zig/std/debug.zig

2207 lines
81 KiB
Zig

const std = @import("std.zig");
const math = std.math;
const mem = std.mem;
const io = std.io;
const os = std.os;
const elf = std.elf;
const DW = std.dwarf;
const macho = std.macho;
const coff = std.coff;
const pdb = std.pdb;
const windows = os.windows;
const ArrayList = std.ArrayList;
const builtin = @import("builtin");
const maxInt = std.math.maxInt;
pub const FailingAllocator = @import("debug/failing_allocator.zig").FailingAllocator;
pub const failing_allocator = &FailingAllocator.init(global_allocator, 0).allocator;
pub const runtime_safety = switch (builtin.mode) {
builtin.Mode.Debug, builtin.Mode.ReleaseSafe => true,
builtin.Mode.ReleaseFast, builtin.Mode.ReleaseSmall => false,
};
const Module = struct {
mod_info: pdb.ModInfo,
module_name: []u8,
obj_file_name: []u8,
populated: bool,
symbols: []u8,
subsect_info: []u8,
checksum_offset: ?usize,
};
/// Tries to write to stderr, unbuffered, and ignores any error returned.
/// Does not append a newline.
var stderr_file: os.File = undefined;
var stderr_file_out_stream: os.File.OutStream = undefined;
var stderr_stream: ?*io.OutStream(os.File.WriteError) = null;
var stderr_mutex = std.Mutex.init();
pub fn warn(comptime fmt: []const u8, args: ...) void {
const held = stderr_mutex.acquire();
defer held.release();
const stderr = getStderrStream() catch return;
stderr.print(fmt, args) catch return;
}
pub fn getStderrStream() !*io.OutStream(os.File.WriteError) {
if (stderr_stream) |st| {
return st;
} else {
stderr_file = try io.getStdErr();
stderr_file_out_stream = stderr_file.outStream();
const st = &stderr_file_out_stream.stream;
stderr_stream = st;
return st;
}
}
/// TODO multithreaded awareness
var self_debug_info: ?DebugInfo = null;
pub fn getSelfDebugInfo() !*DebugInfo {
if (self_debug_info) |*info| {
return info;
} else {
self_debug_info = try openSelfDebugInfo(getDebugInfoAllocator());
return &self_debug_info.?;
}
}
fn wantTtyColor() bool {
var bytes: [128]u8 = undefined;
const allocator = &std.heap.FixedBufferAllocator.init(bytes[0..]).allocator;
return if (std.os.getEnvVarOwned(allocator, "ZIG_DEBUG_COLOR")) |_| true else |_| stderr_file.isTty();
}
/// Tries to print the current stack trace to stderr, unbuffered, and ignores any error returned.
/// TODO multithreaded awareness
pub fn dumpCurrentStackTrace(start_addr: ?usize) void {
const stderr = getStderrStream() catch return;
const debug_info = getSelfDebugInfo() catch |err| {
stderr.print("Unable to dump stack trace: Unable to open debug info: {}\n", @errorName(err)) catch return;
return;
};
writeCurrentStackTrace(stderr, debug_info, wantTtyColor(), start_addr) catch |err| {
stderr.print("Unable to dump stack trace: {}\n", @errorName(err)) catch return;
return;
};
}
/// Returns a slice with the same pointer as addresses, with a potentially smaller len.
/// On Windows, when first_address is not null, we ask for at least 32 stack frames,
/// and then try to find the first address. If addresses.len is more than 32, we
/// capture that many stack frames exactly, and then look for the first address,
/// chopping off the irrelevant frames and shifting so that the returned addresses pointer
/// equals the passed in addresses pointer.
pub fn captureStackTrace(first_address: ?usize, stack_trace: *builtin.StackTrace) void {
switch (builtin.os) {
builtin.Os.windows => {
const addrs = stack_trace.instruction_addresses;
const u32_addrs_len = @intCast(u32, addrs.len);
const first_addr = first_address orelse {
stack_trace.index = windows.RtlCaptureStackBackTrace(
0,
u32_addrs_len,
@ptrCast(**c_void, addrs.ptr),
null,
);
return;
};
var addr_buf_stack: [32]usize = undefined;
const addr_buf = if (addr_buf_stack.len > addrs.len) addr_buf_stack[0..] else addrs;
const n = windows.RtlCaptureStackBackTrace(0, u32_addrs_len, @ptrCast(**c_void, addr_buf.ptr), null);
const first_index = for (addr_buf[0..n]) |addr, i| {
if (addr == first_addr) {
break i;
}
} else {
stack_trace.index = 0;
return;
};
const slice = addr_buf[first_index..n];
// We use a for loop here because slice and addrs may alias.
for (slice) |addr, i| {
addrs[i] = addr;
}
stack_trace.index = slice.len;
},
else => {
var it = StackIterator.init(first_address);
for (stack_trace.instruction_addresses) |*addr, i| {
addr.* = it.next() orelse {
stack_trace.index = i;
return;
};
}
stack_trace.index = stack_trace.instruction_addresses.len;
},
}
}
/// Tries to print a stack trace to stderr, unbuffered, and ignores any error returned.
/// TODO multithreaded awareness
pub fn dumpStackTrace(stack_trace: builtin.StackTrace) void {
const stderr = getStderrStream() catch return;
const debug_info = getSelfDebugInfo() catch |err| {
stderr.print("Unable to dump stack trace: Unable to open debug info: {}\n", @errorName(err)) catch return;
return;
};
writeStackTrace(stack_trace, stderr, getDebugInfoAllocator(), debug_info, wantTtyColor()) catch |err| {
stderr.print("Unable to dump stack trace: {}\n", @errorName(err)) catch return;
return;
};
}
/// This function invokes undefined behavior when `ok` is `false`.
/// In Debug and ReleaseSafe modes, calls to this function are always
/// generated, and the `unreachable` statement triggers a panic.
/// In ReleaseFast and ReleaseSmall modes, calls to this function are
/// optimized away, and in fact the optimizer is able to use the assertion
/// in its heuristics.
/// Inside a test block, it is best to use the `std.testing` module rather
/// than this function, because this function may not detect a test failure
/// in ReleaseFast and ReleaseSafe mode. Outside of a test block, this assert
/// function is the correct function to use.
pub fn assert(ok: bool) void {
if (!ok) unreachable; // assertion failure
}
pub fn panic(comptime format: []const u8, args: ...) noreturn {
@setCold(true);
const first_trace_addr = @returnAddress();
panicExtra(null, first_trace_addr, format, args);
}
/// TODO multithreaded awareness
var panicking: u8 = 0; // TODO make this a bool
pub fn panicExtra(trace: ?*const builtin.StackTrace, first_trace_addr: ?usize, comptime format: []const u8, args: ...) noreturn {
@setCold(true);
if (@atomicRmw(u8, &panicking, builtin.AtomicRmwOp.Xchg, 1, builtin.AtomicOrder.SeqCst) == 1) {
// Panicked during a panic.
// TODO detect if a different thread caused the panic, because in that case
// we would want to return here instead of calling abort, so that the thread
// which first called panic can finish printing a stack trace.
os.abort();
}
const stderr = getStderrStream() catch os.abort();
stderr.print(format ++ "\n", args) catch os.abort();
if (trace) |t| {
dumpStackTrace(t.*);
}
dumpCurrentStackTrace(first_trace_addr);
os.abort();
}
const RED = "\x1b[31;1m";
const GREEN = "\x1b[32;1m";
const CYAN = "\x1b[36;1m";
const WHITE = "\x1b[37;1m";
const DIM = "\x1b[2m";
const RESET = "\x1b[0m";
pub fn writeStackTrace(
stack_trace: builtin.StackTrace,
out_stream: var,
allocator: *mem.Allocator,
debug_info: *DebugInfo,
tty_color: bool,
) !void {
var frame_index: usize = 0;
var frames_left: usize = stack_trace.index;
while (frames_left != 0) : ({
frames_left -= 1;
frame_index = (frame_index + 1) % stack_trace.instruction_addresses.len;
}) {
const return_address = stack_trace.instruction_addresses[frame_index];
try printSourceAtAddress(debug_info, out_stream, return_address, tty_color);
}
}
pub const StackIterator = struct {
first_addr: ?usize,
fp: usize,
pub fn init(first_addr: ?usize) StackIterator {
return StackIterator{
.first_addr = first_addr,
.fp = @frameAddress(),
};
}
fn next(self: *StackIterator) ?usize {
if (self.fp == 0) return null;
self.fp = @intToPtr(*const usize, self.fp).*;
if (self.fp == 0) return null;
if (self.first_addr) |addr| {
while (self.fp != 0) : (self.fp = @intToPtr(*const usize, self.fp).*) {
const return_address = @intToPtr(*const usize, self.fp + @sizeOf(usize)).*;
if (addr == return_address) {
self.first_addr = null;
return return_address;
}
}
}
const return_address = @intToPtr(*const usize, self.fp + @sizeOf(usize)).*;
return return_address;
}
};
pub fn writeCurrentStackTrace(out_stream: var, debug_info: *DebugInfo, tty_color: bool, start_addr: ?usize) !void {
switch (builtin.os) {
builtin.Os.windows => return writeCurrentStackTraceWindows(out_stream, debug_info, tty_color, start_addr),
else => {},
}
var it = StackIterator.init(start_addr);
while (it.next()) |return_address| {
try printSourceAtAddress(debug_info, out_stream, return_address, tty_color);
}
}
pub fn writeCurrentStackTraceWindows(
out_stream: var,
debug_info: *DebugInfo,
tty_color: bool,
start_addr: ?usize,
) !void {
var addr_buf: [1024]usize = undefined;
const n = windows.RtlCaptureStackBackTrace(0, addr_buf.len, @ptrCast(**c_void, &addr_buf), null);
const addrs = addr_buf[0..n];
var start_i: usize = if (start_addr) |saddr| blk: {
for (addrs) |addr, i| {
if (addr == saddr) break :blk i;
}
return;
} else 0;
for (addrs[start_i..]) |addr| {
try printSourceAtAddress(debug_info, out_stream, addr, tty_color);
}
}
pub fn printSourceAtAddress(debug_info: *DebugInfo, out_stream: var, address: usize, tty_color: bool) !void {
switch (builtin.os) {
builtin.Os.macosx => return printSourceAtAddressMacOs(debug_info, out_stream, address, tty_color),
builtin.Os.linux, builtin.Os.freebsd, builtin.Os.netbsd => return printSourceAtAddressLinux(debug_info, out_stream, address, tty_color),
builtin.Os.windows => return printSourceAtAddressWindows(debug_info, out_stream, address, tty_color),
else => return error.UnsupportedOperatingSystem,
}
}
fn printSourceAtAddressWindows(di: *DebugInfo, out_stream: var, relocated_address: usize, tty_color: bool) !void {
const allocator = getDebugInfoAllocator();
const base_address = os.getBaseAddress();
const relative_address = relocated_address - base_address;
var coff_section: *coff.Section = undefined;
const mod_index = for (di.sect_contribs) |sect_contrib| {
if (sect_contrib.Section > di.coff.sections.len) continue;
// Remember that SectionContribEntry.Section is 1-based.
