Surface ASAN errors

Reviewed By: alexmalyshev

Differential Revision: D56644394

fbshipit-source-id: bd2ebd296ddfa0b00a8f3ac9f85330282710a614

cinderx/PythonBin/python.c

@@ -1,17 +1,42 @@
-/* Minimal main program -- everything is loaded from the library */
 
 #include "Python.h"
 
-#ifdef MS_WINDOWS
-int
-wmain(int argc, wchar_t **argv)
-{
-    return Py_Main(argc, argv);
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+
+// In Meta's setup, ASAN_OPTIONS set in an environment variable are ignored.
+// However, we want to respect the log_path we set via cinder_test_runner.py
+// for use by sub-processes of individual tests.
+__attribute__((weak)) void __sanitizer_set_report_fd(void *);
+
+void open_asan_logfile(void) {
+    if (__sanitizer_set_report_fd == NULL) {
+        return;
+    }
+
+    char* asan_options = getenv("ASAN_OPTIONS");
+    if (asan_options == NULL) {
+        return;
+    }
+
+    char* tokenptr = NULL;
+    char* token = strtok_r(asan_options, ",", &tokenptr);
+    const char* log_path_str = "log_path=";
+    const int log_path_len = strlen(log_path_str);
+    while (token != NULL) {
+        if (strncmp(token, log_path_str, log_path_len) == 0) {
+            char* filename = token + log_path_len;
+            int fd = open(filename, O_WRONLY | O_APPEND | O_CREAT, 0666);
+            __sanitizer_set_report_fd((void*)(uintptr_t)fd);
+            break;
+        }
+        token = strtok_r(NULL, ",", &tokenptr);
+    }
 }
-#else
-int
-main(int argc, char **argv)
-{
+
+int main(int argc, char **argv) {
+    open_asan_logfile();
     return Py_BytesMain(argc, argv);
 }
-#endif

cinderx/TestScripts/cinder_test_runner.py

@@ -291,10 +291,10 @@ def __init__(self) -> None:
         self._log_path_base = None
         self._base_asan_options = None
 
-        asan_options = os.environ.get('ASAN_OPTIONS')
-        if asan_options is None:
+        if not is_asan_build():
             return
 
+        asan_options = os.environ.get('ASAN_OPTIONS', '')
         log_path_base = None
         for option in asan_options.split(','):
             if option.startswith('log_path='):