HelloPass

Hello_Pass

This pass is designed to simply print out the name of non-external functions that exist in the program being compiled. It does not modify the program at all, it just inspects it and count the number of times that each opcode appears in a given function .

Build

mkdir build && cd build
cmake ../
make

Test

1- generate bytecode from source file

clang -emit-llvm test.c -c -o test.bc

2- run the pass on it

opt -load-pass-plugin=./build/LLVMPassSample/libHelloNewPMPass.so -passes="hello-new-pm-pass" -S test.bc -o=test.ll

Example :

• Source file :

#include <stdio.h>
int foo(int a,int b) {
  return b+a;
}
int goo(int a,int b) {
  return b-a;
}
int main() {
  int a,b;
  a=foo(3,4);
  b=goo(3,4);
  a = a/b;
  return a;
}

• result :

Function : foo
 add: 1
 alloca: 2
 load: 2
 ret: 1
 store: 2
Function : goo
 alloca: 2
 load: 2
 ret: 1
 store: 2
 sub: 1
Function : main
 alloca: 3
 call: 2
 load: 3
 ret: 1
 sdiv: 1
 store: 4