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stage2: make error{} the same size as anyerror

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Having `error{}` be a zero bit type causes issues when it interracts
with empty inferred error sets which are the same size as `anyerror`.
This commit is contained in:
Veikka Tuominen
2022-06-10 14:11:59 +03:00
parent 488e1e5f51
commit 0333ff4476
11 changed files with 123 additions and 476 deletions
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78
src/codegen/c.zig
View File

@@ -752,12 +752,6 @@ pub const DeclGen = struct {
const error_type = ty.errorUnionSet();
const payload_type = ty.errorUnionPayload();
if (error_type.errorSetCardinality() == .zero) {
// We use the payload directly as the type.
const payload_val = val.castTag(.eu_payload).?.data;
return dg.renderValue(writer, payload_type, payload_val, location);
}
if (!payload_type.hasRuntimeBits()) {
// We use the error type directly as the type.
const err_val = if (val.errorUnionIsPayload()) Value.initTag(.zero) else val;
@@ -1381,13 +1375,8 @@ pub const DeclGen = struct {
return w.writeAll("uint16_t");
},
.ErrorUnion => {
const error_ty = t.errorUnionSet();
const payload_ty = t.errorUnionPayload();
if (error_ty.errorSetCardinality() == .zero) {
return dg.renderType(w, payload_ty);
}
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
return dg.renderType(w, Type.anyerror);
}
@@ -2892,41 +2881,36 @@ fn lowerTry(
operand_is_ptr: bool,
result_ty: Type,
) !CValue {
if (err_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
// If the error set has no fields, then the payload and the error
// union are the same value.
return err_union;
}
const writer = f.object.writer();
const payload_ty = err_union_ty.errorUnionPayload();
const payload_has_bits = payload_ty.hasRuntimeBitsIgnoreComptime();
const writer = f.object.writer();
err: {
if (!payload_has_bits) {
if (operand_is_ptr) {
try writer.writeAll("if(*");
} else {
try writer.writeAll("if(");
if (!err_union_ty.errorUnionSet().errorSetIsEmpty()) {
err: {
if (!payload_has_bits) {
if (operand_is_ptr) {
try writer.writeAll("if(*");
} else {
try writer.writeAll("if(");
}
try f.writeCValue(writer, err_union);
try writer.writeAll(")");
break :err;
}
if (operand_is_ptr or isByRef(err_union_ty)) {
try writer.writeAll("if(");
try f.writeCValue(writer, err_union);
try writer.writeAll("->error)");
break :err;
}
try f.writeCValue(writer, err_union);
try writer.writeAll(")");
break :err;
}
if (operand_is_ptr or isByRef(err_union_ty)) {
try writer.writeAll("if(");
try f.writeCValue(writer, err_union);
try writer.writeAll("->error)");
break :err;
try writer.writeAll(".error)");
}
try writer.writeAll("if(");
try f.writeCValue(writer, err_union);
try writer.writeAll(".error)");
}
try genBody(f, body);
try f.object.indent_writer.insertNewline();
try genBody(f, body);
try f.object.indent_writer.insertNewline();
}
if (!payload_has_bits) {
if (!operand_is_ptr) {
@@ -3466,7 +3450,7 @@ fn airUnwrapErrUnionErr(f: *Function, inst: Air.Inst.Index) !CValue {
if (operand_ty.zigTypeTag() == .Pointer) {
const err_union_ty = operand_ty.childType();
if (err_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
if (err_union_ty.errorUnionSet().errorSetIsEmpty()) {
return CValue{ .bytes = "0" };
}
if (!err_union_ty.errorUnionPayload().hasRuntimeBits()) {
@@ -3478,7 +3462,7 @@ fn airUnwrapErrUnionErr(f: *Function, inst: Air.Inst.Index) !CValue {
try writer.writeAll(";\n");
return local;
}
if (operand_ty.errorUnionSet().errorSetCardinality() == .zero) {
if (operand_ty.errorUnionSet().errorSetIsEmpty()) {
return CValue{ .bytes = "0" };
}
if (!operand_ty.errorUnionPayload().hasRuntimeBits()) {
@@ -3507,10 +3491,6 @@ fn airUnwrapErrUnionPay(f: *Function, inst: Air.Inst.Index, maybe_addrof: [*:0]c
const operand_is_ptr = operand_ty.zigTypeTag() == .Pointer;
const error_union_ty = if (operand_is_ptr) operand_ty.childType() else operand_ty;
if (error_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
return operand;
}
if (!error_union_ty.errorUnionPayload().hasRuntimeBits()) {
return CValue.none;
}
@@ -3575,11 +3555,6 @@ fn airErrUnionPayloadPtrSet(f: *Function, inst: Air.Inst.Index) !CValue {
const error_ty = error_union_ty.errorUnionSet();
const payload_ty = error_union_ty.errorUnionPayload();
if (error_ty.errorSetCardinality() == .zero) {
// TODO: write undefined bytes through the pointer here
return operand;
}
// First, set the non-error value.
