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rework error handling in the backends

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This commit is contained in:
Andrew Kelley
2024-12-03 20:35:23 -08:00
parent 77accf597d
commit 9bf715de74
15 changed files with 323 additions and 512 deletions
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169
src/codegen.zig
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@@ -24,13 +24,6 @@ const Zir = std.zig.Zir;
const Alignment = InternPool.Alignment;
const dev = @import("dev.zig");
pub const Result = union(enum) {
/// The `code` parameter passed to `generateSymbol` has the value.
ok,
/// There was a codegen error.
fail: *ErrorMsg,
};
pub const CodeGenError = error{
OutOfMemory,
/// Compiler was asked to operate on a number larger than supported.
@@ -64,7 +57,7 @@ pub fn generateFunction(
liveness: Liveness,
code: *std.ArrayList(u8),
debug_output: link.File.DebugInfoOutput,
) CodeGenError!Result {
) CodeGenError!void {
const zcu = pt.zcu;
const func = zcu.funcInfo(func_index);
const target = zcu.navFileScope(func.owner_nav).mod.resolved_target.result;
@@ -89,7 +82,7 @@ pub fn generateLazyFunction(
lazy_sym: link.File.LazySymbol,
code: *std.ArrayList(u8),
debug_output: link.File.DebugInfoOutput,
) CodeGenError!Result {
) CodeGenError!void {
const zcu = pt.zcu;
const file = Type.fromInterned(lazy_sym.ty).typeDeclInstAllowGeneratedTag(zcu).?.resolveFile(&zcu.intern_pool);
const target = zcu.fileByIndex(file).mod.resolved_target.result;
@@ -120,17 +113,17 @@ pub fn generateLazySymbol(
code: *std.ArrayList(u8),
debug_output: link.File.DebugInfoOutput,
reloc_parent: link.File.RelocInfo.Parent,
) CodeGenError!Result {
) CodeGenError!void {
_ = reloc_parent;
const tracy = trace(@src());
defer tracy.end();
const comp = bin_file.comp;
const ip = &pt.zcu.intern_pool;
const zcu = pt.zcu;
const ip = &zcu.intern_pool;
const target = comp.root_mod.resolved_target.result;
const endian = target.cpu.arch.endian();
const gpa = comp.gpa;
log.debug("generateLazySymbol: kind = {s}, ty = {}", .{
@tagName(lazy_sym.kind),
@@ -161,26 +154,29 @@ pub fn generateLazySymbol(
string_index += @intCast(err_name.len + 1);
}
mem.writeInt(u32, code.items[offset_index..][0..4], string_index, endian);
return .ok;
} else if (Type.fromInterned(lazy_sym.ty).zigTypeTag(pt.zcu) == .@"enum") {
} else if (Type.fromInterned(lazy_sym.ty).zigTypeTag(zcu) == .@"enum") {
alignment.* = .@"1";
const enum_ty = Type.fromInterned(lazy_sym.ty);
const tag_names = enum_ty.enumFields(pt.zcu);
const tag_names = enum_ty.enumFields(zcu);
for (0..tag_names.len) |tag_index| {
const tag_name = tag_names.get(ip)[tag_index].toSlice(ip);
try code.ensureUnusedCapacity(tag_name.len + 1);
code.appendSliceAssumeCapacity(tag_name);
code.appendAssumeCapacity(0);
}
return .ok;
} else return .{ .fail = try .create(
gpa,
src_loc,
"TODO implement generateLazySymbol for {s} {}",
.{ @tagName(lazy_sym.kind), Type.fromInterned(lazy_sym.ty).fmt(pt) },
) };
} else {
return zcu.codegenFailType(lazy_sym.ty, "TODO implement generateLazySymbol for {s} {}", .{
@tagName(lazy_sym.kind), Type.fromInterned(lazy_sym.ty).fmt(pt),
});
}
}
pub const GenerateSymbolError = error{
OutOfMemory,
/// Compiler was asked to operate on a number larger than supported.