coff_section = &di.coff.sections.toSlice()[sect_contrib.Section - 1];
const vaddr_start = coff_section.header.virtual_address + sect_contrib.Offset;
const vaddr_end = vaddr_start + sect_contrib.Size;
if (relative_address >= vaddr_start and relative_address < vaddr_end) {
break sect_contrib.ModuleIndex;
}
} else {
// we have no information to add to the address
if (tty_color) {
try out_stream.print("???:?:?: ");
setTtyColor(TtyColor.Dim);
try out_stream.print("0x{x} in ??? (???)", relocated_address);
setTtyColor(TtyColor.Reset);
try out_stream.print("\n\n\n");
} else {
try out_stream.print("???:?:?: 0x{x} in ??? (???)\n\n\n", relocated_address);
}
return;
};
const mod = &di.modules[mod_index];
try populateModule(di, mod);
const obj_basename = os.path.basename(mod.obj_file_name);
var symbol_i: usize = 0;
const symbol_name = while (symbol_i != mod.symbols.len) {
const prefix = @ptrCast(*pdb.RecordPrefix, &mod.symbols[symbol_i]);
if (prefix.RecordLen < 2)
return error.InvalidDebugInfo;
switch (prefix.RecordKind) {
pdb.SymbolKind.S_LPROC32 => {
const proc_sym = @ptrCast(*pdb.ProcSym, &mod.symbols[symbol_i + @sizeOf(pdb.RecordPrefix)]);
const vaddr_start = coff_section.header.virtual_address + proc_sym.CodeOffset;
const vaddr_end = vaddr_start + proc_sym.CodeSize;
if (relative_address >= vaddr_start and relative_address < vaddr_end) {
break mem.toSliceConst(u8, @ptrCast([*]u8, proc_sym) + @sizeOf(pdb.ProcSym));
}
},
else => {},
}
symbol_i += prefix.RecordLen + @sizeOf(u16);
if (symbol_i > mod.symbols.len)
return error.InvalidDebugInfo;
} else "???";
const subsect_info = mod.subsect_info;
var sect_offset: usize = 0;
var skip_len: usize = undefined;
const opt_line_info = subsections: {
const checksum_offset = mod.checksum_offset orelse break :subsections null;
while (sect_offset != subsect_info.len) : (sect_offset += skip_len) {
const subsect_hdr = @ptrCast(*pdb.DebugSubsectionHeader, &subsect_info[sect_offset]);
skip_len = subsect_hdr.Length;
sect_offset += @sizeOf(pdb.DebugSubsectionHeader);
switch (subsect_hdr.Kind) {
pdb.DebugSubsectionKind.Lines => {
var line_index = sect_offset;
const line_hdr = @ptrCast(*pdb.LineFragmentHeader, &subsect_info[line_index]);
if (line_hdr.RelocSegment == 0) return error.MissingDebugInfo;
line_index += @sizeOf(pdb.LineFragmentHeader);
const frag_vaddr_start = coff_section.header.virtual_address + line_hdr.RelocOffset;
const frag_vaddr_end = frag_vaddr_start + line_hdr.CodeSize;
if (relative_address >= frag_vaddr_start and relative_address < frag_vaddr_end) {
// There is an unknown number of LineBlockFragmentHeaders (and their accompanying line and column records)
// from now on. We will iterate through them, and eventually find a LineInfo that we're interested in,
// breaking out to :subsections. If not, we will make sure to not read anything outside of this subsection.
const subsection_end_index = sect_offset + subsect_hdr.Length;
while (line_index < subsection_end_index) {
const block_hdr = @ptrCast(*pdb.LineBlockFragmentHeader, &subsect_info[line_index]);
line_index += @sizeOf(pdb.LineBlockFragmentHeader);
const start_line_index = line_index;
const has_column = line_hdr.Flags.LF_HaveColumns;
// All line entries are stored inside their line block by ascending start address.
// Heuristic: we want to find the last line entry that has a vaddr_start <= relative_address.
// This is done with a simple linear search.
var line_i: u32 = 0;
while (line_i < block_hdr.NumLines) : (line_i += 1) {
const line_num_entry = @ptrCast(*pdb.LineNumberEntry, &subsect_info[line_index]);
line_index += @sizeOf(pdb.LineNumberEntry);
const vaddr_start = frag_vaddr_start + line_num_entry.Offset;
if (relative_address <= vaddr_start) {
break;
}
}
// line_i == 0 would mean that no matching LineNumberEntry was found.
if (line_i > 0) {
const subsect_index = checksum_offset + block_hdr.NameIndex;
const chksum_hdr = @ptrCast(*pdb.FileChecksumEntryHeader, &mod.subsect_info[subsect_index]);
const strtab_offset = @sizeOf(pdb.PDBStringTableHeader) + chksum_hdr.FileNameOffset;
try di.pdb.string_table.seekTo(strtab_offset);
const source_file_name = try di.pdb.string_table.readNullTermString(allocator);
const line_entry_idx = line_i - 1;
const column = if (has_column) blk: {
const start_col_index = start_line_index + @sizeOf(pdb.LineNumberEntry) * block_hdr.NumLines;
const col_index = start_col_index + @sizeOf(pdb.ColumnNumberEntry) * line_entry_idx;
const col_num_entry = @ptrCast(*pdb.ColumnNumberEntry, &subsect_info[col_index]);
break :blk col_num_entry.StartColumn;
} else 0;
const found_line_index = start_line_index + line_entry_idx * @sizeOf(pdb.LineNumberEntry);
const line_num_entry = @ptrCast(*pdb.LineNumberEntry, &subsect_info[found_line_index]);
const flags = @ptrCast(*pdb.LineNumberEntry.Flags, &line_num_entry.Flags);
break :subsections LineInfo{
.allocator = allocator,
.file_name = source_file_name,
.line = flags.Start,
.column = column,
};
}
}
// Checking that we are not reading garbage after the (possibly) multiple block fragments.
if (line_index != subsection_end_index) {
return error.InvalidDebugInfo;
}
}
},
else => {},
}
if (sect_offset > subsect_info.len)
return error.InvalidDebugInfo;
} else {
break :subsections null;
}
};
if (tty_color) {
setTtyColor(TtyColor.White);
if (opt_line_info) |li| {
try out_stream.print("{}:{}:{}", li.file_name, li.line, li.column);
} else {
try out_stream.print("???:?:?");
}
setTtyColor(TtyColor.Reset);
try out_stream.print(": ");
setTtyColor(TtyColor.Dim);
try out_stream.print("0x{x} in {} ({})", relocated_address, symbol_name, obj_basename);
setTtyColor(TtyColor.Reset);
if (opt_line_info) |line_info| {
try out_stream.print("\n");
if (printLineFromFileAnyOs(out_stream, line_info)) {
if (line_info.column == 0) {
try out_stream.write("\n");
} else {
{
var col_i: usize = 1;
while (col_i < line_info.column) : (col_i += 1) {
try out_stream.writeByte(' ');
}
}
setTtyColor(TtyColor.Green);
try out_stream.write("^");
setTtyColor(TtyColor.Reset);
try out_stream.write("\n");
}
} else |err| switch (err) {
error.EndOfFile => {},
error.FileNotFound => {
setTtyColor(TtyColor.Dim);
try out_stream.write("file not found\n\n");
setTtyColor(TtyColor.White);
},
else => return err,
}
} else {
try out_stream.print("\n\n\n");
}
} else {
if (opt_line_info) |li| {
try out_stream.print("{}:{}:{}: 0x{x} in {} ({})\n\n\n", li.file_name, li.line, li.column, relocated_address, symbol_name, obj_basename);
} else {
try out_stream.print("???:?:?: 0x{x} in {} ({})\n\n\n", relocated_address, symbol_name, obj_basename);
}
}
}
const TtyColor = enum {
Red,
Green,
Cyan,
White,
Dim,
Bold,
Reset,
};
/// TODO this is a special case hack right now. clean it up and maybe make it part of std.fmt
fn setTtyColor(tty_color: TtyColor) void {
if (os.supportsAnsiEscapeCodes(stderr_file.handle)) {
switch (tty_color) {
TtyColor.Red => {
stderr_file.write(RED) catch return;
},
TtyColor.Green => {
stderr_file.write(GREEN) catch return;
},
TtyColor.Cyan => {
stderr_file.write(CYAN) catch return;
},
TtyColor.White, TtyColor.Bold => {
stderr_file.write(WHITE) catch return;
},
TtyColor.Dim => {
stderr_file.write(DIM) catch return;
},
TtyColor.Reset => {
stderr_file.write(RESET) catch return;
},
}
} else {
const S = struct {
var attrs: windows.WORD = undefined;
var init_attrs = false;
};
if (!S.init_attrs) {
S.init_attrs = true;
var info: windows.CONSOLE_SCREEN_BUFFER_INFO = undefined;
// TODO handle error
_ = windows.GetConsoleScreenBufferInfo(stderr_file.handle, &info);
S.attrs = info.wAttributes;
}
// TODO handle errors
switch (tty_color) {
TtyColor.Red => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, windows.FOREGROUND_RED | windows.FOREGROUND_INTENSITY);
},
TtyColor.Green => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, windows.FOREGROUND_GREEN | windows.FOREGROUND_INTENSITY);
},
TtyColor.Cyan => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, windows.FOREGROUND_GREEN | windows.FOREGROUND_BLUE | windows.FOREGROUND_INTENSITY);
},
TtyColor.White, TtyColor.Bold => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, windows.FOREGROUND_RED | windows.FOREGROUND_GREEN | windows.FOREGROUND_BLUE | windows.FOREGROUND_INTENSITY);
},
TtyColor.Dim => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, windows.FOREGROUND_INTENSITY);
},
TtyColor.Reset => {
_ = windows.SetConsoleTextAttribute(stderr_file.handle, S.attrs);
},
}
}
}
fn populateModule(di: *DebugInfo, mod: *Module) !void {
if (mod.populated)
return;
const allocator = getDebugInfoAllocator();
// At most one can be non-zero.
