Debugger: Move the 'break on qFatal' implementation to gdbbridge

Easier to create invisible breakpoints there.

Task-number: QTCREATORBUG-15276
Change-Id: I76ffa45f9f0de5ffbc3b82a7ef9a4ddcdfff62eb
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

share/qtcreator/debugger/gdbbridge.py

@@ -226,6 +226,11 @@ class Dumper(DumperBase):
         self.qtNamespaceToReport = None
         self.interpreterBreakpointResolvers = []
 
+        # The guess does not need to be updated during a fetchVariables()
+        # as the result is fixed during that time (ignoring "active"
+        # dumpers causing loading of shared objects etc).
+        self.currentQtNamespaceGuess = None
+
     def prepare(self, args):
         self.output = []
         self.currentIName = ""
@@ -238,11 +243,6 @@ class Dumper(DumperBase):
         self.currentType = ReportItem()
         self.currentAddress = None
 
-        # The guess does not need to be updated during a fetchVariables()
-        # as the result is fixed during that time (ignoring "active"
-        # dumpers causing loading of shared objects etc).
-        self.currentQtNamespaceGuess = None
-
         self.resultVarName = args.get("resultvarname", "")
         self.expandedINames = set(args.get("expanded", []))
         self.stringCutOff = int(args.get("stringcutoff", 10000))
@@ -1159,6 +1159,38 @@ class Dumper(DumperBase):
         #    return mem.tobytes()
         return mem
 
+    def createSpecialBreakpoints(self, args):
+        self.specialBreakpoints = []
+        def newSpecial(spec):
+            class SpecialBreakpoint(gdb.Breakpoint):
+                def __init__(self, spec):
+                    super(SpecialBreakpoint, self).\
+                        __init__(spec, gdb.BP_BREAKPOINT, internal=True)
+                    self.spec = spec
+
+                def stop(self):
+                    print("Breakpoint on '%s' hit." % self.spec)
+                    return True
+            return SpecialBreakpoint(spec)
+
+        # FIXME: ns is accessed too early. gdb.Breakpoint() has no
+        # 'rbreak' replacement, and breakpoints created with
+        # 'gdb.execute("rbreak...") cannot be made invisible.
+        # So let's ignore the existing of namespaced builds for this
+        # fringe feature here for now.
+        ns = self.qtNamespace()
+        if args.get('breakonabort', 0):
+            self.specialBreakpoints.append(newSpecial("abort"))
+
+        if args.get('breakonwarning', 0):
+            self.specialBreakpoints.append(newSpecial(ns + "qWarning"))
+            self.specialBreakpoints.append(newSpecial(ns + "QMessageLogger::warning"))
+
+        if args.get('breakonfatal', 0):
+            self.specialBreakpoints.append(newSpecial(ns + "qFatal"))
+            self.specialBreakpoints.append(newSpecial(ns + "QMessageLogger::fatal"))
+
+
     def putFields(self, value, dumpBase = True):
             fields = value.type.fields()
             if self.sortStructMembers:

src/plugins/debugger/gdb/gdbengine.cpp

@@ -735,7 +735,6 @@ void GdbEngine::handleAsyncOutput(const QByteArray &asyncClass, const GdbMi &res
         foreach (const GdbMi &bkpt, res.children()) {
             const QByteArray nr = bkpt["number"].data();
             BreakpointResponseId rid(nr);
-            if (!isHiddenBreakpoint(rid)) {
             if (nr.contains('.')) {
                 // A sub-breakpoint.
                 BreakpointResponse sub;
@@ -751,7 +750,6 @@ void GdbEngine::handleAsyncOutput(const QByteArray &asyncClass, const GdbMi &res
                 bp.setResponse(br);
             }
         }
-        }
     } else if (asyncClass == "breakpoint-created") {
         // "{bkpt={number="1",type="breakpoint",disp="del",enabled="y",
         //  addr="<PENDING>",pending="main",times="0",
@@ -1398,7 +1396,7 @@ void GdbEngine::handleStopResponse(const GdbMi &data)
         showMessage(_("INVALID STOPPED REASON"), LogWarning);
     }
 
-    if (rid.isValid() && frame.isValid() && !isQFatalBreakpoint(rid)) {
+    if (rid.isValid() && frame.isValid()) {
         // Use opportunity to update the breakpoint marker position.
         Breakpoint bp = breakHandler()->findBreakpointByResponseId(rid);
         const BreakpointResponse &response = bp.response();
@@ -1415,7 +1413,6 @@ void GdbEngine::handleStopResponse(const GdbMi &data)
     // Quickly set the location marker.
     if (lineNumber && !boolSetting(OperateByInstruction)
             && QFileInfo::exists(fullName)
-            && !isQFatalBreakpoint(rid)
             && function != "qt_v4TriggeredBreakpointHook"
             && function != "qt_qmlDebugMessageAvailable"
             && language != "js")
@@ -2552,10 +2549,6 @@ void GdbEngine::handleBreakInsert1(const DebuggerResponse &response, Breakpoint
         // the "main" entry. Use the "main" entry to retrieve the
         // already known data from the BreakpointManager, and then
         // iterate over all items to update main- and sub-data.
-        const GdbMi mainbkpt = response.data["bkpt"];
-        const QByteArray mainnr = mainbkpt["number"].data();
-        const BreakpointResponseId mainrid(mainnr);
-        if (!isHiddenBreakpoint(mainrid)) {
         foreach (const GdbMi &bkpt, response.data.children())
             handleBkpt(bkpt, bp);
         if (bp.needsChange()) {
@@ -2564,7 +2557,6 @@ void GdbEngine::handleBreakInsert1(const DebuggerResponse &response, Breakpoint
         } else {
             bp.notifyBreakpointInsertOk();
         }
-        }
     } else if (response.data["msg"].data().contains("Unknown option")) {
         // Older version of gdb don't know the -a option to set tracepoints
         // ^error,msg="mi_cmd_break_insert: Unknown option ``a''"
@@ -4321,24 +4313,25 @@ void GdbEngine::finishInferiorSetup()
 {
     CHECK_STATE(InferiorSetupRequested);
 
