authorgravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2021-10-28 15:59:14-07:00
committergravatar for andrew@ziglang.orgAndrew Kelley <andrew@ziglang.org> 2021-10-28 15:59:14-07:00
logd2f9646d98615d85589d2c46237559d1249f2765
tree87c2297912251993970a282703f688c72932e228
parent234d94e42b832dd17eb9144f5523e03ef4fa8eb3

C backend: fix enough that zig test works

* test_functions: properly add dependencies of the array on test functions and test names so that the order comes out correctly. * fix lowering of struct literals to add parentheses around the type name. * omit const qualifier in slices because otherwise slices cannot be reassigned even when they are local variables. * special case pointer to functions and double pointer to functions in renderTypeAndName. This code will need to be cleaned up but for now it helps us make progress on other C backend stuff. * fix slice element access to lower to `.ptr[` instead of `[`. * airSliceElemVal: respect volatile slices

3 files changed, 117 insertions(+), 48 deletions(-)

src/Module.zig+6
...@@ -4734,6 +4734,10 @@ pub fn populateTestFunctions(mod: *Module) !void {...@@ -4734,6 +4734,10 @@ pub fn populateTestFunctions(mod: *Module) !void {
4734 }),4734 }),
4735 .val = try Value.Tag.array.create(arena, test_fn_vals),4735 .val = try Value.Tag.array.create(arena, test_fn_vals),
4736 });4736 });
4737
4738 // Add a dependency on each test name and function pointer.
4739 try array_decl.dependencies.ensureUnusedCapacity(gpa, test_fn_vals.len * 2);
4740
4737 for (mod.test_functions.keys()) |test_decl, i| {4741 for (mod.test_functions.keys()) |test_decl, i| {
4738 const test_name_slice = mem.sliceTo(test_decl.name, 0);4742 const test_name_slice = mem.sliceTo(test_decl.name, 0);
4739 const test_name_decl = n: {4743 const test_name_decl = n: {
...@@ -4747,6 +4751,8 @@ pub fn populateTestFunctions(mod: *Module) !void {...@@ -4747,6 +4751,8 @@ pub fn populateTestFunctions(mod: *Module) !void {
4747 try test_name_decl.finalizeNewArena(&name_decl_arena);4751 try test_name_decl.finalizeNewArena(&name_decl_arena);
4748 break :n test_name_decl;4752 break :n test_name_decl;
4749 };4753 };
4754 array_decl.dependencies.putAssumeCapacityNoClobber(test_decl, {});
4755 array_decl.dependencies.putAssumeCapacityNoClobber(test_name_decl, {});
4750 try mod.linkerUpdateDecl(test_name_decl);4756 try mod.linkerUpdateDecl(test_name_decl);
47514757
4752 const field_vals = try arena.create([3]Value);4758 const field_vals = try arena.create([3]Value);
src/codegen/c.zig+103-48
...@@ -397,8 +397,9 @@ pub const DeclGen = struct {...@@ -397,8 +397,9 @@ pub const DeclGen = struct {
397 .Struct => {397 .Struct => {
398 const field_vals = val.castTag(.@"struct").?.data;398 const field_vals = val.castTag(.@"struct").?.data;
399399
400 try writer.writeAll("(");
400 try dg.renderType(writer, ty);401 try dg.renderType(writer, ty);
401 try writer.writeAll("{");402 try writer.writeAll("){");
402403
403 for (field_vals) |field_val, i| {404 for (field_vals) |field_val, i| {
404 const field_ty = ty.structFieldType(i);405 const field_ty = ty.structFieldType(i);
...@@ -529,9 +530,9 @@ pub const DeclGen = struct {...@@ -529,9 +530,9 @@ pub const DeclGen = struct {
529 const elem_type = t.elemType();530 const elem_type = t.elemType();
530 try dg.renderType(bw, elem_type);531 try dg.renderType(bw, elem_type);
531 try bw.writeAll(" *");532 try bw.writeAll(" *");
532 if (t.isConstPtr()) {533 // We skip the const qualifier because C's type system
533 try bw.writeAll("const ");534 // would not allow a local mutable variable which is this slice type
534 }535 // to be overwritten with a new slice type.
