From 0cab01adbf8ba495f214f948d34a3e6bd133bbc4 Mon Sep 17 00:00:00 2001 From: Jakub Konka Date: Mon, 6 Jun 2022 09:43:05 +0200 Subject: [PATCH] elf: refactor and enhance logging symtab --- src/link/Elf.zig | 87 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 61 insertions(+), 26 deletions(-) diff --git a/src/link/Elf.zig b/src/link/Elf.zig index 442ad73ea7..f9b6d7861a 100644 --- a/src/link/Elf.zig +++ b/src/link/Elf.zig @@ -497,7 +497,7 @@ fn makeString(self: *Elf, bytes: []const u8) !u32 { return @intCast(u32, result); } -fn getString(self: *Elf, str_off: u32) []const u8 { +fn getString(self: Elf, str_off: u32) []const u8 { assert(str_off < self.shstrtab.items.len); return mem.sliceTo(@ptrCast([*:0]const u8, self.shstrtab.items.ptr + str_off), 0); } @@ -1015,6 +1015,10 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node // mixing local and global symbols within a symbol table. try self.writeAllGlobalSymbols(); + if (build_options.enable_logging) { + self.logSymtab(); + } + if (self.dwarf) |*dw| { if (self.debug_abbrev_section_dirty) { try dw.writeDbgAbbrev(&self.base); @@ -1167,7 +1171,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node for (buf) |*shdr, i| { shdr.* = sectHeaderTo32(self.sections.items[i]); - log.debug("writing section {}", .{shdr.*}); + log.debug("writing section {s}: {}", .{ self.getString(shdr.sh_name), shdr.* }); if (foreign_endian) { mem.byteSwapAllFields(elf.Elf32_Shdr, shdr); } @@ -1180,7 +1184,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node for (buf) |*shdr, i| { shdr.* = self.sections.items[i]; - log.debug("writing section {}", .{shdr.*}); + log.debug("writing section {s}: {}", .{ self.getString(shdr.sh_name), shdr.* }); if (foreign_endian) { mem.byteSwapAllFields(elf.Elf64_Shdr, shdr); } @@ -2794,8 +2798,14 @@ fn writeSymbol(self: *Elf, index: usize) !void { if (needed_size > self.allocatedSize(syms_sect.sh_offset)) { // Move all the symbols to a new file location. const new_offset = self.findFreeSpace(needed_size, sym_align); + log.debug("moving '.symtab' from 0x{x} to 0x{x}", .{ syms_sect.sh_offset, new_offset }); const existing_size = @as(u64, syms_sect.sh_info) * sym_size; - const amt = try self.base.file.?.copyRangeAll(syms_sect.sh_offset, self.base.file.?, new_offset, existing_size); + const amt = try self.base.file.?.copyRangeAll( + syms_sect.sh_offset, + self.base.file.?, + new_offset, + existing_size, + ); if (amt != existing_size) return error.InputOutput; syms_sect.sh_offset = new_offset; } @@ -2804,30 +2814,35 @@ fn writeSymbol(self: *Elf, index: usize) !void { self.shdr_table_dirty = true; // TODO look into only writing one section } const foreign_endian = self.base.options.target.cpu.arch.endian() != builtin.cpu.arch.endian(); + const off = switch (self.ptr_width) { + .p32 => syms_sect.sh_offset + @sizeOf(elf.Elf32_Sym) * index, + .p64 => syms_sect.sh_offset + @sizeOf(elf.Elf64_Sym) * index, + }; + const local = self.local_symbols.items[index]; + log.debug("writing symbol {d}, '{s}' at 0x{x}", .{ index, self.getString(local.st_name), off }); + log.debug(" ({})", .{local}); switch (self.ptr_width) { .p32 => { var sym = [1]elf.Elf32_Sym{ .