From: Alexey Samsonov <vonosmas@gmail.com>
Date: Wed, 22 Apr 2015 20:30:15 +0000 (+0000)
Subject: [ASan] Refactor functions searching/describing globals. NFC.
X-Git-Tag: llvmorg-3.7.0-rc1~6222
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e74ec45b88028c085a97cf28e106b6ba73eff236;p=platform%2Fupstream%2Fllvm.git

[ASan] Refactor functions searching/describing globals. NFC.

llvm-svn: 235539
---

diff --git a/compiler-rt/lib/asan/asan_globals.cc b/compiler-rt/lib/asan/asan_globals.cc
index 8906d1e..65916f9 100644
--- a/compiler-rt/lib/asan/asan_globals.cc
+++ b/compiler-rt/lib/asan/asan_globals.cc
@@ -74,7 +74,7 @@ ALWAYS_INLINE void PoisonRedZones(const Global &g) {
 
 const uptr kMinimalDistanceFromAnotherGlobal = 64;
 
-bool IsAddressNearGlobal(uptr addr, const __asan_global &g) {
+static bool IsAddressNearGlobal(uptr addr, const __asan_global &g) {
   if (addr <= g.beg - kMinimalDistanceFromAnotherGlobal) return false;
   if (addr >= g.beg + g.size_with_redzone) return false;
   return true;
@@ -91,36 +91,27 @@ static void ReportGlobal(const Global &g, const char *prefix) {
   }
 }
 
-static bool DescribeOrGetInfoIfGlobal(uptr addr, uptr size, bool print,
-                                      Global *output_global) {
-  if (!flags()->report_globals) return false;
+// Returns the number of globals close to the provided address and copies
+// them to "globals" array.
+int GetGlobalsForAddress(uptr addr, Global *globals, int max_globals) {
+  if (!flags()->report_globals) return 0;
   BlockingMutexLock lock(&mu_for_globals);
-  bool res = false;
+  int res = 0;
   for (ListOfGlobals *l = list_of_all_globals; l; l = l->next) {
     const Global &g = *l->g;
-    if (print) {
-      if (flags()->report_globals >= 2)
-        ReportGlobal(g, "Search");
-      res |= DescribeAddressRelativeToGlobal(addr, size, g);
-    } else {
-      if (IsAddressNearGlobal(addr, g)) {
-        CHECK(output_global);
-        *output_global = g;
-        return true;
-      }
+    if (flags()->report_globals >= 2)
+      ReportGlobal(g, "Search");
+    if (IsAddressNearGlobal(addr, g)) {
+      globals[res++] = g;
+      if (res == max_globals) break;
     }
   }
   return res;
 }
 
-bool DescribeAddressIfGlobal(uptr addr, uptr size) {
-  return DescribeOrGetInfoIfGlobal(addr, size, /* print */ true,
-                                   /* output_global */ nullptr);
-}
-
 bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr) {
   Global g = {};
-  if (DescribeOrGetInfoIfGlobal(addr, /* size */ 1, /* print */ false, &g)) {
+  if (GetGlobalsForAddress(addr, &g, 1)) {
     internal_strncpy(descr->name, g.name, descr->name_size);
     descr->region_address = g.beg;
     descr->region_size = g.size;
diff --git a/compiler-rt/lib/asan/asan_report.cc b/compiler-rt/lib/asan/asan_report.cc
index 62c814e..a4011af 100644
--- a/compiler-rt/lib/asan/asan_report.cc
+++ b/compiler-rt/lib/asan/asan_report.cc
@@ -281,9 +281,8 @@ static void PrintGlobalLocation(InternalScopedString *str,
     str->append(":%d", g.location->column_no);
 }
 
-bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
-                                     const __asan_global &g) {
-  if (!IsAddressNearGlobal(addr, g)) return false;
+static void DescribeAddressRelativeToGlobal(uptr addr, uptr size,
+                                            const __asan_global &g) {
   InternalScopedString str(4096);
   Decorator d;
   str.append("%s", d.Location());
@@ -306,6 +305,17 @@ bool DescribeAddressRelativeToGlobal(uptr addr, uptr size,
   str.append("%s", d.EndLocation());
   PrintGlobalNameIfASCII(&str, g);
   Printf("%s", str.data());
+}
+
+static bool DescribeAddressIfGlobal(uptr addr, uptr size) {
+  // Assume address is close to at most four globals.
+  const int kMaxGlobalsInReport = 4;
+  __asan_global globals[kMaxGlobalsInReport];
+  int globals_num = GetGlobalsForAddress(addr, globals, ARRAY_SIZE(globals));
+  if (globals_num == 0)
+    return false;
+  for (int i = 0; i < globals_num; i++)
+    DescribeAddressRelativeToGlobal(addr, size, globals[i]);
   return true;
 }
 
diff --git a/compiler-rt/lib/asan/asan_report.h b/compiler-rt/lib/asan/asan_report.h
index 029c914..ad011e3 100644
--- a/compiler-rt/lib/asan/asan_report.h
+++ b/compiler-rt/lib/asan/asan_report.h
@@ -33,14 +33,13 @@ struct AddressDescription {
   const char *region_kind;
 };
 
+// Returns the number of globals close to the provided address and copies
+// them to "globals" array.
+int GetGlobalsForAddress(uptr addr, __asan_global *globals, int max_globals);
+bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr);
 // The following functions prints address description depending
 // on the memory type (shadow/heap/stack/global).
 void DescribeHeapAddress(uptr addr, uptr access_size);
-bool DescribeAddressIfGlobal(uptr addr, uptr access_size);
-bool DescribeAddressRelativeToGlobal(uptr addr, uptr access_size,
-                                     const __asan_global &g);
-bool IsAddressNearGlobal(uptr addr, const __asan_global &g);
-bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr);
 bool DescribeAddressIfShadow(uptr addr, AddressDescription *descr = nullptr,
                              bool print = true);
 bool ParseFrameDescription(const char *frame_descr,