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honey/source/sema/resolve.hon
T

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import "@std/debug"
import "@std/mem"
import "@std/hashmap"
import "@std/strmap"
import "@source/ast"
import "@source/diagnostics"
BuiltinType :: enum { int, float, bool, string, void }
@hide:file
builtins strmap.StaticStringMap(BuiltinType) :: strmap.init([
{ "int", .int },
{ "float", .float },
{ "bool", .bool },
{ "string", .string },
{ "void", .void },
])
BindingKind :: enum { none, declaration, builtin, invalid }
BindingData :: union {
declaration ast.NodeId
builtin BuiltinType
diagnostic diagnostics.DiagnosticId
}
Binding :: struct {
kind BindingKind = .none
data BindingData = BindingData{ diagnostic = diagnostics.no_diagnostic }
}
@hide:file
Storage :: struct {
bindings []mut Binding
allocator mem.Allocator
}
#! owns binding storage and retains its allocator; release with deinit.
#! node and diagnostic IDs refer to the caller's Tree and diagnostics.Store.
Resolution :: struct { storage Storage }
@hide:file
Scope :: struct {
names hashmap.StringHashMap(Binding)
parent ?@Scope
}
@hide:file
State :: struct {
tree @ast.Tree
diagnostics @mut diagnostics.Store
bindings []mut Binding
allocator mem.Allocator
}
#! borrows `tree` and `diagnostic_store` during resolution, without retaining their storage.
#! `allocator` supplies caller-owned bindings and temporary scopes released before return.
#! release the returned Resolution with deinit, which uses the retained allocator.
resolve proc(
allocator mem.Allocator,
tree @ast.Tree,
diagnostic_store @mut diagnostics.Store,
) Resolution ! (mem.AllocError | diagnostics.CapacityError) {
bindings :: try mem.alloc(Binding, allocator, ast.node_count(tree))
errdefer mem.free(allocator, bindings)
mem.set(bindings, Binding{})
state := State{
tree = tree,
diagnostics = diagnostic_store,
bindings = bindings,
allocator = allocator,
}
package_scope := Scope{ names = hashmap.init(allocator), parent = null }
defer hashmap.deinit(&package_scope.names)
for (0..ast.package_decl_count(tree)) |i| {
id :: ast.package_decl(tree, i)
match ast.decl_kind(tree, id) {
.statement: try predeclare(&state, &package_scope, id, ast.statement_decl(tree, id).name)
.function: try predeclare(&state, &package_scope, id, ast.function_decl(tree, id).name)
.invalid: {}
}
}
for (0..ast.package_decl_count(tree)) |i| {
id :: ast.package_decl(tree, i)
match ast.decl_kind(tree, id) {
.statement: try resolve_statement_decl(&state, &package_scope, id)
.function: try resolve_function(&state, &package_scope, id)
.invalid: resolve_invalid(&state, id)
}
}
return Resolution{ storage = Storage{ bindings = bindings, allocator = allocator } }
}
#! releases binding storage with the allocator retained by resolve.
deinit proc(resolution @mut Resolution) void {
mem.free(resolution.storage.allocator, resolution.storage.bindings)
}
binding proc(resolution @Resolution, id ast.NodeId) Binding {
debug.assert(usize(id) < resolution.storage.bindings.len)
return resolution.storage.bindings[usize(id)]
}
@hide:file
lookup proc(scope ?@Scope, name []u8) ?Binding {
if scope |current| {
if hashmap.get(&current.names, name) |found| return found
return lookup(current.parent, name)
}
if strmap.get(&builtins, name) |type| {
return Binding{ kind = .builtin, data = BindingData{ builtin = type } }
}
return null
}
@hide:file
put_name proc(scope @mut Scope, name []u8, value Binding) void ! mem.AllocError {
hashmap.put(&scope.names, name, value) catch |err| {
match err {
.key_exists: unreachable
else: return err
}
}
}
@hide:file
predeclare proc(
state @mut State,
scope @mut Scope,
id ast.NodeId,
name_span ast.Span,
) void ! (mem.AllocError | diagnostics.CapacityError) {
name :: ast.source_text(state.tree, name_span)
if hashmap.get(&scope.names, name) |_| {
diagnostic :: try diagnostics.add(state.diagnostics, .duplicate_name, name_span)
state.bindings[usize(id)] = Binding{
kind = .invalid,
data = BindingData{ diagnostic = diagnostic },
}
return
}
value := Binding{ kind = .declaration, data = BindingData{ declaration = id } }
if lookup(scope.parent, name) |_| {
diagnostic :: try diagnostics.add(state.diagnostics, .duplicate_name, name_span)
# poison the inner name rather than silently binding uses to its ancestor.
value = Binding{ kind = .invalid, data = BindingData{ diagnostic = diagnostic } }
}
try put_name(scope, name, value)
state.bindings[usize(id)] = value
}
@hide:file
resolve_function proc(
state @mut State,
package_scope @Scope,
id ast.NodeId,
) void ! (mem.AllocError | diagnostics.CapacityError) {
tree :: state.tree
function :: ast.function_decl(tree, id)
