Commit 975c185b92a7d470ea705b28f46a8004bdda3c60 | zig

author	Andrew Kelley <andrew@ziglang.org> 2024-08-02 12:00:08-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2024-08-02 14:14:59-07:00
log	975c185b92a7d470ea705b28f46a8004bdda3c60
tree	cb0d037c9a2f38b348ae10b621db417e2f941fa1
parent	48d584e3a33a76ef4ea643905a11d311e9ed8bbf

fix compilation on powerpc GNU systems

...which have a ucontext_t but not a PC register. The current stack
unwinding implementation does not yet support this architecture.

Also fix name of `std.debug.SelfInfo.openSelf` to remove redundancy.

Also removed this hook into root providing an "openSelfDebugInfo"
function. Sorry, this debugging code is not of sufficient quality to
offer a plugin API right now.

6 files changed, 51 insertions(+), 41 deletions(-)

lib
- std
  - debug.zig
  - debug
    Dwarf.zig
    Dwarf
    abi.zig
    expression.zig
    SelfInfo.zig
test
- standalone
  - coff_dwarf
    main.zig

lib/std/debug.zig+15-7

...	...	@@ -88,7 +88,7 @@ pub fn getSelfDebugInfo() !*SelfInfo {
88	88	if (self_debug_info) \|*info\| {
89	89	return info;
90	90	} else {
91		self_debug_info = try SelfInfo.openSelf(getDebugInfoAllocator());
	91	self_debug_info = try SelfInfo.open(getDebugInfoAllocator());
92	92	return &self_debug_info.?;
93	93	}
94	94	}
...	...	@@ -573,17 +573,19 @@ pub const StackIterator = struct {
573	573	pub fn initWithContext(first_address: ?usize, debug_info: SelfInfo, context: posix.ucontext_t) !StackIterator {
574	574	// The implementation of DWARF unwinding on aarch64-macos is not complete. However, Apple mandates that
575	575	// the frame pointer register is always used, so on this platform we can safely use the FP-based unwinder.
576		if (builtin.target.isDarwin() and native_arch == .aarch64) {
	576	if (builtin.target.isDarwin() and native_arch == .aarch64)
577	577	return init(first_address, context.mcontext.ss.fp);
578		} else {
	578
	579	if (SelfInfo.supports_unwinding) {
579	580	var iterator = init(first_address, null);
580	581	iterator.unwind_state = .{
581	582	.debug_info = debug_info,
582	583	.dwarf_context = try SelfInfo.UnwindContext.init(debug_info.allocator, context),
583	584	};
584
585	585	return iterator;
586	586	}
	587
	588	return init(first_address, null);
587	589	}
588	590
589	591	pub fn deinit(it: *StackIterator) void {
...	...	@@ -725,11 +727,13 @@ pub fn writeCurrentStackTrace(
725	727	tty_config: io.tty.Config,
726	728	start_addr: ?usize,
727	729	) !void {
728		var context: ThreadContext = undefined;
729		const has_context = getContext(&context);
730	730	if (native_os == .windows) {
	731	var context: ThreadContext = undefined;
	732	assert(getContext(&context));
731	733	return writeStackTraceWindows(out_stream, debug_info, tty_config, &context, start_addr);
732	734	}
	735	var context: ThreadContext = undefined;
	736	const has_context = getContext(&context);
733	737
734	738	var it = (if (has_context) blk: {
735	739	break :blk StackIterator.initWithContext(start_addr, debug_info, &context) catch null;
...	...	@@ -1340,7 +1344,7 @@ test "manage resources correctly" {
1340	1344	}
1341	1345
1342	1346	const writer = std.io.null_writer;
1343		var di = try SelfInfo.openSelf(testing.allocator);
	1347	var di = try SelfInfo.open(testing.allocator);
1344	1348	defer di.deinit();
1345	1349	try printSourceAtAddress(&di, writer, showMyTrace(), io.tty.detectConfig(std.io.getStdErr()));
1346	1350	}
...	...	@@ -1581,5 +1585,9 @@ pub inline fn inValgrind() bool {
1581	1585	}
1582	1586
1583	1587	test {
	1588	_ = &Dwarf;
	1589	_ = &MemoryAccessor;
	1590	_ = &Pdb;
	1591	_ = &SelfInfo;
1584	1592	_ = &dumpHex;
1585	1593	}

lib/std/debug/Dwarf.zig+24

...	...	@@ -2023,3 +2023,27 @@ fn pcRelBase(field_ptr: usize, pc_rel_offset: i64) !usize {
2023	2023	return std.math.add(usize, field_ptr, @as(usize, @intCast(pc_rel_offset)));
2024	2024	}
2025	2025	}
	2026
	2027	pub fn supportsUnwinding(target: std.Target) bool {
	2028	return switch (target.cpu.arch) {
	2029	.x86 => switch (target.os.tag) {
	2030	.linux, .netbsd, .solaris, .illumos => true,
	2031	else => false,
	2032	},
	2033	.x86_64 => switch (target.os.tag) {
	2034	.linux, .netbsd, .freebsd, .openbsd, .macos, .ios, .solaris, .illumos => true,
	2035	else => false,
	2036	},
	2037	.arm => switch (target.os.tag) {
	2038	.linux => true,
	2039	else => false,
	2040	},
	2041	.aarch64 => switch (target.os.tag) {
	2042	.linux, .netbsd, .freebsd, .macos, .ios => true,
	2043	else => false,
	2044	},
	2045	// Unwinding is possible on other targets but this implementation does
	2046	// not support them...yet!
	2047	else => false,
	2048	};
	2049	}

