zig/std/debug.zig

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const math = @import("math/index.zig");
const mem = @import("mem.zig");
const io = @import("io.zig");
const os = @import("os/index.zig");
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const elf = @import("elf.zig");
const DW = @import("dwarf.zig");
const ArrayList = @import("array_list.zig").ArrayList;
const builtin = @import("builtin");
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error MissingDebugInfo;
error InvalidDebugInfo;
error UnsupportedDebugInfo;
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pub fn assert(ok: bool) {
if (!ok) {
// In ReleaseFast test mode, we still want assert(false) to crash, so
// we insert an explicit call to @panic instead of unreachable.
if (builtin.is_test) {
@panic("assertion failure")
} else {
unreachable // assertion failure
}
}
}
var panicking = false;
/// This is the default panic implementation.
pub fn panic(comptime format: []const u8, args: ...) -> noreturn {
// TODO an intrinsic that labels this as unlikely to be reached
// TODO
// if (@atomicRmw(AtomicOp.XChg, &panicking, true, AtomicOrder.SeqCst)) { }
if (panicking) {
// 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();
} else {
panicking = true;
}
%%io.stderr.printf(format ++ "\n", args);
%%writeStackTrace(&io.stderr, &global_allocator, io.stderr.isTty() %% false, 1);
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%%io.stderr.flush();
os.abort();
}
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pub fn printStackTrace() -> %void {
%return writeStackTrace(&io.stderr, &global_allocator, io.stderr.isTty() %% false, 1);
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%return io.stderr.flush();
}
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const GREEN = "\x1b[32;1m";
const WHITE = "\x1b[37;1m";
const DIM = "\x1b[2m";
const RESET = "\x1b[0m";
pub var user_main_fn: ?fn() -> %void = null;
error PathNotFound;
error InvalidDebugInfo;
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pub fn writeStackTrace(out_stream: &io.OutStream, allocator: &mem.Allocator, tty_color: bool,
ignore_frame_count: usize) -> %void
{
switch (builtin.object_format) {
builtin.ObjectFormat.elf => {
var stack_trace = ElfStackTrace {
.self_exe_stream = undefined,
.elf = undefined,
.debug_info = undefined,
.debug_abbrev = undefined,
.debug_str = undefined,
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.debug_line = undefined,
.abbrev_table_list = ArrayList(AbbrevTableHeader).init(allocator),
.compile_unit_list = ArrayList(CompileUnit).init(allocator),
};
const st = &stack_trace;
st.self_exe_stream = %return io.openSelfExe();
defer st.self_exe_stream.close();
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%return st.elf.openStream(allocator, &st.self_exe_stream);
defer st.elf.close();
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st.debug_info = (%return st.elf.findSection(".debug_info")) ?? return error.MissingDebugInfo;
st.debug_abbrev = (%return st.elf.findSection(".debug_abbrev")) ?? return error.MissingDebugInfo;
st.debug_str = (%return st.elf.findSection(".debug_str")) ?? return error.MissingDebugInfo;
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st.debug_line = (%return st.elf.findSection(".debug_line")) ?? return error.MissingDebugInfo;
%return scanAllCompileUnits(st);
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var ignored_count: usize = 0;
var fp = @ptrToInt(@frameAddress());
while (fp != 0) : (fp = *@intToPtr(&const usize, fp)) {
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if (ignored_count < ignore_frame_count) {
ignored_count += 1;
continue;
}
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const return_address = *@intToPtr(&const usize, fp + @sizeOf(usize));
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// TODO we really should be able to convert @sizeOf(usize) * 2 to a string literal
// at compile time. I'll call it issue #313
const ptr_hex = if (@sizeOf(usize) == 4) "0x{x8}" else "0x{x16}";
const compile_unit = findCompileUnit(st, return_address) ?? {
