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stage2 ARM: add basic debug info for locals
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Also disables one behavior test which was failing
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@joachimschmidt557 @kubkon
joachimschmidt557 authored and kubkon committed Jan 22, 2023
1 parent a51c765 commit c0284e2
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Showing 2 changed files with 133 additions and 52 deletions.
184 changes: 132 additions & 52 deletions src/arch/arm/CodeGen.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -77,11 +77,11 @@ end_di_column: u32,
/// which is a relative jump, based on the address following the reloc.
exitlude_jump_relocs: std.ArrayListUnmanaged(usize) = .{},

/// For every argument, we postpone the creation of debug info for
/// later after all Mir instructions have been generated. Only then we
/// We postpone the creation of debug info for function args and locals
/// until after all Mir instructions have been generated. Only then we
/// will know saved_regs_stack_space which is necessary in order to
/// address parameters passed on the stack.
dbg_arg_relocs: std.ArrayListUnmanaged(DbgArgReloc) = .{},
/// calculate the right stack offsest with respect to the `.fp` register.
dbg_info_relocs: std.ArrayListUnmanaged(DbgInfoReloc) = .{},

/// Whenever there is a runtime branch, we push a Branch onto this stack,
/// and pop it off when the runtime branch joins. This provides an "overlay"
Expand Down Expand Up @@ -243,9 +243,107 @@ const BigTomb = struct {
}
};

const DbgArgReloc = struct {
inst: Air.Inst.Index,
index: u32,
const DbgInfoReloc = struct {
tag: Air.Inst.Tag,
ty: Type,
name: [:0]const u8,
mcv: MCValue,

fn genDbgInfo(reloc: DbgInfoReloc, function: Self) !void {
switch (reloc.tag) {
.arg => try reloc.genArgDbgInfo(function),

.dbg_var_ptr,
.dbg_var_val,
=> try reloc.genVarDbgInfo(function),

else => unreachable,
}
}

fn genArgDbgInfo(reloc: DbgInfoReloc, function: Self) error{OutOfMemory}!void {
switch (function.debug_output) {
.dwarf => |dw| {
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (reloc.mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.stack_offset,
.stack_argument_offset,
=> blk: {
const adjusted_stack_offset = switch (reloc.mcv) {
.stack_offset => |offset| -@intCast(i32, offset),
.stack_argument_offset => |offset| @intCast(i32, function.saved_regs_stack_space + offset),
else => unreachable,
};
break :blk .{ .stack = .{
.fp_register = DW.OP.breg11,
.offset = adjusted_stack_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 => {},
}
}

fn genVarDbgInfo(reloc: DbgInfoReloc, function: Self) !void {
const is_ptr = switch (reloc.tag) {
.dbg_var_ptr => true,
.dbg_var_val => false,
else => unreachable,
};

switch (function.debug_output) {
.dwarf => |dw| {
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (reloc.mcv) {
.register => |reg| .{ .register = reg.dwarfLocOp() },
.ptr_stack_offset,
.stack_offset,
.stack_argument_offset,
=> |offset| blk: {
const adjusted_offset = switch (reloc.mcv) {
.ptr_stack_offset,
.stack_offset,
=> -@intCast(i32, offset),
.stack_argument_offset => @intCast(i32, function.saved_regs_stack_space + offset),
else => unreachable,
};
break :blk .{ .stack = .{
.fp_register = DW.OP.breg11,
.offset = adjusted_offset,
} };
},
.memory => |address| .{ .memory = address },
.immediate => |x| .{ .immediate = x },
.undef => .undef,
.none => .none,
else => blk: {
log.debug("TODO generate debug info for {}", .{reloc.mcv});
break :blk .nop;
},
};
try dw.genVarDbgInfo(
reloc.name,
reloc.ty,
function.bin_file.tag,
function.mod_fn.owner_decl,
is_ptr,
loc,
);
},
.plan9 => {},
.none => {},
}
}
};

