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Merge pull request #13730 from ziglang/gen-dwarf-simple

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dwarf: dedup generation of dwarf info for func args and vars in Dwarf module
This commit is contained in:
Jakub Konka 2022-12-02 17:13:52 +01:00 committed by GitHub
commit 16dc86a49e
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8 changed files with 395 additions and 605 deletions
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224
src/arch/aarch64/CodeGen.zig
View File

@ -146,11 +146,8 @@ const MCValue = union(enum) {
/// If the type is a pointer, it means the pointer address is at
/// this memory location.
memory: u64,
/// The value is in memory but requires a linker relocation fixup:
/// * got - the value is referenced indirectly via GOT entry index (the linker emits a got-type reloc)
/// * direct - the value is referenced directly via symbol index index (the linker emits a displacement reloc)
/// * import - the value is referenced indirectly via import entry index (the linker emits an import-type reloc)
linker_load: struct { type: enum { got, direct, import }, sym_index: u32 },
/// The value is in memory but requires a linker relocation fixup.
linker_load: codegen.LinkerLoad,
/// The value is one of the stack variables.
///
/// If the type is a pointer, it means the pointer address is in
@ -184,52 +181,34 @@ const DbgInfoReloc = struct {
else => unreachable,
}
}
fn genArgDbgInfo(reloc: DbgInfoReloc, function: Self) error{OutOfMemory}!void {
const name_with_null = reloc.name.ptr[0 .. reloc.name.len + 1];
switch (function.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
switch (reloc.mcv) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try function.addDbgInfoTypeReloc(reloc.ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (reloc.mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.stack_offset,
.stack_argument_offset,
=> |offset| {
=> |offset| blk: {
const adjusted_offset = switch (reloc.mcv) {
.stack_offset => -@intCast(i32, offset),
.stack_argument_offset => @intCast(i32, function.saved_regs_stack_space + offset),
else => unreachable,
};
try dbg_info.ensureUnusedCapacity(8);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
Register.x29.dwarfLocOpDeref(), // frame pointer
});
leb128.writeILEB128(dbg_info.writer(), adjusted_offset) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try function.addDbgInfoTypeReloc(reloc.ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
break :blk .{ .stack = .{
.fp_register = Register.x29.dwarfLocOpDeref(),
.offset = adjusted_offset,
} };
},
else => unreachable, // not a possible argument
}
};
try dw.genArgDbgInfo(
reloc.name,
reloc.ty,
function.bin_file.tag,
function.mod_fn.owner_decl,
loc,
);
},
.plan9 => {},
.none => {},
@ -237,32 +216,20 @@ const DbgInfoReloc = struct {
}
fn genVarDbgInfo(reloc: DbgInfoReloc, function: Self) !void {
const name_with_null = reloc.name.ptr[0 .. reloc.name.len + 1];
const ty = switch (reloc.tag) {
.dbg_var_ptr => reloc.ty.childType(),
.dbg_var_val => reloc.ty,
const is_ptr = switch (reloc.tag) {
.dbg_var_ptr => true,
.dbg_var_val => false,
else => unreachable,
};
switch (function.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
try dbg_info.append(@enumToInt(link.File.Dwarf.AbbrevKind.variable));
const endian = function.target.cpu.arch.endian();
switch (reloc.mcv) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
},
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (reloc.mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.ptr_stack_offset,
.stack_offset,
.stack_argument_offset,
=> |offset| {
=> |offset| blk: {
const adjusted_offset = switch (reloc.mcv) {
.ptr_stack_offset,
.stack_offset,
@ -270,110 +237,31 @@ const DbgInfoReloc = struct {
.stack_argument_offset => @intCast(i32, function.saved_regs_stack_space + offset),
else => unreachable,
};
try dbg_info.ensureUnusedCapacity(7);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