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%return out_stream.print("???:?:?: " ++ DIM ++ ptr_hex ++ " in ??? (???)" ++ RESET ++ "\n ???\n\n",
return_address);
%return out_stream.flush();
continue;
};
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const compile_unit_name = %return compile_unit.die.getAttrString(st, DW.AT_name);
if (getLineNumberInfo(st, compile_unit, usize(return_address) - 1)) |line_info| {
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defer line_info.deinit();
%return out_stream.print(WHITE ++ "{}:{}:{}" ++ RESET ++ ": " ++
DIM ++ ptr_hex ++ " in ??? ({})" ++ RESET ++ "\n",
line_info.file_name, line_info.line, line_info.column,
return_address, compile_unit_name);
if (printLineFromFile(st.allocator(), out_stream, line_info)) {
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if (line_info.column == 0) {
%return out_stream.write("\n");
} else {
{var col_i: usize = 1; while (col_i < line_info.column) : (col_i += 1) {
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%return out_stream.writeByte(' ');
}}
%return out_stream.write(GREEN ++ "^" ++ RESET ++ "\n");
}
} else |err| switch (err) {
error.EndOfFile, error.PathNotFound => {},
else => return err,
}
} else |err| switch (err) {
error.MissingDebugInfo, error.InvalidDebugInfo => {
%return out_stream.print(ptr_hex ++ " in ??? ({})\n",
return_address, compile_unit_name);
},
else => return err,
};
%return out_stream.flush();
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}
},
builtin.ObjectFormat.coff => {
%return out_stream.write("(stack trace unavailable for COFF object format)\n");
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},
builtin.ObjectFormat.macho => {
%return out_stream.write("(stack trace unavailable for Mach-O object format)\n");
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},
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builtin.ObjectFormat.wasm => {
%return out_stream.write("(stack trace unavailable for WASM object format)\n");
},
builtin.ObjectFormat.unknown => {
%return out_stream.write("(stack trace unavailable for unknown object format)\n");
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},
}
}
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fn printLineFromFile(allocator: &mem.Allocator, out_stream: &io.OutStream, line_info: &const LineInfo) -> %void {
var f = %return io.InStream.open(line_info.file_name, allocator);
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 = %return f.read(buf[0..]);
const slice = buf[0..amt_read];
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for (slice) |byte| {
if (line == line_info.line) {
%return 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;
}
}
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const ElfStackTrace = struct {
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self_exe_stream: io.InStream,
elf: elf.Elf,
debug_info: &elf.SectionHeader,
debug_abbrev: &elf.SectionHeader,
debug_str: &elf.SectionHeader,
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debug_line: &elf.SectionHeader,
abbrev_table_list: ArrayList(AbbrevTableHeader),
compile_unit_list: ArrayList(CompileUnit),
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pub fn allocator(self: &const ElfStackTrace) -> &mem.Allocator {
return self.abbrev_table_list.allocator;
}
pub fn readString(self: &ElfStackTrace) -> %[]u8 {
return readStringRaw(self.allocator(), &self.self_exe_stream);
}
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};
const PcRange = struct {
start: u64,
end: u64,
};
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const CompileUnit = struct {
version: u16,
is_64: bool,
die: &Die,
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index: usize,
pc_range: ?PcRange,
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};
const AbbrevTable = ArrayList(AbbrevTableEntry);
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const AbbrevTableHeader = struct {
// offset from .debug_abbrev
offset: u64,
table: AbbrevTable,
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};
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const AbbrevTableEntry = struct {
has_children: bool,
abbrev_code: u64,
tag_id: u64,
attrs: ArrayList(AbbrevAttr),
