vieter-v
/
v
2
0
Fork 0
Code Issues Pull Requests Releases Activity

checker/cgen: enable `IfGuardExpr` for `a[k]` and `<-ch` (#9065)

pull/9084/head
Uwe Krüger 2021-03-03 09:10:38 +01:00 committed by GitHub
parent dad7c40306
commit dd475f4e37
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
6 changed files with 127 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
cmd/tools/vtest-self.v
View File

@ -108,6 +108,7 @@ const (
'vlib/v/tests/go_call_generic_fn_test.v',
'vlib/v/tests/generics_test.v',
'vlib/v/tests/go_wait_2_test.v',
'vlib/v/tests/if_guard_test.v',
'vlib/v/tests/in_expression_test.v',
'vlib/v/tests/interface_edge_cases/assign_to_interface_field_test.v',
'vlib/v/tests/interface_fields_test.v',

10
vlib/v/ast/ast.v
View File

@ -599,12 +599,13 @@ pub mut:
// See: token.Kind.is_prefix
pub struct PrefixExpr {
pub:
op token.Kind
right Expr
pos token.Position
op token.Kind
pos token.Position
pub mut:
right_type table.Type
right Expr
or_block OrExpr
is_option bool // IfGuard
}
pub struct IndexExpr {
@ -619,6 +620,7 @@ pub mut:
is_map bool
is_array bool
is_farray bool
is_option bool // IfGuard
}
pub struct IfExpr {
@ -1035,9 +1037,9 @@ pub mut:
pub struct IfGuardExpr {
pub:
var_name string
expr Expr
pos token.Position
pub mut:
expr Expr
expr_type table.Type
}

20
vlib/v/checker/checker.v
View File

@ -3752,7 +3752,25 @@ pub fn (mut c Checker) expr(node ast.Expr) table.Type {
ast.IfGuardExpr {
node.expr_type = c.expr(node.expr)
if !node.expr_type.has_flag(.optional) {
c.error('expression should return an option', node.expr.position())
mut no_opt := true
match mut node.expr {
ast.IndexExpr {
no_opt = false
node.expr_type = node.expr_type.set_flag(.optional)
node.expr.is_option = true
}
ast.PrefixExpr {
if node.expr.op == .arrow {
no_opt = false
node.expr_type = node.expr_type.set_flag(.optional)
node.expr.is_option = true
}
}
else {}
}
if no_opt {
c.error('expression should return an option', node.expr.position())
}
}
return table.bool_type
}

42
vlib/v/gen/c/cgen.v
View File

@ -2768,7 +2768,7 @@ fn (mut g Gen) expr(node ast.Expr) {
}
}
ast.PrefixExpr {
gen_or := node.op == .arrow && node.or_block.kind != .absent
gen_or := node.op == .arrow && (node.or_block.kind != .absent || node.is_option)
if node.op == .amp {
g.is_amp = true
}
@ -2796,7 +2796,9 @@ fn (mut g Gen) expr(node ast.Expr) {
g.expr(node.right)
g.write(')')
if gen_or {
g.or_block(tmp_opt, node.or_block, elem_type)
if !node.is_option {
g.or_block(tmp_opt, node.or_block, elem_type)
}
if is_gen_or_and_assign_rhs {
elem_styp := g.typ(elem_type)
g.write('\n$cur_line*($elem_styp*)${tmp_opt}.data')
@ -4150,11 +4152,16 @@ fn (mut g Gen) if_expr(node ast.IfExpr) {
is_guard = true
guard_idx = i
guard_vars = []string{len: node.branches.len}
g.writeln(';')
g.writeln('{ /* if guard */ ')
}
var_name := g.new_tmp_var()
guard_vars[i] = var_name
g.writeln('${g.typ(cond.expr_type)} $var_name;')
if cond.expr !is ast.IndexExpr && cond.expr !is ast.PrefixExpr {
var_name := g.new_tmp_var()
guard_vars[i] = var_name
g.writeln('${g.typ(cond.expr_type)} $var_name;')
} else {
guard_vars[i] = ''
}
}
}
for i, branch in node.branches {
@ -4172,13 +4179,28 @@ fn (mut g Gen) if_expr(node ast.IfExpr) {
} else {
match branch.cond {
ast.IfGuardExpr {
var_name := guard_vars[i]
g.write('if ($var_name = ')
g.expr(branch.cond.expr)
g.writeln(', ${var_name}.state == 0) {')
mut var_name := guard_vars[i]
mut short_opt := false
if var_name == '' {
short_opt = true // we don't need a further tmp, so use the one we'll get later
var_name = g.new_tmp_var()
guard_vars[i] = var_name // for `else`
g.tmp_count--
g.writeln('if (${var_name}.state == 0) {')
} else {
g.write('if ($var_name = ')
g.expr(branch.cond.expr)
g.writeln(', ${var_name}.state == 0) {')
}
if branch.cond.var_name != '_' {
base_type := g.base_type(branch.cond.expr_type)
g.writeln('\t$base_type $branch.cond.var_name = *($base_type*)${var_name}.data;')
if short_opt {
g.write('\t$base_type $branch.cond.var_name = ')
g.expr(branch.cond.expr)
g.writeln(';')
} else {
g.writeln('\t$base_type $branch.cond.var_name = *($base_type*)${var_name}.data;')
}
}
}
else {

12
vlib/v/gen/c/index.v
View File

@ -92,7 +92,7 @@ fn (mut g Gen) range_expr(node ast.IndexExpr, range ast.RangeExpr) {
}
fn (mut g Gen) index_of_array(node ast.IndexExpr, sym table.TypeSymbol) {
gen_or := node.or_expr.kind != .absent
gen_or := node.or_expr.kind != .absent || node.is_option
left_is_ptr := node.left_type.is_ptr()
info := sym.info as table.Array
elem_type_str := g.typ(info.elem_type)
@ -248,7 +248,9 @@ fn (mut g Gen) index_of_array(node ast.IndexExpr, sym table.TypeSymbol) {
g.writeln('} else {')
g.writeln('\t${tmp_opt}.state = 2; ${tmp_opt}.err = (Error){.msg=_SLIT("array index out of range"), .code=0};')
g.writeln('}')
g.or_block(tmp_opt, node.or_expr, elem_type)
if !node.is_option {
g.or_block(tmp_opt, node.or_expr, elem_type)
}
g.write('\n$cur_line*($elem_type_str*)${tmp_opt}.data')
}
}
@ -287,7 +289,7 @@ fn (mut g Gen) index_of_fixed_array(node ast.IndexExpr, sym table.TypeSymbol) {
}
fn (mut g Gen) index_of_map(node ast.IndexExpr, sym table.TypeSymbol) {
gen_or := node.or_expr.kind != .absent
gen_or := node.or_expr.kind != .absent || node.is_option
left_is_ptr := node.left_type.is_ptr()
info := sym.info as table.Map
key_type_str := g.typ(info.key_type)
@ -414,7 +416,9 @@ fn (mut g Gen) index_of_map(node ast.IndexExpr, sym table.TypeSymbol) {
g.writeln('\t${tmp_opt}.state = 2; ${tmp_opt}.err = (Error){.msg=_SLIT("array index out of range"), .code=0};')
g.writeln('}')
g.or_block(tmp_opt, node.or_expr, elem_type)
if !node.is_option {
g.or_block(tmp_opt, node.or_expr, elem_type)
}
g.write('\n$cur_line*($elem_type_str*)${tmp_opt}.data')
}
}

61
vlib/v/tests/if_guard_test.v 100644
View File

@ -0,0 +1,61 @@
fn f(n int) ?f64 {
if n < 0 {
return error('negative')
}
return 1.5 * f64(n)
}
fn test_fn_return() {
mut res := []f64{cap:2}
for m in [-3, 5] {
if x := f(m) {
res << x
} else {
res << 31.0
}
}
assert res == [31.0, 7.5]
}
fn test_map_get() {
mut m := {'xy': 5, 'zu': 7}
mut res := []int{cap:2}
for k in ['jk', 'zu'] {
if x := m[k] {
res << x
} else {
res << -17
}
}
assert res == [-17, 7]
}
fn test_array_get() {
mut a := [12.5, 6.5, -17.25]
mut res := []f64{cap:2}
for i in [1, 4] {
if x := a[i] {
res << x
} else {
res << -23.0
}
}
assert res == [6.5, -23.0]
}
fn test_chan_pop() {
mut res := []f64{cap:3}
ch := chan f64{cap: 10}
ch <- 6.75
ch <- -3.25
ch.close()
for _ in 0 .. 3 {
if x:= <-ch {
res << x
} else {
res << -37.5
}
}
assert res == [6.75, -3.25, -37.5]
}