Commit b25efb86e1

@@ -2120,22 +2120,28 @@ fn airCall(func: *CodeGen, inst: Air.Inst.Index, modifier: std.builtin.CallModif
         const module = func.bin_file.base.options.module.?;
 
         if (func_val.castTag(.function)) |function| {
-            break :blk module.declPtr(function.data.owner_decl);
+            const decl = module.declPtr(function.data.owner_decl);
+            try decl.link.wasm.ensureInitialized(func.bin_file);
+            break :blk decl;
         } else if (func_val.castTag(.extern_fn)) |extern_fn| {
             const ext_decl = module.declPtr(extern_fn.data.owner_decl);
             const ext_info = ext_decl.ty.fnInfo();
             var func_type = try genFunctype(func.gpa, ext_info.cc, ext_info.param_types, ext_info.return_type, func.target);
             defer func_type.deinit(func.gpa);
+            const atom = &ext_decl.link.wasm;
+            try atom.ensureInitialized(func.bin_file);
             ext_decl.fn_link.wasm.type_index = try func.bin_file.putOrGetFuncType(func_type);
             try func.bin_file.addOrUpdateImport(
                 mem.sliceTo(ext_decl.name, 0),
-                ext_decl.link.wasm.sym_index,
+                atom.getSymbolIndex().?,
                 ext_decl.getExternFn().?.lib_name,
                 ext_decl.fn_link.wasm.type_index,
             );
             break :blk ext_decl;
         } else if (func_val.castTag(.decl_ref)) |decl_ref| {
-            break :blk module.declPtr(decl_ref.data);
+            const decl = module.declPtr(decl_ref.data);
+            try decl.link.wasm.ensureInitialized(func.bin_file);
+            break :blk decl;
         }
         return func.fail("Expected a function, but instead found type '{}'", .{func_val.tag()});
     };
@@ -2752,6 +2758,7 @@ fn lowerDeclRefValue(func: *CodeGen, tv: TypedValue, decl_index: Module.Decl.Ind
     }
 
     module.markDeclAlive(decl);
+    try decl.link.wasm.ensureInitialized(func.bin_file);
 
     const target_sym_index = decl.link.wasm.sym_index;
     if (decl.ty.zigTypeTag() == .Fn) {

@@ -95,6 +95,17 @@ pub fn symbolLoc(atom: Atom) Wasm.SymbolLoc {
     return .{ .file = atom.file, .index = atom.sym_index };
 }
 
+pub fn ensureInitialized(atom: *Atom, wasm_bin: *Wasm) !void {
+    if (atom.getSymbolIndex() != null) return; // already initialized
+    atom.sym_index = try wasm_bin.allocateSymbol();
+    try wasm_bin.symbol_atom.putNoClobber(wasm_bin.base.allocator, atom.symbolLoc(), atom);
+}
+
+pub fn getSymbolIndex(atom: Atom) ?u32 {
+    if (atom.sym_index == 0) return null;
+    return atom.sym_index;
+}
+
 /// Returns the virtual address of the `Atom`. This is the address starting
 /// from the first entry within a section.
 pub fn getVA(atom: Atom, wasm: *const Wasm, symbol: *const Symbol) u32 {

@@ -986,31 +986,23 @@ pub fn deinit(wasm: *Wasm) void {
     }
 }
 
-pub fn allocateDeclIndexes(wasm: *Wasm, decl_index: Module.Decl.Index) !void {
-    if (wasm.llvm_object) |_| return;
-    const decl = wasm.base.options.module.?.declPtr(decl_index);
-    if (decl.link.wasm.sym_index != 0) return;
-
+/// Allocates a new symbol and returns its index.
+/// Will re-use slots when a symbol was freed at an earlier stage.
+pub fn allocateSymbol(wasm: *Wasm) !u32 {
     try wasm.symbols.ensureUnusedCapacity(wasm.base.allocator, 1);
-    try wasm.decls.putNoClobber(wasm.base.allocator, decl_index, {});
-
-    const atom = &decl.link.wasm;
-
     var symbol: Symbol = .{
         .name = undefined, // will be set after updateDecl
         .flags = @enumToInt(Symbol.Flag.WASM_SYM_BINDING_LOCAL),
         .tag = undefined, // will be set after updateDecl
         .index = undefined, // will be set after updateDecl
     };
-
     if (wasm.symbols_free_list.popOrNull()) |index| {
-        atom.sym_index = index;
         wasm.symbols.items[index] = symbol;
-    } else {
-        atom.sym_index = @intCast(u32, wasm.symbols.items.len);
-        wasm.symbols.appendAssumeCapacity(symbol);
+        return index;
     }
-    try wasm.symbol_atom.putNoClobber(wasm.base.allocator, atom.symbolLoc(), atom);
+    const index = @intCast(u32, wasm.symbols.items.len);
+    wasm.symbols.appendAssumeCapacity(symbol);
+    return index;
 }
 
 pub fn updateFunc(wasm: *Wasm, mod: *Module, func: *Module.Fn, air: Air, liveness: Liveness) !void {
@@ -1026,9 +1018,12 @@ pub fn updateFunc(wasm: *Wasm, mod: *Module, func: *Module.Fn, air: Air, livenes
 
     const decl_index = func.owner_decl;
     const decl = mod.declPtr(decl_index);
-    assert(decl.link.wasm.sym_index != 0); // Must call allocateDeclIndexes()
-
-    decl.link.wasm.clear();
+    const atom = &decl.link.wasm;
+    try atom.ensureInitialized(wasm);
+    const gop = try wasm.decls.getOrPut(wasm.base.allocator, decl_index);
+    if (gop.found_existing) {
+        atom.clear();
+    } else gop.value_ptr.* = {};
 