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};
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const AbbrevAttr = struct {
attr_id: u64,
form_id: u64,
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};
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const FormValue = enum {
Address: u64,
Block: []u8,
Const: Constant,
ExprLoc: []u8,
Flag: bool,
SecOffset: u64,
Ref: []u8,
RefAddr: u64,
RefSig8: u64,
String: []u8,
StrPtr: u64,
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};
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const Constant = struct {
payload: []u8,
signed: bool,
fn asUnsignedLe(self: &const Constant) -> %u64 {
if (self.payload.len > @sizeOf(u64))
return error.InvalidDebugInfo;
if (self.signed)
return error.InvalidDebugInfo;
return mem.readInt(self.payload, u64, false);
}
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};
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const Die = struct {
tag_id: u64,
has_children: bool,
attrs: ArrayList(Attr),
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const Attr = struct {
id: u64,
value: FormValue,
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};
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) ?? return error.MissingDebugInfo;
return switch (*form_value) {
FormValue.Address => |value| value,
else => error.InvalidDebugInfo,
};
}
fn getAttrUnsignedLe(self: &const Die, id: u64) -> %u64 {
const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
return switch (*form_value) {
FormValue.Const => |value| value.asUnsignedLe(),
else => error.InvalidDebugInfo,
};
}
fn getAttrString(self: &const Die, st: &ElfStackTrace, id: u64) -> %[]u8 {
const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
return switch (*form_value) {
FormValue.String => |value| value,
FormValue.StrPtr => |offset| getString(st, offset),
else => error.InvalidDebugInfo,
}
}
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};
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const FileEntry = struct {
file_name: []const u8,
dir_index: usize,
mtime: usize,
len_bytes: usize,
};
const LineInfo = struct {
line: usize,
column: usize,
file_name: []u8,
allocator: &mem.Allocator,
fn deinit(self: &const LineInfo) {
self.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),
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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
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{
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 = %return os.path.join(self.file_entries.allocator, dir_name, file_entry.file_name);
%defer self.file_entries.allocator.free(file_name);
return LineInfo {
.line = if (self.prev_line >= 0) 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: &io.InStream) -> %[]u8 {
var buf = ArrayList(u8).init(allocator);
while (true) {
const byte = %return in_stream.readByte();
if (byte == 0)
break;
%return buf.append(byte);
}
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return buf.toSlice();
}
fn getString(st: &ElfStackTrace, offset: u64) -> %[]u8 {
const pos = st.debug_str.offset + offset;
%return st.self_exe_stream.seekTo(pos);
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return st.readString();
}
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fn readAllocBytes(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %[]u8 {
const buf = %return global_allocator.alloc(u8, size);
%defer global_allocator.free(buf);
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if ((%return in_stream.read(buf)) < size) return error.EndOfFile;
return buf;
}
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fn parseFormValueBlockLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
const buf = %return readAllocBytes(allocator, in_stream, size);
return FormValue.Block { buf };
}
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fn parseFormValueBlock(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
const block_len = %return in_stream.readVarInt(false, usize, size);
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return parseFormValueBlockLen(allocator, in_stream, block_len);
}
