regBytes
Returns a slice containing the backing storage for reg_number.
This function assumes the Dwarf information corresponds not necessarily to the current executable, but at least with a matching CPU architecture and OS. It is planned to lift this limitation with a future enhancement.
reg_context describes in what context the register number is used, as it can have different
meanings depending on the DWARF container. It is only required when getting the stack or
frame pointer register on some architectures.
Function parameters
Parameters
- thread_context_ptr:*std.debug.ThreadContext
- reg_number:u8
- reg_context:?RegisterContext
Type definitions in this namespace
Types
Tells whether unwinding for this target is supported by the Dwarf standard.
Functions
- supportsUnwinding
- Tells whether unwinding for this target is supported by the Dwarf standard.
- ipRegNum
- Returns `null` for CPU architectures without an instruction pointer register.
- regBytes
- Returns a slice containing the backing storage for `reg_number`.
- regValueNative
- Returns a pointer to a register stored in a ThreadContext, preserving the
Error sets in this namespace
Error Sets
Source
Implementation
pub fn regBytes(
thread_context_ptr: *std.debug.ThreadContext,
reg_number: u8,
reg_context: ?RegisterContext,
) RegBytesError![]u8 {
if (builtin.os.tag == .windows) {
return switch (builtin.cpu.arch) {
.x86 => switch (reg_number) {
0 => mem.asBytes(&thread_context_ptr.Eax),
1 => mem.asBytes(&thread_context_ptr.Ecx),
2 => mem.asBytes(&thread_context_ptr.Edx),
3 => mem.asBytes(&thread_context_ptr.Ebx),
4 => mem.asBytes(&thread_context_ptr.Esp),
5 => mem.asBytes(&thread_context_ptr.Ebp),
6 => mem.asBytes(&thread_context_ptr.Esi),
7 => mem.asBytes(&thread_context_ptr.Edi),
8 => mem.asBytes(&thread_context_ptr.Eip),
9 => mem.asBytes(&thread_context_ptr.EFlags),
10 => mem.asBytes(&thread_context_ptr.SegCs),
11 => mem.asBytes(&thread_context_ptr.SegSs),
12 => mem.asBytes(&thread_context_ptr.SegDs),
13 => mem.asBytes(&thread_context_ptr.SegEs),
14 => mem.asBytes(&thread_context_ptr.SegFs),
15 => mem.asBytes(&thread_context_ptr.SegGs),
else => error.InvalidRegister,
},
.x86_64 => switch (reg_number) {
0 => mem.asBytes(&thread_context_ptr.Rax),
1 => mem.asBytes(&thread_context_ptr.Rdx),
2 => mem.asBytes(&thread_context_ptr.Rcx),
3 => mem.asBytes(&thread_context_ptr.Rbx),
4 => mem.asBytes(&thread_context_ptr.Rsi),
5 => mem.asBytes(&thread_context_ptr.Rdi),
6 => mem.asBytes(&thread_context_ptr.Rbp),
7 => mem.asBytes(&thread_context_ptr.Rsp),
8 => mem.asBytes(&thread_context_ptr.R8),
9 => mem.asBytes(&thread_context_ptr.R9),
10 => mem.asBytes(&thread_context_ptr.R10),
11 => mem.asBytes(&thread_context_ptr.R11),
12 => mem.asBytes(&thread_context_ptr.R12),
13 => mem.asBytes(&thread_context_ptr.R13),
14 => mem.asBytes(&thread_context_ptr.R14),
15 => mem.asBytes(&thread_context_ptr.R15),
16 => mem.asBytes(&thread_context_ptr.Rip),
else => error.InvalidRegister,
},
.aarch64, .aarch64_be => switch (reg_number) {
0...30 => mem.asBytes(&thread_context_ptr.DUMMYUNIONNAME.X[reg_number]),
31 => mem.asBytes(&thread_context_ptr.Sp),
32 => mem.asBytes(&thread_context_ptr.Pc),
else => error.InvalidRegister,
},
else => error.UnimplementedArch,
};
}
if (!std.debug.have_ucontext) return error.ThreadContextNotSupported;
const ucontext_ptr = thread_context_ptr;
return switch (builtin.cpu.arch) {
.x86 => switch (builtin.os.tag) {
.linux, .netbsd, .solaris, .illumos => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EAX]),
1 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.ECX]),
2 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EDX]),
3 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EBX]),
4...5 => if (reg_context) |r| bytes: {
if (reg_number == 4) {
break :bytes if (r.eh_frame and r.is_macho)
mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EBP])
else
mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.ESP]);
} else {