# signatures cannot see parameters or body-local declarations.
try resolve_expr(state, package_scope, function.return_type)
for (0..ast.function_param_count(tree, id)) |i| {
parameter :: ast.function_param(tree, id, i)
try resolve_expr(state, package_scope, ast.param(tree, parameter).type)
}
scope := Scope{ names = hashmap.init(state.allocator), parent = package_scope }
defer hashmap.deinit(&scope.names)
for (0..ast.function_param_count(tree, id)) |i| {
parameter :: ast.function_param(tree, id, i)
try predeclare(state, &scope, parameter, ast.param(tree, parameter).name)
}
try resolve_block(state, &scope, function.body)
}
@hide:file
resolve_arm proc(state @mut State, parent @Scope, id ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
scope := Scope{ names = hashmap.init(state.allocator), parent = parent }
defer hashmap.deinit(&scope.names)
try resolve_block(state, &scope, id)
}
@hide:file
resolve_block proc(state @mut State, scope @mut Scope, id ast.NodeId) void ! (mem.AllocError | diagnostics.CapacityError) {
tree :: state.tree
for (0..ast.block_statement_count(tree, id)) |i| {
statement :: ast.block_statement(tree, id, i)
if ast.stmt_kind(tree, statement) == .declaration {
try predeclare(state, scope, statement, ast.statement_decl(tree, statement).name)
}
}
for (0..ast.block_statement_count(tree, id)) |i| {
statement :: ast.block_statement(tree, id, i)
match ast.stmt_kind(tree, statement) {
.declaration: try resolve_statement_decl(state, scope, statement)
.expression: try resolve_expr(state, scope, ast.statement_expr(tree, statement))
.return_stmt: {
if (ast.return_stmt(tree, statement).value) |value| try resolve_expr(state, scope, value)
}
.break_stmt, .continue_stmt: {}
.if_stmt: {
conditional :: ast.if_stmt(tree, statement)
try resolve_expr(state, scope, conditional.condition)
try resolve_arm(state, scope, conditional.then_block)
if (conditional.else_block) |other| try resolve_arm(state, scope, other)
}
.assignment_stmt: {
assignment :: ast.assignment_stmt(tree, statement)
try resolve_expr(state, scope, assignment.target)
try resolve_expr(state, scope, assignment.value)
}
.while_stmt: {
loop :: ast.while_stmt(tree, statement)
try resolve_expr(state, scope, loop.condition)
try resolve_arm(state, scope, loop.body)
}
.for_stmt: {
loop :: ast.for_stmt(tree, statement)
try resolve_expr(state, scope, loop.iterable)
body_scope := Scope{ names = hashmap.init(state.allocator), parent = scope }
defer hashmap.deinit(&body_scope.names)
if (loop.capture) |capture| {
try predeclare(state, &body_scope, capture, ast.node_span(tree, capture))
}
if (loop.index) |index| {
try predeclare(state, &body_scope, index, ast.node_span(tree, index))
}
try resolve_block(state, &body_scope, loop.body)
}
.invalid: resolve_invalid(state, statement)
}
}
}
@hide:file
resolve_statement_decl proc(
state @mut State,
scope @Scope,
id ast.NodeId,
) void ! (mem.AllocError | diagnostics.CapacityError) {
declaration :: ast.statement_decl(state.tree, id)
if (declaration.type) |type| try resolve_expr(state, scope, type)
try resolve_expr(state, scope, declaration.initializer)
}
@hide:file
resolve_invalid proc(state @mut State, id ast.NodeId) void {
if (state.bindings[usize(id)].kind != .none) return
state.bindings[usize(id)] = Binding{
kind = .invalid,
data = BindingData{ diagnostic = ast.invalid(state.tree, id).diagnostic },
}
}
@hide:file
resolve_expr proc(
state @mut State,
scope @Scope,
id ast.NodeId,
) void ! (mem.AllocError | diagnostics.CapacityError) {
# grouped parameters share their type node, including any diagnostic it owns.
if (state.bindings[usize(id)].kind != .none) return
tree :: state.tree
match ast.expr_kind(tree, id) {
.literal_int, .literal_float, .literal_bool, .literal_string: {}
.identifier: {
span :: ast.node_span(tree, id)
name :: ast.source_text(tree, span)
if lookup(scope, name) |found| {
state.bindings[usize(id)] = found
} else {
diagnostic :: try diagnostics.add(state.diagnostics, .unknown_name, span)
state.bindings[usize(id)] = Binding{
kind = .invalid,
data = BindingData{ diagnostic = diagnostic },
}
}
}
.unary: try resolve_expr(state, scope, ast.unary_expr(tree, id).operand)
.binary: {
expression :: ast.binary_expr(tree, id)
try resolve_expr(state, scope, expression.left)
try resolve_expr(state, scope, expression.right)
}
.range: {
expression :: ast.range_expr(tree, id)
try resolve_expr(state, scope, expression.start)
try resolve_expr(state, scope, expression.end)
}
.call: {
try resolve_expr(state, scope, ast.call_expr(tree, id).callee)
for (0..ast.call_arg_count(tree, id)) |i| {
try resolve_expr(state, scope, ast.call_arg(tree, id, i))
}
}
.invalid: resolve_invalid(state, id)
}
}