[PATCH 1/3] cobol: Use gcc_fallthrough() instead of __attribute__((fallthrough))

[Pietro Monteiro]

GCC versions lower than 7 don't support __attribute__((fallthrough)).
Use gcc_fallthrough() from system.h.

gcc/cobol/ChangeLog:

        * cdf-copy.cc (esc): Use gcc_fallthrough() instead of
        __attribute__((fallthrough)).
        * lexio.cc (cdftext::free_form_reference_format): Likewise.
        * parse.y: Likewise.
        * scan_ante.h (typed_name): Likewise.
        * util.cc (symbol_field_type_update): Likewise.

Signed-off-by: Pietro Monteiro <pie...@sociotechnical.xyz>
---
 gcc/cobol/cdf-copy.cc |  2 +-
 gcc/cobol/lexio.cc    |  2 +-
 gcc/cobol/parse.y     | 10 +++++-----
 gcc/cobol/scan_ante.h |  6 +++---
 gcc/cobol/util.cc     |  4 ++--
 5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/gcc/cobol/cdf-copy.cc b/gcc/cobol/cdf-copy.cc
index 304360d5257..73b9a8d39e4 100644
--- a/gcc/cobol/cdf-copy.cc
+++ b/gcc/cobol/cdf-copy.cc
@@ -157,7 +157,7 @@ esc( size_t len, const char input[] ) {
         *p++ = *s;
         break;
       }
-      __attribute__((fallthrough));
+      gcc_fallthrough();
     case 0x20: case '\n':
       verify_bounds( (p + sizeof(spacex)) - buffer, sizeof(buffer), buffer );
       p = stpcpy( p, spacex );
diff --git a/gcc/cobol/lexio.cc b/gcc/cobol/lexio.cc
index 8a914ae86a9..12d938d3500 100644
--- a/gcc/cobol/lexio.cc
+++ b/gcc/cobol/lexio.cc
@@ -1830,7 +1830,7 @@ cdftext::free_form_reference_format( int input ) {
         if( lexio_dialect_mf() ) {
           break;
         }
-        __attribute__ ((fallthrough));
+        gcc_fallthrough();
       default: // flag other characters in indicator area
         if( ! ISSPACE(indcol[0]) ) {
           yyerrorvl( mfile.lineno(), cobol_filename(),
diff --git a/gcc/cobol/parse.y b/gcc/cobol/parse.y
index dc2ac9765cd..526376ac216 100644
--- a/gcc/cobol/parse.y
+++ b/gcc/cobol/parse.y
@@ -1997,7 +1997,7 @@ select:         SELECT optional NAME[name] 
select_clauses[clauses] '.'
                     break;
                   case file_disorganized_e:
                     file->org = file_sequential_e;
-                    __attribute__((fallthrough));
+                    gcc_fallthrough();
                   default:
                     if( ($clauses.clauses & record_key_clause_e) != 0 ) {
                       assert(file->keys);
@@ -4411,7 +4411,7 @@ data_clause:    any_length        { $$ = any_length_e; }
                   switch( field->level ) {
                   case 1:
                    if( dialect_ok(@$, MfLevel_1_Occurs, "LEVEL 01 for OCCURS") 
) break;
-                   __attribute__((fallthrough));
+                   gcc_fallthrough();
                   case 77:
                   case 88:
                    error_msg(@$, "%s %s: invalid LEVEL for OCCURS",
@@ -9099,7 +9099,7 @@ set:            SET set_tgts[tgts] TO set_operand[src]
                       YYERROR;
                       break;
                     }
-                    __attribute__((fallthrough));
+                    gcc_fallthrough();
                   case FldPointer:
                     if( !valid_set_targets(*$tgts, true) ) {
                       YYERROR;
@@ -14261,7 +14261,7 @@ eval_subject_t::compare( int token ) {
     break;
   case TRUE_kw:
     tf = very_true_register();
-    __attribute__((fallthrough));
+    gcc_fallthrough();
   case FALSE_kw:
     assert( is_conditional(pcol->field) );
     parser_logop(this->result, pcol->field, xnor_op, field_at(tf));
@@ -14356,7 +14356,7 @@ field_binary_usage( YYLTYPE loc, cbl_field_t *field,
     // COMPUTATIONAL and COMP-5 rely on PICTURE.
   case FldNumericBinary:
     field->attr |= big_endian_e;
-    __attribute__((fallthrough));
+    gcc_fallthrough();
   case FldNumericBin5:
     // If no capacity yet, then no picture, infer $comp.capacity.
     // If field has capacity, ensure USAGE is compatible.
diff --git a/gcc/cobol/scan_ante.h b/gcc/cobol/scan_ante.h
index 20fdf77470c..c6f8a1a1bb8 100644
--- a/gcc/cobol/scan_ante.h
+++ b/gcc/cobol/scan_ante.h
@@ -1169,7 +1169,7 @@ typed_name( const char name[] ) {
     break;
   case FUNCTION_UDF_0:
     yylval.number = symbol_function_token(name);
-    __attribute__((fallthrough));
+    gcc_fallthrough();
   default:
     return token;
   }
@@ -1199,7 +1199,7 @@ typed_name( const char name[] ) {
         }
       }
     }
-    __attribute__((fallthrough));
+    gcc_fallthrough();
   case FldLiteralN:
     {
       const auto f = cbl_field_of(e);
@@ -1215,7 +1215,7 @@ typed_name( const char name[] ) {
         return LITERAL;
       }
     }
-    __attribute__((fallthrough));
+    gcc_fallthrough();
   case FldInvalid:
   case FldGroup:
   case FldForward:
diff --git a/gcc/cobol/util.cc b/gcc/cobol/util.cc
index 554c4fc5702..648a2cf77b9 100644
--- a/gcc/cobol/util.cc
+++ b/gcc/cobol/util.cc
@@ -942,7 +942,7 @@ symbol_field_type_update( cbl_field_t *field,
       if( is_numeric(candidate) ) {
         return false;
       }
-      __attribute__((fallthrough));
+      gcc_fallthrough();
     case FldInvalid:
     case FldGroup:
     case FldNumericDisplay:
@@ -960,7 +960,7 @@ symbol_field_type_update( cbl_field_t *field,
       // MF and GNU allow pic x usage comp-5.
       // Dialect enforcement in that case is in field_binary_usage.
       if( candidate != FldNumericBin5 ) return false;
-      __attribute__((fallthrough));
+      gcc_fallthrough();
     case FldFloat:
     case FldNumericBin5:
     case FldNumericBinary:
-- 
2.43.0