if (mod.mod_info.C11ByteSize != 0 and mod.mod_info.C13ByteSize != 0)
return error.InvalidDebugInfo;
if (mod.mod_info.C13ByteSize == 0)
return;
const modi = di.pdb.getStreamById(mod.mod_info.ModuleSymStream) orelse return error.MissingDebugInfo;
const signature = try modi.stream.readIntLittle(u32);
if (signature != 4)
return error.InvalidDebugInfo;
mod.symbols = try allocator.alloc(u8, mod.mod_info.SymByteSize - 4);
try modi.stream.readNoEof(mod.symbols);
mod.subsect_info = try allocator.alloc(u8, mod.mod_info.C13ByteSize);
try modi.stream.readNoEof(mod.subsect_info);
var sect_offset: usize = 0;
var skip_len: usize = undefined;
while (sect_offset != mod.subsect_info.len) : (sect_offset += skip_len) {
const subsect_hdr = @ptrCast(*pdb.DebugSubsectionHeader, &mod.subsect_info[sect_offset]);
skip_len = subsect_hdr.Length;
sect_offset += @sizeOf(pdb.DebugSubsectionHeader);
switch (subsect_hdr.Kind) {
pdb.DebugSubsectionKind.FileChecksums => {
mod.checksum_offset = sect_offset;
break;
},
else => {},
}
if (sect_offset > mod.subsect_info.len)
return error.InvalidDebugInfo;
}
mod.populated = true;
}
fn machoSearchSymbols(symbols: []const MachoSymbol, address: usize) ?*const MachoSymbol {
var min: usize = 0;
var max: usize = symbols.len - 1; // Exclude sentinel.
while (min < max) {
const mid = min + (max - min) / 2;
const curr = &symbols[mid];
const next = &symbols[mid + 1];
if (address >= next.address()) {
min = mid + 1;
} else if (address < curr.address()) {
max = mid;
} else {
return curr;
}
}
return null;
}
fn printSourceAtAddressMacOs(di: *DebugInfo, out_stream: var, address: usize, tty_color: bool) !void {
const base_addr = std.os.getBaseAddress();
const adjusted_addr = 0x100000000 + (address - base_addr);
const symbol = machoSearchSymbols(di.symbols, adjusted_addr) orelse {
if (tty_color) {
try out_stream.print("???:?:?: " ++ DIM ++ "0x{x} in ??? (???)" ++ RESET ++ "\n\n\n", address);
} else {
try out_stream.print("???:?:?: 0x{x} in ??? (???)\n\n\n", address);
}
return;
};
const symbol_name = mem.toSliceConst(u8, di.strings.ptr + symbol.nlist.n_strx);
const compile_unit_name = if (symbol.ofile) |ofile| blk: {
const ofile_path = mem.toSliceConst(u8, di.strings.ptr + ofile.n_strx);
break :blk os.path.basename(ofile_path);
} else "???";
if (getLineNumberInfoMacOs(di, symbol.*, adjusted_addr)) |line_info| {
defer line_info.deinit();
try printLineInfo(
out_stream,
line_info,
address,
symbol_name,
compile_unit_name,
tty_color,
printLineFromFileAnyOs,
);
} else |err| switch (err) {
error.MissingDebugInfo, error.InvalidDebugInfo => {
if (tty_color) {
try out_stream.print("???:?:?: " ++ DIM ++ "0x{x} in {} ({})" ++ RESET ++ "\n\n\n", address, symbol_name, compile_unit_name);
} else {
try out_stream.print("???:?:?: 0x{x} in {} ({})\n\n\n", address, symbol_name, compile_unit_name);
}
},
else => return err,
}
}
/// This function works in freestanding mode.
/// fn printLineFromFile(out_stream: var, line_info: LineInfo) !void
pub fn printSourceAtAddressDwarf(
debug_info: *DwarfInfo,
out_stream: var,
address: usize,
tty_color: bool,
comptime printLineFromFile: var,
) !void {
const compile_unit = findCompileUnit(debug_info, address) catch {
if (tty_color) {
try out_stream.print("???:?:?: " ++ DIM ++ "0x{x} in ??? (???)" ++ RESET ++ "\n\n\n", address);
} else {
try out_stream.print("???:?:?: 0x{x} in ??? (???)\n\n\n", address);
}
return;
};
const compile_unit_name = try compile_unit.die.getAttrString(debug_info, DW.AT_name);
if (getLineNumberInfoDwarf(debug_info, compile_unit.*, address - 1)) |line_info| {
defer line_info.deinit();
const symbol_name = "???";
try printLineInfo(
out_stream,
line_info,
address,
symbol_name,
compile_unit_name,
tty_color,
printLineFromFile,
);
} else |err| switch (err) {
error.MissingDebugInfo, error.InvalidDebugInfo => {
if (tty_color) {
try out_stream.print("???:?:?: " ++ DIM ++ "0x{x} in ??? ({})" ++ RESET ++ "\n\n\n", address, compile_unit_name);
} else {
try out_stream.print("???:?:?: 0x{x} in ??? ({})\n\n\n", address, compile_unit_name);
}
},
else => return err,
}
}
pub fn printSourceAtAddressLinux(debug_info: *DebugInfo, out_stream: var, address: usize, tty_color: bool) !void {
return printSourceAtAddressDwarf(debug_info, out_stream, address, tty_color, printLineFromFileAnyOs);
}
fn printLineInfo(
out_stream: var,
line_info: LineInfo,
address: usize,
symbol_name: []const u8,
compile_unit_name: []const u8,
tty_color: bool,
comptime printLineFromFile: var,
) !void {
if (tty_color) {
try out_stream.print(
WHITE ++ "{}:{}:{}" ++ RESET ++ ": " ++ DIM ++ "0x{x} in {} ({})" ++ RESET ++ "\n",
line_info.file_name,
line_info.line,
line_info.column,
address,
symbol_name,
compile_unit_name,
);
if (printLineFromFile(out_stream, line_info)) {
if (line_info.column == 0) {
try out_stream.write("\n");
} else {
{
var col_i: usize = 1;
while (col_i < line_info.column) : (col_i += 1) {
try out_stream.writeByte(' ');
}
}
try out_stream.write(GREEN ++ "^" ++ RESET ++ "\n");
}
} else |err| switch (err) {
error.EndOfFile => {},
else => return err,
}
} else {
try out_stream.print(
"{}:{}:{}: 0x{x} in {} ({})\n",
line_info.file_name,
line_info.line,
line_info.column,
address,
symbol_name,
compile_unit_name,
);
}
}
// TODO use this
pub const OpenSelfDebugInfoError = error{
MissingDebugInfo,
OutOfMemory,
UnsupportedOperatingSystem,
};
pub fn openSelfDebugInfo(allocator: *mem.Allocator) !DebugInfo {
switch (builtin.os) {
builtin.Os.linux, builtin.Os.freebsd, builtin.Os.netbsd => return openSelfDebugInfoLinux(allocator),
builtin.Os.macosx, builtin.Os.ios => return openSelfDebugInfoMacOs(allocator),
builtin.Os.windows => return openSelfDebugInfoWindows(allocator),
else => return error.UnsupportedOperatingSystem,
}
}
fn openSelfDebugInfoWindows(allocator: *mem.Allocator) !DebugInfo {
const self_file = try os.openSelfExe();
defer self_file.close();
const coff_obj = try allocator.create(coff.Coff);
coff_obj.* = coff.Coff{
.in_file = self_file,
.allocator = allocator,
.coff_header = undefined,
.pe_header = undefined,
.sections = undefined,
.guid = undefined,
.age = undefined,
};
var di = DebugInfo{
.coff = coff_obj,
.pdb = undefined,
.sect_contribs = undefined,
.modules = undefined,
};
try di.coff.loadHeader();
var path_buf: [windows.MAX_PATH]u8 = undefined;
const len = try di.coff.getPdbPath(path_buf[0..]);
const raw_path = path_buf[0..len];
const path = try os.path.resolve(allocator, [][]const u8{raw_path});
try di.pdb.openFile(di.coff, path);
var pdb_stream = di.pdb.getStream(pdb.StreamType.Pdb) orelse return error.InvalidDebugInfo;
const version = try pdb_stream.stream.readIntLittle(u32);
const signature = try pdb_stream.stream.readIntLittle(u32);
const age = try pdb_stream.stream.readIntLittle(u32);
var guid: [16]u8 = undefined;
try pdb_stream.stream.readNoEof(guid[0..]);
if (!mem.eql(u8, di.coff.guid, guid) or di.coff.age != age)
return error.InvalidDebugInfo;
// We validated the executable and pdb match.