break :bytes if (r.eh_frame and r.is_macho)
mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.ESP])
else
mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EBP]);
}
} else error.RegisterContextRequired,
6 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.ESI]),
7 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EDI]),
8 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EIP]),
9 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.EFL]),
10 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.CS]),
11 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.SS]),
12 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.DS]),
13 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.ES]),
14 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.FS]),
15 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.GS]),
16...23 => error.InvalidRegister, // TODO: Support loading ST0-ST7 from mcontext.fpregs
32...39 => error.InvalidRegister, // TODO: Support loading XMM0-XMM7 from mcontext.fpregs
else => error.InvalidRegister,
},
else => error.UnimplementedOs,
},
.x86_64 => switch (builtin.os.tag) {
.linux, .solaris, .illumos => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RAX]),
1 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RDX]),
2 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RCX]),
3 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RBX]),
4 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RSI]),
5 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RDI]),
6 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RBP]),
7 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RSP]),
8 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R8]),
9 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R9]),
10 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R10]),
11 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R11]),
12 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R12]),
13 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R13]),
14 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R14]),
15 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.R15]),
16 => mem.asBytes(&ucontext_ptr.mcontext.gregs[posix.REG.RIP]),
17...32 => |i| if (builtin.os.tag.isSolarish())
mem.asBytes(&ucontext_ptr.mcontext.fpregs.chip_state.xmm[i - 17])
else
mem.asBytes(&ucontext_ptr.mcontext.fpregs.xmm[i - 17]),
else => error.InvalidRegister,
},
.freebsd => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.rax),
1 => mem.asBytes(&ucontext_ptr.mcontext.rdx),
2 => mem.asBytes(&ucontext_ptr.mcontext.rcx),
3 => mem.asBytes(&ucontext_ptr.mcontext.rbx),
4 => mem.asBytes(&ucontext_ptr.mcontext.rsi),
5 => mem.asBytes(&ucontext_ptr.mcontext.rdi),
6 => mem.asBytes(&ucontext_ptr.mcontext.rbp),
7 => mem.asBytes(&ucontext_ptr.mcontext.rsp),
8 => mem.asBytes(&ucontext_ptr.mcontext.r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.r11),
12 => mem.asBytes(&ucontext_ptr.mcontext.r12),
13 => mem.asBytes(&ucontext_ptr.mcontext.r13),
14 => mem.asBytes(&ucontext_ptr.mcontext.r14),
15 => mem.asBytes(&ucontext_ptr.mcontext.r15),
16 => mem.asBytes(&ucontext_ptr.mcontext.rip),
// TODO: Extract xmm state from mcontext.fpstate?
else => error.InvalidRegister,
},
.openbsd => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.sc_rax),
1 => mem.asBytes(&ucontext_ptr.sc_rdx),
2 => mem.asBytes(&ucontext_ptr.sc_rcx),
3 => mem.asBytes(&ucontext_ptr.sc_rbx),
4 => mem.asBytes(&ucontext_ptr.sc_rsi),
5 => mem.asBytes(&ucontext_ptr.sc_rdi),
6 => mem.asBytes(&ucontext_ptr.sc_rbp),
7 => mem.asBytes(&ucontext_ptr.sc_rsp),
8 => mem.asBytes(&ucontext_ptr.sc_r8),
9 => mem.asBytes(&ucontext_ptr.sc_r9),
10 => mem.asBytes(&ucontext_ptr.sc_r10),
11 => mem.asBytes(&ucontext_ptr.sc_r11),
12 => mem.asBytes(&ucontext_ptr.sc_r12),
13 => mem.asBytes(&ucontext_ptr.sc_r13),
14 => mem.asBytes(&ucontext_ptr.sc_r14),
15 => mem.asBytes(&ucontext_ptr.sc_r15),
16 => mem.asBytes(&ucontext_ptr.sc_rip),
// TODO: Extract xmm state from sc_fpstate?
