Commit 7d75c3d3b8
Changed files (15)
src
arch
aarch64
arm
riscv64
sparc64
wasm
x86_64
Liveness
test
behavior
src/arch/aarch64/CodeGen.zig
@@ -766,6 +766,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.not => try self.airNot(inst),
.int_from_ptr => try self.airIntFromPtr(inst),
.ret => try self.airRet(inst),
+ .ret_safe => try self.airRet(inst), // TODO
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
src/arch/arm/CodeGen.zig
@@ -752,6 +752,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.not => try self.airNot(inst),
.int_from_ptr => try self.airIntFromPtr(inst),
.ret => try self.airRet(inst),
+ .ret_safe => try self.airRet(inst), // TODO
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
src/arch/riscv64/CodeGen.zig
@@ -585,6 +585,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.not => try self.airNot(inst),
.int_from_ptr => try self.airIntFromPtr(inst),
.ret => try self.airRet(inst),
+ .ret_safe => try self.airRet(inst), // TODO
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
src/arch/sparc64/CodeGen.zig
@@ -598,6 +598,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.not => try self.airNot(inst),
.int_from_ptr => try self.airIntFromPtr(inst),
.ret => try self.airRet(inst),
+ .ret_safe => try self.airRet(inst), // TODO
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
src/arch/wasm/CodeGen.zig
@@ -1957,6 +1957,7 @@ fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
.ptr_elem_val => func.airPtrElemVal(inst),
.int_from_ptr => func.airIntFromPtr(inst),
.ret => func.airRet(inst),
+ .ret_safe => func.airRet(inst), // TODO
.ret_ptr => func.airRetPtr(inst),
.ret_load => func.airRetLoad(inst),
.splat => func.airSplat(inst),
src/arch/x86_64/CodeGen.zig
@@ -2018,6 +2018,7 @@ fn genBody(self: *Self, body: []const Air.Inst.Index) InnerError!void {
.loop => try self.airLoop(inst),
.int_from_ptr => try self.airIntFromPtr(inst),
.ret => try self.airRet(inst),
+ .ret_safe => try self.airRet(inst), // TODO
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
src/codegen/c.zig
@@ -3225,6 +3225,7 @@ fn genBodyInner(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail,
.int_from_bool => try airIntFromBool(f, inst),
.load => try airLoad(f, inst),
.ret => try airRet(f, inst, false),
+ .ret_safe => try airRet(f, inst, false), // TODO
.ret_load => try airRet(f, inst, true),
.store => try airStore(f, inst, false),
.store_safe => try airStore(f, inst, true),
src/codegen/llvm.zig
@@ -5078,7 +5078,8 @@ pub const FuncGen = struct {
.load => try self.airLoad(body[i..]),
.loop => try self.airLoop(inst),
.not => try self.airNot(inst),
- .ret => try self.airRet(inst),
+ .ret => try self.airRet(inst, false),
+ .ret_safe => try self.airRet(inst, true),
.ret_load => try self.airRetLoad(inst),
.store => try self.airStore(inst, false),
.store_safe => try self.airStore(inst, true),
@@ -5551,15 +5552,42 @@ pub const FuncGen = struct {
_ = try fg.wip.@"unreachable"();
}
- fn airRet(self: *FuncGen, inst: Air.Inst.Index) !Builder.Value {
+ fn airRet(self: *FuncGen, inst: Air.Inst.Index, safety: bool) !Builder.Value {
const o = self.dg.object;
const mod = o.module;
const un_op = self.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const ret_ty = self.typeOf(un_op);
+
if (self.ret_ptr != .none) {
- const operand = try self.resolveInst(un_op);
const ptr_ty = try mod.singleMutPtrType(ret_ty);
+ const operand = try self.resolveInst(un_op);
+ const val_is_undef = if (try self.air.value(un_op, mod)) |val| val.isUndefDeep(mod) else false;
+ if (val_is_undef and safety) undef: {
+ const ptr_info = ptr_ty.ptrInfo(mod);
+ const needs_bitmask = (ptr_info.packed_offset.host_size != 0);
+ if (needs_bitmask) {
+ // TODO: only some bits are to be undef, we cannot write with a simple memset.
+ // meanwhile, ignore the write rather than stomping over valid bits.
+ // https://github.com/ziglang/zig/issues/15337
+ break :undef;
+ }
+ const len = try o.builder.intValue(try o.lowerType(Type.usize), ret_ty.abiSize(mod));
+ _ = try self.wip.callMemSet(
+ self.ret_ptr,
+ ptr_ty.ptrAlignment(mod).toLlvm(),
+ try o.builder.intValue(.i8, 0xaa),
+ len,
+ if (ptr_ty.isVolatilePtr(mod)) .@"volatile" else .normal,
+ );
+ const owner_mod = self.dg.ownerModule();
+ if (owner_mod.valgrind) {
+ try self.valgrindMarkUndef(self.ret_ptr, len);
+ }
+ _ = try self.wip.retVoid();
+ return .none;
+ }
+
const unwrapped_operand = operand.unwrap();
const unwrapped_ret = self.ret_ptr.unwrap();
@@ -5588,8 +5616,28 @@ pub const FuncGen = struct {
const abi_ret_ty = try lowerFnRetTy(o, fn_info);
const operand = try self.resolveInst(un_op);
+ const val_is_undef = if (try self.air.value(un_op, mod)) |val| val.isUndefDeep(mod) else false;
const alignment = ret_ty.abiAlignment(mod).toLlvm();
+ if (val_is_undef and safety) {
+ const llvm_ret_ty = operand.typeOfWip(&self.wip);
+ const rp = try self.buildAlloca(llvm_ret_ty, alignment);
+ const len = try o.builder.intValue(try o.lowerType(Type.usize), ret_ty.abiSize(mod));
+ _ = try self.wip.callMemSet(
+ rp,
+ alignment,
+ try o.builder.intValue(.i8, 0xaa),
+ len,
+ .normal,
+ );
+ const owner_mod = self.dg.ownerModule();
+ if (owner_mod.valgrind) {
+ try self.valgrindMarkUndef(rp, len);
+ }
+ _ = try self.wip.ret(try self.wip.load(.normal, abi_ret_ty, rp, alignment, ""));
+ return .none;
+ }
+
if (isByRef(ret_ty, mod)) {
// operand is a pointer however self.ret_ptr is null so that means
// we need to return a value.
src/codegen/spirv.zig
@@ -2177,6 +2177,7 @@ const DeclGen = struct {
.cond_br => return self.airCondBr(inst),
.loop => return self.airLoop(inst),
.ret => return self.airRet(inst),
+ .ret_safe => return self.airRet(inst), // TODO
.ret_load => return self.airRetLoad(inst),
.@"try" => try self.airTry(inst),
.switch_br => return self.airSwitchBr(inst),
src/Liveness/Verify.zig
@@ -151,6 +151,7 @@ fn verifyBody(self: *Verify, body: []const Air.Inst.Index) Error!void {
try self.verifyInstOperands(inst, .{ un_op, .none, .none });
},
.ret,
+ .ret_safe,
.ret_load,
=> {
const un_op = data[@intFromEnum(inst)].un_op;
src/Air.zig
@@ -516,6 +516,11 @@ pub const Inst = struct {
/// Uses the `un_op` field.
/// Triggers `resolveTypeLayout` on the return type.
ret,
+ /// Same as `ret`, except if the operand is undefined, the
+ /// returned value is 0xaa bytes, and any other safety metadata
+ /// such as Valgrind integrations should be notified of
+ /// this value being undefined.
+ ret_safe,
/// This instruction communicates that the function's result value is pointed to by
/// the operand. If the function will pass the result by-ref, the operand is a
/// `ret_ptr` instruction. Otherwise, this instruction is equivalent to a `load`
@@ -1439,6 +1444,7 @@ pub fn typeOfIndex(air: *const Air, inst: Air.Inst.Index, ip: *const InternPool)
.cond_br,
.switch_br,
.ret,
+ .ret_safe,
.ret_load,
.unreach,
.trap,
@@ -1613,6 +1619,7 @@ pub fn mustLower(air: Air, inst: Air.Inst.Index, ip: *const InternPool) bool {
.dbg_var_ptr,
.dbg_var_val,
.ret,
+ .ret_safe,
.ret_load,
.store,
.store_safe,
src/Liveness.zig
@@ -435,6 +435,7 @@ pub fn categorizeOperand(
},
.ret,
+ .ret_safe,
.ret_load,
=> {
const o = air_datas[@intFromEnum(inst)].un_op;
@@ -1070,6 +1071,7 @@ fn analyzeInst(
},
.ret,
+ .ret_safe,
.ret_load,
=> {
const operand = inst_datas[@intFromEnum(inst)].un_op;
src/print_air.zig
@@ -175,6 +175,7 @@ const Writer = struct {
.int_from_ptr,
.int_from_bool,
.ret,
+ .ret_safe,
.ret_load,
.is_named_enum_value,
.tag_name,
src/Sema.zig
@@ -19437,14 +19437,15 @@ fn analyzeRet(
try sema.resolveTypeLayout(sema.fn_ret_ty);
+ const air_tag: Air.Inst.Tag = if (block.wantSafety()) .ret_safe else .ret;
if (sema.wantErrorReturnTracing(sema.fn_ret_ty)) {
// Avoid adding a frame to the error return trace in case the value is comptime-known
// to be not an error.
const is_non_err = try sema.analyzeIsNonErr(block, src, operand);
- return sema.retWithErrTracing(block, src, is_non_err, .ret, operand);
+ return sema.retWithErrTracing(block, src, is_non_err, air_tag, operand);
}
- _ = try block.addUnOp(.ret, operand);
+ _ = try block.addUnOp(air_tag, operand);
return always_noreturn;
}
test/behavior/undefined.zig
@@ -97,3 +97,25 @@ test "reslice of undefined global var slice" {
const x = buf[0..1];
try @import("std").testing.expect(x.len == 1 and x[0] == 0);
}
+
+test "returned undef is 0xaa bytes when runtime safety is enabled" {
+ if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+ if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+ if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+ if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
+ if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+
+ const Rect = struct {
+ x: f32,
+ fn getUndefStruct() @This() {
+ @setRuntimeSafety(true);
+ return undefined;
+ }
+ fn getUndefInt() u32 {
+ @setRuntimeSafety(true);
+ return undefined;
+ }
+ };
+ try std.testing.expect(@as(u32, @bitCast(Rect.getUndefStruct().x)) == 0xAAAAAAAA);
+ try std.testing.expect(Rect.getUndefInt() == 0xAAAAAAAA);
+}