-    if (runParameters().startMode == AttachCore) {
-        notifyInferiorSetupOk(); // No breakpoints in core files.
-    } else {
-        if (boolSetting(BreakOnAbort))
-            runCommand({"-break-insert -f abort"});
-        if (boolSetting(BreakOnWarning)) {
-            runCommand({"-break-insert -f '" + qtNamespace() + "qWarning'", NoFlags});
-            runCommand({"-break-insert -f '" + qtNamespace() + "QMessageLogger::warning'", NoFlags});
+    if (runParameters().startMode != AttachCore) { // No breakpoints in core files.
+        const bool onAbort = boolSetting(BreakOnAbort);
+        const bool onWarning = boolSetting(BreakOnWarning);
+        const bool onFatal = boolSetting(BreakOnFatal);
+        if (onAbort || onWarning || onFatal) {
+            DebuggerCommand cmd("createSpecialBreakpoints", PythonCommand);
+            cmd.arg("breakonabort", onAbort);
+            cmd.arg("breakonwarning", onWarning);
+            cmd.arg("breakonfatal", onFatal);
+            runCommand(cmd);
         }
-        if (boolSetting(BreakOnFatal)) {
-            auto cb = [this](const DebuggerResponse &r) { handleBreakOnQFatal(r, false); };
-            runCommand({"-break-insert -f '" + qtNamespace() + "qFatal'", NoFlags, cb});
-            runCommand({"-break-insert -f '" + qtNamespace() + "QMessageLogger::fatal'", NoFlags, cb});
-        } else {
+    }
+
+    // It is ok to cut corners here and not wait for createSpecialBreakpoints()'s
+    // response, as the command is synchronous from Creator's point of view,
+    // and even if it fails (e.g. due to stripped binaries), continuing with
+    // the start up is the best we can do.
     notifyInferiorSetupOk();
 }
-    }
-}
 
 void GdbEngine::handleDebugInfoLocation(const DebuggerResponse &response)
 {
@@ -4354,23 +4347,6 @@ void GdbEngine::handleDebugInfoLocation(const DebuggerResponse &response)
     }
 }
 
-void GdbEngine::handleBreakOnQFatal(const DebuggerResponse &response, bool continueSetup)
-{
-    if (response.resultClass == ResultDone) {
-        GdbMi bkpt = response.data["bkpt"];
-        GdbMi number = bkpt["number"];
-        BreakpointResponseId rid(number.data());
-        if (rid.isValid()) {
-            m_qFatalBreakpointResponseId = rid;
-            runCommand({"-break-commands " + number.data() + " return", NoFlags});
-        }
-    }
-
-    // Continue setup.
-    if (continueSetup)
-        notifyInferiorSetupOk();
-}
-
 void GdbEngine::notifyInferiorSetupFailed(const QString &msg)
 {
     showStatusMessage(tr("Failed to start application:") + QLatin1Char(' ') + msg);
@@ -4431,16 +4407,6 @@ void GdbEngine::resetCommandQueue()
     }
 }
 
-bool GdbEngine::isQFatalBreakpoint(const BreakpointResponseId &id) const
-{
-    return id.isValid() && m_qFatalBreakpointResponseId == id;
-}
-
-bool GdbEngine::isHiddenBreakpoint(const BreakpointResponseId &id) const
-{
-    return isQFatalBreakpoint(id);
-}
-
 bool GdbEngine::usesExecInterrupt() const
 {
     DebuggerStartMode mode = runParameters().startMode;

src/plugins/debugger/gdb/gdbengine.h

@@ -331,8 +331,6 @@ private: ////////// View & Data Stuff //////////
     void fetchDisassemblerByCliRangePlain(const DisassemblerAgentCookie &ac);
     bool handleCliDisassemblerResult(const QByteArray &response, DisassemblerAgent *agent);
 
-    void handleBreakOnQFatal(const DebuggerResponse &response, bool continueSetup);
-
     //
     // Source file specific stuff
     //
@@ -421,14 +419,10 @@ protected:
     // while updating locals.
     bool m_inUpdateLocals;
 
-    bool isQFatalBreakpoint(const BreakpointResponseId &id) const;
-    bool isHiddenBreakpoint(const BreakpointResponseId &id) const;
-
     // HACK:
     QByteArray m_currentThread;
     QString m_lastWinException;
     QString m_lastMissingDebugInfo;
-    BreakpointResponseId m_qFatalBreakpointResponseId;
     bool m_terminalTrap;
     bool m_temporaryStopPending;
     bool usesExecInterrupt() const;