[COMMITTED] algol68: make lexer skip string/character denotations within nestable comments

[Jose E. Marchesi]

---
 gcc/algol68/a68-parser-scanner.cc             | 27 ++++++++++++++-----
 .../compile/error-nested-comment-1.a68        |  6 +++++
 .../algol68/compile/nested-comment-1.a68      |  4 +++
 .../algol68/compile/nested-comment-2.a68      |  6 +++++
 gcc/testsuite/algol68/compile/snobol.a68      |  2 +-
 5 files changed, 37 insertions(+), 8 deletions(-)
 create mode 100644 gcc/testsuite/algol68/compile/error-nested-comment-1.a68
 create mode 100644 gcc/testsuite/algol68/compile/nested-comment-1.a68
 create mode 100644 gcc/testsuite/algol68/compile/nested-comment-2.a68

diff --git a/gcc/algol68/a68-parser-scanner.cc b/gcc/algol68/a68-parser-scanner.cc
index a9e986c46f1..88be8250ecf 100644
--- a/gcc/algol68/a68-parser-scanner.cc
+++ b/gcc/algol68/a68-parser-scanner.cc
@@ -552,7 +552,16 @@ skip_comment (LINE_T **top, char **ch, int delim)
     {
       while (v[0] != NULL_CHAR)
 	{
-	  if (is_bold (v, "COMMENT") && delim == BOLD_COMMENT_SYMBOL)
+	  LINE_T *l = u;
+	  char *c = v;
+
+	  if (v[0] == QUOTE_CHAR && skip_string (&l, &c)
+	      && (delim == BOLD_COMMENT_BEGIN_SYMBOL || delim == BRIEF_COMMENT_BEGIN_SYMBOL))
+	    {
+	      u = l;
+	      v = c;
+	    }
+	  else if (is_bold (v, "COMMENT") && delim == BOLD_COMMENT_SYMBOL)
 	    {
 	      *top = u;
 	      *ch = &v[1];
@@ -1230,7 +1239,7 @@ pragment (int type, LINE_T **ref_l, char **ref_c)
   term_s_length = (int) strlen (term_s);
 
   /* Scan for terminator.  */
-  bool nestable = (beg_s != NO_TEXT);
+  bool nestable_comment = (beg_s != NO_TEXT);
   int nesting_level = 1;
   INIT_BUFFER;
   stop = false;
@@ -1238,8 +1247,11 @@ pragment (int type, LINE_T **ref_l, char **ref_c)
     {
       SCAN_ERROR (c == STOP_CHAR, start_l, start_c,
 		  "unterminated pragment");
-      /* A ".." or '..' delimited string in a PRAGMAT.  */
-      if (pragmat && (c == QUOTE_CHAR || c == '\''))
+
+      /* A ".." or '..' delimited string in a PRAGMAT, or
+	 a ".." in a nestable comment.  */
+      if ((pragmat && (c == QUOTE_CHAR || c == '\''))
+	  || (nestable_comment && c == QUOTE_CHAR))
 	{
 	  char delim = c;
 	  bool eos = false;
@@ -1248,7 +1260,8 @@ pragment (int type, LINE_T **ref_l, char **ref_c)
 	  while (!eos)
 	    {
 	      SCAN_ERROR (EOL (c), start_l, start_c,
-			  "string exceeds end of line");
+			  "string within pragment exceeds end of line");
+
 	      if (c == delim)
 		{
 		  ADD_ONE_CHAR (delim);
@@ -1276,7 +1289,7 @@ pragment (int type, LINE_T **ref_l, char **ref_c)
       else if (ISPRINT (c) || ISSPACE (c))
 	ADD_ONE_CHAR (c);
 
-      if (nestable && chars_in_buf >= beg_s_length)
+      if (nestable_comment && chars_in_buf >= beg_s_length)
 	{
 	  /* If we find another instance of the nestable begin mark, bump the
 	     nesting level and continue scanning.  */
@@ -1295,7 +1308,7 @@ pragment (int type, LINE_T **ref_l, char **ref_c)
 	  if (strcmp (term_s,
 		      &(A68_PARSER (scan_buf)[chars_in_buf - term_s_length])) == 0)
 	    {
-	      if (nestable)
+	      if (nestable_comment)
 		{
 		  gcc_assert (nesting_level > 0);
 		  nesting_level -= 1;
diff --git a/gcc/testsuite/algol68/compile/error-nested-comment-1.a68 b/gcc/testsuite/algol68/compile/error-nested-comment-1.a68
new file mode 100644
index 00000000000..3c78f34a51a
--- /dev/null
+++ b/gcc/testsuite/algol68/compile/error-nested-comment-1.a68
@@ -0,0 +1,6 @@
+{ The string in nested comment is in one logical line.  }
+begin
+      { puts ("{'n { dg-error {} }
+"); { this prints foo }}
+      skip
+end
diff --git a/gcc/testsuite/algol68/compile/nested-comment-1.a68 b/gcc/testsuite/algol68/compile/nested-comment-1.a68
new file mode 100644
index 00000000000..f5752435a0e
--- /dev/null
+++ b/gcc/testsuite/algol68/compile/nested-comment-1.a68
@@ -0,0 +1,4 @@
+{ Comment delimiters within strings get ignored.  }
+begin { puts { ("{""'n"); } }
+      skip
+end
diff --git a/gcc/testsuite/algol68/compile/nested-comment-2.a68 b/gcc/testsuite/algol68/compile/nested-comment-2.a68
new file mode 100644
index 00000000000..9fc912f2687
--- /dev/null
+++ b/gcc/testsuite/algol68/compile/nested-comment-2.a68
@@ -0,0 +1,6 @@
+{ The string in nested comment is in one logical line.  }
+begin
+      { puts ("{'n\
+"); { this prints foo }}
+      skip
+end