Add a wasm disassembly API to cdp

Thic CL adds a CDP API skeleton that will be used to disassemble WASM
modules using V8's new disassembler.

Bug: v8:12917, chromium:1325626
Change-Id: I4ca81aca923e9716653cd90367e5fad319483aae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3721381Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Philip Pfaffe <pfaffe@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81809}

include/js_protocol.pdl

@@ -244,6 +244,40 @@ domain Debugger
       # Wasm bytecode.
       optional binary bytecode
 
+  experimental type WasmDisassemblyChunk extends object
+    properties
+      # The next chunk of disassembled lines.
+      array of string lines
+      # The bytecode offsets describing the start of each line.
+      array of integer bytecodeOffsets
+
+  experimental command disassembleWasmModule
+    parameters
+      # Id of the script to disassemble
+      Runtime.ScriptId scriptId
+    returns
+      # For large modules, return a stream from which additional chunks of
+      # disassembly can be read successively.
+      optional string streamId
+      # The total number of lines in the disassembly text.
+      integer totalNumberOfLines
+      # The offsets of all function bodies plus one additional entry pointing
+      # one by past the end of the last function.
+      array of integer functionBodyOffsets
+      # The first chunk of disassembly.
+      WasmDisassemblyChunk chunk
+
+  # Disassemble the next chunk of lines for the module corresponding to the
+  # stream. If disassembly is complete, this API will invalidate the streamId
+  # and return an empty chunk. Any subsequent calls for the now invalid stream
+  # will return errors.
+  experimental command nextWasmDisassemblyChunk
+    parameters
+      string streamId
+    returns
+      # The next chunk of disassembly.
+      WasmDisassemblyChunk chunk
+
   # This command is deprecated. Use getScriptSource instead.
   deprecated command getWasmBytecode
     parameters

src/inspector/v8-debugger-agent-impl.cc

@@ -5,6 +5,7 @@
 #include "src/inspector/v8-debugger-agent-impl.h"
 
 #include <algorithm>
+#include <memory>
 
 #include "../../third_party/inspector_protocol/crdtp/json.h"
 #include "include/v8-context.h"
@@ -1130,6 +1131,41 @@ Response V8DebuggerAgentImpl::getScriptSource(
 #endif  // V8_ENABLE_WEBASSEMBLY
   return Response::Success();
 }
+Response V8DebuggerAgentImpl::disassembleWasmModule(
+    const String16& in_scriptId, Maybe<String16>* out_streamId,
+    int* out_totalNumberOfLines,
+    std::unique_ptr<protocol::Array<int>>* out_functionBodyOffsets,
+    std::unique_ptr<protocol::Debugger::WasmDisassemblyChunk>* out_chunk) {
+#if V8_ENABLE_WEBASSEMBLY
+  std::vector<String16> lines{{"a", "b", "c"}};
+  std::vector<int> lineOffsets{{0, 4, 8}};
+  *out_functionBodyOffsets = std::make_unique<protocol::Array<int>>();
+  *out_chunk =
+      protocol::Debugger::WasmDisassemblyChunk::create()
+          .setBytecodeOffsets(
+              std::make_unique<protocol::Array<int>>(std::move(lineOffsets)))
+          .setLines(
+              std::make_unique<protocol::Array<String16>>(std::move(lines)))
+          .build();
+  *out_totalNumberOfLines = 3;
+  return Response::Success();
+#else
+  return Response::ServerError("WebAssembly is disabled");
+#endif  // V8_ENABLE_WEBASSEMBLY
+}
+Response V8DebuggerAgentImpl::nextWasmDisassemblyChunk(
+    const String16& in_streamId,
+    std::unique_ptr<protocol::Debugger::WasmDisassemblyChunk>* out_chunk) {
+#if V8_ENABLE_WEBASSEMBLY
+  *out_chunk = protocol::Debugger::WasmDisassemblyChunk::create()
+                   .setBytecodeOffsets(std::make_unique<protocol::Array<int>>())
+                   .setLines(std::make_unique<protocol::Array<String16>>())
+                   .build();
+  return Response::Success();
+#else
+  return Response::ServerError("WebAssembly is disabled");
+#endif  // V8_ENABLE_WEBASSEMBLY
+}
 
 Response V8DebuggerAgentImpl::getWasmBytecode(const String16& scriptId,
                                               protocol::Binary* bytecode) {

src/inspector/v8-debugger-agent-impl.h

@@ -98,6 +98,16 @@ class V8DebuggerAgentImpl : public protocol::Debugger::Backend {
       Maybe<protocol::Runtime::StackTraceId>* asyncStackTraceId) override;
   Response getScriptSource(const String16& scriptId, String16* scriptSource,
                            Maybe<protocol::Binary>* bytecode) override;
+  Response disassembleWasmModule(
+      const String16& in_scriptId, Maybe<String16>* out_streamId,
+      int* out_totalNumberOfLines,
+      std::unique_ptr<protocol::Array<int>>* out_functionBodyOffsets,
+      std::unique_ptr<protocol::Debugger::WasmDisassemblyChunk>* out_chunk)
+      override;
+  Response nextWasmDisassemblyChunk(
+      const String16& in_streamId,
+      std::unique_ptr<protocol::Debugger::WasmDisassemblyChunk>* out_chunk)
+      override;
   Response getWasmBytecode(const String16& scriptId,
                            protocol::Binary* bytecode) override;
   Response pause() override;