[asan] two more internal flags for asan-rt: print_stats (0) and print_legend (1) 

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173671 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/asan/asan_flags.h b/lib/asan/asan_flags.h
index d7b21ea..6c235bf 100644
--- a/lib/asan/asan_flags.h
+++ b/lib/asan/asan_flags.h
@@ -79,6 +79,10 @@
   bool unmap_shadow_on_exit;
   // If set, calls abort() instead of _exit() after printing an error report.
   bool abort_on_error;
+  // Print various statistics after printing an error message or if atexit=1.
+  bool print_stats;
+  // Print the legend for the shadow bytes.
+  bool print_legend;
   // 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
diff --git a/lib/asan/asan_report.cc b/lib/asan/asan_report.cc
index cf57f62..c381f4f 100644
--- a/lib/asan/asan_report.cc
+++ b/lib/asan/asan_report.cc
@@ -120,19 +120,7 @@
   Printf("\n");
 }
 
-static void PrintShadowMemoryForAddress(uptr addr) {
-  if (!AddrIsInMem(addr))
-    return;
-  uptr shadow_addr = MemToShadow(addr);
-  const uptr n_bytes_per_row = 16;
-  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
-  Printf("Shadow bytes around the buggy address:\n");
-  for (int i = -5; i <= 5; i++) {
-    const char *prefix = (i == 0) ? "=>" : "  ";
-    PrintShadowBytes(prefix,
-                     (u8*)(aligned_shadow + i * n_bytes_per_row),
-                     (u8*)shadow_addr, n_bytes_per_row);
-  }
+static void PrintLegend() {
   Printf("Shadow byte legend (one shadow byte represents %d "
          "application bytes):\n", (int)SHADOW_GRANULARITY);
   PrintShadowByte("  Addressable:           ", 0);
@@ -155,6 +143,23 @@
   PrintShadowByte("  ASan internal:         ", kAsanInternalHeapMagic);
 }
 
+static void PrintShadowMemoryForAddress(uptr addr) {
+  if (!AddrIsInMem(addr))
+    return;
+  uptr shadow_addr = MemToShadow(addr);
+  const uptr n_bytes_per_row = 16;
+  uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
+  Printf("Shadow bytes around the buggy address:\n");
+  for (int i = -5; i <= 5; i++) {
+    const char *prefix = (i == 0) ? "=>" : "  ";
+    PrintShadowBytes(prefix,
+                     (u8*)(aligned_shadow + i * n_bytes_per_row),
+                     (u8*)shadow_addr, n_bytes_per_row);
+  }
+  if (flags()->print_legend)
+    PrintLegend();
+}
+
 static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
                                 const char *zone_name) {
   if (zone_ptr) {
@@ -446,7 +451,8 @@
       DescribeThread(curr_thread->summary());
     }
     // Print memory stats.
-    __asan_print_accumulated_stats();
+    if (flags()->print_stats)
+      __asan_print_accumulated_stats();
     if (error_report_callback) {
       error_report_callback(error_message_buffer);
     }
diff --git a/lib/asan/asan_rtl.cc b/lib/asan/asan_rtl.cc
index 8ea5449..d16f1e3 100644
--- a/lib/asan/asan_rtl.cc
+++ b/lib/asan/asan_rtl.cc
@@ -97,6 +97,8 @@
   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->print_stats, "print_stats");
+  ParseFlag(str, &f->print_legend, "print_legend");
   ParseFlag(str, &f->atexit, "atexit");
   ParseFlag(str, &f->disable_core, "disable_core");
   ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix");
@@ -135,6 +137,8 @@
   f->check_malloc_usable_size = true;
   f->unmap_shadow_on_exit = false;
   f->abort_on_error = false;
+  f->print_stats = false;
+  f->print_legend = true;
   f->atexit = false;
   f->disable_core = (SANITIZER_WORDSIZE == 64);
   f->strip_path_prefix = "";