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
try f.writeCValueDeref(writer, operand);
@@ -3623,9 +3598,6 @@ fn airWrapErrUnionPay(f: *Function, inst: Air.Inst.Index) !CValue {
const operand = try f.resolveInst(ty_op.operand);
const inst_ty = f.air.typeOfIndex(inst);
if (inst_ty.errorUnionSet().errorSetCardinality() == .zero) {
return operand;
}
const local = try f.allocLocal(inst_ty, .Const);
try writer.writeAll(" = { .error = 0, .payload = ");
try f.writeCValue(writer, operand);
@@ -3652,7 +3624,7 @@ fn airIsErr(
try writer.writeAll(" = ");
if (error_ty.errorSetCardinality() == .zero) {
if (error_ty.errorSetIsEmpty()) {
try writer.print("0 {s} 0;\n", .{op_str});
} else {
if (is_ptr) {

98
src/codegen/llvm.zig
View File

@@ -1571,22 +1571,6 @@ pub const Object = struct {
},
.ErrorUnion => {
const payload_ty = ty.errorUnionPayload();
switch (ty.errorUnionSet().errorSetCardinality()) {
.zero => {
const payload_di_ty = try o.lowerDebugType(payload_ty, .full);
// The recursive call to `lowerDebugType` means we can't use `gop` anymore.
try o.di_type_map.putContext(gpa, ty, AnnotatedDITypePtr.initFull(payload_di_ty), .{ .mod = o.module });
return payload_di_ty;
},
.one => {
if (payload_ty.isNoReturn()) {
const di_type = dib.createBasicType("void", 0, DW.ATE.signed);
gop.value_ptr.* = AnnotatedDITypePtr.initFull(di_type);
return di_type;
}
},
.many => {},
}
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
const err_set_di_ty = try o.lowerDebugType(Type.anyerror, .full);
// The recursive call to `lowerDebugType` means we can't use `gop` anymore.
@@ -2554,15 +2538,6 @@ pub const DeclGen = struct {
},
.ErrorUnion => {
const payload_ty = t.errorUnionPayload();
switch (t.errorUnionSet().errorSetCardinality()) {
.zero => return dg.lowerType(payload_ty),
.one => {
if (payload_ty.isNoReturn()) {
return dg.context.voidType();
}
},
.many => {},
}
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
return try dg.lowerType(Type.anyerror);
}
@@ -3222,10 +3197,6 @@ pub const DeclGen = struct {
},
.ErrorUnion => {
const payload_type = tv.ty.errorUnionPayload();
if (tv.ty.errorUnionSet().errorSetCardinality() == .zero) {
const payload_val = tv.val.castTag(.eu_payload).?.data;
return dg.lowerValue(.{ .ty = payload_type, .val = payload_val });
}
const is_pl = tv.val.errorUnionIsPayload();
if (!payload_type.hasRuntimeBitsIgnoreComptime()) {
@@ -4795,40 +4766,37 @@ pub const FuncGen = struct {
}
fn lowerTry(fg: *FuncGen, err_union: *const llvm.Value, body: []const Air.Inst.Index, err_union_ty: Type, operand_is_ptr: bool, result_ty: Type) !?*const llvm.Value {
if (err_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
// If the error set has no fields, then the payload and the error
// union are the same value.
