Commit ce88df497c

Jakub Konka <kubkon@jakubkonka.com>
2023-09-13 19:51:19
elf: do not store Symbol's index in Symbol
1 parent dbde746
Changed files (9)
src/arch/aarch64/CodeGen.zig
@@ -4316,7 +4316,7 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallModifier
             if (self.bin_file.cast(link.File.Elf)) |elf_file| {
                 const sym_index = try elf_file.getOrCreateMetadataForDecl(func.owner_decl);
                 const sym = elf_file.symbol(sym_index);
-                _ = try sym.getOrCreateGotEntry(elf_file);
+                _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
                 const got_addr = @as(u32, @intCast(sym.gotAddress(elf_file)));
                 try self.genSetReg(Type.usize, .x30, .{ .memory = got_addr });
             } else if (self.bin_file.cast(link.File.MachO)) |macho_file| {
src/arch/arm/CodeGen.zig
@@ -4296,7 +4296,7 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallModifier
             if (self.bin_file.cast(link.File.Elf)) |elf_file| {
                 const sym_index = try elf_file.getOrCreateMetadataForDecl(func.owner_decl);
                 const sym = elf_file.symbol(sym_index);
-                _ = try sym.getOrCreateGotEntry(elf_file);
+                _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
                 const got_addr = @as(u32, @intCast(sym.gotAddress(elf_file)));
                 try self.genSetReg(Type.usize, .lr, .{ .memory = got_addr });
             } else if (self.bin_file.cast(link.File.MachO)) |_| {
src/arch/riscv64/CodeGen.zig
@@ -1749,7 +1749,7 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallModifier
                 .func => |func| {
                     const sym_index = try elf_file.getOrCreateMetadataForDecl(func.owner_decl);
                     const sym = elf_file.symbol(sym_index);
-                    _ = try sym.getOrCreateGotEntry(elf_file);
+                    _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
                     const got_addr = @as(u32, @intCast(sym.gotAddress(elf_file)));
                     try self.genSetReg(Type.usize, .ra, .{ .memory = got_addr });
                     _ = try self.addInst(.{
src/arch/sparc64/CodeGen.zig
@@ -1351,7 +1351,7 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallModifier
                     const got_addr = if (self.bin_file.cast(link.File.Elf)) |elf_file| blk: {
                         const sym_index = try elf_file.getOrCreateMetadataForDecl(func.owner_decl);
                         const sym = elf_file.symbol(sym_index);
-                        _ = try sym.getOrCreateGotEntry(elf_file);
+                        _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
                         break :blk @as(u32, @intCast(sym.gotAddress(elf_file)));
                     } else unreachable;
 
src/arch/x86_64/CodeGen.zig
@@ -8157,7 +8157,7 @@ fn airCall(self: *Self, inst: Air.Inst.Index, modifier: std.builtin.CallModifier
                 const sym_index = try elf_file.getOrCreateMetadataForDecl(owner_decl);
                 const sym = elf_file.symbol(sym_index);
                 sym.flags.needs_got = true;
-                _ = try sym.getOrCreateGotEntry(elf_file);
+                _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
                 const got_addr = sym.gotAddress(elf_file);
                 try self.asmMemory(.{ ._, .call }, Memory.sib(.qword, .{
                     .base = .{ .reg = .ds },
@@ -10236,7 +10236,7 @@ fn genLazySymbolRef(
             return self.fail("{s} creating lazy symbol", .{@errorName(err)});
         const sym = elf_file.symbol(sym_index);
         sym.flags.needs_got = true;
-        _ = try sym.getOrCreateGotEntry(elf_file);
+        _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
         const got_addr = sym.gotAddress(elf_file);
         const got_mem =
             Memory.sib(.qword, .{ .base = .{ .reg = .ds }, .disp = @intCast(got_addr) });
src/link/Elf/Atom.zig
@@ -322,11 +322,12 @@ pub fn scanRelocs(self: Atom, elf_file: *Elf, undefs: anytype) !void {
 
         if (rel.r_type() == elf.R_X86_64_NONE) continue;
 
-        const symbol = switch (file_ptr) {
-            .zig_module => |x| elf_file.symbol(x.symbol(rel.r_sym())),
-            .object => |x| elf_file.symbol(x.symbols.items[rel.r_sym()]),
+        const symbol_index = switch (file_ptr) {
+            .zig_module => |x| x.symbol(rel.r_sym()),
+            .object => |x| x.symbols.items[rel.r_sym()],
             else => unreachable,
         };
+        const symbol = elf_file.symbol(symbol_index);
 
         // Check for violation of One Definition Rule for COMDATs.
         if (symbol.file(elf_file) == null) {
@@ -340,7 +341,7 @@ pub fn scanRelocs(self: Atom, elf_file: *Elf, undefs: anytype) !void {
         }
 
         // Report an undefined symbol.
-        try self.reportUndefined(elf_file, symbol, rel, undefs);
+        try self.reportUndefined(elf_file, symbol, symbol_index, rel, undefs);
 
         // While traversing relocations, mark symbols that require special handling such as
         // pointer indirection via GOT, or a stub trampoline via PLT.
@@ -379,7 +380,14 @@ pub fn scanRelocs(self: Atom, elf_file: *Elf, undefs: anytype) !void {
 }
 
