL; return SECTION; }
 
   [.]+({SPC}(EJECT|SKIP[123]))*{SPC}EXIT{OSPC}/{DOTSEP} {