Register.x29.dwarfLocOpDeref(), // frame pointer
});
leb128.writeILEB128(dbg_info.writer(), adjusted_offset) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.memory,
.linker_load,
=> {
const ptr_width = @intCast(u8, @divExact(function.target.cpu.arch.ptrBitWidth(), 8));
const is_ptr = switch (reloc.tag) {
.dbg_var_ptr => true,
.dbg_var_val => false,
else => unreachable,
};
try dbg_info.ensureUnusedCapacity(2 + ptr_width);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1 + ptr_width + @boolToInt(is_ptr),
DW.OP.addr, // literal address
});
const offset = @intCast(u32, dbg_info.items.len);
const addr = switch (reloc.mcv) {
.memory => |addr| addr,
else => 0,
};
switch (ptr_width) {
0...4 => {
try dbg_info.writer().writeInt(u32, @intCast(u32, addr), endian);
break :blk .{
.stack = .{
.fp_register = Register.x29.dwarfLocOpDeref(),
.offset = adjusted_offset,
},
5...8 => {
try dbg_info.writer().writeInt(u64, addr, endian);
},
else => unreachable,
}
if (is_ptr) {
// We need deref the address as we point to the value via GOT entry.
try dbg_info.append(DW.OP.deref);
}
switch (reloc.mcv) {
.linker_load => |load_struct| try dw.addExprlocReloc(
load_struct.sym_index,
offset,
is_ptr,
),
else => {},
}
};
},
.immediate => |x| {
try dbg_info.ensureUnusedCapacity(2);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1,
if (ty.isSignedInt()) DW.OP.consts else DW.OP.constu,
});
if (ty.isSignedInt()) {
try leb128.writeILEB128(dbg_info.writer(), @bitCast(i64, x));
} else {
try leb128.writeULEB128(dbg_info.writer(), x);
}
try dbg_info.append(DW.OP.stack_value);
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.undef => {
// DW.AT.location, DW.FORM.exprloc
// uleb128(exprloc_len)
// DW.OP.implicit_value uleb128(len_of_bytes) bytes
const abi_size = @intCast(u32, ty.abiSize(function.target.*));
var implicit_value_len = std.ArrayList(u8).init(function.gpa);
defer implicit_value_len.deinit();
try leb128.writeULEB128(implicit_value_len.writer(), abi_size);
const total_exprloc_len = 1 + implicit_value_len.items.len + abi_size;
try leb128.writeULEB128(dbg_info.writer(), total_exprloc_len);
try dbg_info.ensureUnusedCapacity(total_exprloc_len);
dbg_info.appendAssumeCapacity(DW.OP.implicit_value);
dbg_info.appendSliceAssumeCapacity(implicit_value_len.items);
dbg_info.appendNTimesAssumeCapacity(0xaa, abi_size);
},
.none => {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendSliceAssumeCapacity(&[3]u8{ // DW.AT.location, DW.FORM.exprloc
2, DW.OP.lit0, DW.OP.stack_value,
});
},
else => {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, DW.OP.nop,
});
.memory => |address| .{ .memory = address },
.linker_load => |linker_load| .{ .linker_load = linker_load },
.immediate => |x| .{ .immediate = x },
.undef => .undef,
.none => .none,
else => blk: {
log.debug("TODO generate debug info for {}", .{reloc.mcv});
break :blk .nop;
},
}
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try function.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
};
try dw.genVarDbgInfo(
reloc.name,
reloc.ty,
function.bin_file.tag,
function.mod_fn.owner_decl,
is_ptr,
loc,
);
},
.plan9 => {},
.none => {},
@ -1079,28 +967,6 @@ fn ensureProcessDeathCapacity(self: *Self, additional_count: usize) !void {
try table.ensureUnusedCapacity(self.gpa, additional_count);
}
/// Adds a Type to the .debug_info at the current position. The bytes will be populated later,
/// after codegen for this symbol is done.
fn addDbgInfoTypeReloc(self: Self, ty: Type) !void {
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // DW.AT.type, DW.FORM.ref4
const mod = self.bin_file.options.module.?;
const fn_owner_decl = mod.declPtr(self.mod_fn.owner_decl);
const atom = switch (self.bin_file.tag) {
.elf => &fn_owner_decl.link.elf.dbg_info_atom,
.macho => &fn_owner_decl.link.macho.dbg_info_atom,
else => unreachable,
};
try dw.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
.plan9 => {},
.none => {},
}
}
fn allocMem(
self: *Self,
abi_size: u32,

