Parse Verilog begin_keywords and end_keywords

nickg · Dec 18, 2024 · 017f950 · 017f950
1 parent 12f8f72
commit 017f950
Show file tree

Hide file tree

Showing 5 changed files with 40 additions and 2 deletions.
diff --git a/src/lexer.l b/src/lexer.l
@@ -632,6 +632,8 @@ BEFORE            ?i:before
 <VLOG>"`timescale"       { return tTIMESCALE; }
 <VLOG>"`celldefine"      { }
 <VLOG>"`endcelldefine"   { }
+<VLOG>"`begin_keywords"  { return tBEGINKEYWORDS; }
+<VLOG>"`end_keywords"    { return tENDKEYWORDS; }
 <VLOG>"supply0"          { return tSUPPLY0; }
 <VLOG>"supply1"          { return tSUPPLY1; }
 <VLOG>"pulldown"         { return tPULLDOWN; }

diff --git a/src/scan.c b/src/scan.c
@@ -249,7 +249,7 @@ const char *token_str(token_t tok)
          "enum", "tagged", "abort", "sync_abort", "async_abort", "before",
          "before!", "before_", "before!_", "|->", "|=>", "next", "inf",
          "repeat", "do", "endpoint", "<<", ">>", "<<<", ">>>", "task",
-         "endtask", "endfunction",
+         "endtask", "endfunction", "`begin_keywords", "`end_keywords"
       };
 
       if (tok >= 200 && tok - 200 < ARRAY_LEN(token_strs))

diff --git a/src/scan.h b/src/scan.h
@@ -414,5 +414,7 @@ bool is_scanned_as_psl(void);
 #define tTASK          514
 #define tENDTASK       515
 #define tENDFUNCTION   516
+#define tBEGINKEYWORDS 517
+#define tENDKEYWORDS   518
 
 #endif  // _SCAN_H
diff --git a/src/vlog/vlog-parse.c b/src/vlog/vlog-parse.c
@@ -3631,6 +3631,27 @@ static void p_timescale_compiler_directive(void)
    set_timescale(unit_value, unit_name, prec_value, prec_name, CURRENT_LOC);
 }
 
+static void p_keywords_directive(void)
+{
+   // `begin_keywords "version_specifier"
+
+   BEGIN("keywords directive");
+
+   consume(tBEGINKEYWORDS);
+
+   consume(tSTRING);
+   free(state.last_lval.str);
+}
+
+static void p_endkeywords_directive(void)
+{
+   // `end_keywords
+
+   BEGIN("endkeywords directive");
+
+   consume(tENDKEYWORDS);
+}
+
 static void p_directive_list(void)
 {
    BEGIN("directive list");
@@ -3640,6 +3661,12 @@ static void p_directive_list(void)
       case tTIMESCALE:
          p_timescale_compiler_directive();
          break;
+      case tBEGINKEYWORDS:
+         p_keywords_directive();
+         break;
+      case tENDKEYWORDS:
+         p_endkeywords_directive();
+         break;
       default:
          return;
       }
@@ -3655,9 +3682,12 @@ vlog_node_t vlog_parse(void)
    if (peek() == tEOF)
       return NULL;
 
+   p_directive_list();
+
    make_new_arena();
 
-   p_directive_list();
+   if (peek() == tEOF)
+      return NULL;
 
    return p_description();
 }

diff --git a/test/vlog/simple_sem.v b/test/vlog/simple_sem.v
@@ -20,3 +20,7 @@ module bad_target (input d, output q, output reg r);
   initial q <= 5; // Error
 
 endmodule // bad_target
+
+`begin_keywords "1800-2023"
+`end_keywords
+// End of file