diff options
| -rw-r--r-- | boot/ir.c | 3 | ||||
| -rw-r--r-- | boot/lower.c | 18 | ||||
| -rw-r--r-- | boot/transpile.c | 30 |
3 files changed, 45 insertions, 6 deletions
@@ -468,6 +468,9 @@ struct Function // synthetic structure containing all captured locals. (only stateful lambdas) Type_Id capture_state_type_id; + // for nested functions this is the enclosing function. nil for top-level. + struct Function* parent_function; + // tree-side header which produced this function node. // required for synthesizing the closure type after function is lowered. struct Tree_Function_Header* ast_header; diff --git a/boot/lower.c b/boot/lower.c index 81f39a5..4d00c5d 100644 --- a/boot/lower.c +++ b/boot/lower.c @@ -41,8 +41,8 @@ struct Lower_Local_Lookup_Capture bool captured; // the captured local's declared type struct Type_Ref type; - // which function does this capture belong to? - struct Function* captured_into; + // the function the local lives in. + struct Function* owner; }; // what kind of scope is this? @@ -924,6 +924,7 @@ void lower_record_capture(struct Function* fn, struct String name, struct Type_R void lower_push_scope_function(struct Lower_Context* ctx, struct Function* owner); void lower_pop_scope(struct Lower_Context* ctx, enum Scope_Type expected); void lower_declare_local(struct Lower_Context* ctx, struct String name, struct Type_Ref type); +struct Function* lower_current_function(struct Lower_Context* ctx); struct Expression* lower_expression_integer_literal(struct Lower_Context* ctx, struct Tree_Expression* tree_expr) @@ -971,7 +972,12 @@ lower_expression_name(struct Lower_Context* ctx, struct Tree_Expression* tree_ex // locals that were defined in an upper function scope are captured. struct Lower_Local_Lookup_Capture lookup = lower_local_lookup_capturing(ctx, name); if (lookup.captured) { - lower_record_capture(lookup.captured_into, name, lookup.type); + struct Function* fn = lower_current_function(ctx); + // we walk the enclosing function chain to record every in-between capture. + while (fn && fn != lookup.owner) { + lower_record_capture(fn, name, lookup.type); + fn = fn->parent_function; + } return ir_make_capture_ref(name, tree_expr->span); } @@ -1318,6 +1324,7 @@ lower_expression_function(struct Lower_Context* ctx, struct Tree_Expression* tre struct Function* fn = *array_at(struct Function*, &ctx->unit->functions.entries, id); fn->synthetic = true; + fn->parent_function = lower_current_function(ctx); lower_fill_function_signature(ctx, fn, tree_expr); // lower the body inline so name lookups inside see the enclosing @@ -1507,7 +1514,8 @@ lower_local_lookup(struct Lower_Context* ctx, struct String name, struct Type_Re // walk the scope stack looking for a local, which could be captured. // if the local was declared in some enclosing function that's not us, -// the local becomes captured by our closure function. +// the local becomes captured by our closure function (and any lambdas +// nested between us and the local's owner). struct Lower_Local_Lookup_Capture lower_local_lookup_capturing(struct Lower_Context* ctx, struct String name) { @@ -1522,7 +1530,7 @@ lower_local_lookup_capturing(struct Lower_Context* ctx, struct String name) return (struct Lower_Local_Lookup_Capture){ .captured = from_enclosing, .type = var->type, - .captured_into = from_enclosing ? current : nil, + .owner = scope->containing_function, }; } } diff --git a/boot/transpile.c b/boot/transpile.c index ac480cb..e0af3bf 100644 --- a/boot/transpile.c +++ b/boot/transpile.c @@ -92,6 +92,9 @@ struct Transpiler // expressions use this to decide whether to wrap themselves in parentheses // in the case where their parent expression is stronger than them. uint expression_parent_precedence; + + // the function whose body we are in, if any. + struct Function* current_function; }; void @@ -389,6 +392,9 @@ transpile_visit_function_body(struct Visit* visit, struct Function* function) return; } + struct Function* previous_function = transpiler->current_function; + transpiler->current_function = function; // record current function context + if (function->synthetic) { TRANSPILE_WRITE(" {\n"); transpiler->indent_level++; @@ -406,12 +412,14 @@ transpile_visit_function_body(struct Visit* visit, struct Function* function) transpiler->indent_level--; transpile_emit_indent(transpiler); TRANSPILE_WRITE("}\n"); + transpiler->current_function = previous_function; return; } TRANSPILE_WRITE(" "); VISIT(visit_block, function->body); TRANSPILE_WRITE("\n"); + transpiler->current_function = previous_function; if (function->closure_type_id != 0) transpile_function_emit_thunk(visit, function); } @@ -511,7 +519,27 @@ transpile_visit_expression_reference(struct Visit* visit, struct Expression* exp bool first = true; FOR_EACH_ARRAY (struct Capture, cap, &fn->captures) { if (!first) TRANSPILE_WRITE(", "); - TRANSPILE_WRITE(".%s = &%s", string_c_str(cap->name), string_c_str(cap->name)); + + bool from_constructors_state = false; + if (transpiler->current_function) { + FOR_EACH_ARRAY ( + struct Capture, outer, &transpiler->current_function->captures) { + if (string_equals(outer->name, cap->name)) { + from_constructors_state = true; + break; + } + } + } + + if (from_constructors_state) { + // we are multiple closures deep, steal the reference + // from our closure parent + TRANSPILE_WRITE( + ".%s = state->%s", string_c_str(cap->name), string_c_str(cap->name)); + } else { + // capture reference to a local on the stack + TRANSPILE_WRITE(".%s = &%s", string_c_str(cap->name), string_c_str(cap->name)); + } first = false; } TRANSPILE_WRITE(" }"); |