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fn parseFormValueConstant(allocator: &mem.Allocator, in_stream: &io.InStream, signed: bool, size: usize) -> %FormValue {
FormValue.Const { Constant {
.signed = signed,
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.payload = %return readAllocBytes(allocator, in_stream, size),
}}
}
fn parseFormValueDwarfOffsetSize(in_stream: &io.InStream, is_64: bool) -> %u64 {
return if (is_64) {
%return in_stream.readIntLe(u64)
} else {
u64(%return in_stream.readIntLe(u32))
};
}
fn parseFormValueTargetAddrSize(in_stream: &io.InStream) -> %u64 {
return if (@sizeOf(usize) == 4) {
u64(%return in_stream.readIntLe(u32))
} else if (@sizeOf(usize) == 8) {
%return in_stream.readIntLe(u64)
} else {
unreachable;
};
}
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fn parseFormValueRefLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
const buf = %return readAllocBytes(allocator, in_stream, size);
return FormValue.Ref { buf };
}
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fn parseFormValueRef(allocator: &mem.Allocator, in_stream: &io.InStream, comptime T: type) -> %FormValue {
const block_len = %return in_stream.readIntLe(T);
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return parseFormValueRefLen(allocator, in_stream, block_len);
}
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fn parseFormValue(allocator: &mem.Allocator, in_stream: &io.InStream, form_id: u64, is_64: bool) -> %FormValue {
return switch (form_id) {
DW.FORM_addr => FormValue.Address { %return parseFormValueTargetAddrSize(in_stream) },
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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 => {
const block_len = %return readULeb128(in_stream);
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parseFormValueBlockLen(allocator, in_stream, block_len)
},
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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 block_len = %return readULeb128(in_stream);
const signed = form_id == DW.FORM_sdata;
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parseFormValueConstant(allocator, in_stream, signed, block_len)
},
DW.FORM_exprloc => {
const size = %return readULeb128(in_stream);
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const buf = %return readAllocBytes(allocator, in_stream, size);
return FormValue.ExprLoc { buf };
},
DW.FORM_flag => FormValue.Flag { (%return in_stream.readByte()) != 0 },
DW.FORM_flag_present => FormValue.Flag { true },
DW.FORM_sec_offset => FormValue.SecOffset {
%return parseFormValueDwarfOffsetSize(in_stream, is_64)
},
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DW.FORM_ref1 => parseFormValueRef(allocator, in_stream, u8),
DW.FORM_ref2 => parseFormValueRef(allocator, in_stream, u16),
DW.FORM_ref4 => parseFormValueRef(allocator, in_stream, u32),
DW.FORM_ref8 => parseFormValueRef(allocator, in_stream, u64),
DW.FORM_ref_udata => {
const ref_len = %return readULeb128(in_stream);
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parseFormValueRefLen(allocator, in_stream, ref_len)
},
DW.FORM_ref_addr => FormValue.RefAddr { %return parseFormValueDwarfOffsetSize(in_stream, is_64) },
DW.FORM_ref_sig8 => FormValue.RefSig8 { %return in_stream.readIntLe(u64) },
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DW.FORM_string => FormValue.String { %return readStringRaw(allocator, in_stream) },
DW.FORM_strp => FormValue.StrPtr { %return parseFormValueDwarfOffsetSize(in_stream, is_64) },
DW.FORM_indirect => {
const child_form_id = %return readULeb128(in_stream);
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parseFormValue(allocator, in_stream, child_form_id, is_64)
},
else => error.InvalidDebugInfo,
}
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}
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fn parseAbbrevTable(st: &ElfStackTrace) -> %AbbrevTable {
const in_stream = &st.self_exe_stream;
var result = AbbrevTable.init(st.allocator());
while (true) {
const abbrev_code = %return readULeb128(in_stream);
if (abbrev_code == 0)
return result;
%return result.append(AbbrevTableEntry {
.abbrev_code = abbrev_code,
.tag_id = %return readULeb128(in_stream),
