[vm, profiler] Improve profiler stacks and VM backtraces.

- Fix duplication of top frame from the native stack walker
 - Include frame pointer, useful for debugging stack overflows
 - Print dso name and offset when no symbol is available at runtime to allow offline symbolification

Change-Id: I150d508e7c370c26ddd836b9dd50c2a465c19ebf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/98432
Reviewed-by: Zach Anderson <zra@google.com>

runtime/vm/malloc_hooks_arm.cc

@@ -10,7 +10,7 @@
 
 namespace dart {
 
-const intptr_t kSkipCount = 5;
+const intptr_t kSkipCount = 4;
 
 }  // namespace dart
 

runtime/vm/malloc_hooks_arm64.cc

@@ -10,7 +10,7 @@
 
 namespace dart {
 
-const intptr_t kSkipCount = 5;
+const intptr_t kSkipCount = 4;
 
 }  // namespace dart
 

runtime/vm/malloc_hooks_ia32.cc

@@ -11,9 +11,9 @@
 namespace dart {
 
 #if defined(DEBUG)
-const intptr_t kSkipCount = 6;
-#elif !(defined(PRODUCT) || defined(DEBUG))
 const intptr_t kSkipCount = 5;
+#elif !(defined(PRODUCT) || defined(DEBUG))
+const intptr_t kSkipCount = 4;
 #endif
 
 }  // namespace dart

runtime/vm/malloc_hooks_x64.cc

@@ -11,9 +11,9 @@
 namespace dart {
 
 #if defined(DEBUG)
-const intptr_t kSkipCount = 6;
-#elif !(defined(PRODUCT) || defined(DEBUG))
 const intptr_t kSkipCount = 5;
+#elif !(defined(PRODUCT) || defined(DEBUG))
+const intptr_t kSkipCount = 4;
 #endif
 
 }  // namespace dart

runtime/vm/profiler.cc

@@ -417,6 +417,7 @@ void ClearProfileVisitor::VisitSample(Sample* sample) {
 
 static void DumpStackFrame(intptr_t frame_index,
                            uword pc,
+                           uword fp,
                            bool try_symbolize_dart_frames) {
   Thread* thread = Thread::Current();
   if ((thread != NULL) && !thread->IsAtSafepoint() &&
@@ -430,7 +431,8 @@ static void DumpStackFrame(intptr_t frame_index,
         code = Code::LookupCode(pc);  // In current isolate.
       }
       if (!code.IsNull()) {
-        OS::PrintErr("  [0x%" Pp "] %s\n", pc, code.QualifiedName());
+        OS::PrintErr("  pc 0x%" Pp " fp 0x%" Pp " %s\n", pc, fp,
+                     code.QualifiedName());
         return;
       }
     }
@@ -438,12 +440,24 @@ static void DumpStackFrame(intptr_t frame_index,
 
   uintptr_t start = 0;
   char* native_symbol_name = NativeSymbolResolver::LookupSymbolName(pc, &start);
-  if (native_symbol_name == NULL) {
+  if (native_symbol_name != NULL) {
-    OS::PrintErr("  [0x%" Pp "] Unknown symbol\n", pc);
+    OS::PrintErr("  pc 0x%" Pp " fp 0x%" Pp " %s\n", pc, fp,
-  } else {
+                 native_symbol_name);
-    OS::PrintErr("  [0x%" Pp "] %s\n", pc, native_symbol_name);
     NativeSymbolResolver::FreeSymbolName(native_symbol_name);
+    return;
   }
+
+  char* dso_name;
+  uword dso_base;
+  if (NativeSymbolResolver::LookupSharedObject(pc, &dso_base, &dso_name)) {
+    uword dso_offset = pc - dso_base;
+    OS::PrintErr("  pc 0x%" Pp " fp 0x%" Pp " %s+0x%" Px "\n", pc, fp, dso_name,
+                 dso_offset);
+    NativeSymbolResolver::FreeSymbolName(dso_name);
+    return;
+  }
+
+  OS::PrintErr("  pc 0x%" Pp " fp 0x%" Pp " Uknown symbol\n", pc, fp);
 }
 
 class ProfilerStackWalker : public ValueObject {
@@ -469,14 +483,14 @@ class ProfilerStackWalker : public ValueObject {
     }
   }
 
-  bool Append(uword pc) {
+  bool Append(uword pc, uword fp) {
     if (frames_skipped_ < skip_count_) {
       frames_skipped_++;
       return true;
     }
 
     if (sample_ == NULL) {
-      DumpStackFrame(frame_index_, pc, try_symbolize_dart_frames_);
+      DumpStackFrame(frame_index_, pc, fp, try_symbolize_dart_frames_);
       frame_index_++;
       total_frames_++;
       return true;
@@ -632,7 +646,7 @@ class ProfilerDartStackWalker : public ProfilerStackWalker {
                                                    in_interpreted_frame));
       }
 
-      if (!Append(reinterpret_cast<uword>(pc_))) {
+      if (!Append(reinterpret_cast<uword>(pc_), reinterpret_cast<uword>(fp_))) {
         break;  // Sample is full.
       }
 
@@ -725,7 +739,7 @@ class ProfilerNativeStackWalker : public ProfilerStackWalker {
   void walk() {
     const uword kMaxStep = VirtualMemory::PageSize();
 
-    Append(original_pc_);
+    Append(original_pc_, original_fp_);
 
     uword* pc = reinterpret_cast<uword*>(original_pc_);
     uword* fp = reinterpret_cast<uword*>(original_fp_);
@@ -747,10 +761,6 @@ class ProfilerNativeStackWalker : public ProfilerStackWalker {
     }
 
     while (true) {
-      if (!Append(reinterpret_cast<uword>(pc))) {
-        return;
-      }
-
       pc = CallerPC(fp);
       previous_fp = fp;
       fp = CallerFP(fp);
@@ -794,6 +804,10 @@ class ProfilerNativeStackWalker : public ProfilerStackWalker {
 
       // Move the lower bound up.
       lower_bound_ = reinterpret_cast<uword>(fp);
+
+      if (!Append(reinterpret_cast<uword>(pc), reinterpret_cast<uword>(fp))) {
+        return;
+      }
     }
   }