lldb-bugs.sh

lldb-bugs.sh

#!/bin/bash

cat >dso1.c <<EOF
#include <stdio.h>
void foo(void) {
  printf("foo");
  printf("\n");
}
EOF

cat >dso2.c <<EOF
#include <stdio.h>
void bar(void) {
  printf("bar");
  printf("\n");
}
EOF

cat >main.c <<EOF
#include <assert.h>
#include <dlfcn.h>
void foo(void);
void* not_dlopen(const char* path, int flags) {
  return (void*)0;
}
int main() {
  void* dso2;
  // Demonstrate bugs in LLDB 12:
  //  - With musl-gcc, stepping over foo() doesn't work:
  //    step over failed (Could not create return address breakpoint. Return
  //    address (0x7fffffffdde8) did not point to executable memory.)
  //  - With gcc or clang (glibc), when stepping over a dlopen call that loads
  //    a library (i.e. the second call), the program doesn't stop and instead
  //    runs to completion.
  foo();
  dso2 = dlopen("libdso2.so", RTLD_NOW | RTLD_LOCAL | RTLD_NOLOAD);
  dso2 = dlopen("libdso2.so", RTLD_NOW | RTLD_LOCAL);
  dso2 = dlopen("libdso2.so", RTLD_NOW | RTLD_LOCAL);
  void (*bar)(void) = dlsym(dso2, "bar");
  assert(bar);
  bar();
  return 0;
}
EOF

CC=musl-gcc
#CC=clang
DL=
#DL=-ldl

$CC -g dso1.c -fpic -shared -o libdso1.so
$CC -g dso2.c -fpic -shared -o libdso2.so
$CC -g main.c libdso1.so -o main $DL -Wl,-rpath,'$ORIGIN'