Add support for line numbers in stack traces (Linux/Mac OS X only at this point)

* Add support for debug annotations on statement boundaries to the
  IR, to get accurate line/column information
* Use binary search to retrieve the function and line number for a given
  program counter
* Save the stack trace in the exception class and print it in v4
* Fix initial line number in QV4::Script to start a 1, just like the initial column
  in QQmlJS::Lexer also starts at 1

The native stack frame tracing is currently only implemented on Linux and Mac OS X.
The implementation for Windows using StackWalk64 is still missing.

Change-Id: I771fe44816397e29c69952772a772bf0d985236f
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 22 insertions, 16 deletions

diff --git a/tools/v4/main.cpp b/tools/v4/main.cpp
index 56ec2da7af..ead057c86a 100644
--- a/tools/v4/main.cpp
+++ b/tools/v4/main.cpp
@@ -120,26 +120,32 @@ DEFINE_MANAGED_VTABLE(GC);
 
 } // builtins
 
-static void showException(QV4::ExecutionContext *ctx, const QV4::Value &exception)
+static void showException(QV4::ExecutionContext *ctx, const QV4::Exception &exception)
 {
-    QV4::ErrorObject *e = exception.asErrorObject();
+    QV4::ErrorObject *e = exception.value().asErrorObject();
     if (!e) {
-        std::cerr << "Uncaught exception: " << qPrintable(exception.toString(ctx)->toQString()) << std::endl;
-        return;
-    }
+        std::cerr << "Uncaught exception: " << qPrintable(exception.value().toString(ctx)->toQString()) << std::endl;
+    } else {
+        if (QV4::SyntaxErrorObject *err = e->asSyntaxError()) {
+            QV4::DiagnosticMessage *msg = err->message();
+            if (!msg) {
+                std::cerr << "Uncaught exception: Syntax error" << std::endl;
+                return;
+            }
 
-    if (QV4::SyntaxErrorObject *err = e->asSyntaxError()) {
-        QV4::DiagnosticMessage *msg = err->message();
-        if (!msg) {
-            std::cerr << "Uncaught exception: Syntax error" << std::endl;
-            return;
+            for (; msg; msg = msg->next) {
+                std::cerr << qPrintable(msg->buildFullMessage(ctx)->toQString()) << std::endl;
+            }
+        } else {
+            std::cerr << "Uncaught exception: " << qPrintable(e->get(ctx, ctx->engine->newString(QStringLiteral("message")), 0).toString(ctx)->toQString()) << std::endl;
         }
+    }
 
-        for (; msg; msg = msg->next) {
-            std::cerr << qPrintable(msg->buildFullMessage(ctx)->toQString()) << std::endl;
-        }
-    } else {
-        std::cerr << "Uncaught exception: " << qPrintable(e->get(ctx, ctx->engine->newString(QStringLiteral("message")), 0).toString(ctx)->toQString()) << std::endl;
+    foreach (const QV4::ExecutionEngine::StackFrame &frame, exception.stackTrace()) {
+        std::cerr << "    at " << qPrintable(frame.function) << " (" << qPrintable(frame.source.toLocalFile());
+        if (frame.line >= 0)
+            std::cerr << ":" << frame.line;
+        std::cerr << ")" << std::endl;
     }
 }
 
@@ -390,7 +396,7 @@ int main(int argc, char *argv[])
                     }
                 } catch (QV4::Exception& ex) {
                     ex.accept(ctx);
-                    showException(ctx, ex.value());
+                    showException(ctx, ex);
                     return EXIT_FAILURE;
                 }