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IR: implement maybe return expression

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This commit is contained in:
Andrew Kelley 2016-12-13 19:36:56 -05:00
parent 3f3630d7e3
commit 647d13168a
4 changed files with 78 additions and 85 deletions
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2
src/ast_render.cpp
View File

@ -759,7 +759,7 @@ static void render_node_extra(AstRender *ar, AstNode *node, bool grouped) {
fprintf(ar->f, ": ");
render_node_ungrouped(ar, var_decl->type);
}
fprintf(ar->f, " = ");
fprintf(ar->f, " ?= ");
render_node_grouped(ar, var_decl->expr);
fprintf(ar->f, ") ");
render_node_grouped(ar, node->data.if_var_expr.then_block);

146
src/ir.cpp
View File

@ -1731,7 +1731,13 @@ static void ir_gen_defers_for_block(IrBuilder *irb, Scope *inner_scope, Scope *o
}
}
static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node) {
static void ir_set_cursor_at_end(IrBuilder *irb, IrBasicBlock *basic_block) {
assert(basic_block);
irb->current_basic_block = basic_block;
}
static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node, LValPurpose lval) {
assert(node->type == NodeTypeReturnExpr);
FnTableEntry *fn_entry = exec_fn_entry(irb->exec);
@ -1740,6 +1746,9 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node)
return irb->codegen->invalid_instruction;
}
Scope *outer_scope = fn_entry->child_scope;
bool is_inline = ir_should_inline(irb);
AstNode *expr_node = node->data.return_expr.expr;
switch (node->data.return_expr.kind) {
case ReturnKindUnconditional:
@ -1747,28 +1756,46 @@ static IrInstruction *ir_gen_return(IrBuilder *irb, Scope *scope, AstNode *node)
IrInstruction *return_value;
if (expr_node) {
return_value = ir_gen_node(irb, expr_node, scope);
if (return_value == irb->codegen->invalid_instruction)
return irb->codegen->invalid_instruction;
} else {
return_value = ir_build_const_void(irb, scope, node);
}
Scope *outer_scope = fn_entry->child_scope;
// TODO conditionally gen maybe defers and error defers
ir_gen_defers_for_block(irb, scope, outer_scope, false, false);
return ir_build_return(irb, scope, node, return_value);
}
case ReturnKindError:
zig_panic("TODO gen IR for %%return");
case ReturnKindMaybe:
zig_panic("TODO gen IR for ?return");
{
assert(expr_node);
IrInstruction *maybe_val_ptr = ir_gen_node_extra(irb, expr_node, scope, LValPurposeAddressOf);
if (maybe_val_ptr == irb->codegen->invalid_instruction)
return irb->codegen->invalid_instruction;
IrInstruction *is_nonnull_val = ir_build_test_null(irb, scope, node, maybe_val_ptr);
IrBasicBlock *return_block = ir_build_basic_block(irb, scope, "MaybeRetReturn");
IrBasicBlock *continue_block = ir_build_basic_block(irb, scope, "MaybeRetContinue");
ir_build_cond_br(irb, scope, node, is_nonnull_val, continue_block, return_block, is_inline);
ir_set_cursor_at_end(irb, return_block);
ir_gen_defers_for_block(irb, scope, outer_scope, false, true);
IrInstruction *null = ir_build_const_null(irb, scope, node);
ir_build_return(irb, scope, node, null);
ir_set_cursor_at_end(irb, continue_block);
IrInstruction *unwrapped_ptr = ir_build_unwrap_maybe(irb, scope, node, maybe_val_ptr, false);
if (lval != LValPurposeNone)
return unwrapped_ptr;
else
return ir_build_load_ptr(irb, scope, node, unwrapped_ptr);
}
}
zig_unreachable();
}
static void ir_set_cursor_at_end(IrBuilder *irb, IrBasicBlock *basic_block) {
assert(basic_block);
irb->current_basic_block = basic_block;
}
static VariableTableEntry *create_local_var(CodeGen *codegen, AstNode *node, Scope *parent_scope,
Buf *name, bool src_is_const, bool gen_is_const, bool is_shadowable, bool is_inline)
{
@ -3606,7 +3633,7 @@ static IrInstruction *ir_gen_node_raw(IrBuilder *irb, AstNode *node, Scope *scop
case NodeTypeArrayAccessExpr:
