a68: parser: keyword tables management

This commit adds code to manage the table of keywords (bold words) in
the Algol 68 front-end.

Signed-off-by: Jose E. Marchesi <jemarch@gnu.org>
Co-authored-by: Marcel van der Veer <algol68g@xs4all.nl>

diff --git a/gcc/algol68/a68-parser-keywords.cc b/gcc/algol68/a68-parser-keywords.cc
new file mode 100644 (file)
index 0000000..427e2b3
--- /dev/null
+++ b/gcc/algol68/a68-parser-keywords.cc
@@ -0,0 +1,254 @@
+/* Keyword tables.
+   Copyright (C) 2001-2023 J. Marcel van der Veer.
+   Copyright (C) 2025 Jose E. Marchesi.
+
+   Original implementation by J. Marcel van der Veer.
+   Adapted for GCC by Jose E. Marchesi.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+
+#include "a68.h"
+
+/* Apply stropping to the given keyword and return its written form, which must
+   be upper-case.  */
+
+const char *
+a68_strop_keyword (const char *keyword)
+{
+  char *stropped = (char *) alloca (strlen (keyword) + 1);
+  memcpy (stropped, keyword, strlen (keyword) + 1);
+
+  if (OPTION_STROPPING (&A68_JOB) == SUPPER_STROPPING)
+    {
+      for (char *p = stropped; *p; ++p)
+       *p = TOLOWER (*p);
+    }
+
+  return ggc_strdup (stropped);
+}
+
+/* Add token to the token tree.  */
+
+TOKEN_T *
+a68_add_token (TOKEN_T **p, const char *t)
+{
+  while (*p != NO_TOKEN)
+    {
+      int k = strcmp (t, TEXT (*p));
+
+      if (k < 0)
+       p = &LESS (*p);
+      else if (k > 0)
+       p = &MORE (*p);
+      else
+       return *p;
+    }
+
+  *p = (TOKEN_T *) ggc_cleared_alloc<TOKEN_T> ();
+  TEXT (*p) = ggc_strdup (t);
+  LESS (*p) = MORE (*p) = NO_TOKEN;
+  return *p;
+}
+
+/*  Find keyword, from token name.  */
+
+KEYWORD_T *
+a68_find_keyword (KEYWORD_T *p, const char *t)
+{
+  while (p != NO_KEYWORD)
+    {
+      bool case_insensitive = (OPTION_STROPPING (&A68_JOB) == SUPPER_STROPPING);
+      int k = (case_insensitive
+              ? strcasecmp (t, TEXT (p))
+              : strcmp (t, TEXT (p)));
+
+      if (k < 0)
+       p = LESS (p);
+      else if (k > 0)
+       p = MORE (p);
+      else
+       return p;
+    }
+
+  return NO_KEYWORD;
+}
+
+/* Find keyword, from attribute.  */
+
+KEYWORD_T *
+a68_find_keyword_from_attribute (KEYWORD_T *p, enum a68_attribute a)
+{
+  if (p == NO_KEYWORD)
+    return NO_KEYWORD;
+  else if (a == ATTRIBUTE (p))
+    return p;
+  else
+    {
+      KEYWORD_T *z;
+
+      if ((z = a68_find_keyword_from_attribute (LESS (p), a)) != NO_KEYWORD)
+       return z;
+      else if ((z = a68_find_keyword_from_attribute (MORE (p), a)) != NO_KEYWORD)
+       return z;
+    }
+
+  return NO_KEYWORD;
+}
+
+/* Add keyword to the tree.  */
+
+static void
+add_keyword (KEYWORD_T **p, enum a68_attribute a, const char *t)
+{
+  while (*p != NO_KEYWORD)
+    {
+      bool case_insensitive = (OPTION_STROPPING (&A68_JOB) == SUPPER_STROPPING);
+      int k = (case_insensitive
+              ? strcasecmp (t, TEXT (*p))
+              : strcmp (t, TEXT (*p)));
+      if (k < 0)
+       p = &LESS (*p);
+      else
+       p = &MORE (*p);
+    }
+
+  *p = (KEYWORD_T *) ggc_cleared_alloc<KEYWORD_T> ();
+  ATTRIBUTE (*p) = a;
