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elf: refactor tracking debug section sizes
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@kubkon
kubkon committed Aug 21, 2024
1 parent db48a78 commit e79ac14
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Showing 3 changed files with 46 additions and 96 deletions.
68 changes: 30 additions & 38 deletions src/link/Elf.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4184,26 +4184,21 @@ pub fn allocateNonAllocSections(self: *Elf) !void {
shdr.sh_offset,
new_offset,
});
const zig_object = self.zigObjectPtr().?;
const existing_size = blk: {
if (shndx == self.debug_info_section_index.?)
break :blk zig_object.debug_info_section_zig_size;
if (shndx == self.debug_abbrev_section_index.?)
break :blk zig_object.debug_abbrev_section_zig_size;
if (shndx == self.debug_str_section_index.?)
break :blk zig_object.debug_str_section_zig_size;
if (shndx == self.debug_aranges_section_index.?)
break :blk zig_object.debug_aranges_section_zig_size;
if (shndx == self.debug_line_section_index.?)
break :blk zig_object.debug_line_section_zig_size;
if (shndx == self.debug_line_str_section_index.?)
break :blk zig_object.debug_line_str_section_zig_size;
if (shndx == self.debug_loclists_section_index.?)
break :blk zig_object.debug_loclists_section_zig_size;
if (shndx == self.debug_rnglists_section_index.?)
break :blk zig_object.debug_rnglists_section_zig_size;
unreachable;
};
const zo = self.zigObjectPtr().?;
const existing_size = for ([_]Symbol.Index{
zo.debug_info_index.?,
zo.debug_abbrev_index.?,
zo.debug_aranges_index.?,
zo.debug_str_index.?,
zo.debug_line_index.?,
zo.debug_line_str_index.?,
zo.debug_loclists_index.?,
zo.debug_rnglists_index.?,
}) |sym_index| {
const sym = zo.symbol(sym_index);
const atom_ptr = sym.atom(self).?;
if (atom_ptr.output_section_index == shndx) break atom_ptr.size;
} else 0;
const amt = try self.base.file.?.copyRangeAll(
shdr.sh_offset,
self.base.file.?,
Expand Down Expand Up @@ -4299,24 +4294,21 @@ fn writeAtoms(self: *Elf) !void {

// TODO really, really handle debug section separately
const base_offset = if (self.isDebugSection(@intCast(shndx))) blk: {
const zig_object = self.zigObjectPtr().?;
if (shndx == self.debug_info_section_index.?)
break :blk zig_object.debug_info_section_zig_size;
if (shndx == self.debug_abbrev_section_index.?)
break :blk zig_object.debug_abbrev_section_zig_size;
if (shndx == self.debug_str_section_index.?)
break :blk zig_object.debug_str_section_zig_size;
if (shndx == self.debug_aranges_section_index.?)
break :blk zig_object.debug_aranges_section_zig_size;
if (shndx == self.debug_line_section_index.?)
break :blk zig_object.debug_line_section_zig_size;
if (shndx == self.debug_line_str_section_index.?)
break :blk zig_object.debug_line_str_section_zig_size;
if (shndx == self.debug_loclists_section_index.?)
break :blk zig_object.debug_loclists_section_zig_size;
if (shndx == self.debug_rnglists_section_index.?)
break :blk zig_object.debug_rnglists_section_zig_size;
unreachable;
const zo = self.zigObjectPtr().?;
break :blk for ([_]Symbol.Index{
zo.debug_info_index.?,
zo.debug_abbrev_index.?,
zo.debug_aranges_index.?,
zo.debug_str_index.?,
zo.debug_line_index.?,
zo.debug_line_str_index.?,
zo.debug_loclists_index.?,
zo.debug_rnglists_index.?,
}) |sym_index| {
const sym = zo.symbol(sym_index);
const atom_ptr = sym.atom(self).?;
if (atom_ptr.output_section_index == shndx) break atom_ptr.size;
} else 0;
} else 0;
const sh_offset = shdr.sh_offset + base_offset;
const sh_size = math.cast(usize, shdr.sh_size - base_offset) orelse return error.Overflow;
Expand Down
40 changes: 0 additions & 40 deletions src/link/Elf/ZigObject.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -59,17 +59,6 @@ debug_line_str_index: ?Symbol.Index = null,
debug_loclists_index: ?Symbol.Index = null,
debug_rnglists_index: ?Symbol.Index = null,