lib/std/debug/Dwarf/abi.zig+3-24

...	...	@@ -5,35 +5,14 @@ const mem = std.mem;
5	5	const posix = std.posix;
6	6	const Arch = std.Target.Cpu.Arch;
7	7
8		pub fn supportsUnwinding(target: std.Target) bool {
9		return switch (target.cpu.arch) {
10		.x86 => switch (target.os.tag) {
11		.linux, .netbsd, .solaris, .illumos => true,
12		else => false,
13		},
14		.x86_64 => switch (target.os.tag) {
15		.linux, .netbsd, .freebsd, .openbsd, .macos, .ios, .solaris, .illumos => true,
16		else => false,
17		},
18		.arm => switch (target.os.tag) {
19		.linux => true,
20		else => false,
21		},
22		.aarch64 => switch (target.os.tag) {
23		.linux, .netbsd, .freebsd, .macos, .ios => true,
24		else => false,
25		},
26		else => false,
27		};
28		}
29
30		pub fn ipRegNum(arch: Arch) u8 {
	8	/// Returns `null` for CPU architectures without an instruction pointer register.
	9	pub fn ipRegNum(arch: Arch) ?u8 {
31	10	return switch (arch) {
32	11	.x86 => 8,
33	12	.x86_64 => 16,
34	13	.arm => 15,
35	14	.aarch64 => 32,
36		else => unreachable,
	15	else => null,
37	16	};
38	17	}
39	18

lib/std/debug/Dwarf/expression.zig+2-2

...	...	@@ -1190,11 +1190,11 @@ test "DWARF expressions" {
1190	1190	mem.writeInt(usize, reg_bytes[0..@sizeOf(usize)], 0xee, native_endian);
1191	1191	(try abi.regValueNative(&thread_context, abi.fpRegNum(native_arch, reg_context), reg_context)).* = 1;
1192	1192	(try abi.regValueNative(&thread_context, abi.spRegNum(native_arch, reg_context), reg_context)).* = 2;
1193		(try abi.regValueNative(&thread_context, abi.ipRegNum(native_arch), reg_context)).* = 3;
	1193	(try abi.regValueNative(&thread_context, abi.ipRegNum(native_arch).?, reg_context)).* = 3;
1194	1194
1195	1195	try b.writeBreg(writer, abi.fpRegNum(native_arch, reg_context), @as(usize, 100));
1196	1196	try b.writeBreg(writer, abi.spRegNum(native_arch, reg_context), @as(usize, 200));
1197		try b.writeBregx(writer, abi.ipRegNum(native_arch), @as(usize, 300));
	1197	try b.writeBregx(writer, abi.ipRegNum(native_arch).?, @as(usize, 300));
1198	1198	try b.writeRegvalType(writer, @as(u8, 0), @as(usize, 400));
1199	1199
1200	1200	_ = try stack_machine.run(program.items, allocator, context, 0);

lib/std/debug/SelfInfo.zig+6-7

...	...	@@ -34,18 +34,15 @@ allocator: Allocator,
34	34	address_map: std.AutoHashMap(usize, *Module),
35	35	modules: if (native_os == .windows) std.ArrayListUnmanaged(WindowsModule) else void,
36	36
37		pub const OpenSelfError = error{
	37	pub const OpenError = error{
38	38	MissingDebugInfo,
39	39	UnsupportedOperatingSystem,
40	40	} \|\| @typeInfo(@typeInfo(@TypeOf(SelfInfo.init)).Fn.return_type.?).ErrorUnion.error_set;
41	41
42		pub fn openSelf(allocator: Allocator) OpenSelfError!SelfInfo {
	42	pub fn open(allocator: Allocator) OpenError!SelfInfo {
43	43	nosuspend {
44	44	if (builtin.strip_debug_info)
45	45	return error.MissingDebugInfo;
46		if (@hasDecl(root, "os") and @hasDecl(root.os, "debug") and @hasDecl(root.os.debug, "openSelfDebugInfo")) {
47		return root.os.debug.openSelfDebugInfo(allocator);
48		}
49	46	switch (native_os) {
50	47	.linux,
51	48	.freebsd,
...	...	@@ -1721,6 +1718,8 @@ pub const UnwindContext = struct {
1721	1718	allocator: Allocator,
1722	1719	thread_context: *std.debug.ThreadContext,
1723	1720	) !UnwindContext {
	1721	comptime assert(supports_unwinding);
	1722
1724	1723	const pc = stripInstructionPtrAuthCode(
1725	1724	(try regValueNative(thread_context, ip_reg_num, null)).*,
1726	1725	);
...	...	@@ -1982,8 +1981,8 @@ fn spRegNum(reg_context: Dwarf.abi.RegisterContext) u8 {
1982	1981	return Dwarf.abi.spRegNum(native_arch, reg_context);
1983	1982	}
1984	1983
1985		const ip_reg_num = Dwarf.abi.ipRegNum(native_arch);
1986		const supports_unwinding = Dwarf.abi.supportsUnwinding(builtin.target);
	1984	const ip_reg_num = Dwarf.abi.ipRegNum(native_arch).?;
	1985	pub const supports_unwinding = Dwarf.supportsUnwinding(builtin.target);
1987	1986
1988	1987	fn unwindFrameMachODwarf(
1989	1988	context: *UnwindContext,

test/standalone/coff_dwarf/main.zig+1-1

...	...	@@ -9,7 +9,7 @@ pub fn main() !void {
9	9	defer assert(gpa.deinit() == .ok);
10	10	const allocator = gpa.allocator();
11	11
12		var debug_info = try std.debug.openSelfDebugInfo(allocator);
	12	var debug_info = try std.debug.SelfInfo.open(allocator);
13	13	defer debug_info.deinit();
14	14
15	15	var add_addr: usize = undefined;