87
src/arch/arm/CodeGen.zig
View File

@ -4029,86 +4029,35 @@ fn genInlineMemsetCode(
// end:
}
/// Adds a Type to the .debug_info at the current position. The bytes will be populated later,
/// after codegen for this symbol is done.
fn addDbgInfoTypeReloc(self: *Self, ty: Type) error{OutOfMemory}!void {
switch (self.debug_output) {
.dwarf => |dw| {
assert(ty.hasRuntimeBits());
const dbg_info = &dw.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // DW.AT.type, DW.FORM.ref4
const mod = self.bin_file.options.module.?;
const atom = switch (self.bin_file.tag) {
.elf => &mod.declPtr(self.mod_fn.owner_decl).link.elf.dbg_info_atom,
.macho => unreachable,
else => unreachable,
};
try dw.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
.plan9 => {},
.none => {},
}
}
fn genArgDbgInfo(self: *Self, inst: Air.Inst.Index, arg_index: u32) error{OutOfMemory}!void {
fn genArgDbgInfo(self: Self, inst: Air.Inst.Index, arg_index: u32) error{OutOfMemory}!void {
const mcv = self.args[arg_index];
const ty = self.air.instructions.items(.data)[inst].ty;
const name = self.mod_fn.getParamName(self.bin_file.options.module.?, arg_index);
const name_with_null = name.ptr[0 .. name.len + 1];
switch (mcv) {
.register => |reg| {
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
.plan9 => {},
.none => {},
}
},
.stack_offset,
.stack_argument_offset,
=> {
switch (self.debug_output) {
.dwarf => |dw| {
switch (self.debug_output) {
.dwarf => |dw| {
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.stack_offset,
.stack_argument_offset,
=> blk: {
const adjusted_stack_offset = switch (mcv) {
.stack_offset => |offset| -@intCast(i32, offset),
.stack_argument_offset => |offset| @intCast(i32, self.saved_regs_stack_space + offset),
else => unreachable,
};
const dbg_info = &dw.dbg_info;
try dbg_info.append(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
// Get length of the LEB128 stack offset
var counting_writer = std.io.countingWriter(std.io.null_writer);
leb128.writeILEB128(counting_writer.writer(), adjusted_stack_offset) catch unreachable;
// DW.AT.location, DW.FORM.exprloc
// ULEB128 dwarf expression length
try leb128.writeULEB128(dbg_info.writer(), counting_writer.bytes_written + 1);
try dbg_info.append(DW.OP.breg11);
try leb128.writeILEB128(dbg_info.writer(), adjusted_stack_offset);
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
break :blk .{ .stack = .{
.fp_register = DW.OP.breg11,
.offset = adjusted_stack_offset,
} };
},
.plan9 => {},
.none => {},
}
else => unreachable, // not a possible argument
};
try dw.genArgDbgInfo(name, ty, self.bin_file.tag, self.mod_fn.owner_decl, loc);
},
else => unreachable, // not a possible argument
.plan9 => {},
.none => {},
}
}

65
src/arch/riscv64/CodeGen.zig
View File

@ -772,28 +772,6 @@ fn ensureProcessDeathCapacity(self: *Self, additional_count: usize) !void {
try table.ensureUnusedCapacity(self.gpa, additional_count);
}
/// Adds a Type to the .debug_info at the current position. The bytes will be populated later,
/// after codegen for this symbol is done.
fn addDbgInfoTypeReloc(self: *Self, ty: Type) !void {
switch (self.debug_output) {
.dwarf => |dw| {
assert(ty.hasRuntimeBits());
const dbg_info = &dw.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // DW.AT.type, DW.FORM.ref4
const mod = self.bin_file.options.module.?;
const atom = switch (self.bin_file.tag) {
.elf => &mod.declPtr(self.mod_fn.owner_decl).link.elf.dbg_info_atom,
.macho => unreachable,
else => unreachable,
};
try dw.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
.plan9 => {},
.none => {},
}
}
fn allocMem(self: *Self, inst: Air.Inst.Index, abi_size: u32, abi_align: u32) !u32 {
if (abi_align > self.stack_align)
self.stack_align = abi_align;
@ -1624,39 +1602,24 @@ fn airFieldParentPtr(self: *Self, inst: Air.Inst.Index) !void {
return self.fail("TODO implement codegen airFieldParentPtr", .{});
}
fn genArgDbgInfo(self: *Self, inst: Air.Inst.Index, mcv: MCValue, arg_index: u32) !void {
fn genArgDbgInfo(self: Self, inst: Air.Inst.Index, mcv: MCValue, arg_index: u32) !void {
const ty = self.air.instructions.items(.data)[inst].ty;
const name = self.mod_fn.getParamName(self.bin_file.options.module.?, arg_index);
const name_with_null = name.ptr[0 .. name.len + 1];
switch (mcv) {
.register => |reg| {
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
.plan9 => {},
.none => {},
}
switch (self.debug_output) {
.dwarf => |dw| switch (mcv) {
.register => |reg| try dw.genArgDbgInfo(
name,
ty,
self.bin_file.tag,
self.mod_fn.owner_decl,
.{ .register = reg.dwarfLocOp() },
),
.stack_offset => {},
else => {},
},
.stack_offset => |offset| {
_ = offset;
switch (self.debug_output) {
.dwarf => {},
.plan9 => {},
.none => {},
}
},
else => {},
.plan9 => {},
.none => {},
}
}

