Commit a9b6f2d929
Changed files (1)
lib
std
lib/std/dwarf.zig
@@ -7,6 +7,7 @@ const os = std.os;
const mem = std.mem;
const math = std.math;
const leb = @import("leb128.zig");
+const assert = std.debug.assert;
pub const TAG = @import("dwarf/TAG.zig");
pub const AT = @import("dwarf/AT.zig");
@@ -1530,45 +1531,49 @@ pub const DwarfInfo = struct {
return;
}
- if (di.section(.eh_frame)) |eh_frame| {
- var stream = io.fixedBufferStream(eh_frame);
- while (stream.pos < stream.buffer.len) {
- const entry_header = try EntryHeader.read(&stream, di.endian);
- switch (entry_header.type) {
- .cie => {
- const cie = try CommonInformationEntry.parse(
- entry_header.entry_bytes,
- -@as(i64, @intCast(@intFromPtr(binary_mem.ptr))),
- true,
- entry_header.length_offset,
- @sizeOf(usize),
- di.endian,
- );
- try di.cie_map.put(allocator, entry_header.length_offset, cie);
- },
- .fde => |cie_offset| {
- const cie = di.cie_map.get(cie_offset) orelse return badDwarf();
- const fde = try FrameDescriptionEntry.parse(
- entry_header.entry_bytes,
- -@as(i64, @intCast(@intFromPtr(binary_mem.ptr))),
- true,
- cie,
- @sizeOf(usize),
- di.endian,
- );
- try di.fde_list.append(allocator, fde);
- },
- .terminator => break,
+ const frame_sections = [2]DwarfSection{ .eh_frame, .debug_frame };
+ for (frame_sections) |frame_section| {
+ if (di.section(frame_section)) |eh_frame| {
+ var stream = io.fixedBufferStream(eh_frame);
+ while (stream.pos < stream.buffer.len) {
+ const entry_header = try EntryHeader.read(&stream, frame_section, di.endian);
+ switch (entry_header.type) {
+ .cie => {
+ const cie = try CommonInformationEntry.parse(
+ entry_header.entry_bytes,
+ -@as(i64, @intCast(@intFromPtr(binary_mem.ptr))),
+ true,
+ frame_section,
+ entry_header.length_offset,
+ @sizeOf(usize),
+ di.endian,
+ );
+ try di.cie_map.put(allocator, entry_header.length_offset, cie);
+ },
+ .fde => |cie_offset| {
+ const cie = di.cie_map.get(cie_offset) orelse return badDwarf();
+ const fde = try FrameDescriptionEntry.parse(
+ entry_header.entry_bytes,
+ -@as(i64, @intCast(@intFromPtr(binary_mem.ptr))),
+ true,
+ cie,
+ @sizeOf(usize),
+ di.endian,
+ );
+ try di.fde_list.append(allocator, fde);
+ },
+ .terminator => break,
+ }
}
- }
- // TODO: Avoiding sorting if has_eh_frame_hdr exists
- std.mem.sort(FrameDescriptionEntry, di.fde_list.items, {}, struct {
- fn lessThan(ctx: void, a: FrameDescriptionEntry, b: FrameDescriptionEntry) bool {
- _ = ctx;
- return a.pc_begin < b.pc_begin;
- }
- }.lessThan);
+ // TODO: Avoiding sorting if has_eh_frame_hdr exists
+ std.mem.sort(FrameDescriptionEntry, di.fde_list.items, {}, struct {
+ fn lessThan(ctx: void, a: FrameDescriptionEntry, b: FrameDescriptionEntry) bool {
+ _ = ctx;
+ return a.pc_begin < b.pc_begin;
+ }
+ }.lessThan);
+ }
}
}
@@ -1905,14 +1910,14 @@ pub const ExceptionFrameHeader = struct {
var eh_frame_stream = io.fixedBufferStream(eh_frame);
try eh_frame_stream.seekTo(fde_offset);
- const fde_entry_header = try EntryHeader.read(&eh_frame_stream, builtin.cpu.arch.endian());
+ const fde_entry_header = try EntryHeader.read(&eh_frame_stream, .eh_frame, builtin.cpu.arch.endian());
if (!self.isValidPtr(@intFromPtr(&fde_entry_header.entry_bytes[fde_entry_header.entry_bytes.len - 1]), isValidMemory, eh_frame_len)) return badDwarf();
if (fde_entry_header.type != .fde) return badDwarf();
// CIEs always come before FDEs (the offset is a subtration), so we can assume this memory is readable
const cie_offset = fde_entry_header.type.fde;
try eh_frame_stream.seekTo(cie_offset);
- const cie_entry_header = try EntryHeader.read(&eh_frame_stream, builtin.cpu.arch.endian());
+ const cie_entry_header = try EntryHeader.read(&eh_frame_stream, .eh_frame, builtin.cpu.arch.endian());
if (!self.isValidPtr(@intFromPtr(&cie_entry_header.entry_bytes[cie_entry_header.entry_bytes.len - 1]), isValidMemory, eh_frame_len)) return badDwarf();
if (cie_entry_header.type != .cie) return badDwarf();
@@ -1920,6 +1925,7 @@ pub const ExceptionFrameHeader = struct {
cie_entry_header.entry_bytes,
0,
true,
+ .eh_frame,
cie_entry_header.length_offset,
@sizeOf(usize),
builtin.cpu.arch.endian(),
@@ -1937,7 +1943,7 @@ pub const ExceptionFrameHeader = struct {
};
pub const EntryHeader = struct {
- /// Offset of the length in the backing buffer
+ /// Offset of the length field in the backing buffer
length_offset: usize,
is_64: bool,
type: union(enum) {
@@ -1950,8 +1956,10 @@ pub const EntryHeader = struct {
entry_bytes: []const u8,
/// Reads a header for either an FDE or a CIE, then advances the stream to the position after the trailing structure.
