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dwarf: enable full reuse for debuggers
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@tensorush
tensorush committed Jul 9, 2024
1 parent 854e86c commit b523139
Showing 1 changed file with 52 additions and 50 deletions.
102 changes: 52 additions & 50 deletions lib/std/dwarf.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -154,12 +154,12 @@ pub const CC = enum(u8) {

pub const Format = enum { @"32", @"64" };

const PcRange = struct {
pub const PcRange = struct {
start: u64,
end: u64,
};

const Func = struct {
pub const Func = struct {
pc_range: ?PcRange,
name: ?[]const u8,
};
Expand All @@ -177,38 +177,38 @@ pub const CompileUnit = struct {
frame_base: ?*const FormValue,
};

const Abbrev = struct {
pub const Abbrev = struct {
code: u64,
tag_id: u64,
has_children: bool,
attrs: []Attr,

fn deinit(abbrev: *Abbrev, allocator: mem.Allocator) void {
pub fn deinit(abbrev: *Abbrev, allocator: mem.Allocator) void {
allocator.free(abbrev.attrs);
abbrev.* = undefined;
}

const Attr = struct {
pub const Attr = struct {
id: u64,
form_id: u64,
/// Only valid if form_id is .implicit_const
payload: i64,
};

const Table = struct {
pub const Table = struct {
// offset from .debug_abbrev
offset: u64,
abbrevs: []Abbrev,

fn deinit(table: *Table, allocator: mem.Allocator) void {
pub fn deinit(table: *Table, allocator: mem.Allocator) void {
for (table.abbrevs) |*abbrev| {
abbrev.deinit(allocator);
}
allocator.free(table.abbrevs);
table.* = undefined;
}

fn get(table: *const Table, abbrev_code: u64) ?*const Abbrev {
pub fn get(table: *const Table, abbrev_code: u64) ?*const Abbrev {
return for (table.abbrevs) |*abbrev| {
if (abbrev.code == abbrev_code) break abbrev;
} else null;
Expand All @@ -235,7 +235,7 @@ pub const FormValue = union(enum) {
loclistx: u64,
rnglistx: u64,

fn getString(fv: FormValue, di: DwarfInfo) ![:0]const u8 {
pub fn getString(fv: FormValue, di: DwarfInfo) ![:0]const u8 {
switch (fv) {
.string => |s| return s,
.strp => |off| return di.getString(off),
Expand All @@ -244,7 +244,7 @@ pub const FormValue = union(enum) {
}
}

fn getUInt(fv: FormValue, comptime U: type) !U {
pub fn getUInt(fv: FormValue, comptime U: type) !U {
return switch (fv) {
inline .udata,
.sdata,
Expand All @@ -255,29 +255,29 @@ pub const FormValue = union(enum) {
}
};

const Die = struct {
pub const Die = struct {
tag_id: u64,
has_children: bool,
attrs: []Attr,

const Attr = struct {
pub const Attr = struct {
id: u64,
value: FormValue,
};

fn deinit(self: *Die, allocator: mem.Allocator) void {
pub fn deinit(self: *Die, allocator: mem.Allocator) void {
allocator.free(self.attrs);
self.* = undefined;
}

fn getAttr(self: *const Die, id: u64) ?*const FormValue {
pub fn getAttr(self: *const Die, id: u64) ?*const FormValue {
for (self.attrs) |*attr| {
if (attr.id == id) return &attr.value;
}
return null;
}

fn getAttrAddr(
pub fn getAttrAddr(
self: *const Die,
di: *const DwarfInfo,
id: u64,
Expand All @@ -291,20 +291,20 @@ const Die = struct {
};
}

fn getAttrSecOffset(self: *const Die, id: u64) !u64 {
pub fn getAttrSecOffset(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return form_value.getUInt(u64);
}

fn getAttrUnsignedLe(self: *const Die, id: u64) !u64 {
pub fn getAttrUnsignedLe(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
.Const => |value| value.asUnsignedLe(),
else => error.InvalidDebugInfo,
};
}

