[PUSHED 10/11] gdb/fortran: Add support for the ABS intrinsic function

Andrew Burgess
2019-03-06T18:16:08Z

Adds support for the abs intrinsic function, this requires adding a
new pattern to the Fortran parser. Currently only float and integer
argument types are supported to ABS, complex is still not supported,
this can be added later if needed.

gdb/ChangeLog:

* f-exp.y: New token, UNOP_INTRINSIC.
(exp): New pattern using UNOP_INTRINSIC token.
(f77_keywords): Add 'abs' keyword.
* f-lang.c: Add 'target-float.h' and 'math.h' includes.
(value_from_host_double): New function.
(evaluate_subexp_f): Support UNOP_ABS.

gdb/testsuite/ChangeLog:

* gdb.fortran/intrinsics.exp: Extend to cover ABS.
---
gdb/ChangeLog | 11 +++++++++
gdb/f-exp.y | 8 ++++++-
gdb/f-lang.c | 39 ++++++++++++++++++++++++++++++++
gdb/testsuite/ChangeLog | 4 ++++
gdb/testsuite/gdb.fortran/intrinsics.exp | 9 ++++++++
5 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/gdb/f-exp.y b/gdb/f-exp.y
index d256ff14c1e..88c685a0af3 100644
--- a/gdb/f-exp.y
+++ b/gdb/f-exp.y
@@ -168,6 +168,7 @@ static int parse_number (struct parser_state *, const char *, int,
%token <voidval> DOLLAR_VARIABLE

%token <opcode> ASSIGN_MODIFY
+%token <opcode> UNOP_INTRINSIC

%left ','
%left ABOVE_COMMA
@@ -252,6 +253,10 @@ exp : exp '('
OP_F77_UNDETERMINED_ARGLIST); }
;

+exp : UNOP_INTRINSIC '(' exp ')'
+ { write_exp_elt_opcode (pstate, $1); }
+ ;
+
arglist :
;

@@ -945,7 +950,8 @@ static const struct token f77_keywords[] =
{ "real", REAL_KEYWORD, BINOP_END, true },
/* The following correspond to actual functions in Fortran and are case
insensitive. */
- { "kind", KIND, BINOP_END, false }
+ { "kind", KIND, BINOP_END, false },
+ { "abs", UNOP_INTRINSIC, UNOP_ABS, false }
};

/* Implementation of a dynamically expandable buffer for processing input
diff --git a/gdb/f-lang.c b/gdb/f-lang.c
index c329d602e24..24f0e61a46b 100644
--- a/gdb/f-lang.c
+++ b/gdb/f-lang.c
@@ -34,7 +34,9 @@
#include "cp-support.h"
#include "charset.h"
#include "c-lang.h"
+#include "target-float.h"

+#include <math.h>

/* Local functions */

@@ -239,6 +241,20 @@ f_collect_symbol_completion_matches (completion_tracker &tracker,
text, word, ":", code);
}

+/* Create and return a value object of TYPE containing the value D. The
+ TYPE must be of TYPE_CODE_FLT, and must be large enough to hold D once
+ it is converted to target format. */
+
+static struct value *
+value_from_host_double (struct type *type, double d)
+{
+ struct value *value = allocate_value (type);
+ gdb_assert (TYPE_CODE (type) == TYPE_CODE_FLT);
+ target_float_from_host_double (value_contents_raw (value),
+ value_type (value), d);
+ return value;
+}
+
/* Special expression evaluation cases for Fortran. */
struct value *
evaluate_subexp_f (struct type *expect_type, struct expression *exp,
@@ -259,6 +275,29 @@ evaluate_subexp_f (struct type *expect_type, struct expression *exp,
*pos -= 1;
return evaluate_subexp_standard (expect_type, exp, pos, noside);

+ case UNOP_ABS:
+ arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
+ if (noside == EVAL_SKIP)
+ return eval_skip_value (exp);
+ type = value_type (arg1);
+ switch (TYPE_CODE (type))
+ {
+ case TYPE_CODE_FLT:
+ {
+ double d
+ = fabs (target_float_to_host_double (value_contents (arg1),
+ value_type (arg1)));
+ return value_from_host_double (type, d);
+ }
+ case TYPE_CODE_INT:
+ {
+ LONGEST l = value_as_long (arg1);
+ l = llabs (l);
+ return value_from_longest (type, l);
+ }
+ }
+ error (_("ABS of type %s not supported"), TYPE_SAFE_NAME (type));
+
case UNOP_KIND:
arg1 = evaluate_subexp (NULL, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
type = value_type (arg1);
diff --git a/gdb/testsuite/gdb.fortran/intrinsics.exp b/gdb/testsuite/gdb.fortran/intrinsics.exp
index 674f299c428..00396c74c2f 100644
--- a/gdb/testsuite/gdb.fortran/intrinsics.exp
+++ b/gdb/testsuite/gdb.fortran/intrinsics.exp
@@ -40,3 +40,12 @@ gdb_test "p kind (l2)" " = 2"
gdb_test "p kind (l4)" " = 4"
gdb_test "p kind (l8)" " = 8"
gdb_test "p kind (s1)" "argument to kind must be an intrinsic type"
+
+# Test ABS
+
+gdb_test "p abs (-11)" " = 11"
+gdb_test "p abs (11)" " = 11"
+# Use `$decimal` to match here as we depend on host floating point
+# rounding, which can vary.
+gdb_test "p abs (-9.1)" " = 9.$decimal"
+gdb_test "p abs (9.1)" " = 9.$decimal"
--
2.14.5