return ir_gen_array_access(irb, scope, node, lval);
case NodeTypeReturnExpr:
return ir_lval_wrap(irb, scope, ir_gen_return(irb, scope, node), lval);
return ir_gen_return(irb, scope, node, lval);
case NodeTypeFieldAccessExpr:
return ir_gen_field_access(irb, scope, node, lval);
case NodeTypeThisLiteral:
@ -3827,6 +3854,7 @@ static TypeTableEntry *ir_determine_peer_types(IrAnalyze *ira, AstNode *source_n
return ira->codegen->builtin_types.entry_invalid;
}
bool any_are_pure_error = (prev_inst->type_entry->id == TypeTableEntryIdPureError);
bool any_are_null = (prev_inst->type_entry->id == TypeTableEntryIdNullLit);
for (size_t i = 1; i < instruction_count; i += 1) {
IrInstruction *cur_inst = instructions[i];
TypeTableEntry *cur_type = cur_inst->type_entry;
@ -3836,9 +3864,15 @@ static TypeTableEntry *ir_determine_peer_types(IrAnalyze *ira, AstNode *source_n
} else if (prev_type->id == TypeTableEntryIdPureError) {
prev_inst = cur_inst;
continue;
} else if (prev_type->id == TypeTableEntryIdNullLit) {
prev_inst = cur_inst;
continue;
} else if (cur_type->id == TypeTableEntryIdPureError) {
any_are_pure_error = true;
continue;
} else if (cur_type->id == TypeTableEntryIdNullLit) {
any_are_null = true;
continue;
} else if (types_match_const_cast_only(prev_type, cur_type)) {
continue;
} else if (types_match_const_cast_only(cur_type, prev_type)) {
@ -3889,9 +3923,13 @@ static TypeTableEntry *ir_determine_peer_types(IrAnalyze *ira, AstNode *source_n
return ira->codegen->builtin_types.entry_invalid;
}
} else {
add_node_error(ira->codegen, source_node,
ErrorMsg *msg = add_node_error(ira->codegen, source_node,
buf_sprintf("incompatible types: '%s' and '%s'",
buf_ptr(&prev_type->name), buf_ptr(&cur_type->name)));
add_error_note(ira->codegen, msg, prev_inst->source_node,
buf_sprintf("type '%s' here", buf_ptr(&prev_type->name)));
add_error_note(ira->codegen, msg, cur_inst->source_node,
buf_sprintf("type '%s' here", buf_ptr(&cur_type->name)));
return ira->codegen->builtin_types.entry_invalid;
}
@ -3903,9 +3941,23 @@ static TypeTableEntry *ir_determine_peer_types(IrAnalyze *ira, AstNode *source_n
add_node_error(ira->codegen, source_node,
buf_sprintf("unable to make error union out of number literal"));
return ira->codegen->builtin_types.entry_invalid;
} else if (prev_inst->type_entry->id == TypeTableEntryIdNullLit) {
add_node_error(ira->codegen, source_node,
buf_sprintf("unable to make error union out of null literal"));
return ira->codegen->builtin_types.entry_invalid;
} else {
return get_error_type(ira->codegen, prev_inst->type_entry);
}
} else if (any_are_null && prev_inst->type_entry->id != TypeTableEntryIdNullLit) {
if (prev_inst->type_entry->id == TypeTableEntryIdNumLitInt ||
prev_inst->type_entry->id == TypeTableEntryIdNumLitFloat)
{
add_node_error(ira->codegen, source_node,
buf_sprintf("unable to make maybe out of number literal"));
return ira->codegen->builtin_types.entry_invalid;
} else {
return get_maybe_type(ira->codegen, prev_inst->type_entry);
}
} else {
return prev_inst->type_entry;
}
@ -9053,16 +9105,9 @@ bool ir_has_side_effects(IrInstruction *instruction) {
//static TypeTableEntry *analyze_return_expr(CodeGen *g, ImportTableEntry *import, BlockContext *context,
// TypeTableEntry *expected_type, AstNode *node)
//{
// if (!node->data.return_expr.expr) {
// node->data.return_expr.expr = create_ast_void_node(g, import, node);
// normalize_parent_ptrs(node);
// }
//
// TypeTableEntry *expected_return_type = get_return_type(context);
//
// switch (node->data.return_expr.kind) {
// case ReturnKindUnconditional:
// zig_panic("TODO moved to ir.cpp");
// case ReturnKindError:
// {
// TypeTableEntry *expected_err_type;
@ -9093,34 +9138,6 @@ bool ir_has_side_effects(IrInstruction *instruction) {
// return g->builtin_types.entry_invalid;
// }
// }
// case ReturnKindMaybe:
// {
// TypeTableEntry *expected_maybe_type;
// if (expected_type) {
// expected_maybe_type = get_maybe_type(g, expected_type);
// } else {
// expected_maybe_type = nullptr;
// }
// TypeTableEntry *resolved_type = analyze_expression(g, import, context, expected_maybe_type,
// node->data.return_expr.expr);
// if (resolved_type->id == TypeTableEntryIdInvalid) {
// return resolved_type;
// } else if (resolved_type->id == TypeTableEntryIdMaybe) {
// if (expected_return_type->id != TypeTableEntryIdMaybe) {
// ErrorMsg *msg = add_node_error(g, node,
// buf_sprintf("?return statement in function with return type '%s'",
// buf_ptr(&expected_return_type->name)));
// AstNode *return_type_node = context->fn_entry->fn_def_node->data.fn_def.fn_proto->data.fn_proto.return_type;
// add_error_note(g, msg, return_type_node, buf_sprintf("function return type here"));
// }
//
// return resolved_type->data.maybe.child_type;
// } else {
// add_node_error(g, node->data.return_expr.expr,
// buf_sprintf("expected maybe type, found '%s'", buf_ptr(&resolved_type->name)));
// return g->builtin_types.entry_invalid;
// }
// }
// }
// zig_unreachable();
//}
@ -9344,43 +9361,6 @@ bool ir_has_side_effects(IrInstruction *instruction) {
// return nullptr;
// }
// }
// case ReturnKindMaybe:
// {
// assert(value_type->id == TypeTableEntryIdMaybe);
// TypeTableEntry *child_type = value_type->data.maybe.child_type;
//
// LLVMBasicBlockRef return_block = LLVMAppendBasicBlock(g->cur_fn->fn_value, "MaybeRetReturn");
// LLVMBasicBlockRef continue_block = LLVMAppendBasicBlock(g->cur_fn->fn_value, "MaybeRetContinue");
//
// LLVMValueRef maybe_val_ptr = LLVMBuildStructGEP(g->builder, value, 1, "");
// LLVMValueRef is_non_null = LLVMBuildLoad(g->builder, maybe_val_ptr, "");
//
// LLVMValueRef zero = LLVMConstNull(LLVMInt1Type());
// LLVMValueRef cond_val = LLVMBuildICmp(g->builder, LLVMIntNE, is_non_null, zero, "");
// LLVMBuildCondBr(g->builder, cond_val, continue_block, return_block);
//
// LLVMPositionBuilderAtEnd(g->builder, return_block);
// TypeTableEntry *return_type = g->cur_fn->type_entry->data.fn.fn_type_id.return_type;
// assert(return_type->id == TypeTableEntryIdMaybe);
// if (handle_is_ptr(return_type)) {
// assert(g->cur_ret_ptr);
//
// LLVMValueRef maybe_bit_ptr = LLVMBuildStructGEP(g->builder, g->cur_ret_ptr, 1, "");
// LLVMBuildStore(g->builder, zero, maybe_bit_ptr);
// LLVMBuildRetVoid(g->builder);
// } else {
// LLVMValueRef ret_zero_value = LLVMConstNull(return_type->type_ref);
// gen_return(g, node, ret_zero_value, ReturnKnowledgeKnownNull);
// }
//
// LLVMPositionBuilderAtEnd(g->builder, continue_block);
// if (type_has_bits(child_type)) {
// LLVMValueRef val_ptr = LLVMBuildStructGEP(g->builder, value, 0, "");
// return get_handle_value(g, val_ptr, child_type);
// } else {
// return nullptr;
// }
// }
// }
// zig_unreachable();
//}

2
src/ir_print.cpp
View File

@ -585,7 +585,7 @@ static void ir_print_size_of(IrPrint *irp, IrInstructionSizeOf *instruction) {
static void ir_print_test_null(IrPrint *irp, IrInstructionTestNull *instruction) {
fprintf(irp->f, "*");
ir_print_other_instruction(irp, instruction->value);
fprintf(irp->f, " == null");
fprintf(irp->f, " != null");
}
static void ir_print_unwrap_maybe(IrPrint *irp, IrInstructionUnwrapMaybe *instruction) {

13
test/self_hosted2.zig
View File

@ -343,6 +343,18 @@ fn shlWithOverflow() {
assert(result == 0b1011111111111100);
}
fn assignToIfVarPtr() {
var maybe_bool: ?bool = true;
if (const *b ?= maybe_bool) {
*b = false;
}
assert(??maybe_bool == false);
}
fn assert(ok: bool) {
if (!ok)
@unreachable();
@ -377,6 +389,7 @@ fn runAllTests() {
intTypeBuiltin();
overflowIntrinsics();
shlWithOverflow();
assignToIfVarPtr();
}
export nakedcc fn _start() -> unreachable {