return err_union;
}
const payload_ty = err_union_ty.errorUnionPayload();
const payload_has_bits = payload_ty.hasRuntimeBitsIgnoreComptime();
const target = fg.dg.module.getTarget();
const is_err = err: {
const err_set_ty = try fg.dg.lowerType(Type.anyerror);
const zero = err_set_ty.constNull();
if (!payload_has_bits) {
const loaded = if (operand_is_ptr) fg.builder.buildLoad(err_union, "") else err_union;
if (!err_union_ty.errorUnionSet().errorSetIsEmpty()) {
const is_err = err: {
const err_set_ty = try fg.dg.lowerType(Type.anyerror);
const zero = err_set_ty.constNull();
if (!payload_has_bits) {
const loaded = if (operand_is_ptr) fg.builder.buildLoad(err_union, "") else err_union;
break :err fg.builder.buildICmp(.NE, loaded, zero, "");
}
const err_field_index = errUnionErrorOffset(payload_ty, target);
if (operand_is_ptr or isByRef(err_union_ty)) {
const err_field_ptr = fg.builder.buildStructGEP(err_union, err_field_index, "");
const loaded = fg.builder.buildLoad(err_field_ptr, "");
break :err fg.builder.buildICmp(.NE, loaded, zero, "");
}
const loaded = fg.builder.buildExtractValue(err_union, err_field_index, "");
break :err fg.builder.buildICmp(.NE, loaded, zero, "");
}
const err_field_index = errUnionErrorOffset(payload_ty, target);
if (operand_is_ptr or isByRef(err_union_ty)) {
const err_field_ptr = fg.builder.buildStructGEP(err_union, err_field_index, "");
const loaded = fg.builder.buildLoad(err_field_ptr, "");
break :err fg.builder.buildICmp(.NE, loaded, zero, "");
}
const loaded = fg.builder.buildExtractValue(err_union, err_field_index, "");
break :err fg.builder.buildICmp(.NE, loaded, zero, "");
};
};
const return_block = fg.context.appendBasicBlock(fg.llvm_func, "TryRet");
const continue_block = fg.context.appendBasicBlock(fg.llvm_func, "TryCont");
_ = fg.builder.buildCondBr(is_err, return_block, continue_block);
const return_block = fg.context.appendBasicBlock(fg.llvm_func, "TryRet");
const continue_block = fg.context.appendBasicBlock(fg.llvm_func, "TryCont");
_ = fg.builder.buildCondBr(is_err, return_block, continue_block);
fg.builder.positionBuilderAtEnd(return_block);
try fg.genBody(body);
fg.builder.positionBuilderAtEnd(return_block);
try fg.genBody(body);
fg.builder.positionBuilderAtEnd(continue_block);
fg.builder.positionBuilderAtEnd(continue_block);
}
if (!payload_has_bits) {
if (!operand_is_ptr) return null;
@@ -5665,7 +5633,7 @@ pub const FuncGen = struct {
const err_set_ty = try self.dg.lowerType(Type.initTag(.anyerror));
const zero = err_set_ty.constNull();
if (err_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
if (err_union_ty.errorUnionSet().errorSetIsEmpty()) {
const llvm_i1 = self.context.intType(1);
switch (op) {
.EQ => return llvm_i1.constInt(1, .False), // 0 == 0
@@ -5788,13 +5756,6 @@ pub const FuncGen = struct {
const ty_op = self.air.instructions.items(.data)[inst].ty_op;
const operand = try self.resolveInst(ty_op.operand);
const operand_ty = self.air.typeOf(ty_op.operand);
const error_union_ty = if (operand_is_ptr) operand_ty.childType() else operand_ty;
if (error_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
// If the error set has no fields, then the payload and the error
// union are the same value.
return operand;
}
const result_ty = self.air.typeOfIndex(inst);
const payload_ty = if (operand_is_ptr) result_ty.childType() else result_ty;
const target = self.dg.module.getTarget();
@@ -5825,7 +5786,7 @@ pub const FuncGen = struct {
const operand = try self.resolveInst(ty_op.operand);
const operand_ty = self.air.typeOf(ty_op.operand);
const err_union_ty = if (operand_is_ptr) operand_ty.childType() else operand_ty;
if (err_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
if (err_union_ty.errorUnionSet().errorSetIsEmpty()) {
const err_llvm_ty = try self.dg.lowerType(Type.anyerror);
if (operand_is_ptr) {
return self.builder.buildBitCast(operand, err_llvm_ty.pointerType(0), "");
@@ -5856,10 +5817,6 @@ pub const FuncGen = struct {
const operand = try self.resolveInst(ty_op.operand);
const error_union_ty = self.air.typeOf(ty_op.operand).childType();
if (error_union_ty.errorUnionSet().errorSetCardinality() == .zero) {
// TODO: write undefined bytes through the pointer here
return operand;
}
const payload_ty = error_union_ty.errorUnionPayload();
const non_error_val = try self.dg.lowerValue(.{ .ty = Type.anyerror, .val = Value.zero });
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
@@ -5938,9 +5895,6 @@ pub const FuncGen = struct {
const ty_op = self.air.instructions.items(.data)[inst].ty_op;
const inst_ty = self.air.typeOfIndex(inst);
const operand = try self.resolveInst(ty_op.operand);
if (inst_ty.errorUnionSet().errorSetCardinality() == .zero) {
return operand;
}
const payload_ty = self.air.typeOf(ty_op.operand);
if (!payload_ty.hasRuntimeBitsIgnoreComptime()) {
return operand;