- /// `stream` must be a stream backed by the .eh_frame section.
- pub fn read(stream: *std.io.FixedBufferStream([]const u8), endian: std.builtin.Endian) !EntryHeader {
+ /// `stream` must be a stream backed by either the .eh_frame or .debug_frame sections.
+ pub fn read(stream: *std.io.FixedBufferStream([]const u8), dwarf_section: DwarfSection, endian: std.builtin.Endian) !EntryHeader {
+ assert(dwarf_section == .eh_frame or dwarf_section == .debug_frame);
+
const reader = stream.reader();
const length_offset = stream.pos;
@@ -1967,14 +1975,21 @@ pub const EntryHeader = struct {
const id_len = @as(u8, if (is_64) 8 else 4);
const id = if (is_64) try reader.readInt(u64, endian) else try reader.readInt(u32, endian);
const entry_bytes = stream.buffer[stream.pos..][0 .. length - id_len];
+ const cie_id: u64 = switch (dwarf_section) {
+ .eh_frame => CommonInformationEntry.eh_id,
+ .debug_frame => if (is_64) CommonInformationEntry.dwarf64_id else CommonInformationEntry.dwarf32_id,
+ else => unreachable,
+ };
const result = EntryHeader{
.length_offset = length_offset,
.is_64 = is_64,
- .type = switch (id) {
- 0 => .{ .cie = {} },
- // TODO: Support CommonInformationEntry.dwarf32_id, CommonInformationEntry.dwarf64_id
- else => .{ .fde = stream.pos - id_len - id },
+ .type = if (id == cie_id) .{ .cie = {} } else .{
+ .fde = switch (dwarf_section) {
+ .eh_frame => stream.pos - id_len - id,
+ .debug_frame => id,
+ else => unreachable,
+ },
},
.entry_bytes = entry_bytes,
};
@@ -2004,6 +2019,11 @@ pub const CommonInformationEntry = struct {
length_offset: u64,
version: u8,
+ address_size: u8,
+
+ // Only present in version 4
+ segment_selector_size: ?u8,
+
code_alignment_factor: u32,
data_alignment_factor: i32,
return_address_register: u8,
@@ -2038,11 +2058,12 @@ pub const CommonInformationEntry = struct {
/// of `pc_rel_offset` and `is_runtime`.
///
/// `length_offset` specifies the offset of this CIE's length field in the
- /// .eh_frame section.
+ /// .eh_frame / .debug_framesection.
pub fn parse(
cie_bytes: []const u8,
pc_rel_offset: i64,
is_runtime: bool,
+ dwarf_section: DwarfSection,
length_offset: u64,
addr_size_bytes: u8,
endian: std.builtin.Endian,
@@ -2053,7 +2074,11 @@ pub const CommonInformationEntry = struct {
const reader = stream.reader();
const version = try reader.readByte();
- if (version != 1 and version != 3) return error.UnsupportedDwarfVersion;
+ switch (dwarf_section) {
+ .eh_frame => if (version != 1 and version != 3) return error.UnsupportedDwarfVersion,
+ .debug_frame => if (version != 4) return error.UnsupportedDwarfVersion,
+ else => return error.UnsupportedDwarfSection,
+ }
var has_eh_data = false;
var has_aug_data = false;
@@ -2083,6 +2108,9 @@ pub const CommonInformationEntry = struct {
for (0..addr_size_bytes) |_| _ = try reader.readByte();
}
+ const address_size = if (version == 4) try reader.readByte() else addr_size_bytes;
+ const segment_selector_size = if (version == 4) try reader.readByte() else null;
+
const code_alignment_factor = try leb.readULEB128(u32, reader);
const data_alignment_factor = try leb.readILEB128(i32, reader);
const return_address_register = if (version == 1) try reader.readByte() else try leb.readULEB128(u8, reader);
@@ -2134,6 +2162,8 @@ pub const CommonInformationEntry = struct {
return .{
.length_offset = length_offset,
.version = version,
+ .address_size = address_size,
+ .segment_selector_size = segment_selector_size,
.code_alignment_factor = code_alignment_factor,
.data_alignment_factor = data_alignment_factor,
.return_address_register = return_address_register,