Overflow,
};
pub fn generateSymbol(
bin_file: *link.File,
pt: Zcu.PerThread,
@@ -188,7 +184,7 @@ pub fn generateSymbol(
val: Value,
code: *std.ArrayList(u8),
reloc_parent: link.File.RelocInfo.Parent,
) CodeGenError!Result {
) GenerateSymbolError!void {
const tracy = trace(@src());
defer tracy.end();
@@ -204,7 +200,7 @@ pub fn generateSymbol(
if (val.isUndefDeep(zcu)) {
const abi_size = math.cast(usize, ty.abiSize(zcu)) orelse return error.Overflow;
try code.appendNTimes(0xaa, abi_size);
return .ok;
return;
}
switch (ip.indexToKey(val.toIntern())) {
@@ -266,7 +262,7 @@ pub fn generateSymbol(
if (!payload_ty.hasRuntimeBitsIgnoreComptime(zcu)) {
try code.writer().writeInt(u16, err_val, endian);
return .ok;
return;
}
const payload_align = payload_ty.abiAlignment(zcu);
@@ -281,13 +277,10 @@ pub fn generateSymbol(
// emit payload part of the error union
{
const begin = code.items.len;
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (error_union.val) {
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (error_union.val) {
.err_name => try pt.intern(.{ .undef = payload_ty.toIntern() }),
.payload => |payload| payload,
}), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
}), code, reloc_parent);
const unpadded_end = code.items.len - begin;
const padded_end = abi_align.forward(unpadded_end);
const padding = math.cast(usize, padded_end - unpadded_end) orelse return error.Overflow;
@@ -312,10 +305,7 @@ pub fn generateSymbol(
},
.enum_tag => |enum_tag| {
const int_tag_ty = ty.intTagType(zcu);
switch (try generateSymbol(bin_file, pt, src_loc, try pt.getCoerced(Value.fromInterned(enum_tag.int), int_tag_ty), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, try pt.getCoerced(Value.fromInterned(enum_tag.int), int_tag_ty), code, reloc_parent);
},
.float => |float| switch (float.storage) {
.f16 => |f16_val| writeFloat(f16, f16_val, target, endian, try code.addManyAsArray(2)),
@@ -328,19 +318,10 @@ pub fn generateSymbol(
},
.f128 => |f128_val| writeFloat(f128, f128_val, target, endian, try code.addManyAsArray(16)),
},
.ptr => switch (try lowerPtr(bin_file, pt, src_loc, val.toIntern(), code, reloc_parent, 0)) {
.ok => {},
.fail => |em| return .{ .fail = em },
},
.ptr => try lowerPtr(bin_file, pt, src_loc, val.toIntern(), code, reloc_parent, 0),
.slice => |slice| {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(slice.ptr), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(slice.len), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(slice.ptr), code, reloc_parent);
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(slice.len), code, reloc_parent);
},
.opt => {
const payload_type = ty.optionalChild(zcu);
@@ -349,10 +330,7 @@ pub fn generateSymbol(
if (ty.optionalReprIsPayload(zcu)) {
if (payload_val) |value| {
switch (try generateSymbol(bin_file, pt, src_loc, value, code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, value, code, reloc_parent);
} else {
try code.appendNTimes(0, abi_size);
}
@@ -362,10 +340,7 @@ pub fn generateSymbol(
const value = payload_val orelse Value.fromInterned(try pt.intern(.{
.undef = payload_type.toIntern(),
}));
switch (try generateSymbol(bin_file, pt, src_loc, value, code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, value, code, reloc_parent);
}
try code.writer().writeByte(@intFromBool(payload_val != null));
try code.appendNTimes(0, padding);
@@ -377,17 +352,14 @@ pub fn generateSymbol(
.elems, .repeated_elem => {
var index: u64 = 0;
while (index < array_type.lenIncludingSentinel()) : (index += 1) {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (aggregate.storage) {
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (aggregate.storage) {
.bytes => unreachable,
.elems => |elems| elems[@intCast(index)],
.repeated_elem => |elem| if (index < array_type.len)
elem
else
array_type.sentinel,
}), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
}), code, reloc_parent);
}
},
},
@@ -437,16 +409,13 @@ pub fn generateSymbol(
.elems, .repeated_elem => {
var index: u64 = 0;
while (index < vector_type.len) : (index += 1) {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (aggregate.storage) {
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(switch (aggregate.storage) {
.bytes => unreachable,
.elems => |elems| elems[
math.cast(usize, index) orelse return error.Overflow
],
.repeated_elem => |elem| elem,
}), code, reloc_parent)) {
.ok => {},
.fail => |em| return .{ .fail = em },
}
}), code, reloc_parent);
}
},
}
@@ -476,10 +445,7 @@ pub fn generateSymbol(
.repeated_elem => |elem| elem,
};
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), code, reloc_parent);
const unpadded_field_end = code.items.len - struct_begin;
// Pad struct members if required
@@ -518,10 +484,8 @@ pub fn generateSymbol(
return error.Overflow;
var tmp_list = try std.ArrayList(u8).initCapacity(code.allocator, field_size);
defer tmp_list.deinit();
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), &tmp_list, reloc_parent)) {
.ok => @memcpy(code.items[current_pos..][0..tmp_list.items.len], tmp_list.items),
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), &tmp_list, reloc_parent);
@memcpy(code.items[current_pos..][0..tmp_list.items.len], tmp_list.items);
} else {
Value.fromInterned(field_val).writeToPackedMemory(Type.fromInterned(field_ty), pt, code.items[current_pos..], bits) catch unreachable;
}
@@ -553,10 +517,7 @@ pub fn generateSymbol(
) orelse return error.Overflow;
if (padding > 0) try code.appendNTimes(0, padding);
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(field_val), code, reloc_parent);
}
const size = struct_type.sizeUnordered(ip);
@@ -582,10 +543,7 @@ pub fn generateSymbol(
// Check if we should store the tag first.
