Program slice on function pointers

example-debug.ll

; ModuleID = 'example_2.bc'
source_filename = "example_2.c"
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"

%struct.test_type_t = type { i8*, i32, i32 (%struct.test_type_t*)* }

@test_instance_2 = internal global %struct.test_type_t { i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.1, i32 0, i32 0), i32 0, i32 (%struct.test_type_t*)* @a_func }, align 8
@.str = private unnamed_addr constant [36 x i8] c"after calling the function pointer\0A\00", align 1
@.str.1 = private unnamed_addr constant [11 x i8] c"instance 2\00", align 1

; -- Generated by llvm-slicer --
;   * slicing criteria: 'a_func'
;   * secondary slicing criteria: ''
;   * forward slice: '0'
;   * remove slicing criteria: '0'
;   * undefined are pure: '0'
;   * pointer analysis: flow-sensitive
;   * PTA field sensitivity: full

; Function Attrs: noinline nounwind optnone uwtable
define dso_local i32 @main(i32, i8**) #0 {
  ; x   %3 = alloca i32, align 4
  ; x   %4 = alloca i32, align 4
  ; x   %5 = alloca i8**, align 8
  ; x   %6 = alloca %struct.test_type_t*, align 8
  ; x   store i32 0, i32* %3, align 4
  ; x   store i32 %0, i32* %4, align 4
  ; x   store i8** %1, i8*** %5, align 8
  ; x   store %struct.test_type_t* @test_instance_2, %struct.test_type_t** %6, align 8
  ; x   %7 = load %struct.test_type_t*, %struct.test_type_t** %6, align 8
  ; x   %8 = getelementptr inbounds %struct.test_type_t, %struct.test_type_t* %7, i32 0, i32 2
  ; x   %9 = load i32 (%struct.test_type_t*)*, i32 (%struct.test_type_t*)** %8, align 8
  ; x   %10 = load %struct.test_type_t*, %struct.test_type_t** %6, align 8
  ; x   %11 = call i32 %9(%struct.test_type_t* %10)
  ; x   %12 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([36 x i8], [36 x i8]* @.str, i32 0, i32 0))
  ; x   ret i32 0
}

declare dso_local i32 @printf(i8*, ...) #1

; Function Attrs: noinline nounwind optnone uwtable
define internal i32 @a_func(%struct.test_type_t*) #0 {
  %2 = alloca %struct.test_type_t*, align 8
  store %struct.test_type_t* %0, %struct.test_type_t** %2, align 8
  ret i32 1
}

attributes #0 = { noinline nounwind optnone uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }

!llvm.module.flags = !{!0}
!llvm.ident = !{!1}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{!"clang version 8.0.0-3~ubuntu18.04.2 (tags/RELEASE_800/final)"}

example.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

struct test_type_t {
    char *type_name;
    int type;
    int (*func_p)(struct test_type_t *tttttttt);
};

static int a_func(struct test_type_t *tttttttt) {
    return 1;
}

static struct test_type_t test_instance_2 = {
    .type_name = "instance 2",
    .type = 0,
    .func_p = a_func,
};

int main(int argc, char const *argv[]) {
    struct test_type_t *tt = &test_instance_2;

    tt->func_p(tt);

    printf("after calling the function pointer\n");

    return 0;
}

example.pta-dump.log

NODE   4: i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.1, i32 0, i32  ... (points-to size: 1)
    -> @.str.1 = private unnamed_addr constant [11 x i8] c\"instance 2\00\", al ... + 0
NODE   7: a_func (points-to size: 1)
    -> a_func + 0
NODE  10: <10> PSNodeType::ENTRY (points-to size: 0)
NODE  11: i32 %0 (points-to size: 0)
NODE  12: i8** %1 (points-to size: 0)
NODE  13:   %3 = alloca i32, align 4 [size: 4, heap: 0, zeroed: 0] (points-to size: 1)
    ->   %3 = alloca i32, align 4 + 0
NODE  14:   %4 = alloca i32, align 4 [size: 4, heap: 0, zeroed: 0] (points-to size: 1)
    ->   %4 = alloca i32, align 4 + 0
NODE  15:   %5 = alloca i8**, align 8 [size: 8, heap: 0, zeroed: 0] (points-to size: 1)
    ->   %5 = alloca i8**, align 8 + 0
NODE  16:   %6 = alloca %struct.test_type_t*, align 8 [size: 8, heap: 0, zeroed: 0] (points-to size: 1)
    ->   %6 = alloca %struct.test_type_t*, align 8 + 0
NODE  17:   store i32 0, i32* %3, align 4 (points-to size: 0)
NODE  18:   store i32 %0, i32* %4, align 4 (points-to size: 0)
NODE  19:   store i8** %1, i8*** %5, align 8 (points-to size: 0)
NODE  20:   store %struct.test_type_t* @test_instance_2, %struct.test_type_t** % ... (points-to size: 0)
NODE  21:   %7 = load %struct.test_type_t*, %struct.test_type_t** %6, align 8 (points-to size: 1)
    -> @test_instance_2 = internal global %struct.test_type_t { i8* getelemen ... + 0
NODE  22:   %8 = getelementptr inbounds %struct.test_type_t, %struct.test_type_t ... (points-to size: 1)
    -> @test_instance_2 = internal global %struct.test_type_t { i8* getelemen ... + 16
NODE  23:   %9 = load i32 (%struct.test_type_t*)*, i32 (%struct.test_type_t*)**  ... (points-to size: 1)
    -> null + 0
NODE  24:   %10 = load %struct.test_type_t*, %struct.test_type_t** %6, align 8 (points-to size: 1)
    -> @test_instance_2 = internal global %struct.test_type_t { i8* getelemen ... + 0
NODE  25:   %11 = call i32 %9(%struct.test_type_t* %10) (points-to size: 0)
NODE  26:   %11 = call i32 %9(%struct.test_type_t* %10) (points-to size: 0)
NODE  27:   %12 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([36 x  ... (points-to size: 1)
    -> unknown + Offset::UNKNOWN
NODE  28:   ret i32 0 (points-to size: 1)
    -> null + 0

Process finished with exit code 0