Enable remove_skip to soundly remove skips with labels

Author: tautschnig

src/goto-programs/remove_skip.cpp

@@ -12,7 +12,10 @@ Author: Daniel Kroening, [email protected]
 #include "remove_skip.h"
 #include "goto_model.h"
 
-bool is_skip(const goto_programt &body, goto_programt::const_targett it)
+bool is_skip(
+  const goto_programt &body,
+  goto_programt::const_targett it,
+  bool ignore_labels)
 {
   // we won't remove labelled statements
   // (think about error labels or the like)
@@ -100,7 +103,7 @@ void remove_skip(
       // for collecting labels
       std::list<irep_idt> labels;
 
-      while(is_skip(goto_program, it))
+      while(is_skip(goto_program, it, true))
       {
         // don't remove the last skip statement,
         // it could be a target

src/goto-programs/remove_skip.h

@@ -16,7 +16,10 @@ Author: Daniel Kroening, [email protected]
 
 class goto_modelt;
 
-bool is_skip(const goto_programt &, goto_programt::const_targett);
+bool is_skip(
+  const goto_programt &,
+  goto_programt::const_targett,
+  bool ignore_labels = false);
 void remove_skip(goto_programt &);
 void remove_skip(goto_functionst &);
 void remove_skip(goto_modelt &);