gdb/fortran: add symbol base comparison operators

Fortran supports symbol based comparison operators as well as the
classic text based comparison operators, so we have:

   Text     | Symbol
   Operator | Operator
   ---------|---------
   .eq.     | ==
   .ne.     | /=
   .le.     | <=
   .ge.     | >=
   .gt.     | >
   .lt.     | <

This commit adds the symbol based operators as well as some tests.

gdb/ChangeLog:

	* f-exp.y (dot_ops): Rename to...
	(fortran_operators): ...this.  Add a header comment.  Add symbol
	based operators.
	(yylex): Update to use fortran_operators not dot_ops.  Remove
	special handling for '**', this is now included in
	fortran_operators.

gdb/testsuite/ChangeLog:

	* gdb.fortran/dot-ops.exp: Add new tests.

4 files changed, 61 insertions, 18 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index c33b1d4..720d3b2 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2021-01-12  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* f-exp.y (dot_ops): Rename to...
+	(fortran_operators): ...this.  Add a header comment.  Add symbol
+	based operators.
+	(yylex): Update to use fortran_operators not dot_ops.  Remove
+	special handling for '**', this is now included in
+	fortran_operators.
+
 2021-01-11  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* arch/aarch64-insn.h (aarch64_debug_printf): New.
diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index e0f1b1f..3b0f23d 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -979,7 +979,9 @@ struct token
   bool case_sensitive;
 };
 
-static const struct token dot_ops[] =
+/* List of Fortran operators.  */
+
+static const struct token fortran_operators[] =
 {
   { ".and.", BOOL_AND, BINOP_END, false },
   { ".or.", BOOL_OR, BINOP_END, false },
@@ -987,11 +989,18 @@ static const struct token dot_ops[] =
   { ".eq.", EQUAL, BINOP_END, false },
   { ".eqv.", EQUAL, BINOP_END, false },
   { ".neqv.", NOTEQUAL, BINOP_END, false },
+  { "==", EQUAL, BINOP_END, false },
   { ".ne.", NOTEQUAL, BINOP_END, false },
+  { "/=", NOTEQUAL, BINOP_END, false },
   { ".le.", LEQ, BINOP_END, false },
+  { "<=", LEQ, BINOP_END, false },
   { ".ge.", GEQ, BINOP_END, false },
+  { ">=", GEQ, BINOP_END, false },
   { ".gt.", GREATERTHAN, BINOP_END, false },
+  { ">", GREATERTHAN, BINOP_END, false },
   { ".lt.", LESSTHAN, BINOP_END, false },
+  { "<", LESSTHAN, BINOP_END, false },
+  { "**", STARSTAR, BINOP_EXP, false },
 };
 
 /* Holds the Fortran representation of a boolean, and the integer value we
@@ -1163,26 +1172,17 @@ yylex (void)
 	}
     }
 
-  /* See if it is a special .foo. operator.  */
-  for (int i = 0; i < ARRAY_SIZE (dot_ops); i++)
-    if (strncasecmp (tokstart, dot_ops[i].oper,
-		     strlen (dot_ops[i].oper)) == 0)
+  /* See if it is a Fortran operator.  */
+  for (int i = 0; i < ARRAY_SIZE (fortran_operators); i++)
+    if (strncasecmp (tokstart, fortran_operators[i].oper,
+		     strlen (fortran_operators[i].oper)) == 0)
       {
-	gdb_assert (!dot_ops[i].case_sensitive);
-	pstate->lexptr += strlen (dot_ops[i].oper);
-	yylval.opcode = dot_ops[i].opcode;
-	return dot_ops[i].token;
+	gdb_assert (!fortran_operators[i].case_sensitive);
+	pstate->lexptr += strlen (fortran_operators[i].oper);
+	yylval.opcode = fortran_operators[i].opcode;
+	return fortran_operators[i].token;
       }
 
-  /* See if it is an exponentiation operator.  */
-
-  if (strncmp (tokstart, "**", 2) == 0)
-    {
-      pstate->lexptr += 2;
-      yylval.opcode = BINOP_EXP;
-      return STARSTAR;
-    }
-
   switch (c = *tokstart)
     {
     case 0:
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 65bbebf..e31b712 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2021-01-12  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdb.fortran/dot-ops.exp: Add new tests.
+
 2021-01-11  Tom de Vries  <tdevries@suse.de>
 
 	PR testsuite/26968
diff --git a/gdb/testsuite/gdb.fortran/dot-ops.exp b/gdb/testsuite/gdb.fortran/dot-ops.exp
index 8454f7e..cc9adf3 100644
--- a/gdb/testsuite/gdb.fortran/dot-ops.exp
+++ b/gdb/testsuite/gdb.fortran/dot-ops.exp
@@ -109,6 +109,36 @@ proc test_dot_operations {} {
 	gdb_test "p 4 $gt 4" " = .FALSE."
 	gdb_test "p 3 $gt 4" " = .FALSE."
     }
+
+    # Now test the symbol based comparison operators.
+
+    # Arithmetic EQ
+    gdb_test "p 5 == 4" " = .FALSE."
+    gdb_test "p 4 == 4" " = .TRUE."
+
+    # Arithmetic NE
+    gdb_test "p 5 /= 4" " = .TRUE."
+    gdb_test "p 4 /= 4" " = .FALSE."
+
+    # Arithmetic LE
+    gdb_test "p 5 <= 4" " = .FALSE."
+    gdb_test "p 4 <= 4" " = .TRUE."
+    gdb_test "p 3 <= 4" " = .TRUE."
+
+    # Arithmetic LT
+    gdb_test "p 5 < 4" " = .FALSE."
+    gdb_test "p 4 < 4" " = .FALSE."
+    gdb_test "p 3 < 4" " = .TRUE."
+
+    # Arithmetic GE
+    gdb_test "p 5 >= 4" " = .TRUE."
+    gdb_test "p 4 >= 4" " = .TRUE."
+    gdb_test "p 3 >= 4" " = .FALSE."
+
+    # Arithmetic GT
+    gdb_test "p 5 > 4" " = .TRUE."
+    gdb_test "p 4 > 4" " = .FALSE."
+    gdb_test "p 3 > 4" " = .FALSE."
 }
 
 # Start of test script.