[ASan] move flags description to separate header, add comments about them.

llvm-svn: 159985

4 files changed, 102 insertions, 47 deletions

diff --git a/compiler-rt/lib/asan/asan_flags.h b/compiler-rt/lib/asan/asan_flags.h
new file mode 100644
index 00000000000..2d5249a1a13
--- /dev/null
+++ b/compiler-rt/lib/asan/asan_flags.h
@@ -0,0 +1,97 @@
+//===-- asan_flags.h -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// ASan runtime flags.
+//===----------------------------------------------------------------------===//
+
+#ifndef ASAN_FLAGS_H
+#define ASAN_FLAGS_H
+
+#include "sanitizer_common/sanitizer_interface_defs.h"
+
+// ASan flag values can be defined in three ways:
+// 1) initialized with default values at startup.
+// 2) overriden from user-specified string __asan_default_options.
+// 3) overriden from env variable ASAN_OPTIONS.
+
+extern "C" {
+#if !defined(_WIN32)
+  // We do not need to redefine the defaults right now on Windows.
+  char *__asan_default_options SANITIZER_WEAK_ATTRIBUTE;
+#endif
+}
+
+namespace __asan {
+
+struct Flags {
+  // Size (in bytes) of quarantine used to detect use-after-free errors.
+  // Lower value may reduce memory usage but increase the chance of
+  // false negatives.
+  int  quarantine_size;
+  // If set, uses in-process symbolizer from common sanitizer runtime.
+  bool symbolize;
+  // Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).
+  int  verbosity;
+  // Size (in bytes) of redzones around heap objects.
+  // Requirement: redzone >= 32, is a power of two.
+  int  redzone;
+  // If set, prints some debugging information and does additional checks.
+  bool debug;
+  // Controls the way to handle globals (0 - don't detect buffer overflow
+  // on globals, 1 - detect buffer overflow, 2 - print data about registered
+  // globals).
+  int  report_globals;
+  // Max number of stack frames kept for each allocation.
+  int  malloc_context_size;
+  // If set, uses custom wrappers and replacements for libc string functions
+  // to find more errors.
+  bool replace_str;
+  // If set, uses custom wrappers for memset/memcpy/memmove intinsics.
+  bool replace_intrin;
+  // Used on Mac only. See comments in asan_mac.cc and asan_malloc_mac.cc.
+  bool replace_cfallocator;
+  // Used on Mac only.
+  bool mac_ignore_invalid_free;
+  // ASan allocator flag. See asan_allocator.cc.
+  bool use_fake_stack;
+  // ASan allocator flag. Sets the maximal size of allocation request
+  // that would return memory filled with zero bytes.
+  int  max_malloc_fill_size;
+  // Override exit status if something was reported.
+  int  exitcode;
+  // If set, user may manually mark memory regions as poisoned or unpoisoned.
+  bool allow_user_poisoning;
+  // Number of seconds to sleep between printing an error report and
+  // terminating application. Useful for debug purposes (when one needs
+  // to attach gdb, for example).
+  int  sleep_before_dying;
+  // If set, registers ASan custom segv handler.
+  bool handle_segv;
+  // If set, uses alternate stack for signal handling.
+  bool use_sigaltstack;
+  // Allow the users to work around the bug in Nvidia drivers prior to 295.*.
+  bool check_malloc_usable_size;
+  // If set, explicitly unmaps (huge) shadow at exit.
+  bool unmap_shadow_on_exit;
+  // If set, calls abort() instead of _exit() after printing an error report.
+  bool abort_on_error;
+  // If set, prints ASan exit stats even after program terminates successfully.
+  bool atexit;
+  // By default, disable core dumper on 64-bit - it makes little sense
+  // to dump 16T+ core.
+  bool disable_core;
+};
+Flags *flags();
+void InitializeFlags(Flags *f, const char *env);
+
+}  // namespace __asan
+
+#endif  // ASAN_FLAGS_H
diff --git a/compiler-rt/lib/asan/asan_interface.h b/compiler-rt/lib/asan/asan_interface.h
index 167354e7bce..c625a6217c0 100644
--- a/compiler-rt/lib/asan/asan_interface.h
+++ b/compiler-rt/lib/asan/asan_interface.h
@@ -154,10 +154,6 @@ extern "C" {
   // Prints accumulated stats to stderr. Used for debugging.
   void __asan_print_accumulated_stats()
       SANITIZER_INTERFACE_ATTRIBUTE;
-#if !defined(_WIN32)
-  // We do not need to redefine the defaults right now on Windows.
-  char *__asan_default_options SANITIZER_WEAK_ATTRIBUTE;
-#endif
 }  // namespace
 