const string_table_index = str_tab_index: {
const name_bytes_len = try pdb_stream.stream.readIntLittle(u32);
const name_bytes = try allocator.alloc(u8, name_bytes_len);
try pdb_stream.stream.readNoEof(name_bytes);
const HashTableHeader = packed struct {
Size: u32,
Capacity: u32,
fn maxLoad(cap: u32) u32 {
return cap * 2 / 3 + 1;
}
};
const hash_tbl_hdr = try pdb_stream.stream.readStruct(HashTableHeader);
if (hash_tbl_hdr.Capacity == 0)
return error.InvalidDebugInfo;
if (hash_tbl_hdr.Size > HashTableHeader.maxLoad(hash_tbl_hdr.Capacity))
return error.InvalidDebugInfo;
const present = try readSparseBitVector(&pdb_stream.stream, allocator);
if (present.len != hash_tbl_hdr.Size)
return error.InvalidDebugInfo;
const deleted = try readSparseBitVector(&pdb_stream.stream, allocator);
const Bucket = struct {
first: u32,
second: u32,
};
const bucket_list = try allocator.alloc(Bucket, present.len);
for (present) |_| {
const name_offset = try pdb_stream.stream.readIntLittle(u32);
const name_index = try pdb_stream.stream.readIntLittle(u32);
const name = mem.toSlice(u8, name_bytes.ptr + name_offset);
if (mem.eql(u8, name, "/names")) {
break :str_tab_index name_index;
}
}
return error.MissingDebugInfo;
};
di.pdb.string_table = di.pdb.getStreamById(string_table_index) orelse return error.InvalidDebugInfo;
di.pdb.dbi = di.pdb.getStream(pdb.StreamType.Dbi) orelse return error.MissingDebugInfo;
const dbi = di.pdb.dbi;
// Dbi Header
const dbi_stream_header = try dbi.stream.readStruct(pdb.DbiStreamHeader);
const mod_info_size = dbi_stream_header.ModInfoSize;
const section_contrib_size = dbi_stream_header.SectionContributionSize;
var modules = ArrayList(Module).init(allocator);
// Module Info Substream
var mod_info_offset: usize = 0;
while (mod_info_offset != mod_info_size) {
const mod_info = try dbi.stream.readStruct(pdb.ModInfo);
var this_record_len: usize = @sizeOf(pdb.ModInfo);
const module_name = try dbi.readNullTermString(allocator);
this_record_len += module_name.len + 1;
const obj_file_name = try dbi.readNullTermString(allocator);
this_record_len += obj_file_name.len + 1;
if (this_record_len % 4 != 0) {
const round_to_next_4 = (this_record_len | 0x3) + 1;
const march_forward_bytes = round_to_next_4 - this_record_len;
try dbi.seekForward(march_forward_bytes);
this_record_len += march_forward_bytes;
}
try modules.append(Module{
.mod_info = mod_info,
.module_name = module_name,
.obj_file_name = obj_file_name,
.populated = false,
.symbols = undefined,
.subsect_info = undefined,
.checksum_offset = null,
});
mod_info_offset += this_record_len;
if (mod_info_offset > mod_info_size)
return error.InvalidDebugInfo;
}
di.modules = modules.toOwnedSlice();
// Section Contribution Substream
var sect_contribs = ArrayList(pdb.SectionContribEntry).init(allocator);
var sect_cont_offset: usize = 0;
if (section_contrib_size != 0) {
const ver = @intToEnum(pdb.SectionContrSubstreamVersion, try dbi.stream.readIntLittle(u32));
if (ver != pdb.SectionContrSubstreamVersion.Ver60)
return error.InvalidDebugInfo;
sect_cont_offset += @sizeOf(u32);
}
while (sect_cont_offset != section_contrib_size) {
const entry = try sect_contribs.addOne();
entry.* = try dbi.stream.readStruct(pdb.SectionContribEntry);
sect_cont_offset += @sizeOf(pdb.SectionContribEntry);
if (sect_cont_offset > section_contrib_size)
return error.InvalidDebugInfo;
}
di.sect_contribs = sect_contribs.toOwnedSlice();
return di;
}
fn readSparseBitVector(stream: var, allocator: *mem.Allocator) ![]usize {
const num_words = try stream.readIntLittle(u32);
var word_i: usize = 0;
var list = ArrayList(usize).init(allocator);
while (word_i != num_words) : (word_i += 1) {
const word = try stream.readIntLittle(u32);
var bit_i: u5 = 0;
while (true) : (bit_i += 1) {
if (word & (u32(1) << bit_i) != 0) {
try list.append(word_i * 32 + bit_i);
}
if (bit_i == maxInt(u5)) break;
}
}
return list.toOwnedSlice();
}
fn findDwarfSectionFromElf(elf_file: *elf.Elf, name: []const u8) !?DwarfInfo.Section {
const elf_header = (try elf_file.findSection(name)) orelse return null;
return DwarfInfo.Section{
.offset = elf_header.offset,
.size = elf_header.size,
};
}
/// Initialize DWARF info. The caller has the responsibility to initialize most
/// the DwarfInfo fields before calling. These fields can be left undefined:
/// * abbrev_table_list
/// * compile_unit_list
pub fn openDwarfDebugInfo(di: *DwarfInfo, allocator: *mem.Allocator) !void {
di.abbrev_table_list = ArrayList(AbbrevTableHeader).init(allocator);
di.compile_unit_list = ArrayList(CompileUnit).init(allocator);
try scanAllCompileUnits(di);
}
pub fn openElfDebugInfo(
allocator: *mem.Allocator,
elf_seekable_stream: *DwarfSeekableStream,
elf_in_stream: *DwarfInStream,
) !DwarfInfo {
var efile: elf.Elf = undefined;
try efile.openStream(allocator, elf_seekable_stream, elf_in_stream);
errdefer efile.close();
var di = DwarfInfo{
.dwarf_seekable_stream = elf_seekable_stream,
.dwarf_in_stream = elf_in_stream,
.endian = efile.endian,
.debug_info = (try findDwarfSectionFromElf(&efile, ".debug_info")) orelse return error.MissingDebugInfo,
.debug_abbrev = (try findDwarfSectionFromElf(&efile, ".debug_abbrev")) orelse return error.MissingDebugInfo,
.debug_str = (try findDwarfSectionFromElf(&efile, ".debug_str")) orelse return error.MissingDebugInfo,
.debug_line = (try findDwarfSectionFromElf(&efile, ".debug_line")) orelse return error.MissingDebugInfo,
.debug_ranges = (try findDwarfSectionFromElf(&efile, ".debug_ranges")),
.abbrev_table_list = undefined,
.compile_unit_list = undefined,
};
try openDwarfDebugInfo(&di, allocator);
return di;
}
fn openSelfDebugInfoLinux(allocator: *mem.Allocator) !DwarfInfo {
const S = struct {
var self_exe_file: os.File = undefined;
var self_exe_seekable_stream: os.File.SeekableStream = undefined;
var self_exe_in_stream: os.File.InStream = undefined;
};
S.self_exe_file = try os.openSelfExe();
errdefer S.self_exe_file.close();
S.self_exe_seekable_stream = S.self_exe_file.seekableStream();
S.self_exe_in_stream = S.self_exe_file.inStream();
return openElfDebugInfo(
allocator,
// TODO https://github.com/ziglang/zig/issues/764
@ptrCast(*DwarfSeekableStream, &S.self_exe_seekable_stream.stream),
// TODO https://github.com/ziglang/zig/issues/764
@ptrCast(*DwarfInStream, &S.self_exe_in_stream.stream),
);
}
fn openSelfDebugInfoMacOs(allocator: *mem.Allocator) !DebugInfo {
const hdr = &std.c._mh_execute_header;
assert(hdr.magic == std.macho.MH_MAGIC_64);
const hdr_base = @ptrCast([*]u8, hdr);
var ptr = hdr_base + @sizeOf(macho.mach_header_64);
var ncmd: u32 = hdr.ncmds;
const symtab = while (ncmd != 0) : (ncmd -= 1) {
const lc = @ptrCast(*std.macho.load_command, ptr);
switch (lc.cmd) {
std.macho.LC_SYMTAB => break @ptrCast(*std.macho.symtab_command, ptr),
else => {},
}
ptr += lc.cmdsize; // TODO https://github.com/ziglang/zig/issues/1403
} else {
return error.MissingDebugInfo;
};
const syms = @ptrCast([*]macho.nlist_64, @alignCast(@alignOf(macho.nlist_64), hdr_base + symtab.symoff))[0..symtab.nsyms];
const strings = @ptrCast([*]u8, hdr_base + symtab.stroff)[0..symtab.strsize];
const symbols_buf = try allocator.alloc(MachoSymbol, syms.len);
var ofile: ?*macho.nlist_64 = null;
var reloc: u64 = 0;
var symbol_index: usize = 0;
var last_len: u64 = 0;
for (syms) |*sym| {
if (sym.n_type & std.macho.N_STAB != 0) {
switch (sym.n_type) {
std.macho.N_OSO => {
ofile = sym;
reloc = 0;
},
std.macho.N_FUN => {
if (sym.n_sect == 0) {
last_len = sym.n_value;
} else {
symbols_buf[symbol_index] = MachoSymbol{
.nlist = sym,
.ofile = ofile,
.reloc = reloc,
};
symbol_index += 1;
}
},
std.macho.N_BNSYM => {
if (reloc == 0) {
reloc = sym.n_value;
}
},
else => continue,
}
}
}
const sentinel = try allocator.create(macho.nlist_64);
sentinel.* = macho.nlist_64{
.n_strx = 0,
.n_type = 36,
.n_sect = 0,
.n_desc = 0,
.n_value = symbols_buf[symbol_index - 1].nlist.n_value + last_len,
};
const symbols = allocator.shrink(symbols_buf, symbol_index);
// Even though lld emits symbols in ascending order, this debug code
// should work for programs linked in any valid way.
// This sort is so that we can binary search later.
std.sort.sort(MachoSymbol, symbols, MachoSymbol.addressLessThan);
return DebugInfo{
.ofiles = DebugInfo.OFileTable.init(allocator),
.symbols = symbols,
.strings = strings,
};
}
fn printLineFromFileAnyOs(out_stream: var, line_info: LineInfo) !void {
var f = try os.File.openRead(line_info.file_name);
defer f.close();
// TODO fstat and make sure that the file has the correct size
var buf: [os.page_size]u8 = undefined;
var line: usize = 1;
var column: usize = 1;
var abs_index: usize = 0;
while (true) {
const amt_read = try f.read(buf[0..]);
const slice = buf[0..amt_read];
for (slice) |byte| {
if (line == line_info.line) {
try out_stream.writeByte(byte);
if (byte == '\n') {
return;
}
}
if (byte == '\n') {
line += 1;
column = 1;
} else {
column += 1;
}
}
if (amt_read < buf.len) return error.EndOfFile;
}
}
const MachoSymbol = struct {
nlist: *macho.nlist_64,
ofile: ?*macho.nlist_64,
reloc: u64,
/// Returns the address from the macho file
fn address(self: MachoSymbol) u64 {
return self.nlist.n_value;
}
fn addressLessThan(lhs: MachoSymbol, rhs: MachoSymbol) bool {
return lhs.address() < rhs.address();
}
};
const MachOFile = struct {
bytes: []align(@alignOf(macho.mach_header_64)) const u8,
sect_debug_info: ?*const macho.section_64,
sect_debug_line: ?*const macho.section_64,
};
pub const DwarfSeekableStream = io.SeekableStream(anyerror, anyerror);
pub const DwarfInStream = io.InStream(anyerror);
pub const DwarfInfo = struct {
dwarf_seekable_stream: *DwarfSeekableStream,
dwarf_in_stream: *DwarfInStream,
endian: builtin.Endian,
debug_info: Section,
debug_abbrev: Section,
debug_str: Section,
debug_line: Section,
debug_ranges: ?Section,
abbrev_table_list: ArrayList(AbbrevTableHeader),
compile_unit_list: ArrayList(CompileUnit),
pub const Section = struct {
offset: usize,
size: usize,
};
pub fn allocator(self: DwarfInfo) *mem.Allocator {
return self.abbrev_table_list.allocator;
}
pub fn readString(self: *DwarfInfo) ![]u8 {
return readStringRaw(self.allocator(), self.dwarf_in_stream);
}
};
pub const DebugInfo = switch (builtin.os) {
builtin.Os.macosx, builtin.Os.ios => struct {
symbols: []const MachoSymbol,
strings: []const u8,
ofiles: OFileTable,
const OFileTable = std.HashMap(
*macho.nlist_64,
MachOFile,
std.hash_map.getHashPtrAddrFn(*macho.nlist_64),
std.hash_map.getTrivialEqlFn(*macho.nlist_64),
);
pub fn allocator(self: DebugInfo) *mem.Allocator {
return self.ofiles.allocator;
}
},
builtin.Os.uefi, builtin.Os.windows => struct {
pdb: pdb.Pdb,
coff: *coff.Coff,
sect_contribs: []pdb.SectionContribEntry,
modules: []Module,
},
builtin.Os.linux, builtin.Os.freebsd, builtin.Os.netbsd => DwarfInfo,
else => @compileError("Unsupported OS"),
};
const PcRange = struct {
start: u64,
end: u64,
};
const CompileUnit = struct {
version: u16,
is_64: bool,
die: *Die,
pc_range: ?PcRange,
};
const AbbrevTable = ArrayList(AbbrevTableEntry);
const AbbrevTableHeader = struct {
// offset from .debug_abbrev
offset: u64,
table: AbbrevTable,
};
const AbbrevTableEntry = struct {
has_children: bool,
abbrev_code: u64,
tag_id: u64,
attrs: ArrayList(AbbrevAttr),
};
const AbbrevAttr = struct {
attr_id: u64,
form_id: u64,
};
const FormValue = union(enum) {
Address: u64,
Block: []u8,
Const: Constant,
ExprLoc: []u8,
Flag: bool,
SecOffset: u64,
Ref: u64,
RefAddr: u64,
String: []u8,
StrPtr: u64,
};
const Constant = struct {
payload: u64,
signed: bool,
fn asUnsignedLe(self: *const Constant) !u64 {
if (self.signed) return error.InvalidDebugInfo;
return self.payload;
}
};
const Die = struct {
tag_id: u64,
has_children: bool,
attrs: ArrayList(Attr),
const Attr = struct {
id: u64,
value: FormValue,
};
fn getAttr(self: *const Die, id: u64) ?*const FormValue {
for (self.attrs.toSliceConst()) |*attr| {
if (attr.id == id) return &attr.value;
}
return null;
}
fn getAttrAddr(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
FormValue.Address => |value| value,
else => error.InvalidDebugInfo,
};
}
fn getAttrSecOffset(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
FormValue.Const => |value| value.asUnsignedLe(),
FormValue.SecOffset => |value| value,
else => error.InvalidDebugInfo,
};
}
fn getAttrUnsignedLe(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
FormValue.Const => |value| value.asUnsignedLe(),
else => error.InvalidDebugInfo,
};
}
fn getAttrString(self: *const Die, di: *DwarfInfo, id: u64) ![]u8 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
FormValue.String => |value| value,
FormValue.StrPtr => |offset| getString(di, offset),
else => error.InvalidDebugInfo,
};
}
};
const FileEntry = struct {
file_name: []const u8,
dir_index: usize,
mtime: usize,
len_bytes: usize,
};
pub const LineInfo = struct {
line: usize,
column: usize,
file_name: []const u8,
allocator: ?*mem.Allocator,
fn deinit(self: LineInfo) void {
const allocator = self.allocator orelse return;
allocator.free(self.file_name);
}
};
const LineNumberProgram = struct {
address: usize,
file: usize,
line: isize,
column: usize,
is_stmt: bool,
basic_block: bool,
end_sequence: bool,
target_address: usize,
include_dirs: []const []const u8,
file_entries: *ArrayList(FileEntry),
prev_address: usize,
prev_file: usize,
prev_line: isize,
prev_column: usize,
prev_is_stmt: bool,
prev_basic_block: bool,
prev_end_sequence: bool,
pub fn init(is_stmt: bool, include_dirs: []const []const u8, file_entries: *ArrayList(FileEntry), target_address: usize) LineNumberProgram {
return LineNumberProgram{
.address = 0,
.file = 1,
.line = 1,
.column = 0,
.is_stmt = is_stmt,
.basic_block = false,
.end_sequence = false,
.include_dirs = include_dirs,
.file_entries = file_entries,
.target_address = target_address,
.prev_address = 0,
.prev_file = undefined,
.prev_line = undefined,
.prev_column = undefined,
.prev_is_stmt = undefined,
.prev_basic_block = undefined,
.prev_end_sequence = undefined,
};
}
pub fn checkLineMatch(self: *LineNumberProgram) !?LineInfo {
if (self.target_address >= self.prev_address and self.target_address < self.address) {
const file_entry = if (self.prev_file == 0) {
return error.MissingDebugInfo;
} else if (self.prev_file - 1 >= self.file_entries.len) {
return error.InvalidDebugInfo;
} else
&self.file_entries.items[self.prev_file - 1];
const dir_name = if (file_entry.dir_index >= self.include_dirs.len) {
return error.InvalidDebugInfo;
} else
self.include_dirs[file_entry.dir_index];
const file_name = try os.path.join(self.file_entries.allocator, [][]const u8{ dir_name, file_entry.file_name });
errdefer self.file_entries.allocator.free(file_name);
return LineInfo{
.line = if (self.prev_line >= 0) @intCast(usize, self.prev_line) else 0,
.column = self.prev_column,
.file_name = file_name,
.allocator = self.file_entries.allocator,
};
}
self.prev_address = self.address;
self.prev_file = self.file;
self.prev_line = self.line;
self.prev_column = self.column;
self.prev_is_stmt = self.is_stmt;
self.prev_basic_block = self.basic_block;
self.prev_end_sequence = self.end_sequence;
return null;
}
};
fn readStringRaw(allocator: *mem.Allocator, in_stream: var) ![]u8 {
var buf = ArrayList(u8).init(allocator);
while (true) {
const byte = try in_stream.readByte();
if (byte == 0) break;
try buf.append(byte);
}
return buf.toSlice();
}
fn getString(di: *DwarfInfo, offset: u64) ![]u8 {
const pos = di.debug_str.offset + offset;
try di.dwarf_seekable_stream.seekTo(pos);
return di.readString();
}
fn readAllocBytes(allocator: *mem.Allocator, in_stream: var, size: usize) ![]u8 {
const buf = try allocator.alloc(u8, size);
errdefer allocator.free(buf);
if ((try in_stream.read(buf)) < size) return error.EndOfFile;
return buf;
}
fn parseFormValueBlockLen(allocator: *mem.Allocator, in_stream: var, size: usize) !FormValue {
const buf = try readAllocBytes(allocator, in_stream, size);
return FormValue{ .Block = buf };
}
fn parseFormValueBlock(allocator: *mem.Allocator, in_stream: var, size: usize) !FormValue {
