commit db0bfa1523aea9f3727d5bd3e8eb11b9395befc3
parent 29cd66e401eba7732a017c79bdc966f5a17a630f
Author: Drew DeVault <sir@cmpwn.com>
Date: Mon, 9 Aug 2021 10:57:39 +0200
gen: implement switch
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Diffstat:
3 files changed, 135 insertions(+), 8 deletions(-)
diff --git a/src/gen.c b/src/gen.c
@@ -1115,7 +1115,7 @@ enum match_compat {
static void
gen_nested_match_tests(struct gen_context *ctx, struct gen_value object,
struct qbe_value bmatch, struct qbe_value bnext,
- struct qbe_value tag, struct match_case *_case,
+ struct qbe_value tag, const struct match_case *_case,
struct qbe_value *offset)
{
// This function handles the case where we're matching against a type
@@ -1171,7 +1171,7 @@ gen_nested_match_tests(struct gen_context *ctx, struct gen_value object,
static void
gen_subset_match_tests(struct gen_context *ctx,
struct qbe_value bmatch, struct qbe_value bnext,
- struct qbe_value tag, struct match_case *_case)
+ struct qbe_value tag, const struct match_case *_case)
{
// In this case, we're testing a case which is itself a tagged union,
// and is a subset of the match object.
@@ -1221,8 +1221,8 @@ gen_match_with_tagged(struct gen_context *ctx,
struct qbe_value bout = mklabel(ctx, &lout, ".%d");
struct gen_value bval;
- struct match_case *_default = NULL;
- for (struct match_case *_case = expr->match.cases;
+ const struct match_case *_default = NULL;
+ for (const struct match_case *_case = expr->match.cases;
_case; _case = _case->next) {
if (!_case->type) {
_default = _case;
@@ -1332,8 +1332,8 @@ gen_match_with_nullable(struct gen_context *ctx,
struct qbe_value qobject = mkqval(ctx, &object);
struct gen_value bval;
- struct match_case *_default = NULL;
- for (struct match_case *_case = expr->match.cases;
+ const struct match_case *_default = NULL;
+ for (const struct match_case *_case = expr->match.cases;
_case; _case = _case->next) {
if (!_case->type) {
_default = _case;
@@ -1497,6 +1497,81 @@ gen_expr_struct_at(struct gen_context *ctx,
}
}
+static struct gen_value
+gen_expr_switch_with(struct gen_context *ctx,
+ const struct expression *expr,
+ struct gen_value *out)
+{
+ struct gen_value gvout = gv_void;
+ if (!out) {
+ gvout = mktemp(ctx, expr->result, ".%d");
+ }
+
+ struct qbe_statement lout;
+ struct qbe_value bout = mklabel(ctx, &lout, ".%d");
+ struct gen_value value = gen_expr(ctx, expr->_switch.value);
+
+ struct gen_value bval;
+ const struct switch_case *_default = NULL;
+ for (const struct switch_case *_case = expr->_switch.cases;
+ _case; _case = _case->next) {
+ if (!_case->options) {
+ _default = _case;
+ continue;
+ }
+
+ struct qbe_statement lmatch, lnextcase;
+ struct qbe_value bmatch = mklabel(ctx, &lmatch, "matches.%d");
+ struct qbe_value bnextcase = mklabel(ctx, &lnextcase, "next.%d");
+
+ for (struct case_option *opt = _case->options;
+ opt; opt = opt->next) {
+ struct qbe_statement lnextopt;
+ struct qbe_value bnextopt = mklabel(ctx, &lnextopt, ".%d");
+ struct gen_value test = gen_expr_const(ctx, opt->value);
+ struct expression lvalue = {
+ .type = EXPR_GEN_VALUE,
+ .result = value.type,
+ .user = &value,
+ }, rvalue = {
+ .type = EXPR_GEN_VALUE,
+ .result = test.type,
+ .user = &test,
+ }, compare = {
+ .type = EXPR_BINARITHM,
+ .result = &builtin_type_bool,
+ .binarithm = {
+ .op = BIN_LEQUAL,
+ .lvalue = &lvalue,
+ .rvalue = &rvalue,
+ },
+ };
+ struct gen_value match = gen_expr(ctx, &compare);
+ struct qbe_value cond = mkqval(ctx, &match);
+ pushi(ctx->current, NULL, Q_JNZ,
+ &cond, &bmatch, &bnextopt, NULL);
+ push(&ctx->current->body, &lnextopt);
+ }
+
+ pushi(ctx->current, NULL, Q_JMP, &bnextcase, NULL);
+ push(&ctx->current->body, &lmatch);
+ bval = gen_expr_with(ctx, _case->value, out);
+ branch_copyresult(ctx, bval, gvout, out);
+ if (!_case->value->terminates) {
+ pushi(ctx->current, NULL, Q_JMP, &bout, NULL);
+ }
+ push(&ctx->current->body, &lnextcase);
+ }
+
+ if (_default) {
+ bval = gen_expr_with(ctx, _default->value, out);
+ branch_copyresult(ctx, bval, gvout, out);
+ }
+
+ push(&ctx->current->body, &lout);
+ return gvout;
+}
+
static void
gen_expr_slice_at(struct gen_context *ctx,
const struct expression *expr,
@@ -1710,7 +1785,7 @@ gen_expr(struct gen_context *ctx, const struct expression *expr)
case EXPR_RETURN:
return gen_expr_return(ctx, expr);
case EXPR_SWITCH:
- assert(0); // TODO
+ return gen_expr_switch_with(ctx, expr, NULL);
case EXPR_UNARITHM:
return gen_expr_unarithm(ctx, expr);
case EXPR_SLICE:
@@ -1760,6 +1835,9 @@ gen_expr_at(struct gen_context *ctx,
case EXPR_STRUCT:
gen_expr_struct_at(ctx, expr, out);
return;
+ case EXPR_SWITCH:
+ gen_expr_switch_with(ctx, expr, &out);
+ return;
case EXPR_TUPLE:
gen_expr_tuple_at(ctx, expr, out);
return;
diff --git a/tests/914-switch.ha b/tests/914-switch.ha
@@ -0,0 +1,48 @@
+fn basics() void = {
+ let cases = [[0, 1], [1, 3], [10, 20], [11, 21], [12, 22], [13, 13]];
+ for (let i = 0z; i < len(cases); i += 1) {
+ let x = cases[i][0];
+ let y: int = switch (x) {
+ 0 => x + 1,
+ 1 => x + 2,
+ 10, 11, 12 => x + 10,
+ * => {
+ x;
+ },
+ };
+ assert(y == cases[i][1]);
+ };
+};
+
+fn termination() void = {
+ let x = 42;
+ let y: int = switch (x) {
+ 42 => 1337,
+ 24 => abort(),
+ * => abort(),
+ };
+ assert(y == 1337);
+};
+
+fn tagged_result() void = {
+ let x = 42;
+ let y: (int | uint) = switch (x) {
+ 42 => 1337i,
+ * => 1337u,
+ };
+ assert(y is int);
+
+ x = 24;
+ y = switch (x) {
+ 42 => 1337i,
+ * => 1337u,
+ };
+ assert(y is uint);
+};
+
+export fn main() int = {
+ basics();
+ termination();
+ tagged_result();
+ return 0;
+};
diff --git a/tests/configure b/tests/configure
@@ -17,7 +17,8 @@ tests() {
910-tagged \
911-slices \
912-enums \
- 913-match
+ 913-match \
+ 914-switch
do
cat <<EOF
tests/$t: harec tests/$t.ha tests/rt.o
