InstrProf: Test the functions in the runtime

Check that the profile runtime works as expected.  This tests the
functions that are meant to be available to advanced users.

In particular, check that the `atexit()` hook can be disabled by
defining a custom `__llvm_profile_runtime` variable, that the libc
dependencies are optional, and that the various functions for writing
out files work for basic cases.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@208460 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 30 insertions, 0 deletions

diff --git a/test/profile/instrprof-write-file-only.c b/test/profile/instrprof-write-file-only.c
new file mode 100644
index 000000000..b9a1be4c0
--- /dev/null
+++ b/test/profile/instrprof-write-file-only.c
@@ -0,0 +1,30 @@
+// RUN: %clang_profgen -o %t -O3 %s
+// RUN: env LLVM_PROFILE_FILE=%t.profraw %run %t
+// RUN: llvm-profdata merge -o %t.profdata %t.profraw
+// RUN: %clang_profuse=%t.profdata -o - -S -emit-llvm %s | FileCheck %s
+
+int __llvm_profile_runtime = 0;
+int __llvm_profile_write_file(void);
+void __llvm_profile_set_filename(const char *);
+int foo(int);
+int main(int argc, const char *argv[]) {
+  // CHECK-LABEL: define i32 @main
+  // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}, !prof !1
+  if (argc > 1)
+    return 1;
+
+  // Write out the profile.
+  __llvm_profile_write_file();
+
+  // Change the profile.
+  return foo(0);
+}
+int foo(int X) {
+  // There should be no profiling information for @foo, since it was called
+  // after the profile was written (and the atexit was supressed by defining
+  // profile_runtime).
+  // CHECK-LABEL: define i32 @foo
+  // CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{[^,]+$}}
+  return X <= 0 ? -X : X;
+}
+// CHECK: !1 = metadata !{metadata !"branch_weights", i32 1, i32 2}