From 3ef8218e4968e195f872d938970bd6b9548e3efd Mon Sep 17 00:00:00 2001
From: fcasal <fcasal@users.noreply.github.com>
Date: Sat, 10 Mar 2018 07:27:09 +0000
Subject: [PATCH] Added option to swap conditional jmps (#373)

---
 src/Cutter.cpp                       |  6 +++++
 src/Cutter.h                         |  1 +
 src/menus/DisassemblyContextMenu.cpp | 36 +++++++++++++++++++++++++++-
 src/menus/DisassemblyContextMenu.h   |  3 +++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/Cutter.cpp b/src/Cutter.cpp
index 5b66eca8..0af28336 100644
--- a/src/Cutter.cpp
+++ b/src/Cutter.cpp
@@ -335,6 +335,12 @@ void CutterCore::nopInstruction(RVA addr)
     emit instructionChanged(addr);
 }
 
+void CutterCore::jmpReverse(RVA addr)
+{
+    cmd("wao recj @ " + RAddressString(addr));
+    emit instructionChanged(addr);
+}
+
 void CutterCore::editBytes(RVA addr, const QString &bytes)
 {
     cmd("wx " + bytes + " @ " + RAddressString(addr));
diff --git a/src/Cutter.h b/src/Cutter.h
index b6eb0b02..db988b27 100644
--- a/src/Cutter.h
+++ b/src/Cutter.h
@@ -296,6 +296,7 @@ public:
 
     void editInstruction(RVA addr, const QString &inst);
     void nopInstruction(RVA addr);
+    void jmpReverse(RVA addr);
     
     void editBytes(RVA addr, const QString &inst);
 
diff --git a/src/menus/DisassemblyContextMenu.cpp b/src/menus/DisassemblyContextMenu.cpp
index 8564516c..78a9633d 100644
--- a/src/menus/DisassemblyContextMenu.cpp
+++ b/src/menus/DisassemblyContextMenu.cpp
@@ -14,7 +14,8 @@ DisassemblyContextMenu::DisassemblyContextMenu(QWidget *parent)
         offset(0),
         canCopy(false),
         actionEditInstruction(this),
-        actionNopInstruction(this),        
+        actionNopInstruction(this),
+        actionJmpReverse(this),
         actionEditBytes(this),
         actionCopy(this),
         actionAddComment(this),
@@ -92,10 +93,13 @@ DisassemblyContextMenu::DisassemblyContextMenu(QWidget *parent)
     editMenu->addAction(&actionNopInstruction);
     actionEditBytes.setText(tr("Bytes"));
     editMenu->addAction(&actionEditBytes);
+    actionJmpReverse.setText(tr("Reverse Jump"));
+    editMenu->addAction(&actionJmpReverse);
 
     connect(&actionEditInstruction, SIGNAL(triggered(bool)), this, SLOT(on_actionEditInstruction_triggered()));
     connect(&actionNopInstruction, SIGNAL(triggered(bool)), this, SLOT(on_actionNopInstruction_triggered()));    
     connect(&actionEditBytes, SIGNAL(triggered(bool)), this, SLOT(on_actionEditBytes_triggered()));
+    connect(&actionJmpReverse, SIGNAL(triggered(bool)), this, SLOT(on_actionJmpReverse_triggered()));
 
     connect(&actionSetBaseBinary, SIGNAL(triggered(bool)), this, SLOT(on_actionSetBaseBinary_triggered()));
     connect(&actionSetBaseOctal, SIGNAL(triggered(bool)), this, SLOT(on_actionSetBaseOctal_triggered()));
@@ -202,6 +206,10 @@ void DisassemblyContextMenu::aboutToShowSlot()
     {
         actionRenameUsedHere.setVisible(false);
     }
+
+    // decide to show Reverse jmp option
+    showReverseJmpQuery();
+
 }
 
 QKeySequence DisassemblyContextMenu::getCopySequence() const
@@ -262,6 +270,32 @@ void DisassemblyContextMenu::on_actionNopInstruction_triggered()
     Core()->nopInstruction(offset);
 }
 
+void DisassemblyContextMenu::showReverseJmpQuery()
+{
+    QString type;
+
+    QJsonArray array = Core()->cmdj("pdj 1 @ " + RAddressString(offset)).array();
+    if (array.isEmpty())
+    {
+        return;
+    }
+
+    type = array.first().toObject()["type"].toString();
+    if (type == "cjmp")
+    {
+        actionJmpReverse.setVisible(true);
+    }
+    else
+    {
+        actionJmpReverse.setVisible(false);
+    }
+}
+
+void DisassemblyContextMenu::on_actionJmpReverse_triggered()
+{
+    Core()->jmpReverse(offset);
+}
+
 void DisassemblyContextMenu::on_actionEditBytes_triggered()
 {
     EditInstructionDialog *e = new EditInstructionDialog(this);
diff --git a/src/menus/DisassemblyContextMenu.h b/src/menus/DisassemblyContextMenu.h
index 4c3e3dfc..302881ef 100644
--- a/src/menus/DisassemblyContextMenu.h
+++ b/src/menus/DisassemblyContextMenu.h
@@ -25,6 +25,8 @@ private slots:
 
     void on_actionEditInstruction_triggered();
     void on_actionNopInstruction_triggered();
+    void on_actionJmpReverse_triggered();
+    void showReverseJmpQuery();
     void on_actionEditBytes_triggered();
 
     void on_actionCopy_triggered();
@@ -72,6 +74,7 @@ private:
     QAction *editMenuAction;
     QAction actionEditInstruction;
     QAction actionNopInstruction;
+    QAction actionJmpReverse;
     QAction actionEditBytes;
 
     QAction actionCopy;