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C backend: errors and optionals

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* bitcast treats all pointers as pointers
 * correctly unwrapping error unions with pointers
 * equality operators for primitive optional types
This commit is contained in:
Scibuild
2021-11-18 08:26:15 +11:00
committed by Andrew Kelley
parent 8f1e417757
commit 2e15a404e2
4 changed files with 79 additions and 28 deletions
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60
src/codegen/c.zig
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@@ -1162,12 +1162,12 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO
.slice => try airSlice(f, inst),
.cmp_eq => try airBinOp(f, inst, " == "),
.cmp_eq => try airEquality(f, inst, .cmp_eq),
.cmp_gt => try airBinOp(f, inst, " > "),
.cmp_gte => try airBinOp(f, inst, " >= "),
.cmp_lt => try airBinOp(f, inst, " < "),
.cmp_lte => try airBinOp(f, inst, " <= "),
.cmp_neq => try airBinOp(f, inst, " != "),
.cmp_neq => try airEquality(f, inst, .cmp_neq),
// bool_and and bool_or are non-short-circuit operations
.bool_and => try airBinOp(f, inst, " & "),
@@ -1257,9 +1257,9 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO
.slice_elem_ptr => try airSliceElemPtr(f, inst),
.array_elem_val => try airArrayElemVal(f, inst),
.unwrap_errunion_payload => try airUnwrapErrUnionPay(f, inst),
.unwrap_errunion_payload => try airUnwrapErrUnionPay(f, inst, ""),
.unwrap_errunion_err => try airUnwrapErrUnionErr(f, inst),
.unwrap_errunion_payload_ptr => try airUnwrapErrUnionPay(f, inst),
.unwrap_errunion_payload_ptr => try airUnwrapErrUnionPay(f, inst, "&"),
.unwrap_errunion_err_ptr => try airUnwrapErrUnionErr(f, inst),
.wrap_errunion_payload => try airWrapErrUnionPay(f, inst),
.wrap_errunion_err => try airWrapErrUnionErr(f, inst),
@@ -1908,6 +1908,51 @@ fn airBinOp(f: *Function, inst: Air.Inst.Index, operator: [*:0]const u8) !CValue
return local;
}
fn airEquality(f: *Function, inst: Air.Inst.Index, op: Air.Inst.Tag) !CValue {
if (f.liveness.isUnused(inst))
return CValue.none;
const bin_op = f.air.instructions.items(.data)[inst].bin_op;
const lhs = try f.resolveInst(bin_op.lhs);
const rhs = try f.resolveInst(bin_op.rhs);
const writer = f.object.writer();
const inst_ty = f.air.typeOfIndex(inst);
const local = try f.allocLocal(inst_ty, .Const);
try writer.writeAll(" = ");
const lhs_ty = f.air.typeOf(bin_op.lhs);
if (lhs_ty.tag() == .optional) {
// (A && B) || (C && (A == B))
// A = lhs.is_null ; B = rhs.is_null ; C = rhs.payload == lhs.payload
try writer.writeAll(if (op == .cmp_eq) "((" else "!((");
try f.writeCValue(writer, lhs);
try writer.writeAll(".is_null && ");
try f.writeCValue(writer, rhs);
try writer.writeAll(".is_null) || (");
try f.writeCValue(writer, lhs);
try writer.writeAll(".payload == ");
try f.writeCValue(writer, rhs);
try writer.writeAll(".payload && ");
try f.writeCValue(writer, lhs);
try writer.writeAll(".is_null == ");
try f.writeCValue(writer, rhs);
try writer.writeAll(".is_null));\n");
return local;
}
const operator = if (op == .cmp_eq) "==" else "!=";
try f.writeCValue(writer, lhs);
try writer.print("{s}", .{operator});
try f.writeCValue(writer, rhs);
try writer.writeAll(";\n");
return local;
}
fn airPtrAddSub(f: *Function, inst: Air.Inst.Index, operator: [*:0]const u8) !CValue {
if (f.liveness.isUnused(inst))
return CValue.none;
@@ -2104,8 +2149,8 @@ fn airBitcast(f: *Function, inst: Air.Inst.Index) !CValue {
const writer = f.object.writer();
const inst_ty = f.air.typeOfIndex(inst);
if (inst_ty.zigTypeTag() == .Pointer and
f.air.typeOf(ty_op.operand).zigTypeTag() == .Pointer)
if (inst_ty.isPtrAtRuntime() and
f.air.typeOf(ty_op.operand).isPtrAtRuntime())
{
const local = try f.allocLocal(inst_ty, .Const);
try writer.writeAll(" = (");
@@ -2503,7 +2548,7 @@ fn airUnwrapErrUnionErr(f: *Function, inst: Air.Inst.Index) !CValue {
return local;
}
fn airUnwrapErrUnionPay(f: *Function, inst: Air.Inst.Index) !CValue {
fn airUnwrapErrUnionPay(f: *Function, inst: Air.Inst.Index, maybe_addrof: []const u8) !CValue {
if (f.liveness.isUnused(inst))
return CValue.none;
@@ -2519,7 +2564,6 @@ fn airUnwrapErrUnionPay(f: *Function, inst: Air.Inst.Index) !CValue {
const inst_ty = f.air.typeOfIndex(inst);
const maybe_deref = if (operand_ty.zigTypeTag() == .Pointer) "->" else ".";
const maybe_addrof = if (inst_ty.zigTypeTag() == .Pointer) "&" else "";
const local = try f.allocLocal(inst_ty, .Const);
try writer.print(" = {s}(", .{maybe_addrof});