fn getAttrRef(self: *const Die, id: u64) !u64 {
pub fn getAttrRef(self: *const Die, id: u64) !u64 {
const form_value = self.getAttr(id) orelse return error.MissingDebugInfo;
return switch (form_value.*) {
.ref => |value| value,
Expand Down Expand Up @@ -347,15 +347,15 @@ const Die = struct {
}
};

const FileEntry = struct {
pub const FileEntry = struct {
path: []const u8,
dir_index: u32 = 0,
mtime: u64 = 0,
size: u64 = 0,
md5: [16]u8 = [1]u8{0} ** 16,
};

const LineNumberProgram = struct {
pub const LineNumberProgram = struct {
address: u64,
file: usize,
line: i64,
Expand Down Expand Up @@ -470,12 +470,13 @@ const LineNumberProgram = struct {
}
};

const UnitHeader = struct {
pub const UnitHeader = struct {
format: Format,
header_length: u4,
unit_length: u64,
};
fn readUnitHeader(fbr: *FixedBufferReader) !UnitHeader {

pub fn readUnitHeader(fbr: *FixedBufferReader) !UnitHeader {
return switch (try fbr.readInt(u32)) {
0...0xfffffff0 - 1 => |unit_length| .{
.format = .@"32",
Expand All @@ -491,7 +492,7 @@ fn readUnitHeader(fbr: *FixedBufferReader) !UnitHeader {
};
}

fn parseFormValue(
pub fn parseFormValue(
fbr: *FixedBufferReader,
form_id: u64,
format: Format,
Expand Down Expand Up @@ -656,7 +657,7 @@ pub const DwarfInfo = struct {
return null;
}

fn scanAllFunctions(di: *DwarfInfo, allocator: mem.Allocator) !void {
pub fn scanAllFunctions(di: *DwarfInfo, allocator: mem.Allocator) !void {
var fbr: FixedBufferReader = .{ .buf = di.section(.debug_info).?, .endian = di.endian };
var this_unit_offset: u64 = 0;

Expand Down Expand Up @@ -843,7 +844,7 @@ pub const DwarfInfo = struct {
}
}

fn scanAllCompileUnits(di: *DwarfInfo, allocator: mem.Allocator) !void {
pub fn scanAllCompileUnits(di: *DwarfInfo, allocator: mem.Allocator) !void {
var fbr: FixedBufferReader = .{ .buf = di.section(.debug_info).?, .endian = di.endian };
var this_unit_offset: u64 = 0;

Expand Down Expand Up @@ -931,7 +932,7 @@ pub const DwarfInfo = struct {
}
}

const DebugRangeIterator = struct {
pub const DebugRangeIterator = struct {
base_address: u64,
section_type: DwarfSection,
di: *const DwarfInfo,
Expand Down Expand Up @@ -1096,7 +1097,7 @@ pub const DwarfInfo = struct {

/// Gets an already existing AbbrevTable given the abbrev_offset, or if not found,
/// seeks in the stream and parses it.
fn getAbbrevTable(di: *DwarfInfo, allocator: mem.Allocator, abbrev_offset: u64) !*const Abbrev.Table {
pub fn getAbbrevTable(di: *DwarfInfo, allocator: mem.Allocator, abbrev_offset: u64) !*const Abbrev.Table {
for (di.abbrev_table_list.items) |*table| {
if (table.offset == abbrev_offset) {
return table;
Expand All @@ -1109,7 +1110,7 @@ pub const DwarfInfo = struct {
return &di.abbrev_table_list.items[di.abbrev_table_list.items.len - 1];
}

fn parseAbbrevTable(di: *DwarfInfo, allocator: mem.Allocator, offset: u64) !Abbrev.Table {
pub fn parseAbbrevTable(di: *DwarfInfo, allocator: mem.Allocator, offset: u64) !Abbrev.Table {
var fbr: FixedBufferReader = .{
.buf = di.section(.debug_abbrev).?,
.pos = math.cast(usize, offset) orelse return badDwarf(),
Expand Down Expand Up @@ -1161,7 +1162,7 @@ pub const DwarfInfo = struct {
};
}