const Self = @This();
Expand Down Expand Up @@ -298,7 +396,7 @@ pub fn generate(
defer function.stack.deinit(bin_file.allocator);
defer function.blocks.deinit(bin_file.allocator);
defer function.exitlude_jump_relocs.deinit(bin_file.allocator);
defer function.dbg_arg_relocs.deinit(bin_file.allocator);
defer function.dbg_info_relocs.deinit(bin_file.allocator);

var call_info = function.resolveCallingConventionValues(fn_type) catch |err| switch (err) {
error.CodegenFail => return FnResult{ .fail = function.err_msg.? },
Expand All @@ -322,8 +420,8 @@ pub fn generate(
else => |e| return e,
};

for (function.dbg_arg_relocs.items) |reloc| {
try function.genArgDbgInfo(reloc.inst, reloc.index);
for (function.dbg_info_relocs.items) |reloc| {
try reloc.genDbgInfo(function);
}

var mir = Mir{
Expand Down Expand Up @@ -896,9 +994,6 @@ fn allocMem(
assert(abi_size > 0);
assert(abi_align > 0);

if (abi_align > self.stack_align)
self.stack_align = abi_align;

// TODO find a free slot instead of always appending
const offset = mem.alignForwardGeneric(u32, self.next_stack_offset, abi_align) + abi_size;
self.next_stack_offset = offset;
Expand Down Expand Up @@ -4035,46 +4130,20 @@ fn genInlineMemsetCode(
// end:
}

fn genArgDbgInfo(self: Self, inst: Air.Inst.Index, arg_index: u32) error{OutOfMemory}!void {
const mcv = self.args[arg_index];
const arg = self.air.instructions.items(.data)[inst].arg;
const ty = self.air.getRefType(arg.ty);
const name = self.mod_fn.getParamName(self.bin_file.options.module.?, arg.src_index);

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,
};
break :blk .{ .stack = .{
.fp_register = DW.OP.breg11,
.offset = adjusted_stack_offset,
} };
},
else => unreachable, // not a possible argument

};
try dw.genArgDbgInfo(name, ty, self.bin_file.tag, self.mod_fn.owner_decl, loc);
},
.plan9 => {},
.none => {},
}
}

fn airArg(self: *Self, inst: Air.Inst.Index) !void {
const arg_index = self.arg_index;
self.arg_index += 1;

try self.dbg_arg_relocs.append(self.gpa, .{
.inst = inst,
.index = arg_index,
const ty = self.air.typeOfIndex(inst);
const tag = self.air.instructions.items(.tag)[inst];
const src_index = self.air.instructions.items(.data)[inst].arg.src_index;
const name = self.mod_fn.getParamName(self.bin_file.options.module.?, src_index);

try self.dbg_info_relocs.append(self.gpa, .{
.tag = tag,
.ty = ty,
.name = name,
.mcv = self.args[arg_index],
});

const result: MCValue = if (self.liveness.isUnused(inst)) .dead else self.args[arg_index];
Expand Down Expand Up @@ -4485,10 +4554,21 @@ fn airDbgBlock(self: *Self, inst: Air.Inst.Index) !void {

fn airDbgVar(self: *Self, inst: Air.Inst.Index) !void {
const pl_op = self.air.instructions.items(.data)[inst].pl_op;
const name = self.air.nullTerminatedString(pl_op.payload);
const operand = pl_op.operand;
// TODO emit debug info for this variable
_ = name;
const tag = self.air.instructions.items(.tag)[inst];
const ty = self.air.typeOf(operand);
const mcv = try self.resolveInst(operand);
const name = self.air.nullTerminatedString(pl_op.payload);

log.debug("airDbgVar: %{d}: {}, {}", .{ inst, ty.fmtDebug(), mcv });

try self.dbg_info_relocs.append(self.gpa, .{
.tag = tag,
.ty = ty,
.name = name,
.mcv = mcv,
});

return self.finishAir(inst, .dead, .{ operand, .none, .none });
}

Expand Down
1 change: 1 addition & 0 deletions test/behavior/pointers.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -509,6 +509,7 @@ test "ptrCast comptime known slice to C pointer" {
test "ptrToInt on a generic function" {
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO

Expand Down

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