+  TEXT (*p) = t;
+  LESS (*p) = MORE (*p) = NO_KEYWORD;
+}
+
+/* Make tables of keywords and non-terminals.  */
+
+void
+a68_set_up_tables (void)
+{
+  /* Entries are randomised to balance the tree.  */
+  if (OPTION_STRICT (&A68_JOB) == false)
+    {
+      /* Symbols from GNU extensions.  */
+      add_keyword (&A68 (top_keyword), ANDF_SYMBOL, "ANDTH");
+      add_keyword (&A68 (top_keyword), ORF_SYMBOL, "OREL");
+      add_keyword (&A68 (top_keyword), BRIEF_COMMENT_BEGIN_SYMBOL, "{");
+      add_keyword (&A68 (top_keyword), BRIEF_COMMENT_END_SYMBOL, "}");
+
+      if (OPTION_STROPPING (&A68_JOB) != SUPPER_STROPPING)
+       {
+         add_keyword (&A68 (top_keyword), BOLD_COMMENT_BEGIN_SYMBOL, "NOTE");
+         add_keyword (&A68 (top_keyword), BOLD_COMMENT_END_SYMBOL, "ETON");
+       }
+
+      /* Symbols from MR.  */
+      add_keyword (&A68 (top_keyword), ACCESS_SYMBOL, "ACCESS");
+      add_keyword (&A68 (top_keyword), DEF_SYMBOL, "DEF");
+      add_keyword (&A68 (top_keyword), POSTLUDE_SYMBOL, "POSTLUDE");
+      add_keyword (&A68 (top_keyword), FED_SYMBOL, "FED");
+      add_keyword (&A68 (top_keyword), FORMAL_NEST_SYMBOL, "NEST");
+      add_keyword (&A68 (top_keyword), MODULE_SYMBOL, "MODULE");
+      add_keyword (&A68 (top_keyword), EGG_SYMBOL, "EGG");
+      add_keyword (&A68 (top_keyword), PUBLIC_SYMBOL, "PUB");
+    }
+
+  if (OPTION_STROPPING (&A68_JOB) != SUPPER_STROPPING)
+    {
+      /* The following representations do not work well with stropping regimes
+        in which reserved words live in the same namespace than
+        tags/identifiers.  The alternative "brief" representations for these
+        symbols shall be used instead.  */
+      add_keyword (&A68 (top_keyword), STYLE_I_COMMENT_SYMBOL, "CO");
+      add_keyword (&A68 (top_keyword), BOLD_COMMENT_SYMBOL, "COMMENT");
+      add_keyword (&A68 (top_keyword), STYLE_II_COMMENT_SYMBOL, "#");
+    }
+
+  add_keyword (&A68 (top_keyword), POINT_SYMBOL, ".");
+  add_keyword (&A68 (top_keyword), COLON_SYMBOL, ":");
+  add_keyword (&A68 (top_keyword), THEN_BAR_SYMBOL, "|");
+  add_keyword (&A68 (top_keyword), SUB_SYMBOL, "[");
+  add_keyword (&A68 (top_keyword), BY_SYMBOL, "BY");
+  add_keyword (&A68 (top_keyword), OP_SYMBOL, "OP");
+  add_keyword (&A68 (top_keyword), COMMA_SYMBOL, ",");
+  add_keyword (&A68 (top_keyword), AT_SYMBOL, "AT");
+  add_keyword (&A68 (top_keyword), PRIO_SYMBOL, "PRIO");
+  add_keyword (&A68 (top_keyword), END_SYMBOL, "END");
+  add_keyword (&A68 (top_keyword), GO_SYMBOL, "GO");
+  add_keyword (&A68 (top_keyword), TO_SYMBOL, "TO");
+  add_keyword (&A68 (top_keyword), ELSE_BAR_SYMBOL, "|:");
+  add_keyword (&A68 (top_keyword), THEN_SYMBOL, "THEN");
+  add_keyword (&A68 (top_keyword), TRUE_SYMBOL, "TRUE");
+  add_keyword (&A68 (top_keyword), PROC_SYMBOL, "PROC");
+  add_keyword (&A68 (top_keyword), FOR_SYMBOL, "FOR");
+  add_keyword (&A68 (top_keyword), GOTO_SYMBOL, "GOTO");
+  add_keyword (&A68 (top_keyword), WHILE_SYMBOL, "WHILE");
+  add_keyword (&A68 (top_keyword), IS_SYMBOL, ":=:");
+  add_keyword (&A68 (top_keyword), ASSIGN_TO_SYMBOL, "=:");
