llvm/test/tools/dsymutil/X86/Inputs/tail-call.cpp

   1 /*
   2  * This file is used to test dsymutil support for call site entries with tail
   3  * calls (DW_AT_call_pc).
   4  *
   5  * Instructions for regenerating binaries (on Darwin/x86_64):
   6  *
   7  * 1. Copy the source to a top-level directory to work around having absolute
   8  *    paths in the symtab's OSO entries.
   9  *
  10  *    mkdir -p /Inputs/ && cp tail-call.c /Inputs && cd /Inputs
  11  *
  12  * 2. Compile with call site info enabled. -O2 is used to get tail call
  13  *    promotion.
  14  *
  15  *    clang -g -O2 tail-call.c -c -o tail-call.macho.x86_64.o
  16  *    clang tail-call.macho.x86_64.o -o tail-call.macho.x86_64
  17  *
  18  * 3. Copy the binaries back into the repo's Inputs directory. You'll need
  19  *    -oso-prepend-path=%p to link.
  20  */
  21
  22 volatile int x;
  23
  24 __attribute__((disable_tail_calls, noinline)) void func2() { x++; }
  25
  26 __attribute__((noinline)) void func1() { func2(); /* tail */ }
  27
  28 __attribute__((disable_tail_calls)) int main() { func1(); /* regular */ }