cross-project-tests/debuginfo-tests/dexter-tests/memvars/merged-store.c

   1 // XFAIL: *
   2 // Incorrect location for variable "parama", see PR48719.
   3
   4 // REQUIRES: lldb
   5 // UNSUPPORTED: system-windows
   6 // RUN: %clang -std=gnu11 -O3 -glldb %s -o %t
   7 // RUN: %dexter --fail-lt 1.0 -w --debugger lldb --binary %t -- %s
   8
   9 // 1. parama is escaped by esc(&parama) so it is not promoted by
  10 //    SROA/mem2reg.
  11 // 2. InstCombine's LowerDbgDeclare converts the dbg.declare to a set of
  12 //    dbg.values (tracking the stored SSA values).
  13 // 3. InstCombine replaces the two stores to parama's alloca (the initial
  14 //    parameter register store in entry and the assignment in if.then) with a
  15 //    PHI+store in the common sucessor.
  16 // 4. SimplifyCFG folds the blocks together and converts the PHI to a
  17 //    select.
  18
  19 // The debug info is not updated to account for the merged value in the
  20 // sucessor prior to SimplifyCFG when it exists as a PHI, or during when it
  21 // becomes a select. As a result we see parama=5 for the entire function, when
  22 // we'd expect to see param=20 when stepping onto fluff().
  23
  24 __attribute__((optnone))
  25 void esc(int* p) {}
  26
  27 __attribute__((optnone))
  28 void fluff() {}
  29
  30 __attribute__((noinline))
  31 int fun(int parama, int paramb) {
  32   if (parama)
  33     parama = paramb;
  34   fluff();           // DexLabel('s0')
  35   esc(&parama);
  36   return 0;
  37 }
  38
  39 int main() {
  40   return fun(5, 20);
  41 }
  42
  43 // DexExpectWatchValue('parama', 20, on_line=ref('s0'))