 #endif  // ASAN_INTERFACE_H
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
index 831b76128aa..4f6d9e37b56 100644
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -14,6 +14,7 @@
 #ifndef ASAN_INTERNAL_H
 #define ASAN_INTERNAL_H
 
+#include "asan_flags.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_internal_defs.h"
 #include "sanitizer_common/sanitizer_libc.h"
@@ -136,34 +137,6 @@ bool PlatformHasDifferentMemcpyAndMemmove();
 # define PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE true
 #endif  // __APPLE__
 
-struct Flags {
-  int quarantine_size;
-  bool symbolize;
-  int  verbosity;
-  int redzone;
-  int  debug;
-  int  report_globals;
-  int malloc_context_size;
-  bool replace_str;
-  bool replace_intrin;
-  bool replace_cfallocator;
-  bool mac_ignore_invalid_free;
-  bool use_fake_stack;
-  int max_malloc_fill_size;
-  int  exitcode;
-  bool allow_user_poisoning;
-  int  sleep_before_dying;
-  bool handle_segv;
-  bool use_sigaltstack;
-  bool check_malloc_usable_size;
-  bool unmap_shadow_on_exit;
-  bool abort_on_error;
-  bool atexit;
-  bool disable_core;
-};
-Flags *flags();
-void InitializeFlags(Flags *f, const char *env);
-
 extern int asan_inited;
 // Used to avoid infinite recursion in __asan_init().
 extern bool asan_init_is_running;
diff --git a/compiler-rt/lib/asan/asan_rtl.cc b/compiler-rt/lib/asan/asan_rtl.cc
index 14e33340270..4da1f24ba22 100644
--- a/compiler-rt/lib/asan/asan_rtl.cc
+++ b/compiler-rt/lib/asan/asan_rtl.cc
@@ -67,11 +67,6 @@ Flags *flags() {
   return &asan_flags;
 }
 
-// Can be overriden in frontend.
-void WEAK OverrideFlags(Flags *f) {
-  (void)f;
-}
-
 static void ParseFlagsFromString(Flags *f, const char *str) {
   ParseFlag(str, &f->quarantine_size, "quarantine_size");
   ParseFlag(str, &f->symbolize, "symbolize");
@@ -96,13 +91,10 @@ static void ParseFlagsFromString(Flags *f, const char *str) {
   ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying");
   ParseFlag(str, &f->handle_segv, "handle_segv");
   ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
-  // Allow the users to work around the bug in Nvidia drivers prior to 295.*.
   ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size");
   ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit");
   ParseFlag(str, &f->abort_on_error, "abort_on_error");
   ParseFlag(str, &f->atexit, "atexit");
-  // By default, disable core dumper on 64-bit --
-  // it makes little sense to dump 16T+ core.
   ParseFlag(str, &f->disable_core, "disable_core");
 }
 
@@ -112,14 +104,14 @@ void InitializeFlags(Flags *f, const char *env) {
   f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28;
   f->symbolize = false;
   f->verbosity = 0;
-  f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128;  // power of two, >= 32.
-  f->debug = 0;
+  f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128;
+  f->debug = false;
   f->report_globals = 1;
   f->malloc_context_size = kMallocContextSize;
   f->replace_str = true;
   f->replace_intrin = true;
-  f->replace_cfallocator = true;  // Used on Mac only.
-  f->mac_ignore_invalid_free = false;  // Used on Mac only.
+  f->replace_cfallocator = true;
+  f->mac_ignore_invalid_free = false;
   f->use_fake_stack = true;
   f->max_malloc_fill_size = 0;
   f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
@@ -133,9 +125,6 @@ void InitializeFlags(Flags *f, const char *env) {
   f->atexit = false;
   f->disable_core = (__WORDSIZE == 64);
 
-  // Let a frontend override.
-  OverrideFlags(f);
-
   // Override from user-specified string.
 #if !defined(_WIN32)
   if (__asan_default_options) {