/// Size contribution of Zig's metadata to each debug section.
/// Used to track start of metadata from input object files.
debug_info_section_zig_size: u64 = 0,
debug_abbrev_section_zig_size: u64 = 0,
debug_str_section_zig_size: u64 = 0,
debug_aranges_section_zig_size: u64 = 0,
debug_line_section_zig_size: u64 = 0,
debug_line_str_section_zig_size: u64 = 0,
debug_loclists_section_zig_size: u64 = 0,
debug_rnglists_section_zig_size: u64 = 0,

pub const global_symbol_bit: u32 = 0x80000000;
pub const symbol_mask: u32 = 0x7fffffff;
pub const SHN_ATOM: u16 = 0x100;
Expand Down Expand Up @@ -328,8 +317,6 @@ pub fn flushModule(self: *ZigObject, elf_file: *Elf, tid: Zcu.PerThread.Id) !voi
self.debug_aranges_section_dirty = false;
self.debug_rnglists_section_dirty = false;
self.debug_str_section_dirty = false;

self.saveDebugSectionsSizes(elf_file);
}

// The point of flushModule() is to commit changes, so in theory, nothing should
Expand All @@ -342,33 +329,6 @@ pub fn flushModule(self: *ZigObject, elf_file: *Elf, tid: Zcu.PerThread.Id) !voi
assert(!self.debug_str_section_dirty);
}

fn saveDebugSectionsSizes(self: *ZigObject, elf_file: *Elf) void {
if (elf_file.debug_info_section_index) |shndx| {
self.debug_info_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_abbrev_section_index) |shndx| {
self.debug_abbrev_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_str_section_index) |shndx| {
self.debug_str_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_aranges_section_index) |shndx| {
self.debug_aranges_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_line_section_index) |shndx| {
self.debug_line_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_line_str_section_index) |shndx| {
self.debug_line_str_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_loclists_section_index) |shndx| {
self.debug_loclists_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
if (elf_file.debug_rnglists_section_index) |shndx| {
self.debug_rnglists_section_zig_size = elf_file.shdrs.items[shndx].sh_size;
}
}

fn newSymbol(self: *ZigObject, allocator: Allocator, name_off: u32, st_bind: u4) !Symbol.Index {
try self.symtab.ensureUnusedCapacity(allocator, 1);
try self.symbols.ensureUnusedCapacity(allocator, 1);
Expand Down
34 changes: 16 additions & 18 deletions src/link/Elf/relocatable.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -431,24 +431,21 @@ fn writeAtoms(elf_file: *Elf) !void {

// TODO really, really handle debug section separately
const base_offset = if (elf_file.isDebugSection(@intCast(shndx))) blk: {
const zig_object = elf_file.zigObjectPtr().?;
if (shndx == elf_file.debug_info_section_index.?)
break :blk zig_object.debug_info_section_zig_size;
if (shndx == elf_file.debug_abbrev_section_index.?)
break :blk zig_object.debug_abbrev_section_zig_size;
if (shndx == elf_file.debug_str_section_index.?)
break :blk zig_object.debug_str_section_zig_size;
if (shndx == elf_file.debug_aranges_section_index.?)
break :blk zig_object.debug_aranges_section_zig_size;
if (shndx == elf_file.debug_line_section_index.?)
break :blk zig_object.debug_line_section_zig_size;
if (shndx == elf_file.debug_line_str_section_index.?)
break :blk zig_object.debug_line_str_section_zig_size;
if (shndx == elf_file.debug_loclists_section_index.?)
break :blk zig_object.debug_loclists_section_zig_size;
if (shndx == elf_file.debug_rnglists_section_index.?)
break :blk zig_object.debug_rnglists_section_zig_size;
unreachable;
const zo = elf_file.zigObjectPtr().?;
break :blk for ([_]Symbol.Index{
zo.debug_info_index.?,
zo.debug_abbrev_index.?,
zo.debug_aranges_index.?,
zo.debug_str_index.?,
zo.debug_line_index.?,
zo.debug_line_str_index.?,
zo.debug_loclists_index.?,
zo.debug_rnglists_index.?,
}) |sym_index| {
const sym = zo.symbol(sym_index);
const atom_ptr = sym.atom(elf_file).?;
if (atom_ptr.output_section_index == shndx) break atom_ptr.size;
} else 0;
} else 0;
const sh_offset = shdr.sh_offset + base_offset;
const sh_size = math.cast(usize, shdr.sh_size - base_offset) orelse return error.Overflow;
Expand Down Expand Up @@ -594,3 +591,4 @@ const Compilation = @import("../../Compilation.zig");
const Elf = @import("../Elf.zig");
const File = @import("file.zig").File;
const Object = @import("Object.zig");
const Symbol = @import("Symbol.zig");

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