[XRay] [compiler-rt] Allow logging the first argument of a function call.

Summary:
Functions with the LOG_ARGS_ENTRY sled kind at their beginning will be handled
in a way to (optionally) pass their first call argument to your logging handler.

For practical and performance reasons, only the first argument is supported, and
only up to 64 bits.

Reviewers: javed.absar, dberris

Reviewed By: dberris

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29703

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@297000 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 41 insertions, 0 deletions

diff --git a/test/xray/TestCases/Linux/arg1-logger.cc b/test/xray/TestCases/Linux/arg1-logger.cc
new file mode 100644
index 000000000..3140f4c88
--- /dev/null
+++ b/test/xray/TestCases/Linux/arg1-logger.cc
@@ -0,0 +1,41 @@
+// Check that we can get the first function argument logged
+// using a custom logging function.
+//
+// RUN: %clangxx_xray -std=c++11 %s -o %t
+// RUN: XRAY_OPTIONS="patch_premain=true verbosity=1 xray_logfile_base=arg1-logger-" %run %t 2>&1 | FileCheck %s
+//
+// After all that, clean up the XRay log file.
+//
+// RUN: rm arg1-logger-*
+//
+// At the time of writing, the ARM trampolines weren't written yet.
+// XFAIL: arm || aarch64
+
+#include "xray/xray_interface.h"
+
+#include <cinttypes>
+#include <cstdio>
+
+void arg1logger(int32_t fn, XRayEntryType t, uint64_t a1) {
+  printf("Arg1: %" PRIx64 ", XRayEntryType %u\n", a1, t);
+}
+
+[[clang::xray_always_instrument, clang::xray_log_args(1)]] void foo(void *) {}
+
+int main() {
+  // CHECK: XRay: Log file in 'arg1-logger-{{.*}}'
+
+  __xray_set_handler_arg1(arg1logger);
+  foo(nullptr);
+  // CHECK: Arg1: 0, XRayEntryType 0
+
+  __xray_remove_handler_arg1();
+  foo((void *) 0xBADC0DE);
+  // nothing expected to see here
+
+  __xray_set_handler_arg1(arg1logger);
+  foo((void *) 0xDEADBEEFCAFE);
+  // CHECK-NEXT: Arg1: deadbeefcafe, XRayEntryType 0
+  foo((void *) -1);
+  // CHECK-NEXT: Arg1: ffffffffffffffff, XRayEntryType 0
+}