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stage2: avoid panicking for unimplemented compiler code

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Prevents the compiler from crashing when using `@memset` on extern
unions, for example.
This commit is contained in:
Andrew Kelley
2023-04-26 18:20:22 -07:00
parent a67dec1c9f
commit 82fc360613
2 changed files with 9 additions and 4 deletions
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3
src/Sema.zig
View File

@@ -26954,10 +26954,12 @@ fn storePtrVal(
reinterpret.val_ptr.*.writeToMemory(mut_kit.ty, sema.mod, buffer) catch |err| switch (err) {
error.ReinterpretDeclRef => unreachable,
error.IllDefinedMemoryLayout => unreachable, // Sema was supposed to emit a compile error already
error.Unimplemented => return sema.fail(block, src, "TODO: implement writeToMemory for type '{}'", .{mut_kit.ty.fmt(sema.mod)}),
};
operand_val.writeToMemory(operand_ty, sema.mod, buffer[reinterpret.byte_offset..]) catch |err| switch (err) {
error.ReinterpretDeclRef => unreachable,
error.IllDefinedMemoryLayout => unreachable, // Sema was supposed to emit a compile error already
error.Unimplemented => return sema.fail(block, src, "TODO: implement writeToMemory for type '{}'", .{mut_kit.ty.fmt(sema.mod)}),
};
const arena = mut_kit.beginArena(sema.mod);
@@ -27908,6 +27910,7 @@ fn bitCastVal(
val.writeToMemory(old_ty, sema.mod, buffer) catch |err| switch (err) {
error.ReinterpretDeclRef => return null,
error.IllDefinedMemoryLayout => unreachable, // Sema was supposed to emit a compile error already
error.Unimplemented => return sema.fail(block, src, "TODO: implement writeToMemory for type '{}'", .{old_ty.fmt(sema.mod)}),
};
return try Value.readFromMemory(new_ty, sema.mod, buffer[buffer_offset..], sema.arena);
}

10
src/value.zig
View File

@@ -1281,6 +1281,7 @@ pub const Value = extern union {
pub fn writeToMemory(val: Value, ty: Type, mod: *Module, buffer: []u8) error{
ReinterpretDeclRef,
IllDefinedMemoryLayout,
Unimplemented,
}!void {
const target = mod.getTarget();
const endian = target.cpu.arch.endian();
@@ -1370,19 +1371,19 @@ pub const Value = extern union {
},
.Union => switch (ty.containerLayout()) {
.Auto => return error.IllDefinedMemoryLayout,
.Extern => @panic("TODO implement writeToMemory for extern unions"),
.Extern => return error.Unimplemented,
.Packed => {
const byte_count = (@intCast(usize, ty.bitSize(target)) + 7) / 8;
return writeToPackedMemory(val, ty, mod, buffer[0..byte_count], 0);
},
},
.Pointer => {
assert(!ty.isSlice()); // No well defined layout.
if (ty.isSlice()) return error.IllDefinedMemoryLayout;
if (val.isDeclRef()) return error.ReinterpretDeclRef;
return val.writeToMemory(Type.usize, mod, buffer);
},
.Optional => {
assert(ty.isPtrLikeOptional());
if (!ty.isPtrLikeOptional()) return error.IllDefinedMemoryLayout;
var buf: Type.Payload.ElemType = undefined;
const child = ty.optionalChild(&buf);
const opt_val = val.optionalValue();
@@ -1392,7 +1393,7 @@ pub const Value = extern union {
return writeToMemory(Value.zero, Type.usize, mod, buffer);
}
},
else => @panic("TODO implement writeToMemory for more types"),
else => return error.Unimplemented,
}
}
@@ -5401,6 +5402,7 @@ pub const Value = extern union {
// code late in compilation. So, this error handling is too aggressive and
// causes some false negatives, causing less-than-ideal code generation.
error.IllDefinedMemoryLayout => return null,
error.Unimplemented => return null,
};
const first_byte = byte_buffer[0];
for (byte_buffer[1..]) |byte| {