llvm-project/debuginfo-tests/dexter-tests/memvars/loop.c

57 lines
1.7 KiB
C

// XFAIL: *
//// Suboptimal coverage, see below.
// REQUIRES: lldb
// UNSUPPORTED: system-windows
// RUN: %dexter --fail-lt 1.0 -w --debugger lldb \
// RUN: --builder 'clang-c' --cflags "-O3 -glldb" -- %s
//// Check that escaped local 'param' in function 'fun' has sensible debug info
//// after the escaping function 'use' gets arg promotion (int* -> int). Currently
//// we lose track of param after the loop header.
int g = 0;
//// A no-inline, read-only function with internal linkage is a good candidate
//// for arg promotion.
__attribute__((__noinline__))
static void use(const int* p) {
//// Promoted args would be a good candidate for an DW_OP_implicit_pointer.
//// This desirable behaviour is checked for in the test implicit-ptr.c.
g = *p;
}
__attribute__((__noinline__))
void do_thing(int x) {
g *= x;
}
__attribute__((__noinline__))
int fun(int param) {
do_thing(0); // DexLabel('s2')
for (int i = 0; i < param; ++i) {
use(&param);
}
//// x86 loop body looks like this, with param in ebx:
//// 4004b0: mov edi,ebx
//// 4004b2: call 4004d0 <_ZL3usePKi>
//// 4004b7: add ebp,0xffffffff
//// 4004ba: jne 4004b0 <_Z3funi+0x20>
//// But we lose track of param's location before the loop:
//// DW_TAG_formal_parameter
//// DW_AT_location (0x00000039:
//// [0x0000000000400490, 0x0000000000400495): DW_OP_reg5 RDI
//// [0x0000000000400495, 0x00000000004004a2): DW_OP_reg3 RBX)
//// DW_AT_name ("param")
return g; // DexLabel('s3')
}
int main() {
return fun(5);
}
// DexExpectWatchValue('*p', 5, 5, 5, 5, 5, on_line='s1')
// DexExpectWatchValue('param', 5, from_line='s2', to_line='s3')