.has_children = (%return in_stream.readByte()) == DW.CHILDREN_yes,
.attrs = ArrayList(AbbrevAttr).init(st.allocator()),
});
const attrs = &result.items[result.len - 1].attrs;
while (true) {
const attr_id = %return readULeb128(in_stream);
const form_id = %return readULeb128(in_stream);
if (attr_id == 0 and form_id == 0)
break;
%return 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(st: &ElfStackTrace, abbrev_offset: u64) -> %&const AbbrevTable {
for (st.abbrev_table_list.toSlice()) |*header| {
if (header.offset == abbrev_offset) {
return &header.table;
}
}
%return st.self_exe_stream.seekTo(st.debug_abbrev.offset + abbrev_offset);
%return st.abbrev_table_list.append(AbbrevTableHeader {
.offset = abbrev_offset,
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.table = %return parseAbbrevTable(st),
});
return &st.abbrev_table_list.items[st.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;
}
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fn parseDie(st: &ElfStackTrace, abbrev_table: &const AbbrevTable, is_64: bool) -> %Die {
const in_stream = &st.self_exe_stream;
const abbrev_code = %return readULeb128(in_stream);
const table_entry = getAbbrevTableEntry(abbrev_table, abbrev_code) ?? return error.InvalidDebugInfo;
var result = Die {
.tag_id = table_entry.tag_id,
.has_children = table_entry.has_children,
.attrs = ArrayList(Die.Attr).init(st.allocator()),
};
%return result.attrs.resize(table_entry.attrs.len);
for (table_entry.attrs.toSliceConst()) |attr, i| {
result.attrs.items[i] = Die.Attr {
.id = attr.attr_id,
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.value = %return parseFormValue(st.allocator(), &st.self_exe_stream, attr.form_id, is_64),
};
}
return result;
}
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fn getLineNumberInfo(st: &ElfStackTrace, compile_unit: &const CompileUnit, target_address: usize) -> %LineInfo {
const compile_unit_cwd = %return compile_unit.die.getAttrString(st, DW.AT_comp_dir);
const in_stream = &st.self_exe_stream;
const debug_line_end = st.debug_line.offset + st.debug_line.size;
var this_offset = st.debug_line.offset;
var this_index: usize = 0;
while (this_offset < debug_line_end) : (this_index += 1) {
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%return in_stream.seekTo(this_offset);
var is_64: bool = undefined;
const unit_length = %return readInitialLength(in_stream, &is_64);
if (unit_length == 0)
return error.MissingDebugInfo;
const next_offset = unit_length + (if (is_64) usize(12) else usize(4));
if (compile_unit.index != this_index) {
this_offset += next_offset;
continue;
}
const version = %return in_stream.readInt(st.elf.is_big_endian, u16);
if (version != 2) return error.InvalidDebugInfo;
const prologue_length = %return in_stream.readInt(st.elf.is_big_endian, u32);
const prog_start_offset = (%return in_stream.getPos()) + prologue_length;
const minimum_instruction_length = %return in_stream.readByte();
if (minimum_instruction_length == 0) return error.InvalidDebugInfo;
const default_is_stmt = (%return in_stream.readByte()) != 0;
const line_base = %return in_stream.readByteSigned();
const line_range = %return in_stream.readByte();
if (line_range == 0)
return error.InvalidDebugInfo;
const opcode_base = %return in_stream.readByte();
const standard_opcode_lengths = %return st.allocator().alloc(u8, opcode_base - 1);
{var i: usize = 0; while (i < opcode_base - 1) : (i += 1) {
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standard_opcode_lengths[i] = %return in_stream.readByte();
}}
var include_directories = ArrayList([]u8).init(st.allocator());
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%return include_directories.append(compile_unit_cwd);
while (true) {
const dir = %return st.readString();
if (dir.len == 0)
break;
%return include_directories.append(dir);
}
var file_entries = ArrayList(FileEntry).init(st.allocator());
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var prog = LineNumberProgram.init(default_is_stmt, include_directories.toSliceConst(),
&file_entries, target_address);
while (true) {
const file_name = %return st.readString();
if (file_name.len == 0)
break;