57
src/arch/sparc64/CodeGen.zig
View File

@ -2460,26 +2460,6 @@ fn airWrapOptional(self: *Self, inst: Air.Inst.Index) !void {
// Common helper functions
/// Adds a Type to the .debug_info at the current position. The bytes will be populated later,
/// after codegen for this symbol is done.
fn addDbgInfoTypeReloc(self: *Self, ty: Type) !void {
switch (self.debug_output) {
.dwarf => |dw| {
assert(ty.hasRuntimeBits());
const dbg_info = &dw.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // DW.AT.type, DW.FORM.ref4
const mod = self.bin_file.options.module.?;
const atom = switch (self.bin_file.tag) {
.elf => &mod.declPtr(self.mod_fn.owner_decl).link.elf.dbg_info_atom,
else => unreachable,
};
try dw.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
else => {},
}
}
fn addInst(self: *Self, inst: Mir.Inst) error{OutOfMemory}!Mir.Inst.Index {
const gpa = self.gpa;
try self.mir_instructions.ensureUnusedCapacity(gpa, 1);
@ -3272,35 +3252,20 @@ fn finishAir(self: *Self, inst: Air.Inst.Index, result: MCValue, operands: [Live
self.finishAirBookkeeping();
}
fn genArgDbgInfo(self: *Self, inst: Air.Inst.Index, mcv: MCValue, arg_index: u32) !void {
fn genArgDbgInfo(self: Self, inst: Air.Inst.Index, mcv: MCValue, arg_index: u32) !void {
const ty = self.air.instructions.items(.data)[inst].ty;
const name = self.mod_fn.getParamName(self.bin_file.options.module.?, arg_index);
const name_with_null = name.ptr[0 .. name.len + 1];
switch (mcv) {
.register => |reg| {
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
else => {},
}
},
.stack_offset => |offset| {
_ = offset;
switch (self.debug_output) {
.dwarf => {},
else => {},
}
switch (self.debug_output) {
.dwarf => |dw| switch (mcv) {
.register => |reg| try dw.genArgDbgInfo(
name,
ty,
self.bin_file.tag,
self.mod_fn.owner_decl,
.{ .register = reg.dwarfLocOp() },
),
else => {},
},
else => {},
}

69
src/arch/wasm/CodeGen.zig
View File

@ -1291,23 +1291,6 @@ fn firstParamSRet(cc: std.builtin.CallingConvention, return_type: Type, target:
}
}
/// For a given `Type`, add debug information to .debug_info at the current position.
/// The actual bytes will be written to the position after relocation.
fn addDbgInfoTypeReloc(func: *CodeGen, ty: Type) !void {
switch (func.debug_output) {
.dwarf => |dwarf| {
assert(ty.hasRuntimeBitsIgnoreComptime());
const dbg_info = &dwarf.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4);
const atom = &func.decl.link.wasm.dbg_info_atom;
try dwarf.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
.plan9 => unreachable,
.none => {},
}
}
/// Lowers a Zig type and its value based on a given calling convention to ensure
/// it matches the ABI.
fn lowerArg(func: *CodeGen, cc: std.builtin.CallingConvention, ty: Type, value: WValue) !void {
@ -2358,24 +2341,9 @@ fn airArg(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
.dwarf => |dwarf| {
// TODO: Get the original arg index rather than wasm arg index
const name = func.mod_fn.getParamName(func.bin_file.base.options.module.?, arg_index);
const leb_size = link.File.Wasm.getULEB128Size(arg.local.value);
const dbg_info = &dwarf.dbg_info;
try dbg_info.ensureUnusedCapacity(3 + leb_size + 5 + name.len + 1);
// wasm locations are encoded as follow:
// DW_OP_WASM_location wasm-op
// where wasm-op is defined as
// wasm-op := wasm-local | wasm-global | wasm-operand_stack
// where each argument is encoded as
// <opcode> i:uleb128
dbg_info.appendSliceAssumeCapacity(&.{
@enumToInt(link.File.Dwarf.AbbrevKind.parameter),
std.dwarf.OP.WASM_location,
std.dwarf.OP.WASM_local,
try dwarf.genArgDbgInfo(name, arg_ty, .wasm, func.mod_fn.owner_decl, .{
.wasm_local = arg.local.value,
});
leb.writeULEB128(dbg_info.writer(), arg.local.value) catch unreachable;
try func.addDbgInfoTypeReloc(arg_ty);
dbg_info.appendSliceAssumeCapacity(name);
dbg_info.appendAssumeCapacity(0);
},
else => {},
}
@ -5345,38 +5313,21 @@ fn airDbgVar(func: *CodeGen, inst: Air.Inst.Index, is_ptr: bool) !void {
const pl_op = func.air.instructions.items(.data)[inst].pl_op;
const ty = func.air.typeOf(pl_op.operand);
const operand = try func.resolveInst(pl_op.operand);
const op_ty = if (is_ptr) ty.childType() else ty;
log.debug("airDbgVar: %{d}: {}, {}", .{ inst, op_ty.fmtDebug(), operand });
log.debug("airDbgVar: %{d}: {}, {}", .{ inst, ty.fmtDebug(), operand });
const name = func.air.nullTerminatedString(pl_op.payload);
log.debug(" var name = ({s})", .{name});
const dbg_info = &func.debug_output.dwarf.dbg_info;
try dbg_info.append(@enumToInt(link.File.Dwarf.AbbrevKind.variable));
switch (operand) {
.local => |local| {
const leb_size = link.File.Wasm.getULEB128Size(local.value);
try dbg_info.ensureUnusedCapacity(2 + leb_size);
// wasm locals are encoded as follow:
// DW_OP_WASM_location wasm-op
// where wasm-op is defined as
// wasm-op := wasm-local | wasm-global | wasm-operand_stack
// where wasm-local is encoded as
// wasm-local := 0x00 i:uleb128
dbg_info.appendSliceAssumeCapacity(&.{
std.dwarf.OP.WASM_location,
std.dwarf.OP.WASM_local,
});
leb.writeULEB128(dbg_info.writer(), local.value) catch unreachable;
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (operand) {
.local => |local| .{ .wasm_local = local.value },
else => blk: {
log.debug("TODO generate debug info for {}", .{operand});
break :blk .nop;
},
else => {}, // TODO
}
};
try func.debug_output.dwarf.genVarDbgInfo(name, ty, .wasm, func.mod_fn.owner_decl, is_ptr, loc);
try dbg_info.ensureUnusedCapacity(5 + name.len + 1);
try func.addDbgInfoTypeReloc(op_ty);
dbg_info.appendSliceAssumeCapacity(name);
dbg_info.appendAssumeCapacity(0);
func.finishAir(inst, .none, &.{});
}