fn parseDie(
pub fn parseDie(
fbr: *FixedBufferReader,
attrs_buf: []Die.Attr,
abbrev_table: *const Abbrev.Table,
Expand Down Expand Up @@ -1450,15 +1451,15 @@ pub const DwarfInfo = struct {
return missingDwarf();
}

fn getString(di: DwarfInfo, offset: u64) ![:0]const u8 {
pub fn getString(di: DwarfInfo, offset: u64) ![:0]const u8 {
return getStringGeneric(di.section(.debug_str), offset);
}

fn getLineString(di: DwarfInfo, offset: u64) ![:0]const u8 {
pub fn getLineString(di: DwarfInfo, offset: u64) ![:0]const u8 {
return getStringGeneric(di.section(.debug_line_str), offset);
}

fn readDebugAddr(di: DwarfInfo, compile_unit: CompileUnit, index: u64) !u64 {
pub fn readDebugAddr(di: DwarfInfo, compile_unit: CompileUnit, index: u64) !u64 {
const debug_addr = di.section(.debug_addr) orelse return badDwarf();

// addr_base points to the first item after the header, however we
Expand Down Expand Up @@ -1771,7 +1772,7 @@ pub const DwarfInfo = struct {
};

/// Returns the DWARF register number for an x86_64 register number found in compact unwind info
fn compactUnwindToDwarfRegNumber(unwind_reg_number: u3) !u8 {
pub fn compactUnwindToDwarfRegNumber(unwind_reg_number: u3) !u8 {
return switch (unwind_reg_number) {
1 => 3, // RBX
2 => 12, // R12
Expand Down Expand Up @@ -2114,7 +2115,7 @@ pub fn unwindFrameMachO(context: *UnwindContext, unwind_info: []const u8, eh_fra
return new_ip;
}

fn unwindFrameMachODwarf(context: *UnwindContext, eh_frame: []const u8, fde_offset: usize) !usize {
pub fn unwindFrameMachODwarf(context: *UnwindContext, eh_frame: []const u8, fde_offset: usize) !usize {
var di = DwarfInfo{
.endian = native_endian,
.is_macho = true,
Expand Down Expand Up @@ -2179,17 +2180,17 @@ pub fn openDwarfDebugInfo(di: *DwarfInfo, allocator: mem.Allocator) !void {

/// This function is to make it handy to comment out the return and make it
/// into a crash when working on this file.
fn badDwarf() error{InvalidDebugInfo} {
pub fn badDwarf() error{InvalidDebugInfo} {
//if (true) @panic("badDwarf"); // can be handy to uncomment when working on this file
return error.InvalidDebugInfo;
}

fn missingDwarf() error{MissingDebugInfo} {
pub fn missingDwarf() error{MissingDebugInfo} {
//if (true) @panic("missingDwarf"); // can be handy to uncomment when working on this file
return error.MissingDebugInfo;
}

fn getStringGeneric(opt_str: ?[]const u8, offset: u64) ![:0]const u8 {
pub fn getStringGeneric(opt_str: ?[]const u8, offset: u64) ![:0]const u8 {
const str = opt_str orelse return badDwarf();
if (offset > str.len) return badDwarf();
const casted_offset = math.cast(usize, offset) orelse return badDwarf();
Expand All @@ -2198,7 +2199,7 @@ fn getStringGeneric(opt_str: ?[]const u8, offset: u64) ![:0]const u8 {
return str[casted_offset..last :0];
}

const EhPointerContext = struct {
pub const EhPointerContext = struct {
// The address of the pointer field itself
pc_rel_base: u64,