+  add_keyword (&A68 (top_keyword), COMPL_SYMBOL, "COMPL");
+  add_keyword (&A68 (top_keyword), FROM_SYMBOL, "FROM");
+  add_keyword (&A68 (top_keyword), BOLD_PRAGMAT_SYMBOL, "PRAGMAT");
+  add_keyword (&A68 (top_keyword), DO_SYMBOL, "DO");
+  add_keyword (&A68 (top_keyword), CASE_SYMBOL, "CASE");
+  add_keyword (&A68 (top_keyword), LOC_SYMBOL, "LOC");
+  add_keyword (&A68 (top_keyword), CHAR_SYMBOL, "CHAR");
+  add_keyword (&A68 (top_keyword), ISNT_SYMBOL, ":/=:");
+  add_keyword (&A68 (top_keyword), REF_SYMBOL, "REF");
+  add_keyword (&A68 (top_keyword), NIL_SYMBOL, "NIL");
+  add_keyword (&A68 (top_keyword), ASSIGN_SYMBOL, ":=");
+  add_keyword (&A68 (top_keyword), FI_SYMBOL, "FI");
+  add_keyword (&A68 (top_keyword), FILE_SYMBOL, "FILE");
+  add_keyword (&A68 (top_keyword), PAR_SYMBOL, "PAR");
+  add_keyword (&A68 (top_keyword), ASSERT_SYMBOL, "ASSERT");
+  add_keyword (&A68 (top_keyword), OUSE_SYMBOL, "OUSE");
+  add_keyword (&A68 (top_keyword), IN_SYMBOL, "IN");
+  add_keyword (&A68 (top_keyword), LONG_SYMBOL, "LONG");
+  add_keyword (&A68 (top_keyword), SEMI_SYMBOL, ";");
+  add_keyword (&A68 (top_keyword), EMPTY_SYMBOL, "EMPTY");
+  add_keyword (&A68 (top_keyword), MODE_SYMBOL, "MODE");
+  add_keyword (&A68 (top_keyword), IF_SYMBOL, "IF");
+  add_keyword (&A68 (top_keyword), OD_SYMBOL, "OD");
+  add_keyword (&A68 (top_keyword), OF_SYMBOL, "OF");
+  add_keyword (&A68 (top_keyword), STRUCT_SYMBOL, "STRUCT");
+  add_keyword (&A68 (top_keyword), STYLE_I_PRAGMAT_SYMBOL, "PR");
+  add_keyword (&A68 (top_keyword), BUS_SYMBOL, "]");
+  add_keyword (&A68 (top_keyword), SKIP_SYMBOL, "SKIP");
+  add_keyword (&A68 (top_keyword), SHORT_SYMBOL, "SHORT");
+  add_keyword (&A68 (top_keyword), IS_SYMBOL, "IS");
+  add_keyword (&A68 (top_keyword), ESAC_SYMBOL, "ESAC");
+  add_keyword (&A68 (top_keyword), CHANNEL_SYMBOL, "CHANNEL");
+  add_keyword (&A68 (top_keyword), REAL_SYMBOL, "REAL");
+  add_keyword (&A68 (top_keyword), STRING_SYMBOL, "STRING");
+  add_keyword (&A68 (top_keyword), BOOL_SYMBOL, "BOOL");
+  add_keyword (&A68 (top_keyword), ISNT_SYMBOL, "ISNT");
+  add_keyword (&A68 (top_keyword), FALSE_SYMBOL, "FALSE");
+  add_keyword (&A68 (top_keyword), UNION_SYMBOL, "UNION");
+  add_keyword (&A68 (top_keyword), OUT_SYMBOL, "OUT");
+  add_keyword (&A68 (top_keyword), BRIEF_COMMENT_END_SYMBOL, "{");
+  add_keyword (&A68 (top_keyword), OPEN_SYMBOL, "(");
+  add_keyword (&A68 (top_keyword), BEGIN_SYMBOL, "BEGIN");
+  add_keyword (&A68 (top_keyword), FLEX_SYMBOL, "FLEX");
+  add_keyword (&A68 (top_keyword), VOID_SYMBOL, "VOID");
+  add_keyword (&A68 (top_keyword), BITS_SYMBOL, "BITS");
+  add_keyword (&A68 (top_keyword), ELSE_SYMBOL, "ELSE");
+  add_keyword (&A68 (top_keyword), EXIT_SYMBOL, "EXIT");
+  add_keyword (&A68 (top_keyword), HEAP_SYMBOL, "HEAP");
+  add_keyword (&A68 (top_keyword), INT_SYMBOL, "INT");
+  add_keyword (&A68 (top_keyword), BYTES_SYMBOL, "BYTES");
+  add_keyword (&A68 (top_keyword), SEMA_SYMBOL, "SEMA");
+  add_keyword (&A68 (top_keyword), CLOSE_SYMBOL, ")");
+  add_keyword (&A68 (top_keyword), AT_SYMBOL, "@");
+  add_keyword (&A68 (top_keyword), ELIF_SYMBOL, "ELIF");
+}