wasm-linker: export symbols by virtual address

When exporting a data symbol, generate a regular global and use
the data symbol's virtual addres as the value (init) of the global.

1 files changed, 8 insertions, 18 deletions

diff --git a/src/link/Wasm.zig b/src/link/Wasm.zig
index 42cc2883e2..e03c8b1ba0 100644
--- a/src/link/Wasm.zig
+++ b/src/link/Wasm.zig
@@ -112,8 +112,6 @@ func_types: std.ArrayListUnmanaged(std.wasm.Type) = .{},
 functions: std.AutoArrayHashMapUnmanaged(struct { file: ?u16, index: u32 }, std.wasm.Func) = .{},
 /// Output global section
 wasm_globals: std.ArrayListUnmanaged(std.wasm.Global) = .{},
-/// Global symbols for exported data symbols
-address_globals: std.ArrayListUnmanaged(SymbolLoc) = .{},
 /// Memory section
 memories: std.wasm.Memory = .{ .limits = .{ .min = 0, .max = null } },
 /// Output table section
@@ -880,7 +878,6 @@ pub fn deinit(wasm: *Wasm) void {
     wasm.func_types.deinit(gpa);
     wasm.functions.deinit(gpa);
     wasm.wasm_globals.deinit(gpa);
-    wasm.address_globals.deinit(gpa);
     wasm.function_table.deinit(gpa);
     wasm.tables.deinit(gpa);
     wasm.exports.deinit(gpa);
@@ -1879,8 +1876,13 @@ fn setupExports(wasm: *Wasm) !void {
             break :blk try wasm.string_table.put(wasm.base.allocator, sym_name);
         };
         const exp: types.Export = if (symbol.tag == .data) exp: {
-            const global_index = @intCast(u32, wasm.wasm_globals.items.len + wasm.address_globals.items.len);
-            try wasm.address_globals.append(wasm.base.allocator, sym_loc);
+            const atom = wasm.symbol_atom.get(sym_loc).?;
+            const va = atom.getVA(wasm, symbol);
+            const global_index = @intCast(u32, wasm.imported_globals_count + wasm.wasm_globals.items.len);
+            try wasm.wasm_globals.append(wasm.base.allocator, .{
+                .global_type = .{ .valtype = .i32, .mutable = false },
+                .init = .{ .i32_const = @intCast(i32, va) },
+            });
             break :exp .{
                 .name = export_name,
                 .kind = .global,
@@ -2741,22 +2743,10 @@ fn writeToFile(
     if (wasm.wasm_globals.items.len > 0) {
         const header_offset = try reserveVecSectionHeader(&binary_bytes);
 
-        var global_count: u32 = 0;
         for (wasm.wasm_globals.items) |global| {
             try binary_writer.writeByte(std.wasm.valtype(global.global_type.valtype));
             try binary_writer.writeByte(@boolToInt(global.global_type.mutable));
             try emitInit(binary_writer, global.init);
-            global_count += 1;
-        }
-
-        for (wasm.address_globals.items) |sym_loc| {
-            const atom = wasm.symbol_atom.get(sym_loc).?;
-            try binary_writer.writeByte(std.wasm.valtype(.i32));
-            try binary_writer.writeByte(0); // immutable
-            try emitInit(binary_writer, .{
-                .i32_const = @bitCast(i32, atom.offset),
-            });
-            global_count += 1;
         }
 
         try writeVecSectionHeader(
@@ -2764,7 +2754,7 @@ fn writeToFile(
             header_offset,
             .global,
             @intCast(u32, binary_bytes.items.len - header_offset - header_size),
-            @intCast(u32, global_count),
+            @intCast(u32, wasm.wasm_globals.items.len),
         );
         section_count += 1;
     }