251
src/arch/x86_64/CodeGen.zig
View File

@ -128,11 +128,8 @@ pub const MCValue = union(enum) {
/// The value is in memory at a hard-coded address.
/// If the type is a pointer, it means the pointer address is at this memory location.
memory: u64,
/// The value is in memory but requires a linker relocation fixup:
/// * got - the value is referenced indirectly via GOT entry index (the linker emits a got-type reloc)
/// * direct - the value is referenced directly via symbol index index (the linker emits a displacement reloc)
/// * import - the value is referenced indirectly via import entry index (the linker emits an import-type reloc)
linker_load: struct { type: enum { got, direct, import }, sym_index: u32 },
/// The value is in memory but requires a linker relocation fixup.
linker_load: codegen.LinkerLoad,
/// The value is one of the stack variables.
/// If the type is a pointer, it means the pointer address is in the stack at this offset.
stack_offset: i32,
@ -3818,41 +3815,60 @@ fn airArg(self: *Self, inst: Air.Inst.Index) !void {
}
fn genArgDbgInfo(self: Self, ty: Type, name: [:0]const u8, mcv: MCValue) !void {
const name_with_null = name.ptr[0 .. name.len + 1];
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
switch (mcv) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.stack_offset => |off| .{
.stack = .{
// TODO handle -fomit-frame-pointer
.fp_register = Register.rbp.dwarfLocOpDeref(),
.offset = -off,
},
},
.stack_offset => |off| {
try dbg_info.ensureUnusedCapacity(8);
dbg_info.appendAssumeCapacity(@enumToInt(link.File.Dwarf.AbbrevKind.parameter));
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
Register.rbp.dwarfLocOpDeref(), // TODO handle -fomit-frame-pointer
});
leb128.writeILEB128(dbg_info.writer(), -off) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
else => unreachable, // not a valid function parameter
}
};
try dw.genArgDbgInfo(name, ty, self.bin_file.tag, self.mod_fn.owner_decl, loc);
},
.plan9 => {},
.none => {},
}
}
fn genVarDbgInfo(
self: Self,
tag: Air.Inst.Tag,
ty: Type,
mcv: MCValue,
name: [:0]const u8,
) !void {
const is_ptr = switch (tag) {
.dbg_var_ptr => true,
.dbg_var_val => false,
else => unreachable,
};
switch (self.debug_output) {
.dwarf => |dw| {
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.ptr_stack_offset,
.stack_offset,
=> |off| .{ .stack = .{
.fp_register = Register.rbp.dwarfLocOpDeref(),
.offset = -off,
} },
.memory => |address| .{ .memory = address },
.linker_load => |linker_load| .{ .linker_load = linker_load },
.immediate => |x| .{ .immediate = x },
.undef => .undef,
.none => .none,
else => blk: {
log.debug("TODO generate debug info for {}", .{mcv});
break :blk .nop;
},
};
try dw.genVarDbgInfo(name, ty, self.bin_file.tag, self.mod_fn.owner_decl, is_ptr, loc);
},
.plan9 => {},
.none => {},
@ -4418,172 +4434,11 @@ fn airDbgVar(self: *Self, inst: Air.Inst.Index) !void {
const name = self.air.nullTerminatedString(pl_op.payload);
const tag = self.air.instructions.items(.tag)[inst];
switch (tag) {
.dbg_var_ptr => try self.genVarDbgInfo(tag, ty.childType(), mcv, name),
.dbg_var_val => try self.genVarDbgInfo(tag, ty, mcv, name),
else => unreachable,
}
try self.genVarDbgInfo(tag, ty, mcv, name);
return self.finishAir(inst, .dead, .{ operand, .none, .none });
}
fn genVarDbgInfo(
self: Self,
tag: Air.Inst.Tag,
ty: Type,
mcv: MCValue,
name: [:0]const u8,
) !void {
const name_with_null = name.ptr[0 .. name.len + 1];
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
try dbg_info.append(@enumToInt(link.File.Dwarf.AbbrevKind.variable));
const endian = self.target.cpu.arch.endian();
switch (mcv) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg.dwarfLocOp(),
});
},
.ptr_stack_offset,
.stack_offset,
=> |off| {
try dbg_info.ensureUnusedCapacity(7);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
Register.rbp.dwarfLocOpDeref(), // TODO handle -fomit-frame-pointer
});
leb128.writeILEB128(dbg_info.writer(), -off) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.memory,
.linker_load,
