src: print builtins and unnamed stack frames

src/llnode.cc

@@ -11,7 +11,19 @@
 
 namespace llnode {
 
-using namespace lldb;
+using lldb::SBCommandInterpreter;
+using lldb::SBCommandReturnObject;
+using lldb::SBDebugger;
+using lldb::SBError;
+using lldb::SBExpressionOptions;
+using lldb::SBFrame;
+using lldb::SBStream;
+using lldb::SBSymbol;
+using lldb::SBTarget;
+using lldb::SBThread;
+using lldb::SBValue;
+using lldb::eReturnStatusFailed;
+using lldb::eReturnStatusSuccessFinishResult;
 
 v8::LLV8 llv8;
 
@@ -97,30 +109,37 @@ bool BacktraceCmd::DoExecute(SBDebugger d, char** cmd,
   if (number != -1) num_frames = number;
   for (uint32_t i = 0; i < num_frames; i++) {
     SBFrame frame = thread.GetFrameAtIndex(i);
-    SBSymbol symbol = frame.GetSymbol();
-
-    // C++ symbol
-    if (symbol.IsValid()) {
-      SBStream desc;
-      if (!frame.GetDescription(desc)) continue;
-      result.Printf(frame == selected_frame ? "  * %s" : "    %s",
-                    desc.GetData());
-      continue;
+    const char star = (frame == selected_frame ? '*' : ' ');
+    const uint64_t pc = frame.GetPC();
+
+    if (!frame.GetSymbol().IsValid()) {
+      v8::Error err;
+      v8::JSFrame v8_frame(&llv8, static_cast<int64_t>(frame.GetFP()));
+      std::string res = v8_frame.Inspect(true, err);
+      if (err.Success()) {
+        result.Printf("  %c frame #%u: 0x%016llx %s\n", star, i, pc,
+                      res.c_str());
+        continue;
+      }
     }
 
-    // V8 frame
-    v8::Error err;
-    v8::JSFrame v8_frame(&llv8, static_cast<int64_t>(frame.GetFP()));
-    std::string res = v8_frame.Inspect(true, err);
-
-    // Skip invalid frames
-    if (err.Fail()) continue;
+#ifdef LLDB_SBMemoryRegionInfoList_h_
+    // Heuristic: a PC in WX memory is almost certainly a V8 builtin.
+    // TODO(bnoordhuis) Find a way to map the PC to the builtin's name.
+    {
+      lldb::SBMemoryRegionInfo info;
+      if (target.GetProcess().GetMemoryRegionInfo(pc, info).Success() &&
+          info.IsExecutable() && info.IsWritable()) {
+        result.Printf("  %c frame #%u: 0x%016llx <builtin>\n", star, i, pc);
+        continue;
+      }
+    }
+#endif  // LLDB_SBMemoryRegionInfoList_h_
 
-    // V8 symbol
-    result.Printf(frame == selected_frame ? "  * frame #%u: 0x%016llx %s\n"
-                                          : "    frame #%u: 0x%016llx %s\n",
-                  i, static_cast<unsigned long long int>(frame.GetPC()),
-                  res.c_str());
+    // C++ stack frame.
+    SBStream desc;
+    if (frame.GetDescription(desc))
+      result.Printf("  %c %s", star, desc.GetData());
   }
 
   result.SetStatus(eReturnStatusSuccessFinishResult);

src/llscan.cc

@@ -17,13 +17,23 @@
 
 namespace llnode {
 
+using lldb::SBCommandReturnObject;
+using lldb::SBDebugger;
+using lldb::SBError;
+using lldb::SBExpressionOptions;
+using lldb::SBMemoryRegionInfo;
+using lldb::SBMemoryRegionInfoList;
+using lldb::SBStream;
+using lldb::SBTarget;
+using lldb::SBValue;
+using lldb::eReturnStatusFailed;
+using lldb::eReturnStatusSuccessFinishResult;
+
 // Defined in llnode.cc
 extern v8::LLV8 llv8;
 
 LLScan llscan;
 
-using namespace lldb;
-
 
 bool FindObjectsCmd::DoExecute(SBDebugger d, char** cmd,
                                SBCommandReturnObject& result) {

src/llv8-constants.cc

@@ -12,7 +12,14 @@ namespace llnode {
 namespace v8 {
 namespace constants {
 
-using namespace lldb;
+using lldb::SBAddress;
+using lldb::SBError;
+using lldb::SBProcess;
+using lldb::SBSymbol;
+using lldb::SBSymbolContext;
+using lldb::SBSymbolContextList;
+using lldb::SBTarget;
+using lldb::addr_t;
 
 static std::string kConstantPrefix = "v8dbg_";
 

src/llv8.cc

@@ -8,7 +8,9 @@
 namespace llnode {
 namespace v8 {
 
-using namespace lldb;
+using lldb::SBError;
+using lldb::SBTarget;
+using lldb::addr_t;
 
 static std::string kConstantPrefix = "v8dbg_";
 

test/frame-test.js

@@ -15,6 +15,10 @@ tape('v8 stack', (t) => {
   sess.linesUntil(/eyecatcher/, (lines) => {
     lines.reverse();
     t.ok(lines.length > 4, 'frame count');
+    // FIXME(bnoordhuis) This can fail with versions of lldb that don't
+    // support the GetMemoryRegions() API; llnode won't be able to identify
+    // V8 builtins stack frames, it just prints them as anonymous frames.
+    lines = lines.filter((s) => !/<builtin>/.test(s));
     const eyecatcher = lines[0];
     const adapter = lines[1];
     const crasher = lines[2];

test/scan-test.js

@@ -69,12 +69,12 @@ tape('v8 findrefs and friends', (t) => {
 
   sess.linesUntil(/lldb\-/, (lines) => {
     // `class Deflate extends Zlib` makes instances show up as
-    // Transform objects (which Zlib inherits from) in node.js >= 8.
-    // Note that the version check will have to be redone for node.js >= 10
-    // but that is still a year out and by then llnode probably needs more
-    // fixups anyway.
+    // Transform objects (which Zlib inherits from) in node.js 8.0.0.
+    // That change was reverted in https://github.com/nodejs/node/pull/13374
+    // and released in 8.1.0.
     const re =
-        (process.version >= 'v8.' ? /Transform\._handle/ : /Deflate\._handle/);
+        (process.version === 'v8.0.0' ?
+            /Transform\._handle/ : /Deflate\._handle/);
     t.ok(re.test(lines.join('\n')), 'Should find reference');
     t.ok(/Object\.holder/.test(lines.join('\n')), 'Should find reference #2');
     t.ok(/\(Array\)\[1\]/.test(lines.join('\n')), 'Should find reference #3');