const block_len = try in_stream.readVarInt(usize, builtin.Endian.Little, size);
return parseFormValueBlockLen(allocator, in_stream, block_len);
}
fn parseFormValueConstant(allocator: *mem.Allocator, in_stream: var, signed: bool, size: i32) !FormValue {
return FormValue{
.Const = Constant{
.signed = signed,
.payload = switch (size) {
1 => try in_stream.readIntLittle(u8),
2 => try in_stream.readIntLittle(u16),
4 => try in_stream.readIntLittle(u32),
8 => try in_stream.readIntLittle(u64),
-1 => if (signed) try readULeb128(in_stream) else @intCast(u64, try readILeb128(in_stream)),
else => unreachable,
},
},
};
}
fn parseFormValueDwarfOffsetSize(in_stream: var, is_64: bool) !u64 {
return if (is_64) try in_stream.readIntLittle(u64) else u64(try in_stream.readIntLittle(u32));
}
fn parseFormValueTargetAddrSize(in_stream: var) !u64 {
return if (@sizeOf(usize) == 4) u64(try in_stream.readIntLittle(u32)) else if (@sizeOf(usize) == 8) try in_stream.readIntLittle(u64) else unreachable;
}
fn parseFormValueRef(allocator: *mem.Allocator, in_stream: var, size: i32) !FormValue {
return FormValue{
.Ref = switch (size) {
1 => try in_stream.readIntLittle(u8),
2 => try in_stream.readIntLittle(u16),
4 => try in_stream.readIntLittle(u32),
8 => try in_stream.readIntLittle(u64),
-1 => try readULeb128(in_stream),
else => unreachable,
},
};
}
fn parseFormValue(allocator: *mem.Allocator, in_stream: var, form_id: u64, is_64: bool) anyerror!FormValue {
return switch (form_id) {
DW.FORM_addr => FormValue{ .Address = try parseFormValueTargetAddrSize(in_stream) },
DW.FORM_block1 => parseFormValueBlock(allocator, in_stream, 1),
DW.FORM_block2 => parseFormValueBlock(allocator, in_stream, 2),
DW.FORM_block4 => parseFormValueBlock(allocator, in_stream, 4),
DW.FORM_block => x: {
const block_len = try readULeb128(in_stream);
return parseFormValueBlockLen(allocator, in_stream, block_len);
},
DW.FORM_data1 => parseFormValueConstant(allocator, in_stream, false, 1),
DW.FORM_data2 => parseFormValueConstant(allocator, in_stream, false, 2),
DW.FORM_data4 => parseFormValueConstant(allocator, in_stream, false, 4),
DW.FORM_data8 => parseFormValueConstant(allocator, in_stream, false, 8),
DW.FORM_udata, DW.FORM_sdata => {
const signed = form_id == DW.FORM_sdata;
return parseFormValueConstant(allocator, in_stream, signed, -1);
},
DW.FORM_exprloc => {
const size = try readULeb128(in_stream);
const buf = try readAllocBytes(allocator, in_stream, size);
return FormValue{ .ExprLoc = buf };
},
DW.FORM_flag => FormValue{ .Flag = (try in_stream.readByte()) != 0 },
DW.FORM_flag_present => FormValue{ .Flag = true },
DW.FORM_sec_offset => FormValue{ .SecOffset = try parseFormValueDwarfOffsetSize(in_stream, is_64) },
DW.FORM_ref1 => parseFormValueRef(allocator, in_stream, 1),
DW.FORM_ref2 => parseFormValueRef(allocator, in_stream, 2),
DW.FORM_ref4 => parseFormValueRef(allocator, in_stream, 4),
DW.FORM_ref8 => parseFormValueRef(allocator, in_stream, 8),
DW.FORM_ref_udata => parseFormValueRef(allocator, in_stream, -1),
DW.FORM_ref_addr => FormValue{ .RefAddr = try parseFormValueDwarfOffsetSize(in_stream, is_64) },
DW.FORM_ref_sig8 => FormValue{ .Ref = try in_stream.readIntLittle(u64) },
DW.FORM_string => FormValue{ .String = try readStringRaw(allocator, in_stream) },
DW.FORM_strp => FormValue{ .StrPtr = try parseFormValueDwarfOffsetSize(in_stream, is_64) },
DW.FORM_indirect => {
const child_form_id = try readULeb128(in_stream);
return parseFormValue(allocator, in_stream, child_form_id, is_64);
},
else => error.InvalidDebugInfo,
};
}
fn parseAbbrevTable(di: *DwarfInfo) !AbbrevTable {
var result = AbbrevTable.init(di.allocator());
while (true) {
const abbrev_code = try readULeb128(di.dwarf_in_stream);
if (abbrev_code == 0) return result;
try result.append(AbbrevTableEntry{
.abbrev_code = abbrev_code,
.tag_id = try readULeb128(di.dwarf_in_stream),
.has_children = (try di.dwarf_in_stream.readByte()) == DW.CHILDREN_yes,
.attrs = ArrayList(AbbrevAttr).init(di.allocator()),
});
const attrs = &result.items[result.len - 1].attrs;
while (true) {
const attr_id = try readULeb128(di.dwarf_in_stream);
const form_id = try readULeb128(di.dwarf_in_stream);
if (attr_id == 0 and form_id == 0) break;
try attrs.append(AbbrevAttr{
.attr_id = attr_id,
.form_id = form_id,
});
}
}
}
/// Gets an already existing AbbrevTable given the abbrev_offset, or if not found,
/// seeks in the stream and parses it.
fn getAbbrevTable(di: *DwarfInfo, abbrev_offset: u64) !*const AbbrevTable {
for (di.abbrev_table_list.toSlice()) |*header| {
if (header.offset == abbrev_offset) {
return &header.table;
}
}
try di.dwarf_seekable_stream.seekTo(di.debug_abbrev.offset + abbrev_offset);
try di.abbrev_table_list.append(AbbrevTableHeader{
.offset = abbrev_offset,
.table = try parseAbbrevTable(di),
});
return &di.abbrev_table_list.items[di.abbrev_table_list.len - 1].table;
}
fn getAbbrevTableEntry(abbrev_table: *const AbbrevTable, abbrev_code: u64) ?*const AbbrevTableEntry {
for (abbrev_table.toSliceConst()) |*table_entry| {
if (table_entry.abbrev_code == abbrev_code) return table_entry;
}
return null;
}
fn parseDie(di: *DwarfInfo, abbrev_table: *const AbbrevTable, is_64: bool) !Die {
const abbrev_code = try readULeb128(di.dwarf_in_stream);
const table_entry = getAbbrevTableEntry(abbrev_table, abbrev_code) orelse return error.InvalidDebugInfo;
var result = Die{
.tag_id = table_entry.tag_id,
.has_children = table_entry.has_children,
.attrs = ArrayList(Die.Attr).init(di.allocator()),
};
try result.attrs.resize(table_entry.attrs.len);
for (table_entry.attrs.toSliceConst()) |attr, i| {
result.attrs.items[i] = Die.Attr{
.id = attr.attr_id,
.value = try parseFormValue(di.allocator(), di.dwarf_in_stream, attr.form_id, is_64),
};
}
return result;
}
fn getLineNumberInfoMacOs(di: *DebugInfo, symbol: MachoSymbol, target_address: usize) !LineInfo {
const ofile = symbol.ofile orelse return error.MissingDebugInfo;
const gop = try di.ofiles.getOrPut(ofile);
const mach_o_file = if (gop.found_existing) &gop.kv.value else blk: {
errdefer _ = di.ofiles.remove(ofile);
const ofile_path = mem.toSliceConst(u8, di.strings.ptr + ofile.n_strx);
gop.kv.value = MachOFile{
.bytes = try std.io.readFileAllocAligned(di.ofiles.allocator, ofile_path, @alignOf(macho.mach_header_64)),
.sect_debug_info = null,
.sect_debug_line = null,
};
const hdr = @ptrCast(*const macho.mach_header_64, gop.kv.value.bytes.ptr);
if (hdr.magic != std.macho.MH_MAGIC_64) return error.InvalidDebugInfo;
const hdr_base = @ptrCast([*]const u8, hdr);
var ptr = hdr_base + @sizeOf(macho.mach_header_64);
var ncmd: u32 = hdr.ncmds;
const segcmd = while (ncmd != 0) : (ncmd -= 1) {
const lc = @ptrCast(*const std.macho.load_command, ptr);
switch (lc.cmd) {
std.macho.LC_SEGMENT_64 => break @ptrCast(*const std.macho.segment_command_64, @alignCast(@alignOf(std.macho.segment_command_64), ptr)),
else => {},
}
ptr += lc.cmdsize; // TODO https://github.com/ziglang/zig/issues/1403
} else {
return error.MissingDebugInfo;
};
const sections = @ptrCast([*]const macho.section_64, @alignCast(@alignOf(macho.section_64), ptr + @sizeOf(std.macho.segment_command_64)))[0..segcmd.nsects];
for (sections) |*sect| {
if (sect.flags & macho.SECTION_TYPE == macho.S_REGULAR and
(sect.flags & macho.SECTION_ATTRIBUTES) & macho.S_ATTR_DEBUG == macho.S_ATTR_DEBUG)
{
const sect_name = mem.toSliceConst(u8, &sect.sectname);
if (mem.eql(u8, sect_name, "__debug_line")) {
gop.kv.value.sect_debug_line = sect;
} else if (mem.eql(u8, sect_name, "__debug_info")) {
gop.kv.value.sect_debug_info = sect;
}
}
}
break :blk &gop.kv.value;
};
const sect_debug_line = mach_o_file.sect_debug_line orelse return error.MissingDebugInfo;
var ptr = mach_o_file.bytes.ptr + sect_debug_line.offset;
var is_64: bool = undefined;
const unit_length = try readInitialLengthMem(&ptr, &is_64);
if (unit_length == 0) return error.MissingDebugInfo;