=> {
const ptr_width = @intCast(u8, @divExact(self.target.cpu.arch.ptrBitWidth(), 8));
const is_ptr = switch (tag) {
.dbg_var_ptr => true,
.dbg_var_val => false,
else => unreachable,
};
try dbg_info.ensureUnusedCapacity(2 + ptr_width);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1 + ptr_width + @boolToInt(is_ptr),
DW.OP.addr, // literal address
});
const offset = @intCast(u32, dbg_info.items.len);
const addr = switch (mcv) {
.memory => |addr| addr,
else => 0,
};
switch (ptr_width) {
0...4 => {
try dbg_info.writer().writeInt(u32, @intCast(u32, addr), endian);
},
5...8 => {
try dbg_info.writer().writeInt(u64, addr, endian);
},
else => unreachable,
}
if (is_ptr) {
// We need deref the address as we point to the value via GOT entry.
try dbg_info.append(DW.OP.deref);
}
switch (mcv) {
.linker_load => |load_struct| try dw.addExprlocReloc(
load_struct.sym_index,
offset,
is_ptr,
),
else => {},
}
},
.immediate => |x| {
try dbg_info.ensureUnusedCapacity(2);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1,
if (ty.isSignedInt()) DW.OP.consts else DW.OP.constu,
});
if (ty.isSignedInt()) {
try leb128.writeILEB128(dbg_info.writer(), @bitCast(i64, x));
} else {
try leb128.writeULEB128(dbg_info.writer(), x);
}
try dbg_info.append(DW.OP.stack_value);
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.undef => {
// DW.AT.location, DW.FORM.exprloc
// uleb128(exprloc_len)
// DW.OP.implicit_value uleb128(len_of_bytes) bytes
const abi_size = @intCast(u32, ty.abiSize(self.target.*));
var implicit_value_len = std.ArrayList(u8).init(self.gpa);
defer implicit_value_len.deinit();
try leb128.writeULEB128(implicit_value_len.writer(), abi_size);
const total_exprloc_len = 1 + implicit_value_len.items.len + abi_size;
try leb128.writeULEB128(dbg_info.writer(), total_exprloc_len);
try dbg_info.ensureUnusedCapacity(total_exprloc_len);
dbg_info.appendAssumeCapacity(DW.OP.implicit_value);
dbg_info.appendSliceAssumeCapacity(implicit_value_len.items);
dbg_info.appendNTimesAssumeCapacity(0xaa, abi_size);
},
.none => {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendSliceAssumeCapacity(&[3]u8{ // DW.AT.location, DW.FORM.exprloc
2, DW.OP.lit0, DW.OP.stack_value,
});
},
else => {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, DW.OP.nop,
});
log.debug("TODO generate debug info for {}", .{mcv});
},
}
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
try self.addDbgInfoTypeReloc(ty); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
},
.plan9 => {},
.none => {},
}
}
/// Adds a Type to the .debug_info at the current position. The bytes will be populated later,
/// after codegen for this symbol is done.
fn addDbgInfoTypeReloc(self: Self, ty: Type) !void {
switch (self.debug_output) {
.dwarf => |dw| {
const dbg_info = &dw.dbg_info;
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // DW.AT.type, DW.FORM.ref4
const mod = self.bin_file.options.module.?;
const fn_owner_decl = mod.declPtr(self.mod_fn.owner_decl);
const atom = switch (self.bin_file.tag) {
.elf => &fn_owner_decl.link.elf.dbg_info_atom,
.macho => &fn_owner_decl.link.macho.dbg_info_atom,
else => unreachable,
};
try dw.addTypeRelocGlobal(atom, ty, @intCast(u32, index));
},
.plan9 => {},
.none => {},
}
}
fn genCondBrMir(self: *Self, ty: Type, mcv: MCValue) !u32 {
const abi_size = ty.abiSize(self.target.*);
switch (mcv) {

13
src/codegen.zig
View File

@ -68,6 +68,19 @@ pub const DebugInfoOutput = union(enum) {
none,
};
/// Helper struct to denote that the value is in memory but requires a linker relocation fixup:
/// * got - the value is referenced indirectly via GOT entry index (the linker emits a got-type reloc)
/// * direct - the value is referenced directly via symbol index index (the linker emits a displacement reloc)
/// * import - the value is referenced indirectly via import entry index (the linker emits an import-type reloc)
pub const LinkerLoad = struct {
type: enum {
got,
direct,
import,
},
sym_index: u32,
};
pub fn generateFunction(
bin_file: *link.File,
src_loc: Module.SrcLoc,

