Hey Will, Thanks for the quick reply. Yeah I need the int3 instruction to be statically included in he binary so I can't use any dynamic instrumentation tool.
On Fri, Oct 23, 2015 at 10:32 AM, William Cohen <wco...@redhat.com> wrote: > On 10/23/2015 01:37 AM, Yasser Shalabi wrote: >> Hello, >> >> I am new to the GCC code. I want to make a simple modification to the >> back end. I want to add a debug exception (int3) to be generated >> before any instance of certain x86 instructions. >> >> I tried to modify gcc/config/i386/i386.md by adding a "int3" to the >> define_insn for instructions of interest. But that just caused >> configure to fail (cannot run generated C programs). >> >> Any pointers on how to approach this? Also, suggestions for >> alternative approaches are also welcome. >> >> Thanks! >> > > Hi, > > Do you need the int3 specifically before those instructions? Or are you just > looking to instrument the code and collect some information before those > instructions are executed? Some alternative instrumentation tools you might > look at to instrument existing code are: > > dyninst http://www.dyninst.org/ > Valgrind http://valgrind.org/ > Intel's Pin tool > https://software.intel.com/en-us/articles/pin-a-dynamic-binary-instrumentation-tool > > -Will