const version = readIntMem(&ptr, u16, builtin.Endian.Little);
// TODO support 3 and 5
if (version != 2 and version != 4) return error.InvalidDebugInfo;
const prologue_length = if (is_64)
readIntMem(&ptr, u64, builtin.Endian.Little)
else
readIntMem(&ptr, u32, builtin.Endian.Little);
const prog_start = ptr + prologue_length;
const minimum_instruction_length = readByteMem(&ptr);
if (minimum_instruction_length == 0) return error.InvalidDebugInfo;
if (version >= 4) {
// maximum_operations_per_instruction
ptr += 1;
}
const default_is_stmt = readByteMem(&ptr) != 0;
const line_base = readByteSignedMem(&ptr);
const line_range = readByteMem(&ptr);
if (line_range == 0) return error.InvalidDebugInfo;
const opcode_base = readByteMem(&ptr);
const standard_opcode_lengths = ptr[0 .. opcode_base - 1];
ptr += opcode_base - 1;
var include_directories = ArrayList([]const u8).init(di.allocator());
try include_directories.append("");
while (true) {
const dir = readStringMem(&ptr);
if (dir.len == 0) break;
try include_directories.append(dir);
}
var file_entries = ArrayList(FileEntry).init(di.allocator());
var prog = LineNumberProgram.init(default_is_stmt, include_directories.toSliceConst(), &file_entries, target_address);
while (true) {
const file_name = readStringMem(&ptr);
if (file_name.len == 0) break;
const dir_index = try readULeb128Mem(&ptr);
const mtime = try readULeb128Mem(&ptr);
const len_bytes = try readULeb128Mem(&ptr);
try file_entries.append(FileEntry{
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
}
ptr = prog_start;
while (true) {
const opcode = readByteMem(&ptr);
if (opcode == DW.LNS_extended_op) {
const op_size = try readULeb128Mem(&ptr);
if (op_size < 1) return error.InvalidDebugInfo;
var sub_op = readByteMem(&ptr);
switch (sub_op) {
DW.LNE_end_sequence => {
prog.end_sequence = true;
if (try prog.checkLineMatch()) |info| return info;
return error.MissingDebugInfo;
},
DW.LNE_set_address => {
const addr = readIntMem(&ptr, usize, builtin.Endian.Little);
prog.address = symbol.reloc + addr;
},
DW.LNE_define_file => {
const file_name = readStringMem(&ptr);
const dir_index = try readULeb128Mem(&ptr);
const mtime = try readULeb128Mem(&ptr);
const len_bytes = try readULeb128Mem(&ptr);
try file_entries.append(FileEntry{
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
},
else => {
ptr += op_size - 1;
},
}
} else if (opcode >= opcode_base) {
// special opcodes
const adjusted_opcode = opcode - opcode_base;
const inc_addr = minimum_instruction_length * (adjusted_opcode / line_range);
const inc_line = i32(line_base) + i32(adjusted_opcode % line_range);
prog.line += inc_line;
prog.address += inc_addr;
if (try prog.checkLineMatch()) |info| return info;
prog.basic_block = false;
} else {
switch (opcode) {
DW.LNS_copy => {
if (try prog.checkLineMatch()) |info| return info;
prog.basic_block = false;
},
DW.LNS_advance_pc => {
const arg = try readULeb128Mem(&ptr);
prog.address += arg * minimum_instruction_length;
},
DW.LNS_advance_line => {
const arg = try readILeb128Mem(&ptr);
prog.line += arg;
},
DW.LNS_set_file => {
const arg = try readULeb128Mem(&ptr);
prog.file = arg;
},
DW.LNS_set_column => {
const arg = try readULeb128Mem(&ptr);
prog.column = arg;
},
DW.LNS_negate_stmt => {
prog.is_stmt = !prog.is_stmt;
},
DW.LNS_set_basic_block => {
prog.basic_block = true;
},
DW.LNS_const_add_pc => {
const inc_addr = minimum_instruction_length * ((255 - opcode_base) / line_range);
prog.address += inc_addr;
},
DW.LNS_fixed_advance_pc => {
const arg = readIntMem(&ptr, u16, builtin.Endian.Little);
prog.address += arg;
},
DW.LNS_set_prologue_end => {},
else => {
if (opcode - 1 >= standard_opcode_lengths.len) return error.InvalidDebugInfo;
const len_bytes = standard_opcode_lengths[opcode - 1];
ptr += len_bytes;
},
}
}
}
return error.MissingDebugInfo;
}
fn getLineNumberInfoDwarf(di: *DwarfInfo, compile_unit: CompileUnit, target_address: usize) !LineInfo {
const compile_unit_cwd = try compile_unit.die.getAttrString(di, DW.AT_comp_dir);
const line_info_offset = try compile_unit.die.getAttrSecOffset(DW.AT_stmt_list);
assert(line_info_offset < di.debug_line.size);
try di.dwarf_seekable_stream.seekTo(di.debug_line.offset + line_info_offset);
var is_64: bool = undefined;
const unit_length = try readInitialLength(@typeOf(di.dwarf_in_stream.readFn).ReturnType.ErrorSet, di.dwarf_in_stream, &is_64);
if (unit_length == 0) {
return error.MissingDebugInfo;
}
const next_offset = unit_length + (if (is_64) usize(12) else usize(4));
const version = try di.dwarf_in_stream.readInt(u16, di.endian);
// TODO support 3 and 5
if (version != 2 and version != 4) return error.InvalidDebugInfo;
const prologue_length = if (is_64) try di.dwarf_in_stream.readInt(u64, di.endian) else try di.dwarf_in_stream.readInt(u32, di.endian);
const prog_start_offset = (try di.dwarf_seekable_stream.getPos()) + prologue_length;
const minimum_instruction_length = try di.dwarf_in_stream.readByte();
if (minimum_instruction_length == 0) return error.InvalidDebugInfo;
if (version >= 4) {
// maximum_operations_per_instruction
_ = try di.dwarf_in_stream.readByte();
}
const default_is_stmt = (try di.dwarf_in_stream.readByte()) != 0;
const line_base = try di.dwarf_in_stream.readByteSigned();
const line_range = try di.dwarf_in_stream.readByte();
if (line_range == 0) return error.InvalidDebugInfo;
const opcode_base = try di.dwarf_in_stream.readByte();
const standard_opcode_lengths = try di.allocator().alloc(u8, opcode_base - 1);
{
var i: usize = 0;
while (i < opcode_base - 1) : (i += 1) {
standard_opcode_lengths[i] = try di.dwarf_in_stream.readByte();
}
}
var include_directories = ArrayList([]u8).init(di.allocator());
try include_directories.append(compile_unit_cwd);
while (true) {
const dir = try di.readString();
if (dir.len == 0) break;
try include_directories.append(dir);
}
var file_entries = ArrayList(FileEntry).init(di.allocator());
var prog = LineNumberProgram.init(default_is_stmt, include_directories.toSliceConst(), &file_entries, target_address);
while (true) {
const file_name = try di.readString();
if (file_name.len == 0) break;
const dir_index = try readULeb128(di.dwarf_in_stream);
const mtime = try readULeb128(di.dwarf_in_stream);
const len_bytes = try readULeb128(di.dwarf_in_stream);
try file_entries.append(FileEntry{
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
}
try di.dwarf_seekable_stream.seekTo(prog_start_offset);
while (true) {
const opcode = try di.dwarf_in_stream.readByte();
if (opcode == DW.LNS_extended_op) {
const op_size = try readULeb128(di.dwarf_in_stream);
if (op_size < 1) return error.InvalidDebugInfo;
var sub_op = try di.dwarf_in_stream.readByte();
switch (sub_op) {
DW.LNE_end_sequence => {
prog.end_sequence = true;
if (try prog.checkLineMatch()) |info| return info;
return error.MissingDebugInfo;
},
DW.LNE_set_address => {
const addr = try di.dwarf_in_stream.readInt(usize, di.endian);
prog.address = addr;
},
DW.LNE_define_file => {
const file_name = try di.readString();
const dir_index = try readULeb128(di.dwarf_in_stream);
const mtime = try readULeb128(di.dwarf_in_stream);
const len_bytes = try readULeb128(di.dwarf_in_stream);
try file_entries.append(FileEntry{
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
},
else => {
const fwd_amt = math.cast(isize, op_size - 1) catch return error.InvalidDebugInfo;
try di.dwarf_seekable_stream.seekForward(fwd_amt);
},
}
} else if (opcode >= opcode_base) {
// special opcodes
const adjusted_opcode = opcode - opcode_base;
const inc_addr = minimum_instruction_length * (adjusted_opcode / line_range);
const inc_line = i32(line_base) + i32(adjusted_opcode % line_range);
prog.line += inc_line;
prog.address += inc_addr;
if (try prog.checkLineMatch()) |info| return info;
prog.basic_block = false;
} else {
switch (opcode) {
DW.LNS_copy => {
if (try prog.checkLineMatch()) |info| return info;
prog.basic_block = false;
},
