Commit 3f22bb96f3

@@ -111,7 +111,7 @@ pub fn resolveRelocs(atom: *Atom, wasm_bin: *const Wasm) void {
             .R_WASM_GLOBAL_INDEX_I32,
             .R_WASM_MEMORY_ADDR_I32,
             .R_WASM_SECTION_OFFSET_I32,
-            => std.mem.writeInt(u32, atom.code.items[reloc.offset - atom.original_offset ..][0..4], @as(u32, @intCast(value)), .little),
+            => std.mem.writeInt(u32, atom.code.items[reloc.offset - atom.original_offset ..][0..4], @as(u32, @truncate(value)), .little),
             .R_WASM_TABLE_INDEX_I64,
             .R_WASM_MEMORY_ADDR_I64,
             => std.mem.writeInt(u64, atom.code.items[reloc.offset - atom.original_offset ..][0..8], value, .little),
@@ -124,7 +124,7 @@ pub fn resolveRelocs(atom: *Atom, wasm_bin: *const Wasm) void {
             .R_WASM_TABLE_NUMBER_LEB,
             .R_WASM_TYPE_INDEX_LEB,
             .R_WASM_MEMORY_ADDR_TLS_SLEB,
-            => leb.writeUnsignedFixed(5, atom.code.items[reloc.offset - atom.original_offset ..][0..5], @as(u32, @intCast(value))),
+            => leb.writeUnsignedFixed(5, atom.code.items[reloc.offset - atom.original_offset ..][0..5], @as(u32, @truncate(value))),
             .R_WASM_MEMORY_ADDR_LEB64,
             .R_WASM_MEMORY_ADDR_SLEB64,
             .R_WASM_TABLE_INDEX_SLEB64,
@@ -140,6 +140,13 @@ pub fn resolveRelocs(atom: *Atom, wasm_bin: *const Wasm) void {
 fn relocationValue(atom: Atom, relocation: types.Relocation, wasm_bin: *const Wasm) u64 {
     const target_loc = (Wasm.SymbolLoc{ .file = atom.file, .index = relocation.index }).finalLoc(wasm_bin);
     const symbol = target_loc.getSymbol(wasm_bin);
+    if (relocation.relocation_type != .R_WASM_TYPE_INDEX_LEB and
+        symbol.tag != .section and
+        symbol.isDead())
+    {
+        const val = atom.thombstone(wasm_bin) orelse relocation.addend;
+        return @bitCast(val);
+    }
     switch (relocation.relocation_type) {
         .R_WASM_FUNCTION_INDEX_LEB => return symbol.index,
         .R_WASM_TABLE_NUMBER_LEB => return symbol.index,
@@ -170,30 +177,43 @@ fn relocationValue(atom: Atom, relocation: types.Relocation, wasm_bin: *const Wa
             if (symbol.isUndefined()) {
                 return 0;
             }
-            const va = @as(i64, @intCast(symbol.virtual_address));
+            const va: i33 = @intCast(symbol.virtual_address);
             return @intCast(va + relocation.addend);
         },
         .R_WASM_EVENT_INDEX_LEB => return symbol.index,
         .R_WASM_SECTION_OFFSET_I32 => {
             const target_atom_index = wasm_bin.symbol_atom.get(target_loc).?;
             const target_atom = wasm_bin.getAtom(target_atom_index);
-            const rel_value: i32 = @intCast(target_atom.offset);
+            const rel_value: i33 = @intCast(target_atom.offset);
             return @intCast(rel_value + relocation.addend);
         },
         .R_WASM_FUNCTION_OFFSET_I32 => {
-            const target_atom_index = wasm_bin.symbol_atom.get(target_loc) orelse {
-                return @as(u32, @bitCast(@as(i32, -1)));
-            };
+            if (symbol.isUndefined()) {
+                const val = atom.thombstone(wasm_bin) orelse relocation.addend;
+                return @bitCast(val);
+            }
+            const target_atom_index = wasm_bin.symbol_atom.get(target_loc).?;
             const target_atom = wasm_bin.getAtom(target_atom_index);
-            const offset: u32 = 11 + Wasm.getULEB128Size(target_atom.size); // Header (11 bytes fixed-size) + body size (leb-encoded)
-            const rel_value: i32 = @intCast(target_atom.offset + offset);
+            const rel_value: i33 = @intCast(target_atom.offset);
             return @intCast(rel_value + relocation.addend);
         },
         .R_WASM_MEMORY_ADDR_TLS_SLEB,
         .R_WASM_MEMORY_ADDR_TLS_SLEB64,
         => {
-            const va: i32 = @intCast(symbol.virtual_address);
+            const va: i33 = @intCast(symbol.virtual_address);
             return @intCast(va + relocation.addend);
         },
     }
 }
+
+// For a given `Atom` returns whether it has a thombstone value or not.
+/// This defines whether we want a specific value when a section is dead.
+fn thombstone(atom: Atom, wasm: *const Wasm) ?i64 {
+    const atom_name = atom.symbolLoc().getName(wasm);
+    if (std.mem.eql(u8, atom_name, ".debug_ranges") or std.mem.eql(u8, atom_name, ".debug_loc")) {
+        return -2;
+    } else if (std.mem.startsWith(u8, atom_name, ".debug_")) {
+        return -1;
+    }
+    return null;
+}