const dir_index = %return readULeb128(in_stream);
const mtime = %return readULeb128(in_stream);
const len_bytes = %return readULeb128(in_stream);
%return file_entries.append(FileEntry {
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
}
%return in_stream.seekTo(prog_start_offset);
while (true) {
//const pos = (%return in_stream.getPos()) - this_offset;
//if (pos == 0x1a3) @breakpoint();
//%%io.stderr.printf("\n{x8}\n", pos);
const opcode = %return in_stream.readByte();
var sub_op: u8 = undefined; // TODO move this to the correct scope and fix the compiler crash
if (opcode == DW.LNS_extended_op) {
const op_size = %return readULeb128(in_stream);
if (op_size < 1)
return error.InvalidDebugInfo;
sub_op = %return in_stream.readByte();
switch (sub_op) {
DW.LNE_end_sequence => {
//%%io.stdout.printf(" [0x{x8}] End Sequence\n", pos);
prog.end_sequence = true;
if (%return prog.checkLineMatch()) |info| return info;
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return error.MissingDebugInfo;
},
DW.LNE_set_address => {
const addr = %return in_stream.readInt(st.elf.is_big_endian, usize);
prog.address = addr;
//%%io.stdout.printf(" [0x{x8}] Extended opcode {}: set Address to 0x{x}\n",
// pos, sub_op, addr);
},
DW.LNE_define_file => {
//%%io.stdout.printf(" [0x{x8}] Define File\n", pos);
const file_name = %return st.readString();
const dir_index = %return readULeb128(in_stream);
const mtime = %return readULeb128(in_stream);
const len_bytes = %return readULeb128(in_stream);
%return file_entries.append(FileEntry {
.file_name = file_name,
.dir_index = dir_index,
.mtime = mtime,
.len_bytes = len_bytes,
});
},
else => {
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const fwd_amt = math.cast(isize, op_size - 1) %% return error.InvalidDebugInfo;
%return in_stream.seekForward(fwd_amt);
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},
}
} 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;
//%%io.stdout.printf(
// " [0x{x8}] Special opcode {}: advance Address by {} to 0x{x} and Line by {} to {}\n",
// pos, adjusted_opcode, inc_addr, prog.address, inc_line, prog.line);
if (%return prog.checkLineMatch()) |info| return info;
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prog.basic_block = false;
} else {
switch (opcode) {
DW.LNS_copy => {
//%%io.stdout.printf(" [0x{x8}] Copy\n", pos);
if (%return prog.checkLineMatch()) |info| return info;
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prog.basic_block = false;
},
DW.LNS_advance_pc => {
const arg = %return readULeb128(in_stream);
prog.address += arg * minimum_instruction_length;
//%%io.stdout.printf(" [0x{x8}] Advance PC by {} to 0x{x}\n", pos, arg, prog.address);
},
DW.LNS_advance_line => {
const arg = %return readILeb128(in_stream);
prog.line += arg;
//%%io.stdout.printf(" [0x{x8}] Advance Line by {} to {}\n", pos, arg, prog.line);
},
DW.LNS_set_file => {
const arg = %return readULeb128(in_stream);
prog.file = arg;
//%%io.stdout.printf(" [0x{x8}] Set File Name to entry {} in the File Name Table\n",
// pos, arg);
},
DW.LNS_set_column => {
const arg = %return readULeb128(in_stream);
prog.column = arg;
//%%io.stdout.printf(" [0x{x8}] Set column to {}\n", pos, arg);
},
DW.LNS_negate_stmt => {
prog.is_stmt = !prog.is_stmt;
//%%io.stdout.printf(" [0x{x8}] Set is_stmt to {}\n", pos, if (prog.is_stmt) u8(1) else u8(0));
},
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;
//%%io.stdout.printf(" [0x{x8}] Advance PC by constant {} to 0x{x}\n",
// pos, inc_addr, prog.address);
},
DW.LNS_fixed_advance_pc => {
const arg = %return in_stream.readInt(st.elf.is_big_endian, u16);
prog.address += arg;
},
DW.LNS_set_prologue_end => {
//%%io.stdout.printf(" [0x{x8}] Set prologue_end to true\n", pos);
},
else => {
if (opcode - 1 >= standard_opcode_lengths.len)
return error.InvalidDebugInfo;
//%%io.stdout.printf(" [0x{x8}] unknown op code {}\n", pos, opcode);
const len_bytes = standard_opcode_lengths[opcode - 1];
%return in_stream.seekForward(len_bytes);
},
}
}
}
this_offset += next_offset;
}
return error.MissingDebugInfo;
}
fn scanAllCompileUnits(st: &ElfStackTrace) -> %void {
const debug_info_end = st.debug_info.offset + st.debug_info.size;