DW.LNS_advance_pc => {
const arg = try readULeb128(di.dwarf_in_stream);
prog.address += arg * minimum_instruction_length;
},
DW.LNS_advance_line => {
const arg = try readILeb128(di.dwarf_in_stream);
prog.line += arg;
},
DW.LNS_set_file => {
const arg = try readULeb128(di.dwarf_in_stream);
prog.file = arg;
},
DW.LNS_set_column => {
const arg = try readULeb128(di.dwarf_in_stream);
prog.column = arg;
},
DW.LNS_negate_stmt => {
prog.is_stmt = !prog.is_stmt;
},
DW.LNS_set_basic_block => {
prog.basic_block = true;
},
DW.LNS_const_add_pc => {
const inc_addr = minimum_instruction_length * ((255 - opcode_base) / line_range);
prog.address += inc_addr;
},
DW.LNS_fixed_advance_pc => {
const arg = try di.dwarf_in_stream.readInt(u16, di.endian);
prog.address += arg;
},
DW.LNS_set_prologue_end => {},
else => {
if (opcode - 1 >= standard_opcode_lengths.len) return error.InvalidDebugInfo;
const len_bytes = standard_opcode_lengths[opcode - 1];
try di.dwarf_seekable_stream.seekForward(len_bytes);
},
}
}
}
return error.MissingDebugInfo;
}
fn scanAllCompileUnits(di: *DwarfInfo) !void {
const debug_info_end = di.debug_info.offset + di.debug_info.size;
var this_unit_offset = di.debug_info.offset;
while (this_unit_offset < debug_info_end) {
try di.dwarf_seekable_stream.seekTo(this_unit_offset);
var is_64: bool = undefined;
const unit_length = try readInitialLength(@typeOf(di.dwarf_in_stream.readFn).ReturnType.ErrorSet, di.dwarf_in_stream, &is_64);
if (unit_length == 0) return;
const next_offset = unit_length + (if (is_64) usize(12) else usize(4));
const version = try di.dwarf_in_stream.readInt(u16, di.endian);
if (version < 2 or version > 5) return error.InvalidDebugInfo;
const debug_abbrev_offset = if (is_64) try di.dwarf_in_stream.readInt(u64, di.endian) else try di.dwarf_in_stream.readInt(u32, di.endian);
const address_size = try di.dwarf_in_stream.readByte();
if (address_size != @sizeOf(usize)) return error.InvalidDebugInfo;
const compile_unit_pos = try di.dwarf_seekable_stream.getPos();
const abbrev_table = try getAbbrevTable(di, debug_abbrev_offset);
try di.dwarf_seekable_stream.seekTo(compile_unit_pos);
const compile_unit_die = try di.allocator().create(Die);
compile_unit_die.* = try parseDie(di, abbrev_table, is_64);
if (compile_unit_die.tag_id != DW.TAG_compile_unit) return error.InvalidDebugInfo;
const pc_range = x: {
if (compile_unit_die.getAttrAddr(DW.AT_low_pc)) |low_pc| {
if (compile_unit_die.getAttr(DW.AT_high_pc)) |high_pc_value| {
const pc_end = switch (high_pc_value.*) {
FormValue.Address => |value| value,
FormValue.Const => |value| b: {
const offset = try value.asUnsignedLe();
break :b (low_pc + offset);
},
else => return error.InvalidDebugInfo,
};
break :x PcRange{
.start = low_pc,
.end = pc_end,
};
} else {
break :x null;
}
} else |err| {
if (err != error.MissingDebugInfo) return err;
break :x null;
}
};
try di.compile_unit_list.append(CompileUnit{
.version = version,
.is_64 = is_64,
.pc_range = pc_range,
.die = compile_unit_die,
});
this_unit_offset += next_offset;
}
}
fn findCompileUnit(di: *DwarfInfo, target_address: u64) !*const CompileUnit {
for (di.compile_unit_list.toSlice()) |*compile_unit| {
if (compile_unit.pc_range) |range| {
if (target_address >= range.start and target_address < range.end) return compile_unit;
}
if (compile_unit.die.getAttrSecOffset(DW.AT_ranges)) |ranges_offset| {
var base_address: usize = 0;
if (di.debug_ranges) |debug_ranges| {
try di.dwarf_seekable_stream.seekTo(debug_ranges.offset + ranges_offset);
while (true) {
const begin_addr = try di.dwarf_in_stream.readIntLittle(usize);
const end_addr = try di.dwarf_in_stream.readIntLittle(usize);
if (begin_addr == 0 and end_addr == 0) {
break;
}
if (begin_addr == maxInt(usize)) {
base_address = begin_addr;
continue;
}
if (target_address >= begin_addr and target_address < end_addr) {
return compile_unit;
}
}
}
} else |err| {
if (err != error.MissingDebugInfo) return err;
continue;
}
}
return error.MissingDebugInfo;
}
fn readIntMem(ptr: *[*]const u8, comptime T: type, endian: builtin.Endian) T {
// TODO https://github.com/ziglang/zig/issues/863
const result = mem.readIntSlice(T, ptr.*[0..@sizeOf(T)], endian);
ptr.* += @sizeOf(T);
return result;
}
fn readByteMem(ptr: *[*]const u8) u8 {
const result = ptr.*[0];
ptr.* += 1;
return result;
}
fn readByteSignedMem(ptr: *[*]const u8) i8 {
return @bitCast(i8, readByteMem(ptr));
}
fn readInitialLengthMem(ptr: *[*]const u8, is_64: *bool) !u64 {
// TODO this code can be improved with https://github.com/ziglang/zig/issues/863
const first_32_bits = mem.readIntSliceLittle(u32, ptr.*[0..4]);
is_64.* = (first_32_bits == 0xffffffff);
if (is_64.*) {
ptr.* += 4;
const result = mem.readIntSliceLittle(u64, ptr.*[0..8]);
ptr.* += 8;
return result;
} else {
if (first_32_bits >= 0xfffffff0) return error.InvalidDebugInfo;
ptr.* += 4;
return u64(first_32_bits);
}
}
fn readStringMem(ptr: *[*]const u8) []const u8 {
const result = mem.toSliceConst(u8, ptr.*);
ptr.* += result.len + 1;
return result;
}
fn readULeb128Mem(ptr: *[*]const u8) !u64 {
var result: u64 = 0;
var shift: usize = 0;
var i: usize = 0;
while (true) {
const byte = ptr.*[i];
i += 1;
var operand: u64 = undefined;
if (@shlWithOverflow(u64, byte & 0b01111111, @intCast(u6, shift), &operand)) return error.InvalidDebugInfo;
result |= operand;
if ((byte & 0b10000000) == 0) {
ptr.* += i;
return result;
}
shift += 7;
}
}
fn readILeb128Mem(ptr: *[*]const u8) !i64 {
var result: i64 = 0;
var shift: usize = 0;
var i: usize = 0;
while (true) {
const byte = ptr.*[i];
i += 1;
var operand: i64 = undefined;
if (@shlWithOverflow(i64, byte & 0b01111111, @intCast(u6, shift), &operand)) return error.InvalidDebugInfo;
result |= operand;
shift += 7;
if ((byte & 0b10000000) == 0) {
if (shift < @sizeOf(i64) * 8 and (byte & 0b01000000) != 0) result |= -(i64(1) << @intCast(u6, shift));
ptr.* += i;
return result;
}
}
}
fn readInitialLength(comptime E: type, in_stream: *io.InStream(E), is_64: *bool) !u64 {
const first_32_bits = try in_stream.readIntLittle(u32);
is_64.* = (first_32_bits == 0xffffffff);
if (is_64.*) {
return in_stream.readIntLittle(u64);
} else {
if (first_32_bits >= 0xfffffff0) return error.InvalidDebugInfo;
return u64(first_32_bits);
}
}
fn readULeb128(in_stream: var) !u64 {
var result: u64 = 0;
var shift: usize = 0;
while (true) {
const byte = try in_stream.readByte();
var operand: u64 = undefined;
if (@shlWithOverflow(u64, byte & 0b01111111, @intCast(u6, shift), &operand)) return error.InvalidDebugInfo;
result |= operand;
if ((byte & 0b10000000) == 0) return result;
shift += 7;
}
}
fn readILeb128(in_stream: var) !i64 {
var result: i64 = 0;
var shift: usize = 0;
while (true) {
const byte = try in_stream.readByte();
var operand: i64 = undefined;
if (@shlWithOverflow(i64, byte & 0b01111111, @intCast(u6, shift), &operand)) return error.InvalidDebugInfo;
result |= operand;
shift += 7;
if ((byte & 0b10000000) == 0) {
if (shift < @sizeOf(i64) * 8 and (byte & 0b01000000) != 0) result |= -(i64(1) << @intCast(u6, shift));
return result;
}
}
}
/// This should only be used in temporary test programs.
pub const global_allocator = &global_fixed_allocator.allocator;
var global_fixed_allocator = std.heap.ThreadSafeFixedBufferAllocator.init(global_allocator_mem[0..]);
var global_allocator_mem: [100 * 1024]u8 = undefined;
/// TODO multithreaded awareness
var debug_info_allocator: ?*mem.Allocator = null;
var debug_info_direct_allocator: std.heap.DirectAllocator = undefined;
var debug_info_arena_allocator: std.heap.ArenaAllocator = undefined;
fn getDebugInfoAllocator() *mem.Allocator {
if (debug_info_allocator) |a| return a;
debug_info_direct_allocator = std.heap.DirectAllocator.init();
debug_info_arena_allocator = std.heap.ArenaAllocator.init(&debug_info_direct_allocator.allocator);
debug_info_allocator = &debug_info_arena_allocator.allocator;
return &debug_info_arena_allocator.allocator;
}