Initial commit

force_lvar_width.py

@@ -0,0 +1,111 @@
+""" Forcibly change the width of an lvar.
+Useful for making an lvar smaller (which Hex-Rays does not let you do apparently)
+Tags (for search engines):
+IDA Pro Hex-Rays make stack variable smaller force variable size decrease width delete variable split up break up variable into smaller
+"""
+
+import idautils
+import idaapi
+import idc
+import ida_hexrays
+
+import traceback
+
+force_width_actname = "forcelvarwidth:forcewidth"
+
+class force_width_action_handler_t(idaapi.action_handler_t):
+    def __init__(self, callback_info):
+        idaapi.action_handler_t.__init__(self)
+        self.callback_info = callback_info
+
+    def activate(self, ctx):
+        vdui = idaapi.get_widget_vdui(ctx.widget)
+        self.callback_info.gui_action_callback(vdui)
+        return 1
+
+    def update(self, ctx):
+        return idaapi.AST_ENABLE_FOR_WIDGET if \
+            ctx.widget_type == idaapi.BWN_PSEUDOCODE else \
+            idaapi.AST_DISABLE_FOR_WIDGET
+
+
+class hexrays_callback_info(object):
+
+    def __init__(self):
+        self.vu = None
+        return
+
+    def load(self):
+        return
+
+    def save(self):
+        return
+
+    def do_force_width(self, cfunc, insn):
+
+        if insn.opname != 'if':
+            return False
+
+        cif = insn.details
+
+        if not cif.ithen or not cif.ielse:
+            return False
+
+        idaapi.qswap(cif.ithen, cif.ielse)
+        cond = idaapi.cexpr_t(cif.expr)
+        notcond = idaapi.lnot(cond)
+
+        cif.expr.swap(notcond)
+
+        return True
+
+    def gui_action_callback(self, vu):
+
+        cfunc = vu.cfunc.__deref__()
+        
+        if not vu.get_current_item(idaapi.USE_KEYBOARD):
+            print "Force lvar width: you don't have anything selected"
+            return False
+            
+        badlv = vu.item.get_lvar()
+        if not badlv:
+            print "Force lvar width: you don't have an lvar selected"
+            return False
+
+        new_width = idc.AskLong(badlv.width, "Enter the new width for " + badlv.name)
+        if new_width == None: # cancelled
+            print "Force lvar width: operation cancelled"
+            return False
+
+        if new_width <= 0:
+            print "Force lvar width: not allowed. Non-positive width will crash IDA"
+            return False
+
+        badlv.set_width(new_width)
+        print 'Set the type in IDA (Y) for it to apply'
+        idaapi.process_ui_action('hx:SetType')
+
+        # vu.refresh_ctext()
+        print 'Force lvar width: OK.'
+        return True
+
+    def event_callback(self, event, *args):
+
+        if event == idaapi.hxe_populating_popup:
+            widget, phandle, vu = args
+            res = idaapi.attach_action_to_popup(vu.ct, None, force_width_actname)
+
+        return 0
+
+if idaapi.init_hexrays_plugin():
+    i = hexrays_callback_info()
+    idaapi.register_action(
+        idaapi.action_desc_t(
+            force_width_actname,
+            "Force lvar width",
+            force_width_action_handler_t(i),
+            "Shift-W"))
+    idaapi.install_hexrays_callback(i.event_callback)
+else:
+    print 'Force lvar width: hexrays is not available.'
+