[XRay][compiler-rt] Support patching/unpatching specific functions

Summary:
This change allows us to patch/unpatch specific functions using the
function ID. This is useful in cases where implementations might want to
do coverage-style, or more fine-grained control of which functions to
patch or un-patch at runtime.

Depends on D32693.

Reviewers: dblaikie, echristo, kpw

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D32695

llvm-svn: 302112

1 files changed, 4 insertions, 0 deletions

diff --git a/compiler-rt/lib/xray/xray_init.cc b/compiler-rt/lib/xray/xray_init.cc
index 6f558d65614..aa660baa992 100644
--- a/compiler-rt/lib/xray/xray_init.cc
+++ b/compiler-rt/lib/xray/xray_init.cc
@@ -25,6 +25,8 @@ extern "C" {
 void __xray_init();
 extern const XRaySledEntry __start_xray_instr_map[] __attribute__((weak));
 extern const XRaySledEntry __stop_xray_instr_map[] __attribute__((weak));
+extern const XRayFunctionSledIndex __start_xray_fn_idx[] __attribute__((weak));
+extern const XRayFunctionSledIndex __stop_xray_fn_idx[] __attribute__((weak));
 }
 
 using namespace __xray;
@@ -55,6 +57,8 @@ void __xray_init() XRAY_NEVER_INSTRUMENT {
     __sanitizer::SpinMutexLock Guard(&XRayInstrMapMutex);
     XRayInstrMap.Sleds = __start_xray_instr_map;
     XRayInstrMap.Entries = __stop_xray_instr_map - __start_xray_instr_map;
+    XRayInstrMap.SledsIndex = __start_xray_fn_idx;
+    XRayInstrMap.Functions = __stop_xray_fn_idx - __start_xray_fn_idx;
   }
   __sanitizer::atomic_store(&XRayInitialized, true,
                             __sanitizer::memory_order_release);