Commit `476202eec0`

Luuk de Gram <luuk@degram.dev>

2022-12-16 18:31:24

wasm-linker: Fix archive symbols parsing

When parsing the table of contents containing the symbols and their positions we initially used the index within the map to retrieve the offset. However, during resizing of the underlaying array this would invalidate those indexes which meant incorrect offsets were being stored for symbols. We now use the current symbol index to also get the index into the symbol position instead.

master

1 parent ae106db

Changed files (2)

src

link

Wasm

Archive.zig

Wasm.zig

@@ -157,13 +157,12 @@ fn parseTableOfContents(archive: *Archive, allocator: Allocator, reader: anytype
     };
 
     var i: usize = 0;
-    while (i < sym_tab.len) {
-        const string = mem.sliceTo(sym_tab[i..], 0);
-        if (string.len == 0) {
-            i += 1;
-            continue;
-        }
-        i += string.len;
+    var pos: usize = 0;
+    while (i < num_symbols) : (i += 1) {
+        const string = mem.sliceTo(sym_tab[pos..], 0);
+        pos += string.len + 1;
+        if (string.len == 0) continue;
+
         const name = try allocator.dupe(u8, string);
         errdefer allocator.free(name);
         const gop = try archive.toc.getOrPut(allocator, name);
@@ -172,7 +171,7 @@ fn parseTableOfContents(archive: *Archive, allocator: Allocator, reader: anytype
         } else {
             gop.value_ptr.* = .{};
         }
-        try gop.value_ptr.append(allocator, symbol_positions[gop.index]);
+        try gop.value_ptr.append(allocator, symbol_positions[i]);
     }
 }

@@ -625,7 +625,7 @@ fn resolveSymbolsInObject(wasm: *Wasm, object_index: u16) !void {
         try wasm.resolved_symbols.put(wasm.base.allocator, location, {});
         assert(wasm.resolved_symbols.swapRemove(existing_loc));
         if (existing_sym.isUndefined()) {
-            assert(wasm.undefs.swapRemove(sym_name));
+            _ = wasm.undefs.swapRemove(sym_name);
         }
     }
 }
@@ -636,8 +636,7 @@ fn resolveSymbolsInArchives(wasm: *Wasm) !void {
     log.debug("Resolving symbols in archives", .{});
     var index: u32 = 0;
     undef_loop: while (index < wasm.undefs.count()) {
-        const undef_sym_loc = wasm.undefs.values()[index];
-        const sym_name = undef_sym_loc.getName(wasm);
+        const sym_name = wasm.undefs.keys()[index];
 
         for (wasm.archives.items) |archive| {
             const offset = archive.toc.get(sym_name) orelse {

Commit 476202eec0

Commit `476202eec0`