var this_unit_offset = st.debug_info.offset;
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var cu_index: usize = 0;
while (this_unit_offset < debug_info_end) {
%return st.self_exe_stream.seekTo(this_unit_offset);
var is_64: bool = undefined;
const unit_length = %return readInitialLength(&st.self_exe_stream, &is_64);
if (unit_length == 0)
return;
const next_offset = unit_length + (if (is_64) usize(12) else usize(4));
const version = %return st.self_exe_stream.readInt(st.elf.is_big_endian, u16);
if (version < 2 or version > 5) return error.InvalidDebugInfo;
const debug_abbrev_offset = if (is_64) {
%return st.self_exe_stream.readInt(st.elf.is_big_endian, u64)
} else {
%return st.self_exe_stream.readInt(st.elf.is_big_endian, u32)
};
const address_size = %return st.self_exe_stream.readByte();
if (address_size != @sizeOf(usize)) return error.InvalidDebugInfo;
const compile_unit_pos = %return st.self_exe_stream.getPos();
const abbrev_table = %return getAbbrevTable(st, debug_abbrev_offset);
%return st.self_exe_stream.seekTo(compile_unit_pos);
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const compile_unit_die = %return st.allocator().create(Die);
*compile_unit_die = %return parseDie(st, abbrev_table, is_64);
if (compile_unit_die.tag_id != DW.TAG_compile_unit)
return error.InvalidDebugInfo;
const pc_range = {
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| {
const offset = %return value.asUnsignedLe();
low_pc + offset
},
else => return error.InvalidDebugInfo,
};
PcRange {
.start = low_pc,
.end = pc_end,
}
} else {
null
}
} else |err| {
if (err != error.MissingDebugInfo)
return err;
null
}
};
%return st.compile_unit_list.append(CompileUnit {
.version = version,
.is_64 = is_64,
.pc_range = pc_range,
.die = compile_unit_die,
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.index = cu_index,
});
this_unit_offset += next_offset;
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cu_index += 1;
}
}
fn findCompileUnit(st: &ElfStackTrace, target_address: u64) -> ?&const CompileUnit {
for (st.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;
}
}
return null;
}
fn readInitialLength(in_stream: &io.InStream, is_64: &bool) -> %u64 {
const first_32_bits = %return in_stream.readIntLe(u32);
*is_64 = (first_32_bits == 0xffffffff);
return if (*is_64) {
%return in_stream.readIntLe(u64)
} else {
if (first_32_bits >= 0xfffffff0) return error.InvalidDebugInfo;
u64(first_32_bits)
};
}
fn readULeb128(in_stream: &io.InStream) -> %u64 {
var result: u64 = 0;
var shift: usize = 0;
while (true) {
const byte = %return in_stream.readByte();
var operand: u64 = undefined;
if (@shlWithOverflow(u64, byte & 0b01111111, u6(shift), &operand))
return error.InvalidDebugInfo;
result |= operand;
if ((byte & 0b10000000) == 0)
return result;
shift += 7;
}
}
fn readILeb128(in_stream: &io.InStream) -> %i64 {
var result: i64 = 0;
var shift: usize = 0;
while (true) {
const byte = %return in_stream.readByte();
var operand: i64 = undefined;
if (@shlWithOverflow(i64, byte & 0b01111111, 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) << u6(shift));
return result;
}
}
}
pub var global_allocator = mem.Allocator {
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.allocFn = globalAlloc,
.reallocFn = globalRealloc,
.freeFn = globalFree,
};
var some_mem: [100 * 1024]u8 = undefined;
var some_mem_index: usize = 0;
error OutOfMemory;
fn globalAlloc(self: &mem.Allocator, n: usize, alignment: usize) -> %[]u8 {
const addr = @ptrToInt(&some_mem[some_mem_index]);
const rem = @rem(addr, alignment);
const march_forward_bytes = if (rem == 0) 0 else (alignment - rem);
const adjusted_index = some_mem_index + march_forward_bytes;
const end_index = adjusted_index + n;
if (end_index > some_mem.len) {
return error.OutOfMemory;
}
const result = some_mem[adjusted_index .. end_index];
some_mem_index = end_index;
return result;
}
fn globalRealloc(self: &mem.Allocator, old_mem: []u8, new_size: usize, alignment: usize) -> %[]u8 {
const result = %return globalAlloc(self, new_size, alignment);
@memcpy(result.ptr, old_mem.ptr, old_mem.len);
return result;
}
fn globalFree(self: &mem.Allocator, ptr: &u8) { }