Hide some symbols to avoid a crash on shutdown when using code coverage

Summary:
gcov / gcda-based profiling crashes when shared libraries are unloaded

Patch by Benoit Belley and test by Marco Castelluccio for Firefox

See https://bugs.llvm.org/show_bug.cgi?id=27224 & https://bugzilla.mozilla.org/show_bug.cgi?id=1401230

Reviewers: davidxl, rnk, void

Subscribers: jessicah, marco-c, belleyb, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D38124

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@321703 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 32 insertions, 0 deletions

diff --git a/test/profile/Inputs/instrprof-dlopen-dlclose-main.c b/test/profile/Inputs/instrprof-dlopen-dlclose-main.c
new file mode 100644
index 000000000..fe7eaf0b5
--- /dev/null
+++ b/test/profile/Inputs/instrprof-dlopen-dlclose-main.c
@@ -0,0 +1,26 @@
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[]) {
+  dlerror();
+  void *f1_handle = dlopen("func.shared", RTLD_LAZY | RTLD_GLOBAL);
+  if (f1_handle == NULL) {
+    fprintf(stderr, "unable to open 'func.shared': %s\n", dlerror());
+    return EXIT_FAILURE;
+  }
+
+  void *f2_handle = dlopen("func2.shared", RTLD_LAZY | RTLD_GLOBAL);
+  if (f2_handle == NULL) {
+    fprintf(stderr, "unable to open 'func2.shared': %s\n", dlerror());
+    return EXIT_FAILURE;
+  }
+
+  if (dlclose(f2_handle) != 0) {
+    fprintf(stderr, "unable to close 'func2.shared': %s\n", dlerror());
+    return EXIT_FAILURE;
+  }
+
+  return EXIT_SUCCESS;
+}
+
diff --git a/test/profile/instrprof-dlopen-dlclose-gcov.test b/test/profile/instrprof-dlopen-dlclose-gcov.test
new file mode 100644
index 000000000..a785fe32d
--- /dev/null
+++ b/test/profile/instrprof-dlopen-dlclose-gcov.test
@@ -0,0 +1,6 @@
+RUN: mkdir -p %t.d
+RUN: %clang --coverage -o %t.d/func.shared -fPIC -shared %S/Inputs/instrprof-dlopen-func.c
+RUN: %clang --coverage -o %t.d/func2.shared -fPIC -shared %S/Inputs/instrprof-dlopen-func2.c
+RUN: %clang --coverage -o %t -fPIC -rpath %t.d %S/Inputs/instrprof-dlopen-dlclose-main.c
+
+RUN: %run %t