 // This function will report any undefined non-weak symbols that are not imports.
-fn reportUndefined(self: Atom, elf_file: *Elf, sym: *const Symbol, rel: elf.Elf64_Rela, undefs: anytype) !void {
+fn reportUndefined(
+    self: Atom,
+    elf_file: *Elf,
+    sym: *const Symbol,
+    sym_index: Symbol.Index,
+    rel: elf.Elf64_Rela,
+    undefs: anytype,
+) !void {
     const rel_esym = switch (elf_file.file(self.file_index).?) {
         .zig_module => |x| x.elfSym(rel.r_sym()).*,
         .object => |x| x.symtab[rel.r_sym()],
@@ -392,7 +400,7 @@ fn reportUndefined(self: Atom, elf_file: *Elf, sym: *const Symbol, rel: elf.Elf6
         !sym.flags.import and
         esym.st_shndx == elf.SHN_UNDEF)
     {
-        const gop = try undefs.getOrPut(sym.index);
+        const gop = try undefs.getOrPut(sym_index);
         if (!gop.found_existing) {
             gop.value_ptr.* = std.ArrayList(Atom.Index).init(elf_file.base.allocator);
         }
src/link/Elf/Symbol.zig
@@ -1,7 +1,5 @@
 //! Represents a defined symbol.
 
-index: Index = 0,
-
 /// Allocated address value of this symbol.
 value: u64 = 0,
 
@@ -117,10 +115,10 @@ const GetOrCreateGotEntryResult = struct {
     index: GotSection.Index,
 };
 
-pub fn getOrCreateGotEntry(symbol: *Symbol, elf_file: *Elf) !GetOrCreateGotEntryResult {
+pub fn getOrCreateGotEntry(symbol: *Symbol, symbol_index: Index, elf_file: *Elf) !GetOrCreateGotEntryResult {
     assert(symbol.flags.needs_got);
     if (symbol.flags.has_got) return .{ .found_existing = true, .index = symbol.extra(elf_file).?.got };
-    const index = try elf_file.got.addGotSymbol(symbol.index, elf_file);
+    const index = try elf_file.got.addGotSymbol(symbol_index, elf_file);
     symbol.flags.has_got = true;
     return .{ .found_existing = false, .index = index };
 }
@@ -270,7 +268,7 @@ fn format2(
     _ = options;
     _ = unused_fmt_string;
     const symbol = ctx.symbol;
-    try writer.print("%{d} : {s} : @{x}", .{ symbol.index, symbol.fmtName(ctx.elf_file), symbol.value });
+    try writer.print("%{d} : {s} : @{x}", .{ symbol.esym_index, symbol.fmtName(ctx.elf_file), symbol.value });
     if (symbol.file(ctx.elf_file)) |file_ptr| {
         if (symbol.isAbs(ctx.elf_file)) {
             if (symbol.elfSym(ctx.elf_file).st_shndx == elf.SHN_UNDEF) {
src/link/Elf.zig
@@ -1082,9 +1082,10 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
         if (comp.compiler_rt_obj) |x| break :blk x.full_object_path;
         break :blk null;
     };
-    if (compiler_rt_path) |path| {
-        try positionals.append(.{ .path = path });
-    }
+    _ = compiler_rt_path;
+    // if (compiler_rt_path) |path| {
+    //     try positionals.append(.{ .path = path });
+    // }
 
     for (positionals.items) |obj| {
         const in_file = try std.fs.cwd().openFile(obj.path, .{});
@@ -1643,11 +1644,11 @@ fn scanRelocs(self: *Elf) !void {
 
     try self.reportUndefined(&undefs);
 
-    for (self.symbols.items) |*sym| {
+    for (self.symbols.items, 0..) |*sym, sym_index| {
         if (sym.flags.needs_got) {
             log.debug("'{s}' needs GOT", .{sym.name(self)});
             // TODO how can we tell we need to write it again, aka the entry is dirty?
-            const gop = try sym.getOrCreateGotEntry(self);
+            const gop = try sym.getOrCreateGotEntry(@intCast(sym_index), self);
             try self.got.writeEntry(self, gop.index);
         }
     }
@@ -2695,7 +2696,7 @@ fn updateDeclCode(
         esym.st_value = atom_ptr.value;
 
         sym.flags.needs_got = true;
-        const gop = try sym.getOrCreateGotEntry(self);
+        const gop = try sym.getOrCreateGotEntry(sym_index, self);
         try self.got.writeEntry(self, gop.index);
     }
 
@@ -2930,7 +2931,7 @@ fn updateLazySymbol(self: *Elf, sym: link.File.LazySymbol, symbol_index: Symbol.
     local_esym.st_value = atom_ptr.value;
 
     local_sym.flags.needs_got = true;
-    const gop = try local_sym.getOrCreateGotEntry(self);
+    const gop = try local_sym.getOrCreateGotEntry(symbol_index, self);
     try self.got.writeEntry(self, gop.index);
 
     const section_offset = atom_ptr.value - self.phdrs.items[phdr_index].p_vaddr;
@@ -3801,7 +3802,7 @@ pub fn addSymbol(self: *Elf) !Symbol.Index {
             break :blk index;
         }
     };
-    self.symbols.items[index] = .{ .index = index };
+    self.symbols.items[index] = .{};
     return index;
 }
 
src/codegen.zig
@@ -861,7 +861,7 @@ fn genDeclRef(
         const sym_index = try elf_file.getOrCreateMetadataForDecl(decl_index);
         const sym = elf_file.symbol(sym_index);
         sym.flags.needs_got = true;
-        _ = try sym.getOrCreateGotEntry(elf_file);
+        _ = try sym.getOrCreateGotEntry(sym_index, elf_file);
         return GenResult.mcv(.{ .memory = sym.gotAddress(elf_file) });
     } else if (bin_file.cast(link.File.MachO)) |macho_file| {
         const atom_index = try macho_file.getOrCreateAtomForDecl(decl_index);