{ - .st_name = self.local_symbols.items[index].st_name, - .st_value = @intCast(u32, self.local_symbols.items[index].st_value), - .st_size = @intCast(u32, self.local_symbols.items[index].st_size), - .st_info = self.local_symbols.items[index].st_info, - .st_other = self.local_symbols.items[index].st_other, - .st_shndx = self.local_symbols.items[index].st_shndx, + .st_name = local.st_name, + .st_value = @intCast(u32, local.st_value), + .st_size = @intCast(u32, local.st_size), + .st_info = local.st_info, + .st_other = local.st_other, + .st_shndx = local.st_shndx, }, }; if (foreign_endian) { mem.byteSwapAllFields(elf.Elf32_Sym, &sym[0]); } - const off = syms_sect.sh_offset + @sizeOf(elf.Elf32_Sym) * index; try self.base.file.?.pwriteAll(mem.sliceAsBytes(sym[0..1]), off); }, .p64 => { - var sym = [1]elf.Elf64_Sym{self.local_symbols.items[index]}; + var sym = [1]elf.Elf64_Sym{local}; if (foreign_endian) { mem.byteSwapAllFields(elf.Elf64_Sym, &sym[0]); } - const off = syms_sect.sh_offset + @sizeOf(elf.Elf64_Sym) * index; try self.base.file.?.pwriteAll(mem.sliceAsBytes(sym[0..1]), off); }, } @@ -2847,8 +2862,14 @@ fn writeAllGlobalSymbols(self: *Elf) !void { if (needed_size > self.allocatedSize(syms_sect.sh_offset)) { // Move all the symbols to a new file location. const new_offset = self.findFreeSpace(needed_size, sym_align); + log.debug("moving '.symtab' from 0x{x} to 0x{x}", .{ syms_sect.sh_offset, new_offset }); const existing_size = @as(u64, syms_sect.sh_info) * sym_size; - const amt = try self.base.file.?.copyRangeAll(syms_sect.sh_offset, self.base.file.?, new_offset, existing_size); + const amt = try self.base.file.?.copyRangeAll( + syms_sect.sh_offset, + self.base.file.?, + new_offset, + existing_size, + ); if (amt != existing_size) return error.InputOutput; syms_sect.sh_offset = new_offset; } @@ -2857,19 +2878,21 @@ fn writeAllGlobalSymbols(self: *Elf) !void { const foreign_endian = self.base.options.target.cpu.arch.endian() != builtin.cpu.arch.endian(); const global_syms_off = syms_sect.sh_offset + self.local_symbols.items.len * sym_size; + log.debug("writing {d} global symbols at 0x{x}", .{ self.global_symbols.items.len, global_syms_off }); switch (self.ptr_width) { .p32 => { const buf = try self.base.allocator.alloc(elf.Elf32_Sym, self.global_symbols.items.len); defer self.base.allocator.free(buf); for (buf) |*sym, i| { + const global = self.global_symbols.items[i]; sym.* = .{ - .st_name = self.global_symbols.items[i].st_name, - .st_value = @intCast(u32, self.global_symbols.items[i].st_value), - .st_size = @intCast(u32, self.global_symbols.items[i].st_size), - .st_info = self.global_symbols.items[i].st_info, - .st_other = self.global_symbols.items[i].st_other, - .st_shndx = self.global_symbols.items[i].st_shndx, + .st_name = global.st_name, + .st_value = @intCast(u32, global.st_value), + .st_size = @intCast(u32, global.st_size), + .st_info = global.st_info, + .st_other = global.st_other, + .st_shndx = global.st_shndx, }; if (foreign_endian) { mem.byteSwapAllFields(elf.Elf32_Sym, sym); @@ -2882,13 +2905,14 @@ fn writeAllGlobalSymbols(self: *Elf) !void { defer self.base.allocator.free(buf); for (buf) |*sym, i| { + const global = self.global_symbols.items[i]; sym.* = .{ - .st_name = self.global_symbols.items[i].st_name, - .st_value = self.global_symbols.items[i].st_value, - .st_size = self.global_symbols.items[i].st_size, - .st_info = self.global_symbols.items[i].st_info, - .st_other = self.global_symbols.items[i].st_other, - .st_shndx = self.global_symbols.items[i].st_shndx, + .st_name = global.st_name, + .st_value = global.st_value, + .st_size = global.st_size, + .st_info = global.st_info, + .st_other = global.st_other, + .st_shndx = global.st_shndx, }; if (foreign_endian) { mem.byteSwapAllFields(elf.Elf64_Sym, sym); @@ -3194,3 +3218,14 @@ const CsuObjects = struct { self.crtn = crtn; } }; + +fn logSymtab(self: Elf) void { + log.debug("locals:", .{}); + for (self.local_symbols.items) |sym, id| { + log.debug(" {d}: {s}: @{x} in {d}", .{ id, self.getString(sym.st_name), sym.st_value, sym.st_shndx }); + } + log.debug("globals:", .{}); + for (self.global_symbols.items) |sym, id| { + log.debug(" {d}: {s}: @{x} in {d}", .{ id, self.getString(sym.st_name), sym.st_value, sym.st_shndx }); + } +}