LLVM Pass Development

Find more on my blog: LLVM Pass Development I: Branch-Pointer Trace

It's for LLVM 17.

Contribution

Biqing Su(bsu5)

Compile & Run

1. Make the script executable by running chmod +x setup_and_run.sh in the terminal.
2. Execute the script by typing ./setup_and_run.sh.

Input

#include <stdio.h>

int c;

void fun(int a) {
  printf("Value of a is %d\n", a);
}

int main() {
  void (*fun_ptr)(int) = &fun;
  (*fun_ptr)(10);

  int b;
  for (c = 0; c < 3; c++) {
    b = c + 1;
  }

  return c;
}

Output

main: func_0x147e4af98
Branch Dictionary:
br_0: test1.c, 14, 15
br_1: test1.c, 14, 18
Value of a is 10
br_0
br_0
br_0
br_1

Manually Compile & Run

$ mkdir build
$ cd build
$ cmake ..
$ make
$ cd ..

$ cc -c logPrint.c
$ clang -fpass-plugin='build/skeleton/SkeletonPass.dylib' -c test1.c -g
$ cc test1.o logPrint.o
$ ./a.out

Test Files

test1.c

• Type: small contrived program
• Code source: from project description
• Run test: execute the setup_and_run.sh script.
• Result:

test2.c

• Type: small contrived program
• Code source: generate by gpt4
• Run test: change test1 to test2 in setup_and_run.sh before executing the script.
• Result:

test3.c

• Type: real-world substitute
• Code source: Employee Management System github link
• Number of non-comment non-blank lines: 583 lines
• Changes made: added function getch; moved the main to the end.
• Run test: change test1 to test3 in setup_and_run.sh before executing the script.
• Result: