feat: execute conditionals through typed IR

Use typed singleton arrays for braceless arm blocks: &[statement] compiled but trapped under the Bro bootstrap.
This commit is contained in:
2026-10-09 23:43:44 +02:00
parent 0821b84bc3
commit 9932750e21
20 changed files with 1511 additions and 124 deletions
+121 -60
View File
@@ -5,7 +5,7 @@ import "@source/ast"
import "@source/diagnostics"
sema :: import "@source/sema"
TypeKind :: enum { none, invalid, int, float, string, void, function }
TypeKind :: enum { none, invalid, int, float, bool, string, void, function }
Type :: struct {
kind TypeKind = .none
@@ -27,7 +27,7 @@ Result :: struct { storage Storage }
no_index :: maxval!(usize)
@hide:file
Role :: enum { none, expression, declaration, parameter, function, annotation, invalid, body, return_stmt }
Role :: enum { none, expression, declaration, parameter, function, annotation, invalid, body, return_stmt, if_stmt }
@hide:file
Cell :: struct {
@@ -161,6 +161,7 @@ check proc(
.unary: try require_numeric(&state, id, ast.unary_expr(tree, id).operand)
.binary: {
expression :: ast.binary_expr(tree, id)
if (bool_equality(&state, id)) continue
try require_numeric(&state, id, expression.left)
try require_numeric(&state, id, expression.right)
}
@@ -178,10 +179,14 @@ check proc(
.unary: try numeric_operand(&state, id, ast.unary_expr(tree, id).operand)
.binary: {
expression :: ast.binary_expr(tree, id)
try numeric_operand(&state, id, expression.left)
try numeric_operand(&state, id, expression.right)
if (expression.operator == .divide) {
try impose(&state, id, .float, .integer_division, expression.span)
if (comparison(expression.operator)) {
if (!bool_equality(&state, id)) try comparison_operands(&state, id)
} else {
try numeric_operand(&state, id, expression.left)
try numeric_operand(&state, id, expression.right)
if (expression.operator == .divide) {
try impose(&state, id, .float, .integer_division, expression.span)
}
}
}
else: {}
@@ -246,6 +251,28 @@ check proc(
# errors travel only from dependencies to users. A rejected use never poisons
# an explicitly typed declaration, and body errors do not erase signatures.
propagate(&state, queue)
# validate conditions after operand errors have reached their users.
for (0..count) |i| {
if (cells[i].role != .if_stmt) continue
condition :: ast.if_stmt(tree, ast.NodeId(i)).condition
actual :: types[usize(condition)]
if (actual.kind != .invalid and actual.kind != .bool) {
try fail(&state, condition, .condition_not_bool, ast.node_span(tree, condition))
}
}
propagate(&state, queue)
for (0..ast.package_decl_count(tree)) |i| {
id :: ast.package_decl(tree, i)
if (ast.decl_kind(tree, id) != .function) continue
function :: ast.function_decl(tree, id)
result :: types[usize(function.return_type)]
if (result.kind == .void or result.kind == .invalid or types[usize(id)].kind == .invalid) continue
if (block_falls_through(&state, function.body)) {
# lowering must find this diagnostic even when another arm failed.
diagnostic :: try diagnostics.add(diagnostic_store, .missing_return, ast.node_span(tree, function.body))
types[usize(function.body)] = invalid_type(diagnostic)
}
}
return Result{ storage = Storage{ types = types, allocator = allocator } }
}
@@ -371,6 +398,7 @@ check_annotation proc(state @mut State, id ast.NodeId, allow_void bool) Type ! (
type.kind = match binding.data.builtin {
.int: .int
.float: .float
.bool: .bool
.string: .string
.void: .void
}
@@ -427,25 +455,44 @@ collect_function proc(state @mut State, id ast.NodeId) void ! (mem.AllocError |
state.cells[usize(id)].type = invalid_type(binding.data.diagnostic)
state.cells[usize(id)].type.function = id
}
state.cells[usize(function.body)].role = .body
for (0..ast.block_statement_count(tree, function.body)) |i| {
statement :: ast.block_statement(tree, function.body, i)
try collect_block(state, function.body, function.return_type)
}
@hide:file
collect_block proc(state @mut State, id, return_annotation ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
tree :: state.tree
state.cells[usize(id)].role = .body
for (0..ast.block_statement_count(tree, id)) |i| {
statement :: ast.block_statement(tree, id, i)
match ast.stmt_kind(tree, statement) {
.declaration: try collect_declaration(state, statement)
.expression: try collect_expression(state, ast.statement_expr(tree, statement))
.return_stmt: {
state.cells[usize(statement)].role = .return_stmt
state.cells[usize(statement)].type = Type{ kind = .void }
state.cells[usize(statement)].return_annotation = function.return_type
state.cells[usize(statement)].return_annotation = return_annotation
if (ast.return_stmt(tree, statement).value) |value| {
try collect_expression(state, value)
try depend(state, value, statement)
}
}
.if_stmt: {
conditional :: ast.if_stmt(tree, statement)
state.cells[usize(statement)].role = .if_stmt
state.cells[usize(statement)].type = Type{ kind = .void }
try collect_expression(state, conditional.condition)
try depend(state, conditional.condition, statement)
try collect_block(state, conditional.then_block, return_annotation)
try depend(state, conditional.then_block, id)
if (conditional.else_block) |other| {
try collect_block(state, other, return_annotation)
try depend(state, other, id)
}
}
.invalid: collect_invalid(state, statement)
}
source :: if (ast.stmt_kind(tree, statement) == .expression) ast.statement_expr(tree, statement) else statement
try depend(state, source, function.body)
try depend(state, source, id)
}
}
@@ -460,6 +507,7 @@ collect_expression proc(state @mut State, id ast.NodeId) void ! (mem.AllocError
state.cells[usize(id)].anchored = true
}
.literal_float: state.cells[usize(id)].type = Type{ kind = .float }
.literal_bool: state.cells[usize(id)].type = Type{ kind = .bool }
.literal_string: state.cells[usize(id)].type = Type{ kind = .string }
.identifier: {
binding :: sema.binding(state.resolution, id)
@@ -476,8 +524,12 @@ collect_expression proc(state @mut State, id ast.NodeId) void ! (mem.AllocError
try depend(state, operand, id)
}
.binary: {
state.cells[usize(id)].numeric = true
expression :: ast.binary_expr(tree, id)
if (comparison(expression.operator)) {
state.cells[usize(id)].type = Type{ kind = .bool }
} else {
state.cells[usize(id)].numeric = true
}
try collect_expression(state, expression.left)
try collect_expression(state, expression.right)
try depend(state, expression.left, id)
@@ -502,6 +554,40 @@ numeric_kind proc(kind TypeKind) bool {
return kind == .int or kind == .float
}
@hide:file
comparison proc(operator ast.BinaryOperator) bool {
return (
operator == .equal or operator == .not_equal or operator == .less
or operator == .less_equal or operator == .greater or operator == .greater_equal
)
}
@hide:file
bool_equality proc(state @mut State, id ast.NodeId) bool {
expression :: ast.binary_expr(state.tree, id)
return (
(expression.operator == .equal or expression.operator == .not_equal)
and group_type(state, expression.left).kind == .bool
and group_type(state, expression.right).kind == .bool
)
}
@hide:file
comparison_operands proc(state @mut State, id ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
if (state.types[usize(id)].kind == .invalid) return
expression :: ast.binary_expr(state.tree, id)
left :: root(state, usize(expression.left))
right :: root(state, usize(expression.right))
# only operand groups receive numeric demands; the result stays bool.
if (state.cells[left].numeric or state.cells[left].type.kind == .none) {
state.cells[left].numeric = true
try numeric_constraint(state, expression.left, expression.right, id)
} else if (state.cells[right].numeric or state.cells[right].type.kind == .none) {
state.cells[right].numeric = true
try numeric_constraint(state, expression.right, expression.left, id)
}
}
@hide:file
impose proc(state @mut State, id ast.NodeId, kind TypeKind, code diagnostics.Code, span ast.Span) void ! (mem.AllocError | diagnostics.CapacityError) {
index :: root(state, usize(id))
@@ -516,6 +602,11 @@ impose proc(state @mut State, id ast.NodeId, kind TypeKind, code diagnostics.Cod
@hide:file
numeric_operand proc(state @mut State, expression, operand ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
try numeric_constraint(state, expression, operand, expression)
}
@hide:file
numeric_constraint proc(state @mut State, expression, operand, operation ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
index :: root(state, usize(operand))
type :: state.cells[index].type
if (state.types[usize(expression)].kind == .invalid or state.types[usize(operand)].kind == .invalid) return
@@ -525,13 +616,13 @@ numeric_operand proc(state @mut State, expression, operand ast.NodeId) void ! (m
operand_demand :: state.cells[index].demand
join(state, expression, operand)
if (expression_demand != .none) {
try impose(state, expression, expression_demand, .invalid_operand, ast.node_span(state.tree, expression))
try impose(state, expression, expression_demand, .invalid_operand, ast.node_span(state.tree, operation))
}
if (operand_demand != .none) {
try impose(state, expression, operand_demand, .invalid_operand, ast.node_span(state.tree, expression))
try impose(state, expression, operand_demand, .invalid_operand, ast.node_span(state.tree, operation))
}
} else if (numeric_kind(type.kind)) {
try impose(state, expression, type.kind, .invalid_operand, ast.node_span(state.tree, expression))
try impose(state, expression, type.kind, .invalid_operand, ast.node_span(state.tree, operation))
}
}
@@ -568,20 +659,6 @@ validate proc(state @mut State, id ast.NodeId) void ! (mem.AllocError | diagnost
}
if (declaration.type) |type| try compatible(state, declaration.initializer, state.types[usize(type)])
}
.function: {
function :: ast.function_decl(tree, id)
result :: state.types[usize(function.return_type)]
if (result.kind == .void or result.kind == .invalid or state.types[usize(id)].kind == .invalid) return
for (0..ast.block_statement_count(tree, function.body)) |i| {
if (ast.stmt_kind(tree, ast.block_statement(tree, function.body, i)) == .return_stmt) return
}
if (syntactically_valid_body(tree, function.body)) {
diagnostic :: try diagnostics.add(state.diagnostics, .missing_return, ast.node_span(tree, function.body))
if (state.types[usize(function.body)].kind != .invalid) {
state.types[usize(function.body)] = invalid_type(diagnostic)
}
}
}
.return_stmt: {
statement :: ast.return_stmt(tree, id)
expected :: state.types[usize(state.cells[usize(id)].return_annotation)]
@@ -611,6 +688,8 @@ validate proc(state @mut State, id ast.NodeId) void ! (mem.AllocError | diagnost
left :: state.types[usize(expression.left)]
right :: state.types[usize(expression.right)]
if (left.kind == .invalid or right.kind == .invalid) return
if ((expression.operator == .equal or expression.operator == .not_equal)
and left.kind == .bool and right.kind == .bool) return
if (!numeric_kind(left.kind) or !numeric_kind(right.kind) or left.kind != right.kind) {
try fail(state, id, .invalid_operand, expression.span)
} else if (expression.operator == .divide and left.kind == .int) {
@@ -649,43 +728,25 @@ validate_call proc(state @mut State, id ast.NodeId) void ! (mem.AllocError | dia
}
}
@hide:file
syntactically_valid_expression proc(tree @ast.Tree, id ast.NodeId) bool {
match ast.expr_kind(tree, id) {
.invalid: return false
.unary: return syntactically_valid_expression(tree, ast.unary_expr(tree, id).operand)
.binary: {
expression :: ast.binary_expr(tree, id)
return syntactically_valid_expression(tree, expression.left) and syntactically_valid_expression(tree, expression.right)
}
.call: {
if (!syntactically_valid_expression(tree, ast.call_expr(tree, id).callee)) return false
for (0..ast.call_arg_count(tree, id)) |i| {
if (!syntactically_valid_expression(tree, ast.call_arg(tree, id, i))) return false
}
}
else: {}
}
return true
}
@hide:file
syntactically_valid_body proc(tree @ast.Tree, id ast.NodeId) bool {
block_falls_through proc(state @State, id ast.NodeId) bool {
tree :: state.tree
for (0..ast.block_statement_count(tree, id)) |i| {
statement :: ast.block_statement(tree, id, i)
match ast.stmt_kind(tree, statement) {
.invalid: return false
.expression: {
if (!syntactically_valid_expression(tree, ast.statement_expr(tree, statement))) return false
}
.return_stmt: {
if (ast.return_stmt(tree, statement).value) |value| {
if (!syntactically_valid_expression(tree, value)) return false
kind :: ast.stmt_kind(tree, statement)
source :: if (kind == .expression) ast.statement_expr(tree, statement) else statement
if (state.types[usize(source)].kind == .invalid) return false
match kind {
.return_stmt, .invalid: return false
.if_stmt: {
conditional :: ast.if_stmt(tree, statement)
then_falls :: block_falls_through(state, conditional.then_block)
if (conditional.else_block) |other| {
if (!then_falls and !block_falls_through(state, other)) return false
}
}
.declaration: {
if (!syntactically_valid_expression(tree, ast.statement_decl(tree, statement).initializer)) return false
}
else: {}
}
}
return true
+237
View File
@@ -731,3 +731,240 @@ return_errors_preserve_identity_check_unreachable_code_and_suppress_missing_retu
try testing.expect_equal(2, code_count(&diagnostic_store, .unexpected_token))
try testing.expect_equal(8, diagnostics.count(&diagnostic_store))
}
checks_bool_comparisons_recursive_returns_and_nested_numeric_context test {
strpool.strings = strpool.init(mem.c_allocator)
defer strpool.deinit(&strpool.strings)
diagnostic_store := diagnostics.init(mem.c_allocator)
defer diagnostics.deinit(&diagnostic_store)
source ::
`flag bool :: true
`same :: flag == false
`different :: true != flag
`less :: alias < 4.0
`less_equal :: seed <= 5
`greater :: 6 > seed
`greater_equal :: seed >= 1
`equal :: seed == 3
`not_equal :: seed != 2
`alias :: seed
`seed := 3
`identity proc(value bool) bool { return value }
`factorial proc(n int) int {
` if n <= 1 { return 1 }
` return n * factorial(n - 1)
`}
`fraction proc(value bool) float {
` if value {
` before :: later
` later := 3
` return -before / 2
` } else if false {
` later :: 4
` return later
` } else {
` return 5
` }
`}
`main proc() bool { return identity(flag) }
scan_state := lexer.init(mem.c_allocator)
defer lexer.deinit(&scan_state)
try lexer.scan(&scan_state, source, &diagnostic_store)
tree := try parser.parse(mem.c_allocator, scan_state.tokens.items, source, &diagnostic_store)
defer ast.deinit(&tree)
resolution := try sema.resolve(mem.c_allocator, &tree, &diagnostic_store)
defer sema.deinit(&resolution)
result := try check(mem.c_allocator, &tree, &resolution, &diagnostic_store)
defer deinit(&result)
for (0..usize(9)) |i| {
declaration :: ast.package_decl(&tree, i)
try expect_kind(&result, declaration, .bool)
try expect_kind(&result, ast.statement_decl(&tree, declaration).initializer, .bool)
if (i < 3) continue
comparison_view :: ast.binary_expr(&tree, ast.statement_decl(&tree, declaration).initializer)
try expect_kind(&result, comparison_view.left, .float)
try expect_kind(&result, comparison_view.right, .float)
}
for (usize(9)..usize(11)) |i| try expect_kind(&result, ast.package_decl(&tree, i), .float)
identity :: ast.package_decl(&tree, 11)
try expect_kind(&result, ast.param(&tree, ast.function_param(&tree, identity, 0)).type, .bool)
try expect_kind(&result, ast.function_decl(&tree, identity).return_type, .bool)
factorial :: ast.package_decl(&tree, 12)
factorial_view :: ast.function_decl(&tree, factorial)
try expect_kind(&result, factorial, .function)
conditional :: ast.if_stmt(&tree, ast.block_statement(&tree, factorial_view.body, 0))
try expect_kind(&result, conditional.condition, .bool)
operands :: ast.binary_expr(&tree, conditional.condition)
try expect_kind(&result, operands.left, .int)
try expect_kind(&result, operands.right, .int)
fraction :: ast.function_decl(&tree, ast.package_decl(&tree, 13))
arms :: ast.if_stmt(&tree, ast.block_statement(&tree, fraction.body, 0))
for (0..usize(2)) |i| {
declaration :: ast.block_statement(&tree, arms.then_block, i)
try expect_kind(&result, declaration, .float)
try expect_kind(&result, ast.statement_decl(&tree, declaration).initializer, .float)
}
if (arms.else_block) |other| {
nested :: ast.if_stmt(&tree, ast.block_statement(&tree, other, 0))
try expect_kind(&result, ast.block_statement(&tree, nested.then_block, 0), .float)
} else {
return .expectation_failed
}
try testing.expect_equal(0, diagnostics.count(&diagnostic_store))
}
rejects_bool_numeric_mixing_and_preserves_invalid_condition_identity test {
strpool.strings = strpool.init(mem.c_allocator)
defer strpool.deinit(&strpool.strings)
diagnostic_store := diagnostics.init(mem.c_allocator)
defer diagnostics.deinit(&diagnostic_store)
source ::
`sum :: true + false
`order :: true < false
`mixed :: true == 1
`strings :: "x" == "x"
`wrong_bool bool :: 1
`wrong_int int :: false
`main proc() void {
` if (1) { okay :: true }
` if "text" { okay :: false }
` if absent { okay :: true }
` if true + false { okay :: false }
` if true { return } else { -"bad" }
`}
scan_state := lexer.init(mem.c_allocator)
defer lexer.deinit(&scan_state)
try lexer.scan(&scan_state, source, &diagnostic_store)
tree := try parser.parse(mem.c_allocator, scan_state.tokens.items, source, &diagnostic_store)
defer ast.deinit(&tree)
resolution := try sema.resolve(mem.c_allocator, &tree, &diagnostic_store)
defer sema.deinit(&resolution)
result := try check(mem.c_allocator, &tree, &resolution, &diagnostic_store)
defer deinit(&result)
for (0..usize(4)) |i| {
expression :: ast.statement_decl(&tree, ast.package_decl(&tree, i)).initializer
_ = try expect_error(&result, &diagnostic_store, expression, .invalid_operand, ast.node_span(&tree, expression))
}
for (usize(4)..usize(6)) |i| {
expression :: ast.statement_decl(&tree, ast.package_decl(&tree, i)).initializer
_ = try expect_error(&result, &diagnostic_store, expression, .type_mismatch, ast.node_span(&tree, expression))
}
function :: ast.package_decl(&tree, 6)
body :: ast.function_decl(&tree, function).body
for (0..usize(2)) |i| {
statement :: ast.block_statement(&tree, body, i)
condition :: ast.if_stmt(&tree, statement).condition
diagnostic :: try expect_error(&result, &diagnostic_store, condition, .condition_not_bool, ast.node_span(&tree, condition))
try testing.expect_equal(diagnostic, type_of(&result, statement).diagnostic)
}
unknown :: ast.if_stmt(&tree, ast.block_statement(&tree, body, 2)).condition
original :: sema.binding(&resolution, unknown).data.diagnostic
try testing.expect_equal(original, type_of(&result, unknown).diagnostic)
failed :: ast.if_stmt(&tree, ast.block_statement(&tree, body, 3)).condition
_ = try expect_error(&result, &diagnostic_store, failed, .invalid_operand, ast.node_span(&tree, failed))
final_if :: ast.block_statement(&tree, body, 4)
try expect_kind(&result, final_if, .void)
final_view :: ast.if_stmt(&tree, final_if)
if (final_view.else_block) |other| {
error_expr :: ast.statement_expr(&tree, ast.block_statement(&tree, other, 0))
_ = try expect_error(&result, &diagnostic_store, error_expr, .invalid_operand, ast.node_span(&tree, error_expr))
} else {
return .expectation_failed
}
try expect_kind(&result, function, .function)
try testing.expect_equal(2, code_count(&diagnostic_store, .condition_not_bool))
try testing.expect_equal(6, code_count(&diagnostic_store, .invalid_operand))
try testing.expect_equal(2, code_count(&diagnostic_store, .type_mismatch))
try testing.expect_equal(1, code_count(&diagnostic_store, .unknown_name))
try testing.expect_equal(11, diagnostics.count(&diagnostic_store))
}
analyzes_return_paths_after_trap_propagation_without_poisoning_signatures test {
strpool.strings = strpool.init(mem.c_allocator)
defer strpool.deinit(&strpool.strings)
diagnostic_store := diagnostics.init(mem.c_allocator)
defer diagnostics.deinit(&diagnostic_store)
source ::
`both proc(flag bool) int {
` if flag { return 1 } else { return 2 }
`}
`missing proc() int { if true { return 1 } }
`bad_arm proc(flag bool) int { if flag { -"bad" } }
`trap_and_return proc(flag bool) int {
` if flag { return 1 } else { bad int :: false }
`}
`invalid_condition proc() int { if 1 {} }
`invalid_expression proc() int { -"bad" }
`invalid_declaration proc() int { bad bool :: 1 }
`syntax_trap proc() int {
` return 1 stray
`}
`unreachable proc() int {
` return 1
` -"bad"
`}
`nested proc(a bool, b bool) int {
` if a { if b { return 1 } else { return 2 } } else { return 3 }
`}
`join proc(flag bool) int {
` if flag {} else { return 1 }
` return 2
`}
`answer :: bad_arm(false)
`wrong_return proc(flag bool) int {
` if flag { return false } else { return 1 }
`}
scan_state := lexer.init(mem.c_allocator)
defer lexer.deinit(&scan_state)
try lexer.scan(&scan_state, source, &diagnostic_store)
tree := try parser.parse(mem.c_allocator, scan_state.tokens.items, source, &diagnostic_store)
defer ast.deinit(&tree)
resolution := try sema.resolve(mem.c_allocator, &tree, &diagnostic_store)
defer sema.deinit(&resolution)
result := try check(mem.c_allocator, &tree, &resolution, &diagnostic_store)
defer deinit(&result)
for (0..usize(11)) |i| try expect_kind(&result, ast.package_decl(&tree, i), .function)
for (usize(1)..usize(3)) |i| {
body :: ast.function_decl(&tree, ast.package_decl(&tree, i)).body
_ = try expect_error(&result, &diagnostic_store, body, .missing_return, ast.node_span(&tree, body))
}
bad_body :: ast.function_decl(&tree, ast.package_decl(&tree, 2)).body
conditional :: ast.block_statement(&tree, bad_body, 0)
try expect_kind(&result, conditional, .void)
arm :: ast.if_stmt(&tree, conditional).then_block
operand :: ast.statement_expr(&tree, ast.block_statement(&tree, arm, 0))
original :: try expect_error(&result, &diagnostic_store, operand, .invalid_operand, ast.node_span(&tree, operand))
try testing.expect_equal(original, type_of(&result, arm).diagnostic)
try testing.expect(type_of(&result, bad_body).diagnostic != original)
condition_body :: ast.function_decl(&tree, ast.package_decl(&tree, 4)).body
condition :: ast.if_stmt(&tree, ast.block_statement(&tree, condition_body, 0)).condition
condition_diag :: try expect_error(&result, &diagnostic_store, condition, .condition_not_bool, ast.node_span(&tree, condition))
try testing.expect_equal(condition_diag, type_of(&result, condition_body).diagnostic)
recovered :: ast.function_decl(&tree, ast.package_decl(&tree, 7)).body
syntax :: ast.block_statement(&tree, recovered, 0)
try testing.expect_equal(ast.invalid(&tree, syntax).diagnostic, type_of(&result, recovered).diagnostic)
unreachable_body :: ast.function_decl(&tree, ast.package_decl(&tree, 8)).body
checked_after_return :: ast.statement_expr(&tree, ast.block_statement(&tree, unreachable_body, 1))
_ = try expect_error(&result, &diagnostic_store, checked_after_return, .invalid_operand, ast.node_span(&tree, checked_after_return))
try expect_kind(&result, ast.package_decl(&tree, 11), .int)
wrong_function :: ast.package_decl(&tree, 12)
try expect_kind(&result, wrong_function, .function)
wrong_body :: ast.function_decl(&tree, wrong_function).body
wrong_if :: ast.block_statement(&tree, wrong_body, 0)
try expect_kind(&result, wrong_if, .void)
wrong_arm :: ast.if_stmt(&tree, wrong_if).then_block
wrong_statement :: ast.block_statement(&tree, wrong_arm, 0)
if (ast.return_stmt(&tree, wrong_statement).value) |value| {
mismatch :: try expect_error(&result, &diagnostic_store, value, .return_type_mismatch, ast.node_span(&tree, value))
try testing.expect_equal(mismatch, type_of(&result, wrong_statement).diagnostic)
try testing.expect_equal(mismatch, type_of(&result, wrong_body).diagnostic)
} else {
return .expectation_failed
}
try testing.expect_equal(1, code_count(&diagnostic_store, .return_type_mismatch))
try testing.expect_equal(2, code_count(&diagnostic_store, .missing_return))
try testing.expect_equal(1, code_count(&diagnostic_store, .condition_not_bool))
}