if (layout.tag_size > 0 and layout.tag_align.compare(.gte, layout.payload_align)) {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.tag), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.tag), code, reloc_parent);
}
const union_obj = zcu.typeToUnion(ty).?;
@@ -595,10 +553,7 @@ pub fn generateSymbol(
if (!field_ty.hasRuntimeBits(zcu)) {
try code.appendNTimes(0xaa, math.cast(usize, layout.payload_size) orelse return error.Overflow);
} else {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.val), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.val), code, reloc_parent);
const padding = math.cast(usize, layout.payload_size - field_ty.abiSize(zcu)) orelse return error.Overflow;
if (padding > 0) {
@@ -606,17 +561,11 @@ pub fn generateSymbol(
}
}
} else {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.val), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.val), code, reloc_parent);
}
if (layout.tag_size > 0 and layout.tag_align.compare(.lt, layout.payload_align)) {
switch (try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.tag), code, reloc_parent)) {
.ok => {},
.fail => |em| return Result{ .fail = em },
}
try generateSymbol(bin_file, pt, src_loc, Value.fromInterned(un.tag), code, reloc_parent);
if (layout.padding > 0) {
try code.appendNTimes(0, layout.padding);
@@ -625,7 +574,6 @@ pub fn generateSymbol(
},
.memoized_call => unreachable,
}
return .ok;
}
fn lowerPtr(
@@ -636,7 +584,7 @@ fn lowerPtr(
code: *std.ArrayList(u8),
reloc_parent: link.File.RelocInfo.Parent,
prev_offset: u64,
) CodeGenError!Result {
) GenerateSymbolError!void {
const zcu = pt.zcu;
const ptr = zcu.intern_pool.indexToKey(ptr_val).ptr;
const offset: u64 = prev_offset + ptr.byte_offset;
@@ -689,7 +637,7 @@ fn lowerUavRef(
code: *std.ArrayList(u8),
reloc_parent: link.File.RelocInfo.Parent,
offset: u64,
) CodeGenError!Result {
) GenerateSymbolError!void {
const zcu = pt.zcu;
const gpa = zcu.gpa;
const ip = &zcu.intern_pool;
@@ -702,14 +650,7 @@ fn lowerUavRef(
const is_fn_body = uav_ty.zigTypeTag(zcu) == .@"fn";
if (!is_fn_body and !uav_ty.hasRuntimeBits(zcu)) {
try code.appendNTimes(0xaa, ptr_width_bytes);
return .ok;
}
const uav_align = ip.indexToKey(uav.orig_ty).ptr_type.flags.alignment;
const res = try lf.lowerUav(pt, uav_val, uav_align, src_loc);
switch (res) {
.mcv => {},
.fail => |em| return .{ .fail = em },
return;
}
switch (lf.tag) {
@@ -727,11 +668,17 @@ fn lowerUavRef(
.pointee = .{ .uav_index = uav.val },
});
try code.appendNTimes(0, ptr_width_bytes);
return .ok;
return;
},
else => {},
}
const uav_align = ip.indexToKey(uav.orig_ty).ptr_type.flags.alignment;
switch (try lf.lowerUav(pt, uav_val, uav_align, src_loc)) {
.mcv => {},
.fail => |em| std.debug.panic("TODO rework lowerUav. internal error: {s}", .{em.msg}),
}
const vaddr = try lf.getUavVAddr(uav_val, .{
.parent = reloc_parent,
.offset = code.items.len,
@@ -744,8 +691,6 @@ fn lowerUavRef(
8 => mem.writeInt(u64, try code.addManyAsArray(8), vaddr, endian),
else => unreachable,
}
return Result.ok;
}
fn lowerNavRef(
@@ -756,7 +701,7 @@ fn lowerNavRef(
code: *std.ArrayList(u8),
reloc_parent: link.File.RelocInfo.Parent,
offset: u64,
) CodeGenError!Result {
) GenerateSymbolError!void {
_ = src_loc;
const zcu = pt.zcu;
const gpa = zcu.gpa;
@@ -768,7 +713,7 @@ fn lowerNavRef(
const is_fn_body = nav_ty.zigTypeTag(zcu) == .@"fn";
if (!is_fn_body and !nav_ty.hasRuntimeBits(zcu)) {
try code.appendNTimes(0xaa, ptr_width_bytes);
return Result.ok;
return;
}
switch (lf.tag) {
@@ -786,16 +731,16 @@ fn lowerNavRef(
.pointee = .{ .nav_index = nav_index },
});
try code.appendNTimes(0, ptr_width_bytes);
return .ok;
return;
},
else => {},
}
const vaddr = try lf.getNavVAddr(pt, nav_index, .{
const vaddr = lf.getNavVAddr(pt, nav_index, .{
.parent = reloc_parent,
.offset = code.items.len,
.addend = @intCast(offset),
});
}) catch @panic("TODO rework getNavVAddr");
const endian = target.cpu.arch.endian();
switch (ptr_width_bytes) {
2 => mem.writeInt(u16, try code.addManyAsArray(2), @intCast(vaddr), endian),
@@ -803,8 +748,6 @@ fn lowerNavRef(
8 => mem.writeInt(u64, try code.addManyAsArray(8), vaddr, endian),
else => unreachable,
}
return .ok;
}
/// Helper struct to denote that the value is in memory but requires a linker relocation fixup: