1 files changed, 44 insertions, 0 deletions
diff --git a/toolchain-extras/profile-globals.c b/toolchain-extras/profile-globals.c
new file mode 100644
index 00000000..309f0606
--- /dev/null
+++ b/toolchain-extras/profile-globals.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+// This file provides a wrapper for getenv that appends the userid (geteuid())
+// of the current process to GCOV_PREFIX.  This avoids conflicts and permissions
+// issues when different processes try to create/access the same directories and
+// files under $GCOV_PREFIX.
+//
+// When this file is linked to a binary, the -Wl,--wrap,getenv flag must be
+// used.  The linker redirects calls to getenv to __wrap_getenv and sets
+// __real_getenv to point to libc's getenv.
+
+char *__real_getenv(const char *name);
+
+static char modified_gcov_prefix[128];
+
+__attribute__((weak)) char *__wrap_getenv(const char *name) {
+  if (strcmp(name, "GCOV_PREFIX") != 0) {
+    return __real_getenv(name);
+  }
+
+  sprintf(modified_gcov_prefix, "%s/%u", __real_getenv(name), geteuid());
+  mkdir(modified_gcov_prefix, 0777);
+  return modified_gcov_prefix;
+}