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- fix remember_state

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- implement def_cfa_register
This commit is contained in:
kcbanner 2023-05-09 02:24:57 -04:00
parent f3f3c877e0
commit 338df862d1
1 changed files with 37 additions and 44 deletions
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81
lib/std/dwarf/call_frame.zig
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@ -233,17 +233,10 @@ pub const Instruction = union(Opcode) {
.register => {},
.remember_state => {},
.restore_state => {},
.def_cfa => |i| {
try abi.writeRegisterName(writer, arch, i.operands.register);
try writer.print(" {d:<1}", .{@intCast(i64, i.operands.offset)});
},
.def_cfa_register => {},
.def_cfa_offset => |i| {
try writer.print("{d:<1}", .{@intCast(i64, i.operands.offset)});
},
.def_cfa_expression => |i| {
try writeExpression(writer, i.operands.block, arch, addr_size_bytes, endian);
},
.def_cfa => |i| try writer.print("{} {d:<1}", .{ abi.fmtRegister(i.operands.register, arch), @intCast(i64, i.operands.offset)}),
.def_cfa_register => |i| try abi.writeRegisterName(writer, arch, i.operands.register),
.def_cfa_offset => |i| try writer.print("{d:<1}", .{@intCast(i64, i.operands.offset)}),
.def_cfa_expression => |i| try writeExpression(writer, i.operands.block, arch, addr_size_bytes, endian),
.expression => {},
.offset_extended_sf => {},
.def_cfa_sf => {},
@ -318,16 +311,6 @@ fn writeExpression(
}
}
// fn formatOffset(data: i64, comptime fmt: []const u8, options: std.fmt.FormatOptions, writer: anytype) !void {
// _ = fmt;
// if (data >= 0) try writer.writeByte('+');
// return std.fmt.formatInt(data, 10, .lower, options, writer);
// }
// fn fmtOffset(offset: i64) std.fmt.Formatter(formatOffset) {
// return .{ .data = offset };
// }
/// See section 6.4.1 of the DWARF5 specification
pub const VirtualMachine = struct {
const RegisterRule = union(enum) {
@ -387,7 +370,7 @@ pub const VirtualMachine = struct {
}
};
/// Each row contains unwinding rules for a set of registers at a specific location in the program.
/// Each row contains unwinding rules for a set of registers at a specific location in the
pub const Row = struct {
/// Offset from pc_begin
offset: u64 = 0,
@ -395,31 +378,33 @@ pub const VirtualMachine = struct {
/// The register field of this column defines the register that CFA is derived
/// from, while other columns define registers in terms of the CFA.
cfa: Column = .{},
columns: ColumnRange = .{},
};
const ColumnRange = struct {
/// Index into `columns` of the first column in this row.
columns_start: usize = undefined,
columns_len: u8 = 0,
start: usize = undefined,
len: u8 = 0,
};
columns: std.ArrayListUnmanaged(Column) = .{},
row_stack: std.ArrayListUnmanaged(Row) = .{},
stack: std.ArrayListUnmanaged(ColumnRange) = .{},
current_row: Row = .{},
// TODO: Add stack machine stack
pub fn reset(self: *VirtualMachine) void {
self.row_stack.clearRetainingCapacity();
self.stack.clearRetainingCapacity();
self.columns.clearRetainingCapacity();
self.current_row = .{};
}
pub fn deinit(self: *VirtualMachine, allocator: std.mem.Allocator) void {
self.row_stack.deinit(allocator);
self.stack.deinit(allocator);
self.columns.deinit(allocator);
self.* = undefined;
}
pub fn getColumns(self: VirtualMachine, row: Row) []Column {
return self.columns.items[row.columns_start..][0..row.columns_len];
return self.columns.items[row.columns.start..][0..row.columns.len];
}
fn getOrAddColumn(self: *VirtualMachine, allocator: std.mem.Allocator, register: u8) !*Column {
@ -427,10 +412,10 @@ pub const VirtualMachine = struct {
if (c.register == register) return c;
}
if (self.current_row.columns_len == 0) {
self.current_row.columns_start = self.columns.items.len;
if (self.current_row.columns.len == 0) {
self.current_row.columns.start = self.columns.items.len;
}
self.current_row.columns_len += 1;
self.current_row.columns.len += 1;
const column = try self.columns.addOne(allocator);
column.* = .{
@ -443,7 +428,7 @@ pub const VirtualMachine = struct {
pub fn step(self: *VirtualMachine, allocator: std.mem.Allocator, cie: dwarf.CommonInformationEntry, instruction: Instruction) !void {
switch (instruction) {
inline .advance_loc, .advance_loc1, .advance_loc2, .advance_loc4 => |i| {
self.current_row.offset += i.operands.delta;
self.current_row.offset += i.operands.delta * cie.code_alignment_factor;
},
.offset => |i| {
const column = try self.getOrAddColumn(allocator, i.operands.register);
@ -458,18 +443,22 @@ pub const VirtualMachine = struct {
.same_value => {},
.register => {},
.remember_state => {
try self.stack.append(allocator, self.current_row.columns);
errdefer _ = self.stack.pop();
// TODO: The row stack only actually needs the column information
// TODO: Also it needs to copy the columns because changes can edit the referenced columns
// TODO: This function could push the column range onto the stack, the copy the columns and update current row
try self.row_stack.append(allocator, self.current_row);
const new_start = self.columns.items.len;
if (self.current_row.columns.len > 0) {
// Since we're copying from the same backing array, ensure it won't be reallocated
try self.columns.ensureUnusedCapacity(allocator, self.current_row.columns.len);
self.columns.appendSliceAssumeCapacity(self.getColumns(self.current_row));
self.current_row.columns.start = new_start;
}
},
.restore_state => {
if (self.row_stack.items.len == 0) return error.InvalidOperation;
const row = self.row_stack.pop();
self.current_row.columns_len = row.columns_len;
self.current_row.columns_start = row.columns_start;
// TODO: Is it possible to remove the duplicate from above? Other instructions may have added columns since then though
const columns = self.stack.popOrNull() orelse return error.InvalidOperation;
self.current_row.columns.len = columns.len;
self.current_row.columns.start = columns.start;
},
.def_cfa => |i| {
self.current_row.cfa = .{
@ -477,8 +466,12 @@ pub const VirtualMachine = struct {
.rule = .{ .offset = @intCast(i64, i.operands.offset) },
};
},
.def_cfa_register => {},
.def_cfa_register => |i| {
// TODO: Verify the the current row is using a register and offset (validation)
self.current_row.cfa.register = i.operands.register;
},
.def_cfa_offset => |i| {
// TODO: Verify the the current row is using a register and offset (validation)
self.current_row.cfa.rule = .{ .offset = @intCast(i64, i.operands.offset) };
},
.def_cfa_expression => |i| {