Expand All @@ -2213,7 +2214,8 @@ const EhPointerContext = struct {
text_rel_base: ?u64 = null,
function_rel_base: ?u64 = null,
};
fn readEhPointer(fbr: *FixedBufferReader, enc: u8, addr_size_bytes: u8, ctx: EhPointerContext) !?u64 {

pub fn readEhPointer(fbr: *FixedBufferReader, enc: u8, addr_size_bytes: u8, ctx: EhPointerContext) !?u64 {
if (enc == EH.PE.omit) return null;

const value: union(enum) {
Expand Down Expand Up @@ -2295,7 +2297,7 @@ pub const ExceptionFrameHeader = struct {
};
}

fn isValidPtr(
pub fn isValidPtr(
self: ExceptionFrameHeader,
ptr: usize,
isValidMemory: *const fn (address: usize) bool,
Expand Down Expand Up @@ -2717,7 +2719,7 @@ pub const FrameDescriptionEntry = struct {
}
};

fn pcRelBase(field_ptr: usize, pc_rel_offset: i64) !usize {
pub fn pcRelBase(field_ptr: usize, pc_rel_offset: i64) !usize {
if (pc_rel_offset < 0) {
return math.sub(usize, field_ptr, @as(usize, @intCast(-pc_rel_offset)));
} else {
Expand All @@ -2734,12 +2736,12 @@ pub const FixedBufferReader = struct {

pub const Error = error{ EndOfBuffer, Overflow };

fn seekTo(fbr: *FixedBufferReader, pos: u64) Error!void {
pub fn seekTo(fbr: *FixedBufferReader, pos: u64) Error!void {
if (pos > fbr.buf.len) return error.EndOfBuffer;
fbr.pos = @intCast(pos);
}

fn seekForward(fbr: *FixedBufferReader, amount: u64) Error!void {
pub fn seekForward(fbr: *FixedBufferReader, amount: u64) Error!void {
if (fbr.buf.len - fbr.pos < amount) return error.EndOfBuffer;
fbr.pos += @intCast(amount);
}
Expand All @@ -2750,39 +2752,39 @@ pub const FixedBufferReader = struct {
return fbr.buf[fbr.pos];
}

fn readByteSigned(fbr: *FixedBufferReader) Error!i8 {
pub fn readByteSigned(fbr: *FixedBufferReader) Error!i8 {
return @bitCast(try fbr.readByte());
}

fn readInt(fbr: *FixedBufferReader, comptime T: type) Error!T {
pub fn readInt(fbr: *FixedBufferReader, comptime T: type) Error!T {
const size = @divExact(@typeInfo(T).Int.bits, 8);
if (fbr.buf.len - fbr.pos < size) return error.EndOfBuffer;
defer fbr.pos += size;
return mem.readInt(T, fbr.buf[fbr.pos..][0..size], fbr.endian);
}

fn readUleb128(fbr: *FixedBufferReader, comptime T: type) Error!T {
pub fn readUleb128(fbr: *FixedBufferReader, comptime T: type) Error!T {
return std.leb.readUleb128(T, fbr);
}

fn readIleb128(fbr: *FixedBufferReader, comptime T: type) Error!T {
pub fn readIleb128(fbr: *FixedBufferReader, comptime T: type) Error!T {
return std.leb.readIleb128(T, fbr);
}

fn readAddress(fbr: *FixedBufferReader, format: Format) Error!u64 {
pub fn readAddress(fbr: *FixedBufferReader, format: Format) Error!u64 {
return switch (format) {
.@"32" => try fbr.readInt(u32),
.@"64" => try fbr.readInt(u64),
};
}

fn readBytes(fbr: *FixedBufferReader, len: usize) Error![]const u8 {
pub fn readBytes(fbr: *FixedBufferReader, len: usize) Error![]const u8 {
if (fbr.buf.len - fbr.pos < len) return error.EndOfBuffer;
defer fbr.pos += len;
return fbr.buf[fbr.pos..][0..len];
}

fn readBytesTo(fbr: *FixedBufferReader, comptime sentinel: u8) Error![:sentinel]const u8 {
pub fn readBytesTo(fbr: *FixedBufferReader, comptime sentinel: u8) Error![:sentinel]const u8 {
const end = @call(.always_inline, mem.indexOfScalarPos, .{
u8,
fbr.buf,
Expand Down

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