[ch10] Stack Trace

zaki-yama · Jul 28, 2021 · 5e983a6 · 5e983a6
1 parent 87e3c04
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diff --git a/the-art-of-webassembly/ch10/README.md b/the-art-of-webassembly/ch10/README.md
@@ -14,3 +14,13 @@
 
 - WAT の要所要所で console.log する
 - 識別しやすいように message id という名の index をログ出力する箇所に連番ふっていく、というかなり泥臭いデバッグ手法
+
+## Using Alerts
+
+- 前節のロギング用関数 (`log_f64`) の console.log を alert に変えるだけ
+
+## Stack Trace
+
+Chrome (実際には Edge) の Dev Tools、Wasm の stack trace は本に書かれてる当時よりは読みやすくなってるっぽい。
+
+![]("./stack-trace.png")
diff --git a/the-art-of-webassembly/ch10/stack-trace.png b/the-art-of-webassembly/ch10/stack-trace.png
diff --git a/the-art-of-webassembly/ch10/stack_trace.html b/the-art-of-webassembly/ch10/stack_trace.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
+    <title>Document</title>
+  </head>
+  <body>
+    <h1>Stack Trace</h1>
+    <script>
+      const importObject = {
+        js: {
+          log_stack_trace: function (level) {
+            console.trace(`level=${level}`);
+          },
+        },
+      };
+
+      (async () => {
+        const obj = await WebAssembly.instantiateStreaming(
+          fetch("stack_trace.wasm"),
+          importObject
+        );
+        obj.instance.exports.call_stack_trace();
+      })();
+    </script>
+  </body>
+</html>
diff --git a/the-art-of-webassembly/ch10/stack_trace.wasm b/the-art-of-webassembly/ch10/stack_trace.wasm
diff --git a/the-art-of-webassembly/ch10/stack_trace.wat b/the-art-of-webassembly/ch10/stack_trace.wat
@@ -0,0 +1,25 @@
+(module
+  (import "js" "log_stack_trace" (func $log_stack_trace (param i32)))
+
+  (func $call_level_1 (param $level i32)
+    local.get $level
+    call $log_stack_trace
+  )
+
+  (func $call_level_2 (param $level i32)
+    local.get $level
+    call $call_level_1
+  )
+
+  (func $call_level_3 (param $level i32)
+    local.get $level
+    call $call_level_2
+  )
+
+  (func $call_stack_trace (export "call_stack_trace")
+    (call $log_stack_trace (i32.const 0))
+    (call $call_level_1 (i32.const 1))
+    (call $call_level_2 (i32.const 2))
+    (call $call_level_3 (i32.const 3))
+  )
+)