Commit b478a0dd1a

Jakub Konka <kubkon@jakubkonka.com>
2023-09-12 15:14:38
elf: mark imports-exports; populate symtab with objects
1 parent 962b461
Changed files (4)
src/link/Elf/Object.zig
@@ -430,7 +430,7 @@ pub fn markLive(self: *Object, elf_file: *Elf) void {
         const global = elf_file.symbol(index);
         const file = global.getFile(elf_file) orelse continue;
         const should_keep = sym.st_shndx == elf.SHN_UNDEF or
-            (sym.st_shndx == elf.SHN_COMMON and global.sourceSymbol(elf_file).st_shndx != elf.SHN_COMMON);
+            (sym.st_shndx == elf.SHN_COMMON and global.elfSym(elf_file).st_shndx != elf.SHN_COMMON);
         if (should_keep and !file.isAlive()) {
             file.setAlive();
             file.markLive(elf_file);
@@ -526,25 +526,22 @@ pub fn convertCommonSymbols(self: *Object, elf_file: *Elf) !void {
     }
 }
 
-pub fn calcSymtabSize(self: *Object, elf_file: *Elf) !void {
-    if (elf_file.options.strip_all) return;
-
+pub fn updateSymtabSize(self: *Object, elf_file: *Elf) void {
     for (self.locals()) |local_index| {
         const local = elf_file.symbol(local_index);
         if (local.atom(elf_file)) |atom| if (!atom.alive) continue;
-        const s_sym = local.getSourceSymbol(elf_file);
-        switch (s_sym.st_type()) {
+        const esym = local.elfSym(elf_file);
+        switch (esym.st_type()) {
             elf.STT_SECTION, elf.STT_NOTYPE => continue,
             else => {},
         }
         local.flags.output_symtab = true;
         self.output_symtab_size.nlocals += 1;
-        self.output_symtab_size.strsize += @as(u32, @intCast(local.getName(elf_file).len + 1));
     }
 
     for (self.globals()) |global_index| {
         const global = elf_file.symbol(global_index);
-        if (global.getFile(elf_file)) |file| if (file.getIndex() != self.index) continue;
+        if (global.file(elf_file)) |file| if (file.index() != self.index) continue;
         if (global.atom(elf_file)) |atom| if (!atom.alive) continue;
         global.flags.output_symtab = true;
         if (global.isLocal()) {
@@ -552,35 +549,28 @@ pub fn calcSymtabSize(self: *Object, elf_file: *Elf) !void {
         } else {
             self.output_symtab_size.nglobals += 1;
         }
-        self.output_symtab_size.strsize += @as(u32, @intCast(global.getName(elf_file).len + 1));
     }
 }
 
-pub fn writeSymtab(self: *Object, elf_file: *Elf, ctx: Elf.WriteSymtabCtx) !void {
-    if (elf_file.options.strip_all) return;
-
-    const gpa = elf_file.base.allocator;
-
+pub fn writeSymtab(self: *Object, elf_file: *Elf, ctx: anytype) void {
     var ilocal = ctx.ilocal;
     for (self.locals()) |local_index| {
         const local = elf_file.symbol(local_index);
         if (!local.flags.output_symtab) continue;
-        const st_name = try ctx.strtab.insert(gpa, local.getName(elf_file));
-        ctx.symtab[ilocal] = local.asElfSym(st_name, elf_file);
+        local.setOutputSym(elf_file, &ctx.symtab[ilocal]);
         ilocal += 1;
     }
 
     var iglobal = ctx.iglobal;
     for (self.globals()) |global_index| {
         const global = elf_file.symbol(global_index);
-        if (global.getFile(elf_file)) |file| if (file.getIndex() != self.index) continue;
+        if (global.file(elf_file)) |file| if (file.index() != self.index) continue;
         if (!global.flags.output_symtab) continue;
-        const st_name = try ctx.strtab.insert(gpa, global.getName(elf_file));
         if (global.isLocal()) {
-            ctx.symtab[ilocal] = global.asElfSym(st_name, elf_file);
+            global.setOutputSym(elf_file, &ctx.symtab[ilocal]);
             ilocal += 1;
         } else {
-            ctx.symtab[iglobal] = global.asElfSym(st_name, elf_file);
+            global.setOutputSym(elf_file, &ctx.symtab[iglobal]);
             iglobal += 1;
         }
     }
src/link/Elf/Symbol.zig
@@ -20,7 +20,7 @@ atom_index: Atom.Index = 0,
 output_section_index: u16 = 0,
 
