[PATCH 045/203] Change parameters to rust_subscript

Tom Tromey
2021-01-01T21:48:00Z

This changes the parameters to rust_subscript, making it more suitable
for reuse by the (coming) new expression code. In particular,
rust_subscript no longer evaluates its subexpressions. Instead, they
are passed in.

gdb/ChangeLog
2021-01-01 Tom Tromey <tom@tromey.com>

* rust-lang.c (rust_subscript): Change parameters.
(rust_evaluate_subexp): Update.
---
gdb/ChangeLog | 5 +++++
gdb/rust-lang.c | 24 +++++++++++++++---------
2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/gdb/rust-lang.c b/gdb/rust-lang.c
index c460d03172e..a635c8b8449 100644
--- a/gdb/rust-lang.c
+++ b/gdb/rust-lang.c
@@ -1168,10 +1168,11 @@ rust_compute_range (struct type *type, struct value *range,
/* A helper for rust_evaluate_subexp that handles BINOP_SUBSCRIPT. */

static struct value *
-rust_subscript (struct expression *exp, int *pos, enum noside noside,
- int for_addr)
+rust_subscript (struct type *expect_type, struct expression *exp,
+ enum noside noside, bool for_addr,
+ struct value *lhs, struct value *rhs)
{
- struct value *lhs, *rhs, *result;
+ struct value *result;
struct type *rhstype;
LONGEST low, high_bound;
/* Initialized to appease the compiler. */
@@ -1179,10 +1180,6 @@ rust_subscript (struct expression *exp, int *pos, enum noside noside,
LONGEST high = 0;
int want_slice = 0;

- ++*pos;
- lhs = evaluate_subexp (nullptr, exp, pos, noside);
- rhs = evaluate_subexp (nullptr, exp, pos, noside);
-
if (noside == EVAL_SKIP)
return lhs;

@@ -1374,7 +1371,12 @@ rust_evaluate_subexp (struct type *expect_type, struct expression *exp,
break;

case BINOP_SUBSCRIPT:
- result = rust_subscript (exp, pos, noside, 0);
+ {
+ ++*pos;
+ struct value *lhs = evaluate_subexp (nullptr, exp, pos, noside);
+ struct value *rhs = evaluate_subexp (nullptr, exp, pos, noside);
+ result = rust_subscript (expect_type, exp, noside, false, lhs, rhs);
+ }
break;

case OP_FUNCALL:
@@ -1628,7 +1630,11 @@ tuple structs, and tuple-like enum variants"));
if (exp->elts[*pos + 1].opcode == BINOP_SUBSCRIPT)
{
++*pos;
- result = rust_subscript (exp, pos, noside, 1);
+ ++*pos;
+ struct value *lhs = evaluate_subexp (nullptr, exp, pos, noside);
+ struct value *rhs = evaluate_subexp (nullptr, exp, pos, noside);
+
+ result = rust_subscript (expect_type, exp, noside, true, lhs, rhs);
break;
}
/* Fall through. */
--
2.26.2