else => error.InvalidRegister,
},
.macos, .ios => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.ss.rax),
1 => mem.asBytes(&ucontext_ptr.mcontext.ss.rdx),
2 => mem.asBytes(&ucontext_ptr.mcontext.ss.rcx),
3 => mem.asBytes(&ucontext_ptr.mcontext.ss.rbx),
4 => mem.asBytes(&ucontext_ptr.mcontext.ss.rsi),
5 => mem.asBytes(&ucontext_ptr.mcontext.ss.rdi),
6 => mem.asBytes(&ucontext_ptr.mcontext.ss.rbp),
7 => mem.asBytes(&ucontext_ptr.mcontext.ss.rsp),
8 => mem.asBytes(&ucontext_ptr.mcontext.ss.r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.ss.r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.ss.r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.ss.r11),
12 => mem.asBytes(&ucontext_ptr.mcontext.ss.r12),
13 => mem.asBytes(&ucontext_ptr.mcontext.ss.r13),
14 => mem.asBytes(&ucontext_ptr.mcontext.ss.r14),
15 => mem.asBytes(&ucontext_ptr.mcontext.ss.r15),
16 => mem.asBytes(&ucontext_ptr.mcontext.ss.rip),
else => error.InvalidRegister,
},
else => error.UnimplementedOs,
},
.arm, .armeb, .thumb, .thumbeb => switch (builtin.os.tag) {
.linux => switch (reg_number) {
0 => mem.asBytes(&ucontext_ptr.mcontext.arm_r0),
1 => mem.asBytes(&ucontext_ptr.mcontext.arm_r1),
2 => mem.asBytes(&ucontext_ptr.mcontext.arm_r2),
3 => mem.asBytes(&ucontext_ptr.mcontext.arm_r3),
4 => mem.asBytes(&ucontext_ptr.mcontext.arm_r4),
5 => mem.asBytes(&ucontext_ptr.mcontext.arm_r5),
6 => mem.asBytes(&ucontext_ptr.mcontext.arm_r6),
7 => mem.asBytes(&ucontext_ptr.mcontext.arm_r7),
8 => mem.asBytes(&ucontext_ptr.mcontext.arm_r8),
9 => mem.asBytes(&ucontext_ptr.mcontext.arm_r9),
10 => mem.asBytes(&ucontext_ptr.mcontext.arm_r10),
11 => mem.asBytes(&ucontext_ptr.mcontext.arm_fp),
12 => mem.asBytes(&ucontext_ptr.mcontext.arm_ip),
13 => mem.asBytes(&ucontext_ptr.mcontext.arm_sp),
14 => mem.asBytes(&ucontext_ptr.mcontext.arm_lr),
15 => mem.asBytes(&ucontext_ptr.mcontext.arm_pc),
// CPSR is not allocated a register number (See: https://github.com/ARM-software/abi-aa/blob/main/aadwarf32/aadwarf32.rst, Section 4.1)
else => error.InvalidRegister,
},
else => error.UnimplementedOs,
},
.aarch64, .aarch64_be => switch (builtin.os.tag) {
.macos, .ios, .watchos => switch (reg_number) {
0...28 => mem.asBytes(&ucontext_ptr.mcontext.ss.regs[reg_number]),
29 => mem.asBytes(&ucontext_ptr.mcontext.ss.fp),
30 => mem.asBytes(&ucontext_ptr.mcontext.ss.lr),
31 => mem.asBytes(&ucontext_ptr.mcontext.ss.sp),
32 => mem.asBytes(&ucontext_ptr.mcontext.ss.pc),
// TODO: Find storage for this state
//34 => mem.asBytes(&ucontext_ptr.ra_sign_state),
// V0-V31
64...95 => mem.asBytes(&ucontext_ptr.mcontext.ns.q[reg_number - 64]),
else => error.InvalidRegister,
},
.netbsd => switch (reg_number) {
0...34 => mem.asBytes(&ucontext_ptr.mcontext.gregs[reg_number]),
else => error.InvalidRegister,
},
.freebsd => switch (reg_number) {
0...29 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.x[reg_number]),
30 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.lr),
31 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.sp),
// TODO: This seems wrong, but it was in the previous debug.zig code for mapping PC, check this
32 => mem.asBytes(&ucontext_ptr.mcontext.gpregs.elr),
else => error.InvalidRegister,
},
.openbsd => switch (reg_number) {
0...30 => mem.asBytes(&ucontext_ptr.sc_x[reg_number]),
31 => mem.asBytes(&ucontext_ptr.sc_sp),
32 => mem.asBytes(&ucontext_ptr.sc_lr),
33 => mem.asBytes(&ucontext_ptr.sc_elr),
34 => mem.asBytes(&ucontext_ptr.sc_spsr),
else => error.InvalidRegister,
},
else => switch (reg_number) {
0...30 => mem.asBytes(&ucontext_ptr.mcontext.regs[reg_number]),
31 => mem.asBytes(&ucontext_ptr.mcontext.sp),
32 => mem.asBytes(&ucontext_ptr.mcontext.pc),
else => error.InvalidRegister,
},
},
else => error.UnimplementedArch,
};
}