     var decl_state: ?Dwarf.DeclState = if (wasm.dwarf) |*dwarf| try dwarf.initDeclState(mod, decl_index) else null;
     defer if (decl_state) |*ds| ds.deinit();
@@ -1083,16 +1078,19 @@ pub fn updateDecl(wasm: *Wasm, mod: *Module, decl_index: Module.Decl.Index) !voi
     defer tracy.end();
 
     const decl = mod.declPtr(decl_index);
-    assert(decl.link.wasm.sym_index != 0); // Must call allocateDeclIndexes()
-
-    decl.link.wasm.clear();
-
     if (decl.val.castTag(.function)) |_| {
         return;
     } else if (decl.val.castTag(.extern_fn)) |_| {
         return;
     }
 
+    const atom = &decl.link.wasm;
+    try atom.ensureInitialized(wasm);
+    const gop = try wasm.decls.getOrPut(wasm.base.allocator, decl_index);
+    if (gop.found_existing) {
+        atom.clear();
+    } else gop.value_ptr.* = {};
+
     if (decl.isExtern()) {
         const variable = decl.getVariable().?;
         const name = mem.sliceTo(decl.name, 0);
@@ -1148,8 +1146,8 @@ fn finishUpdateDecl(wasm: *Wasm, decl: *Module.Decl, code: []const u8) !void {
     try atom.code.appendSlice(wasm.base.allocator, code);
     try wasm.resolved_symbols.put(wasm.base.allocator, atom.symbolLoc(), {});
 
-    if (code.len == 0) return;
     atom.size = @intCast(u32, code.len);
+    if (code.len == 0) return;
     atom.alignment = decl.ty.abiAlignment(wasm.base.options.target);
 }
 
@@ -1211,28 +1209,19 @@ pub fn lowerUnnamedConst(wasm: *Wasm, tv: TypedValue, decl_index: Module.Decl.In
     defer wasm.base.allocator.free(fqdn);
     const name = try std.fmt.allocPrintZ(wasm.base.allocator, "__unnamed_{s}_{d}", .{ fqdn, local_index });
     defer wasm.base.allocator.free(name);
-    var symbol: Symbol = .{
-        .name = try wasm.string_table.put(wasm.base.allocator, name),
-        .flags = 0,
-        .tag = .data,
-        .index = undefined,
-    };
-    symbol.setFlag(.WASM_SYM_BINDING_LOCAL);
 
     const atom = try decl.link.wasm.locals.addOne(wasm.base.allocator);
     atom.* = Atom.empty;
+    try atom.ensureInitialized(wasm);
     atom.alignment = tv.ty.abiAlignment(wasm.base.options.target);
-    try wasm.symbols.ensureUnusedCapacity(wasm.base.allocator, 1);
+    wasm.symbols.items[atom.sym_index] = .{
+        .name = try wasm.string_table.put(wasm.base.allocator, name),
+        .flags = @enumToInt(Symbol.Flag.WASM_SYM_BINDING_LOCAL),
+        .tag = .data,
+        .index = undefined,
+    };
 
-    if (wasm.symbols_free_list.popOrNull()) |index| {
-        atom.sym_index = index;
-        wasm.symbols.items[index] = symbol;
-    } else {
-        atom.sym_index = @intCast(u32, wasm.symbols.items.len);
-        wasm.symbols.appendAssumeCapacity(symbol);
-    }
     try wasm.resolved_symbols.putNoClobber(wasm.base.allocator, atom.symbolLoc(), {});
-    try wasm.symbol_atom.putNoClobber(wasm.base.allocator, atom.symbolLoc(), atom);
 
     var value_bytes = std.ArrayList(u8).init(wasm.base.allocator);
     defer value_bytes.deinit();
@@ -1304,8 +1293,8 @@ pub fn getDeclVAddr(
 ) !u64 {
     const mod = wasm.base.options.module.?;
     const decl = mod.declPtr(decl_index);
+    try decl.link.wasm.ensureInitialized(wasm);
     const target_symbol_index = decl.link.wasm.sym_index;
-    assert(target_symbol_index != 0);
     assert(reloc_info.parent_atom_index != 0);
     const atom = wasm.symbol_atom.get(.{ .file = null, .index = reloc_info.parent_atom_index }).?;
     const is_wasm32 = wasm.base.options.target.cpu.arch == .wasm32;
@@ -1363,6 +1352,7 @@ pub fn updateDeclExports(
     }
 
     const decl = mod.declPtr(decl_index);
+    if (decl.link.wasm.getSymbolIndex() == null) return; // unititialized
 
     for (exports) |exp| {
         if (exp.options.section) |section| {

@@ -615,7 +615,6 @@ pub const File = struct {
             return;
         }
         switch (base.tag) {
-            .wasm => return @fieldParentPtr(Wasm, "base", base).allocateDeclIndexes(decl_index),
             .plan9 => return @fieldParentPtr(Plan9, "base", base).allocateDeclIndexes(decl_index),
 
             .coff,
@@ -624,6 +623,7 @@ pub const File = struct {
             .c,
             .spirv,
             .nvptx,
+            .wasm,
             => {},
         }
     }

@@ -5328,6 +5328,7 @@ pub fn deleteUnusedDecl(mod: *Module, decl_index: Decl.Index) void {
         .elf,
         .macho,
         .c,
+        .wasm,
         => {}, // this linker backend has already migrated to the new API
 
         else => if (decl.has_tv) {