diff --git a/ir/ir.rs b/ir/ir.rs
index 2d9b60cc..bd23a03f 100644
--- a/ir/ir.rs
+++ b/ir/ir.rs
@@ -46,14 +46,18 @@ impl ItemsBuilder {
/// assigned.
pub fn add_item(&mut self, item: Item) -> Id {
let id = item.id;
- self.size_added += item.size;
- self.items.insert(id, item);
+ let size = item.size;
- let old_value = self.parsed.insert(id);
- assert!(
- old_value,
- "should not parse the same key into multiple items"
- );
+ match self.items.get_mut(&id) {
+ None => {
+ self.size_added += size;
+ self.items.insert(id, item);
+ self.parsed.insert(id);
+ }
+ Some(prev) => {
+ prev.size += size;
+ }
+ }
id
}
diff --git a/notes.txt b/notes.txt
new file mode 100644
index 00000000..18443b41
--- /dev/null
+++ b/notes.txt
@@ -0,0 +1,74 @@
+```
+;; `threads.wat` fixture
+;;
+;; Built with `wat2wasm --enable-bulk-memory --enable-threads`
+(module
+ (memory $0 1 1)
+ (data (i32.const 0) "")
+ (func $f (data.drop 0))
+)
+```
+
+```
+; wasm-objdump --headers twiggy/tests/all/fixtures/threads.wasm
+
+threads.wasm: file format wasm 0x1
+
+Sections:
+
+ Type start=0x0000000a end=0x0000000e (size=0x00000004) count: 1
+ Function start=0x00000010 end=0x00000012 (size=0x00000002) count: 1
+ Memory start=0x00000014 end=0x00000018 (size=0x00000004) count: 1
+DataCount start=0x0000001a end=0x0000001b (size=0x00000001) count: 1
+ Code start=0x0000001d end=0x00000024 (size=0x00000007) count: 1
+ Data start=0x00000026 end=0x0000002c (size=0x00000006) count: 1
+```
+
+```
+; wasm-objdump --full-contents twiggy/tests/all/fixtures/threads.wasm
+
+threads.wasm: file format wasm 0x1
+
+Contents of section Type:
+000000a: 0160 0000 .`..
+
+Contents of section Function:
+0000010: 0100 ..
+
+Contents of section Memory:
+0000014: 0101 0101 ....
+
+Contents of section DataCount:
+000001a: 01 .
+
+Contents of section Code:
+000001d: 0105 00fc 0900 0b .......
+
+Contents of section Data:
+0000026: 0100 4100 0b00 ..A...
+```
+
+```
+; target/debug/twiggy top twiggy/tests/all/fixtures/threads.wasm
+
+ Shallow Bytes │ Shallow % │ Item
+───────────────┼───────────┼───────────────────────
+ 8 ┊ 18.18% ┊ wasm magic bytes
+ 7 ┊ 15.91% ┊ code[0]
+ 6 ┊ 13.64% ┊ code section headers
+ 5 ┊ 11.36% ┊ data[0]
+ 3 ┊ 6.82% ┊ type[0]: () -> nil
+ 3 ┊ 6.82% ┊ type section headers
+ 3 ┊ 6.82% ┊ memory[0]
+ 3 ┊ 6.82% ┊ memory section headers
+ 3 ┊ 6.82% ┊ "data count" section
+ 3 ┊ 6.82% ┊ data section headers
+ 44 ┊ 100.00% ┊ Σ [10 Total Rows]
+```
+
+```
+; exa -l --header twiggy/tests/all/fixtures/threads.wasm
+
+Permissions Size User Date Modified Name
+.rw-rw-r-- 44 katelyn 21 Jun 23:07 twiggy/tests/all/fixtures/threads.wasm
+```
diff --git a/parser/wasm_parse/mod.rs b/parser/wasm_parse/mod.rs
index 634f3c97..2ae15a4f 100644
--- a/parser/wasm_parse/mod.rs
+++ b/parser/wasm_parse/mod.rs
@@ -792,6 +792,7 @@ struct DataCountSection<'a>(wasmparser::Section<'a>);
impl<'a> Parse<'a> for DataCountSection<'a> {
type ItemsExtra = usize;
+ // Worth looking here...
fn parse_items(
&mut self,
items: &mut ir::ItemsBuilder,
diff --git a/twiggy/tests/all/expectations/top_threaded_module b/twiggy/tests/all/expectations/top_threaded_module
new file mode 100644
index 00000000..3f566e60
--- /dev/null
+++ b/twiggy/tests/all/expectations/top_threaded_module
@@ -0,0 +1,13 @@
+ Shallow Bytes │ Shallow % │ Item
+───────────────┼───────────┼───────────────────────
+ 8 ┊ 18.18% ┊ wasm magic bytes
+ 7 ┊ 15.91% ┊ code[0]
+ 6 ┊ 13.64% ┊ code section headers
+ 5 ┊ 11.36% ┊ data[0]
+ 3 ┊ 6.82% ┊ type[0]: () -> nil
+ 3 ┊ 6.82% ┊ type section headers
+ 3 ┊ 6.82% ┊ memory[0]
+ 3 ┊ 6.82% ┊ memory section headers
+ 3 ┊ 6.82% ┊ "data count" section
+ 3 ┊ 6.82% ┊ data section headers
+ 44 ┊ 100.00% ┊ Σ [10 Total Rows]
diff --git a/twiggy/tests/all/fixtures/threads.wasm b/twiggy/tests/all/fixtures/threads.wasm
new file mode 100644
index 00000000..dbc75834
Binary files /dev/null and b/twiggy/tests/all/fixtures/threads.wasm differ
diff --git a/twiggy/tests/all/fixtures/threads.wat b/twiggy/tests/all/fixtures/threads.wat
new file mode 100644
index 00000000..fa5d5903
--- /dev/null
+++ b/twiggy/tests/all/fixtures/threads.wat
@@ -0,0 +1,6 @@
+;; Built with `wat2wasm --enable-bulk-memory --enable-threads`
+(module
+ (memory $0 1 1)
+ (data (i32.const 0) "")
+ (func $f (data.drop 0))
+)
diff --git a/twiggy/tests/all/fixtures/threads_test.wasm b/twiggy/tests/all/fixtures/threads_test.wasm
new file mode 100644
index 00000000..1bd3ae2f
Binary files /dev/null and b/twiggy/tests/all/fixtures/threads_test.wasm differ
diff --git a/twiggy/tests/all/fixtures/threads_working.wasm b/twiggy/tests/all/fixtures/threads_working.wasm
new file mode 100644
index 00000000..1bd3ae2f
Binary files /dev/null and b/twiggy/tests/all/fixtures/threads_working.wasm differ
diff --git a/twiggy/tests/all/top_tests.rs b/twiggy/tests/all/top_tests.rs
index 6e8173ef..f32c4eb8 100644
--- a/twiggy/tests/all/top_tests.rs
+++ b/twiggy/tests/all/top_tests.rs
@@ -79,3 +79,12 @@ test!(
// Regression test for https://github.com/rustwasm/twiggy/issues/151
test!(top_mono, "top", "./fixtures/mono.wasm", "-n", "10");
+
+// Threaded modules should not cause a panic.
+test!(
+ top_threaded_module,
+ "top",
+ "-n",
+ "25",
+ "./fixtures/threads.wasm"
+);