 /// Index of the source symbol this symbol references.
-/// Use `sourceSymbol` to pull the source symbol from the relevant file.
+/// Use `elfSym` to pull the source symbol from the relevant file.
 esym_index: Index = 0,
 
 /// Index of the source version symbol this symbol references if any.
@@ -48,7 +48,7 @@ pub inline fn isIFunc(symbol: Symbol, elf_file: *Elf) bool {
 }
 
 pub fn @"type"(symbol: Symbol, elf_file: *Elf) u4 {
-    const s_sym = symbol.sourceSymbol(elf_file);
+    const s_sym = symbol.elfSym(elf_file);
     // const file_ptr = symbol.file(elf_file).?;
     // if (s_sym.st_type() == elf.STT_GNU_IFUNC and file_ptr == .shared) return elf.STT_FUNC;
     return s_sym.st_type();
@@ -66,7 +66,7 @@ pub fn file(symbol: Symbol, elf_file: *Elf) ?File {
     return elf_file.file(symbol.file_index);
 }
 
-pub fn sourceSymbol(symbol: Symbol, elf_file: *Elf) elf.Elf64_Sym {
+pub fn elfSym(symbol: Symbol, elf_file: *Elf) elf.Elf64_Sym {
     const file_ptr = symbol.file(elf_file).?;
     switch (file_ptr) {
         .zig_module => |x| {
@@ -82,7 +82,7 @@ pub fn sourceSymbol(symbol: Symbol, elf_file: *Elf) elf.Elf64_Sym {
 
 pub fn symbolRank(symbol: Symbol, elf_file: *Elf) u32 {
     const file_ptr = symbol.file(elf_file) orelse return std.math.maxInt(u32);
-    const sym = symbol.sourceSymbol(elf_file);
+    const sym = symbol.elfSym(elf_file);
     const in_archive = switch (file_ptr) {
         .object => |x| !x.alive,
         else => false,
@@ -173,13 +173,13 @@ pub fn setOutputSym(symbol: Symbol, elf_file: *Elf, out: *elf.Elf64_Sym) void {
         out.* = Elf.null_sym;
         return;
     };
-    const s_sym = symbol.sourceSymbol(elf_file);
+    const esym = symbol.elfSym(elf_file);
     const st_type = symbol.type(elf_file);
     const st_bind: u8 = blk: {
         if (symbol.isLocal()) break :blk 0;
         if (symbol.flags.weak) break :blk elf.STB_WEAK;
         // if (file_ptr == .shared) break :blk elf.STB_GLOBAL;
-        break :blk s_sym.st_bind();
+        break :blk esym.st_bind();
     };
     const st_shndx = blk: {
         // if (symbol.flags.copy_rel) break :blk elf_file.copy_rel_sect_index.?;
@@ -202,10 +202,10 @@ pub fn setOutputSym(symbol: Symbol, elf_file: *Elf, out: *elf.Elf64_Sym) void {
     out.* = .{
         .st_name = symbol.name_offset,
         .st_info = (st_bind << 4) | st_type,
-        .st_other = s_sym.st_other,
+        .st_other = esym.st_other,
         .st_shndx = st_shndx,
         .st_value = st_value,
-        .st_size = s_sym.st_size,
+        .st_size = esym.st_size,
     };
 }
 