535 if (t.isVolatilePtr()) {536 if (t.isVolatilePtr()) {
536 try bw.writeAll("volatile ");537 try bw.writeAll("volatile ");
537 }538 }
...@@ -549,15 +550,40 @@ pub const DeclGen = struct {...@@ -549,15 +550,40 @@ pub const DeclGen = struct {
549 try t.copy(dg.typedefs_arena),550 try t.copy(dg.typedefs_arena),
550 .{ .name = name, .rendered = rendered },551 .{ .name = name, .rendered = rendered },
551 );552 );
552 } else {553 return;
553 try dg.renderType(w, t.elemType());554 }
554 try w.writeAll(" *");555 if (t.castPtrToFn()) |fn_ty| {
555 if (t.isConstPtr()) {556 const fn_info = fn_ty.fnInfo();
556 try w.writeAll("const ");557 try dg.renderType(w, fn_info.return_type);
558 try w.writeAll(" (*)(");
559 const param_len = fn_info.param_types.len;
560 const is_var_args = fn_info.is_var_args;
561 if (param_len == 0 and !is_var_args)
562 try w.writeAll("void")
563 else {
564 var index: usize = 0;
565 while (index < param_len) : (index += 1) {
566 if (index > 0) {
567 try w.writeAll(", ");
568 }
569 try dg.renderType(w, fn_info.param_types[index]);
570 }
557 }571 }
558 if (t.isVolatilePtr()) {572 if (is_var_args) {
559 try w.writeAll("volatile ");573 if (param_len != 0) try w.writeAll(", ");
574 try w.writeAll("...");
560 }575 }
576 try w.writeByte(')');
577 return;
578 }
579
580 try dg.renderType(w, t.elemType());
581 try w.writeAll(" *");
582 if (t.isConstPtr()) {
583 try w.writeAll("const ");
584 }
585 if (t.isVolatilePtr()) {
586 try w.writeAll("volatile ");
561 }587 }
562 },588 },
563 .Array => {589 .Array => {
...@@ -685,28 +711,7 @@ pub const DeclGen = struct {...@@ -685,28 +711,7 @@ pub const DeclGen = struct {
685 try dg.renderType(w, int_tag_ty);711 try dg.renderType(w, int_tag_ty);
686 },712 },
687 .Union => return dg.fail("TODO: C backend: implement type Union", .{}),713 .Union => return dg.fail("TODO: C backend: implement type Union", .{}),
688 .Fn => {714 .Fn => unreachable, // This is a function body, not a function pointer.
689 try dg.renderType(w, t.fnReturnType());
690 try w.writeAll(" (*)(");
691 const param_len = t.fnParamLen();
692 const is_var_args = t.fnIsVarArgs();
693 if (param_len == 0 and !is_var_args)
694 try w.writeAll("void")
695 else {
696 var index: usize = 0;
697 while (index < param_len) : (index += 1) {
698 if (index > 0) {
699 try w.writeAll(", ");
700 }
701 try dg.renderType(w, t.fnParamType(index));
702 }
703 }
704 if (is_var_args) {
705 if (param_len != 0) try w.writeAll(", ");
706 try w.writeAll("...");
707 }
708 try w.writeByte(')');
709 },
710 .Opaque => return dg.fail("TODO: C backend: implement type Opaque", .{}),715 .Opaque => return dg.fail("TODO: C backend: implement type Opaque", .{}),
711 .Frame => return dg.fail("TODO: C backend: implement type Frame", .{}),716 .Frame => return dg.fail("TODO: C backend: implement type Frame", .{}),
712 .AnyFrame => return dg.fail("TODO: C backend: implement type AnyFrame", .{}),717 .AnyFrame => return dg.fail("TODO: C backend: implement type AnyFrame", .{}),
...@@ -742,8 +747,59 @@ pub const DeclGen = struct {...@@ -742,8 +747,59 @@ pub const DeclGen = struct {
742 render_ty = render_ty.elemType();747 render_ty = render_ty.elemType();
743 }748 }
744749
745 if (render_ty.zigTypeTag() == .Fn) {750 // TODO this is duplicated from the code below and does not handle
746 const ret_ty = render_ty.fnReturnType();751 // arbitrary nesting of pointers. This renderTypeAndName function
752 // needs to be reworked by someone who understands C's insane type syntax. That
753 // person might be future me but it is certainly not present me.