234
src/link/Dwarf.zig
View File

@ -16,6 +16,7 @@ const DW = std.dwarf;
const File = link.File;
const LinkBlock = File.LinkBlock;
const LinkFn = File.LinkFn;
const LinkerLoad = @import("../codegen.zig").LinkerLoad;
const Module = @import("../Module.zig");
const Value = @import("../value.zig").Value;
const Type = @import("../type.zig").Type;
@ -101,7 +102,7 @@ pub const DeclState = struct {
self.exprloc_relocs.deinit(self.gpa);
}
pub fn addExprlocReloc(self: *DeclState, target: u32, offset: u32, is_ptr: bool) !void {
fn addExprlocReloc(self: *DeclState, target: u32, offset: u32, is_ptr: bool) !void {
log.debug("{x}: target sym %{d}, via GOT {}", .{ offset, target, is_ptr });
try self.exprloc_relocs.append(self.gpa, .{
.type = if (is_ptr) .got_load else .direct_load,
@ -112,7 +113,7 @@ pub const DeclState = struct {
/// Adds local type relocation of the form: @offset => @this + addend
/// @this signifies the offset within the .debug_abbrev section of the containing atom.
pub fn addTypeRelocLocal(self: *DeclState, atom: *const Atom, offset: u32, addend: u32) !void {
fn addTypeRelocLocal(self: *DeclState, atom: *const Atom, offset: u32, addend: u32) !void {
log.debug("{x}: @this + {x}", .{ offset, addend });
try self.abbrev_relocs.append(self.gpa, .{
.target = null,
@ -125,7 +126,7 @@ pub const DeclState = struct {
/// Adds global type relocation of the form: @offset => @symbol + 0
/// @symbol signifies a type abbreviation posititioned somewhere in the .debug_abbrev section
/// which we use as our target of the relocation.
pub fn addTypeRelocGlobal(self: *DeclState, atom: *const Atom, ty: Type, offset: u32) !void {
fn addTypeRelocGlobal(self: *DeclState, atom: *const Atom, ty: Type, offset: u32) !void {
const resolv = self.abbrev_resolver.getContext(ty, .{
.mod = self.mod,
}) orelse blk: {
@ -560,6 +561,233 @@ pub const DeclState = struct {
},
}
}
pub const DbgInfoLoc = union(enum) {
register: u8,
stack: struct {
fp_register: u8,
offset: i32,
},
wasm_local: u32,
memory: u64,
linker_load: LinkerLoad,
immediate: u64,
undef,
none,
nop,
};
pub fn genArgDbgInfo(
self: *DeclState,
name: [:0]const u8,
ty: Type,
tag: File.Tag,
owner_decl: Module.Decl.Index,
loc: DbgInfoLoc,
) error{OutOfMemory}!void {
const dbg_info = &self.dbg_info;
const atom = self.getDbgInfoAtom(tag, owner_decl);
const name_with_null = name.ptr[0 .. name.len + 1];
switch (loc) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendAssumeCapacity(@enumToInt(AbbrevKind.parameter));
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg,
});
},
.stack => |info| {
try dbg_info.ensureUnusedCapacity(8);
dbg_info.appendAssumeCapacity(@enumToInt(AbbrevKind.parameter));
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
info.fp_register, // frame pointer
});
leb128.writeILEB128(dbg_info.writer(), info.offset) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.wasm_local => |value| {
const leb_size = link.File.Wasm.getULEB128Size(value);
try dbg_info.ensureUnusedCapacity(3 + leb_size);
// wasm locations are encoded as follow:
// DW_OP_WASM_location wasm-op
// where wasm-op is defined as
// wasm-op := wasm-local | wasm-global | wasm-operand_stack
// where each argument is encoded as
// <opcode> i:uleb128
dbg_info.appendSliceAssumeCapacity(&.{
@enumToInt(AbbrevKind.parameter),
DW.OP.WASM_location,
DW.OP.WASM_local,
});
leb128.writeULEB128(dbg_info.writer(), value) catch unreachable;
},
else => unreachable,
}
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // dw.at.type, dw.form.ref4
try self.addTypeRelocGlobal(atom, ty, @intCast(u32, index)); // DW.AT.type, DW.FORM.ref4
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
}
pub fn genVarDbgInfo(
self: *DeclState,
name: [:0]const u8,
ty: Type,
tag: File.Tag,
owner_decl: Module.Decl.Index,
is_ptr: bool,
loc: DbgInfoLoc,
) error{OutOfMemory}!void {
const dbg_info = &self.dbg_info;
const atom = self.getDbgInfoAtom(tag, owner_decl);
const name_with_null = name.ptr[0 .. name.len + 1];
try dbg_info.append(@enumToInt(AbbrevKind.variable));