@@ -274,7 +274,7 @@ fn format2(
     try writer.print("%{d} : {s} : @{x}", .{ symbol.index, symbol.fmtName(ctx.elf_file), symbol.value });
     if (symbol.file(ctx.elf_file)) |file_ptr| {
         if (symbol.isAbs(ctx.elf_file)) {
-            if (symbol.sourceSymbol(ctx.elf_file).st_shndx == elf.SHN_UNDEF) {
+            if (symbol.elfSym(ctx.elf_file).st_shndx == elf.SHN_UNDEF) {
                 try writer.writeAll(" : undef");
             } else {
                 try writer.writeAll(" : absolute");
src/link/Elf/ZigModule.zig
@@ -105,7 +105,7 @@ pub fn resolveSymbols(self: *ZigModule, elf_file: *Elf) void {
 pub fn updateSymtabSize(self: *ZigModule, elf_file: *Elf) void {
     for (self.locals()) |local_index| {
         const local = elf_file.symbol(local_index);
-        const esym = local.sourceSymbol(elf_file);
+        const esym = local.elfSym(elf_file);
         switch (esym.st_type()) {
             elf.STT_SECTION, elf.STT_NOTYPE => {
                 local.flags.output_symtab = false;
src/link/Elf.zig
@@ -1047,6 +1047,7 @@ pub fn flushModule(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node
 
     // Resolve symbols
     self.resolveSymbols();
+    self.markImportsExports();
 
     if (self.unresolved.keys().len > 0) try self.reportUndefined();
 
@@ -1336,6 +1337,52 @@ fn resolveSymbols(self: *Elf) void {
     }
 }
 
+fn markImportsExports(self: *Elf) void {
+    const is_dyn_lib = self.base.options.output_mode == .Lib and self.base.options.link_mode == .Dynamic;
+
+    if (self.zig_module_index) |index| {
+        const zig_module = self.file(index).?.zig_module;
+        for (zig_module.globals()) |global_index| {
+            const global = self.symbol(global_index);
+            if (global.version_index == elf.VER_NDX_LOCAL) continue;
+            const file_ptr = global.file(self) orelse continue;
+            const vis = @as(elf.STV, @enumFromInt(global.elfSym(self).st_other));
+            if (vis == .HIDDEN) continue;
+            // if (file == .shared and !global.isAbs(self)) {
+            //     global.flags.import = true;
+            //     continue;
+            // }
+            if (file_ptr.index() == index) {
+                global.flags.@"export" = true;
+                if (is_dyn_lib and vis != .PROTECTED) {
+                    global.flags.import = true;
+                }
+            }
+        }
+    }
+
+    for (self.objects.items) |index| {
+        const object = self.file(index).?.object;
+        for (object.globals()) |global_index| {
+            const global = self.symbol(global_index);
+            if (global.version_index == elf.VER_NDX_LOCAL) continue;
+            const file_ptr = global.file(self) orelse continue;
+            const vis = @as(elf.STV, @enumFromInt(global.elfSym(self).st_other));
+            if (vis == .HIDDEN) continue;
+            // if (file == .shared and !global.isAbs(self)) {
+            //     global.flags.import = true;
+            //     continue;
+            // }
+            if (file_ptr.index() == index) {
+                global.flags.@"export" = true;
+                if (is_dyn_lib and vis != .PROTECTED) {
+                    global.flags.import = true;
+                }
+            }
+        }
+    }
+}
+
 fn linkWithLLD(self: *Elf, comp: *Compilation, prog_node: *std.Progress.Node) !void {
     const tracy = trace(@src());
     defer tracy.end();
@@ -2941,6 +2988,13 @@ fn updateSymtabSize(self: *Elf) !void {
         sizes.nglobals += zig_module.output_symtab_size.nglobals;
     }
 
+    for (self.objects.items) |index| {
+        const object = self.file(index).?.object;
+        object.updateSymtabSize(self);
+        sizes.nlocals += object.output_symtab_size.nlocals;
+        sizes.nglobals += object.output_symtab_size.nglobals;
+    }
+
     if (self.got_section_index) |_| {
         self.got.updateSymtabSize(self);
         sizes.nlocals += self.got.output_symtab_size.nlocals;
@@ -2996,6 +3050,13 @@ fn writeSymtab(self: *Elf) !void {
         ctx.iglobal += zig_module.output_symtab_size.nglobals;
     }
 
+    for (self.objects.items) |index| {
+        const object = self.file(index).?.object;
+        object.writeSymtab(self, ctx);
+        ctx.ilocal += object.output_symtab_size.nlocals;
+        ctx.iglobal += object.output_symtab_size.nglobals;
+    }
+
     if (self.got_section_index) |_| {
         try self.got.writeSymtab(self, ctx);
         ctx.ilocal += self.got.output_symtab_size.nlocals;