754 if (render_ty.zigTypeTag() == .Pointer and
755 render_ty.childType().zigTypeTag() == .Pointer and
756 render_ty.childType().childType().zigTypeTag() == .Fn)
757 {
758 const ptr2_ty = render_ty.childType();
759 const fn_info = ptr2_ty.childType().fnInfo();
760 const ret_ty = fn_info.return_type;
761 if (ret_ty.zigTypeTag() == .NoReturn) {
762 // noreturn attribute is not allowed here.
763 try w.writeAll("void");
764 } else {
765 try dg.renderType(w, ret_ty);
766 }
767 try w.writeAll(" (*");
768 switch (mutability) {
769 .Const => try w.writeAll("const "),
770 .Mut => {},
771 }
772 if (!ptr2_ty.ptrIsMutable()) {
773 try w.writeAll("*const ");
774 } else {
775 try w.writeAll("*");
776 }
777 try dg.writeCValue(w, name);
778 try w.writeAll(")(");
779 const param_len = fn_info.param_types.len;
780 const is_var_args = fn_info.is_var_args;
781 if (param_len == 0 and !is_var_args)
782 try w.writeAll("void")
783 else {
784 var index: usize = 0;
785 while (index < param_len) : (index += 1) {
786 if (index > 0) {
787 try w.writeAll(", ");
788 }
789 try dg.renderType(w, fn_info.param_types[index]);
790 }
791 }
792 if (is_var_args) {
793 if (param_len != 0) try w.writeAll(", ");
794 try w.writeAll("...");
795 }
796 try w.writeByte(')');
797 return;
798 }
799
800 if (render_ty.castPtrToFn()) |fn_ty| {
801 const fn_info = fn_ty.fnInfo();
802 const ret_ty = fn_info.return_type;
747 if (ret_ty.zigTypeTag() == .NoReturn) {803 if (ret_ty.zigTypeTag() == .NoReturn) {
748 // noreturn attribute is not allowed here.804 // noreturn attribute is not allowed here.
749 try w.writeAll("void");805 try w.writeAll("void");
...@@ -757,8 +813,8 @@ pub const DeclGen = struct {...@@ -757,8 +813,8 @@ pub const DeclGen = struct {
757 }813 }
758 try dg.writeCValue(w, name);814 try dg.writeCValue(w, name);
759 try w.writeAll(")(");815 try w.writeAll(")(");
760 const param_len = render_ty.fnParamLen();816 const param_len = fn_info.param_types.len;
761 const is_var_args = render_ty.fnIsVarArgs();817 const is_var_args = fn_info.is_var_args;
762 if (param_len == 0 and !is_var_args)818 if (param_len == 0 and !is_var_args)
763 try w.writeAll("void")819 try w.writeAll("void")
764 else {820 else {
...@@ -767,7 +823,7 @@ pub const DeclGen = struct {...@@ -767,7 +823,7 @@ pub const DeclGen = struct {
767 if (index > 0) {823 if (index > 0) {
768 try w.writeAll(", ");824 try w.writeAll(", ");
769 }825 }
770 try dg.renderType(w, render_ty.fnParamType(index));826 try dg.renderType(w, fn_info.param_types[index]);
771 }827 }
772 }828 }
773 if (is_var_args) {829 if (is_var_args) {
...@@ -1083,7 +1139,7 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO...@@ -1083,7 +1139,7 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO
10831139
1084 .ptr_elem_val => try airPtrElemVal(f, inst, "["),1140 .ptr_elem_val => try airPtrElemVal(f, inst, "["),
1085 .ptr_elem_ptr => try airPtrElemPtr(f, inst),1141 .ptr_elem_ptr => try airPtrElemPtr(f, inst),
1086 .slice_elem_val => try airSliceElemVal(f, inst, "["),1142 .slice_elem_val => try airSliceElemVal(f, inst),
1087 .slice_elem_ptr => try airSliceElemPtr(f, inst),1143 .slice_elem_ptr => try airSliceElemPtr(f, inst),
1088 .array_elem_val => try airArrayElemVal(f, inst),1144 .array_elem_val => try airArrayElemVal(f, inst),
10891145
...@@ -1149,27 +1205,26 @@ fn airPtrElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {...@@ -1149,27 +1205,26 @@ fn airPtrElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {
1149 return f.fail("TODO: C backend: airPtrElemPtr", .{});1205 return f.fail("TODO: C backend: airPtrElemPtr", .{});
1150}1206}
11511207
1152fn airSliceElemVal(f: *Function, inst: Air.Inst.Index, prefix: []const u8) !CValue {1208fn airSliceElemVal(f: *Function, inst: Air.Inst.Index) !CValue {
1153 const is_volatile = false; // TODO
1154 if (!is_volatile and f.liveness.isUnused(inst))
1155 return CValue.none;
1156
1157 const bin_op = f.air.instructions.items(.data)[inst].bin_op;1209 const bin_op = f.air.instructions.items(.data)[inst].bin_op;
1210 const slice_ty = f.air.typeOf(bin_op.lhs);
1211 if (!slice_ty.isVolatilePtr() and f.liveness.isUnused(inst)) return CValue.none;
1212
1158 const slice = try f.resolveInst(bin_op.lhs);1213 const slice = try f.resolveInst(bin_op.lhs);
1159 const index = try f.resolveInst(bin_op.rhs);1214 const index = try f.resolveInst(bin_op.rhs);
1160 const writer = f.object.writer();1215 const writer = f.object.writer();
1161 const local = try f.allocLocal(f.air.typeOfIndex(inst), .Const);1216 const local = try f.allocLocal(f.air.typeOfIndex(inst), .Const);
1162 try writer.writeAll(" = ");1217 try writer.writeAll(" = ");
1163 try f.writeCValue(writer, slice);1218 try f.writeCValue(writer, slice);
1164 try writer.writeAll(prefix);1219 try writer.writeAll(".ptr[");
1165 try f.writeCValue(writer, index);1220 try f.writeCValue(writer, index);
1166 try writer.writeAll("];\n");1221 try writer.writeAll("];\n");
1167 return local;1222 return local;
1168}1223}
11691224
1170fn airSliceElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {1225fn airSliceElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {
1171 if (f.liveness.isUnused(inst))1226 if (f.liveness.isUnused(inst)) return CValue.none;
1172 return CValue.none;1227
1173 const ty_pl = f.air.instructions.items(.data)[inst].ty_pl;1228 const ty_pl = f.air.instructions.items(.data)[inst].ty_pl;
1174 const bin_op = f.air.extraData(Air.Bin, ty_pl.payload).data;1229 const bin_op = f.air.extraData(Air.Bin, ty_pl.payload).data;
11751230
...@@ -1179,7 +1234,7 @@ fn airSliceElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {...@@ -1179,7 +1234,7 @@ fn airSliceElemPtr(f: *Function, inst: Air.Inst.Index) !CValue {
1179 const local = try f.allocLocal(f.air.typeOfIndex(inst), .Const);1234 const local = try f.allocLocal(f.air.typeOfIndex(inst), .Const);
1180 try writer.writeAll(" = &");1235 try writer.writeAll(" = &");
1181 try f.writeCValue(writer, slice);1236 try f.writeCValue(writer, slice);
1182 try writer.writeByte('[');1237 try writer.writeAll(".ptr[");
1183 try f.writeCValue(writer, index);1238 try f.writeCValue(writer, index);
1184 try writer.writeAll("];\n");1239 try writer.writeAll("];\n");
1185 return local;1240 return local;
src/type.zig+8
...@@ -252,6 +252,14 @@ pub const Type = extern union {...@@ -252,6 +252,14 @@ pub const Type = extern union {
252 };252 };
253 }253 }
254254
255 /// If it is a function pointer, returns the function type. Otherwise returns null.
256 pub fn castPtrToFn(ty: Type) ?Type {
257 if (ty.zigTypeTag() != .Pointer) return null;
258 const elem_ty = ty.childType();
259 if (elem_ty.zigTypeTag() != .Fn) return null;
260 return elem_ty;
261 }
262
255 pub fn ptrIsMutable(ty: Type) bool {263 pub fn ptrIsMutable(ty: Type) bool {
256 return switch (ty.tag()) {264 return switch (ty.tag()) {
257 .single_const_pointer_to_comptime_int,265 .single_const_pointer_to_comptime_int,