const target = self.mod.getTarget();
const endian = target.cpu.arch.endian();
const child_ty = if (is_ptr) ty.childType() else ty;
switch (loc) {
.register => |reg| {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // ULEB128 dwarf expression length
reg,
});
},
.stack => |info| {
try dbg_info.ensureUnusedCapacity(7);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, // we will backpatch it after we encode the displacement in LEB128
info.fp_register,
});
leb128.writeILEB128(dbg_info.writer(), info.offset) catch unreachable;
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.wasm_local => |value| {
const leb_size = link.File.Wasm.getULEB128Size(value);
try dbg_info.ensureUnusedCapacity(2 + leb_size);
// wasm locals are encoded as follow:
// DW_OP_WASM_location wasm-op
// where wasm-op is defined as
// wasm-op := wasm-local | wasm-global | wasm-operand_stack
// where wasm-local is encoded as
// wasm-local := 0x00 i:uleb128
dbg_info.appendSliceAssumeCapacity(&.{
DW.OP.WASM_location,
DW.OP.WASM_local,
});
leb128.writeULEB128(dbg_info.writer(), value) catch unreachable;
},
.memory,
.linker_load,
=> {
const ptr_width = @intCast(u8, @divExact(target.cpu.arch.ptrBitWidth(), 8));
try dbg_info.ensureUnusedCapacity(2 + ptr_width);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1 + ptr_width + @boolToInt(is_ptr),
DW.OP.addr, // literal address
});
const offset = @intCast(u32, dbg_info.items.len);
const addr = switch (loc) {
.memory => |x| x,
else => 0,
};
switch (ptr_width) {
0...4 => {
try dbg_info.writer().writeInt(u32, @intCast(u32, addr), endian);
},
5...8 => {
try dbg_info.writer().writeInt(u64, addr, endian);
},
else => unreachable,
}
if (is_ptr) {
// We need deref the address as we point to the value via GOT entry.
try dbg_info.append(DW.OP.deref);
}
switch (loc) {
.linker_load => |load_struct| try self.addExprlocReloc(
load_struct.sym_index,
offset,
is_ptr,
),
else => {},
}
},
.immediate => |x| {
try dbg_info.ensureUnusedCapacity(2);
const fixup = dbg_info.items.len;
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1,
if (child_ty.isSignedInt()) DW.OP.consts else DW.OP.constu,
});
if (child_ty.isSignedInt()) {
try leb128.writeILEB128(dbg_info.writer(), @bitCast(i64, x));
} else {
try leb128.writeULEB128(dbg_info.writer(), x);
}
try dbg_info.append(DW.OP.stack_value);
dbg_info.items[fixup] += @intCast(u8, dbg_info.items.len - fixup - 2);
},
.undef => {
// DW.AT.location, DW.FORM.exprloc
// uleb128(exprloc_len)
// DW.OP.implicit_value uleb128(len_of_bytes) bytes
const abi_size = @intCast(u32, child_ty.abiSize(target));
var implicit_value_len = std.ArrayList(u8).init(self.gpa);
defer implicit_value_len.deinit();
try leb128.writeULEB128(implicit_value_len.writer(), abi_size);
const total_exprloc_len = 1 + implicit_value_len.items.len + abi_size;
try leb128.writeULEB128(dbg_info.writer(), total_exprloc_len);
try dbg_info.ensureUnusedCapacity(total_exprloc_len);
dbg_info.appendAssumeCapacity(DW.OP.implicit_value);
dbg_info.appendSliceAssumeCapacity(implicit_value_len.items);
dbg_info.appendNTimesAssumeCapacity(0xaa, abi_size);
},
.none => {
try dbg_info.ensureUnusedCapacity(3);
dbg_info.appendSliceAssumeCapacity(&[3]u8{ // DW.AT.location, DW.FORM.exprloc
2, DW.OP.lit0, DW.OP.stack_value,
});
},
.nop => {
try dbg_info.ensureUnusedCapacity(2);
dbg_info.appendSliceAssumeCapacity(&[2]u8{ // DW.AT.location, DW.FORM.exprloc
1, DW.OP.nop,
});
},
}
try dbg_info.ensureUnusedCapacity(5 + name_with_null.len);
const index = dbg_info.items.len;
try dbg_info.resize(index + 4); // dw.at.type, dw.form.ref4
try self.addTypeRelocGlobal(atom, child_ty, @intCast(u32, index));
dbg_info.appendSliceAssumeCapacity(name_with_null); // DW.AT.name, DW.FORM.string
}
fn getDbgInfoAtom(self: *DeclState, tag: File.Tag, decl_index: Module.Decl.Index) *Atom {
const decl = self.mod.declPtr(decl_index);
return switch (tag) {
.elf => &decl.link.elf.dbg_info_atom,
.macho => &decl.link.macho.dbg_info_atom,
.wasm => &decl.link.wasm.dbg_info_atom,
else => unreachable,
};
}
};
pub const AbbrevEntry = struct {