Split DescribeAddressIfGlobal between a function that gets all the information, and one that prints it.

Summary:
Replacement for part of D23518
This deals with global variable addresses.

(This commit is written on top of D23605, but can be applied by itself)

Reviewers: kcc, samsonov

Subscribers: kubabrecka, llvm-commits

Differential Revision: https://reviews.llvm.org/D23607

llvm-svn: 278959

compiler-rt/lib/asan/asan_debugging.cc

@@ -71,7 +71,13 @@ void AsanLocateAddress(uptr addr, AddressDescription *descr) {
     descr->region_kind = ShadowNames[shadow_descr.kind];
     return;
   }
-  if (GetInfoForAddressIfGlobal(addr, descr)) {
+  GlobalAddressDescription global_descr;
+  if (GetGlobalAddressInformation(addr, &global_descr)) {
+    descr->region_kind = "global";
+    auto &g = global_descr.globals[0];
+    internal_strlcpy(descr->name, g.name, descr->name_size);
+    descr->region_address = g.beg;
+    descr->region_size = g.size;
     return;
   }
   asanThreadRegistry().Lock();

compiler-rt/lib/asan/asan_descriptions.cc

@@ -353,4 +353,54 @@ bool DescribeAddressIfStack(uptr addr, uptr access_size) {
   return true;
 }
 
+// Global descriptions
+static void DescribeAddressRelativeToGlobal(uptr addr, uptr access_size,
+                                            const __asan_global &g) {
+  InternalScopedString str(4096);
+  Decorator d;
+  str.append("%s", d.Location());
+  if (addr < g.beg) {
+    str.append("%p is located %zd bytes to the left", (void *)addr,
+               g.beg - addr);
+  } else if (addr + access_size > g.beg + g.size) {
+    if (addr < g.beg + g.size) addr = g.beg + g.size;
+    str.append("%p is located %zd bytes to the right", (void *)addr,
+               addr - (g.beg + g.size));
+  } else {
+    // Can it happen?
+    str.append("%p is located %zd bytes inside", (void *)addr, addr - g.beg);
+  }
+  str.append(" of global variable '%s' defined in '",
+             MaybeDemangleGlobalName(g.name));
+  PrintGlobalLocation(&str, g);
+  str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
+  str.append("%s", d.EndLocation());
+  PrintGlobalNameIfASCII(&str, g);
+  Printf("%s", str.data());
+}
+
+bool GetGlobalAddressInformation(uptr addr, GlobalAddressDescription *descr) {
+  descr->addr = addr;
+  int globals_num = GetGlobalsForAddress(addr, descr->globals, descr->reg_sites,
+                                         ARRAY_SIZE(descr->globals));
+  descr->size = globals_num;
+  return globals_num != 0;
+}
+
+bool DescribeAddressIfGlobal(uptr addr, uptr access_size,
+                             const char *bug_type) {
+  GlobalAddressDescription descr;
+  if (!GetGlobalAddressInformation(addr, &descr)) return false;
+
+  for (int i = 0; i < descr.size; i++) {
+    DescribeAddressRelativeToGlobal(descr.addr, access_size, descr.globals[i]);
+    if (0 == internal_strcmp(bug_type, "initialization-order-fiasco") &&
+        descr.reg_sites[i]) {
+      Printf("  registered at:\n");
+      StackDepotGet(descr.reg_sites[i]).Print();
+    }
+  }
+  return true;
+}
+
 }  // namespace __asan

compiler-rt/lib/asan/asan_descriptions.h

@@ -133,4 +133,16 @@ struct StackAddressDescription {
 bool GetStackAddressInformation(uptr addr, StackAddressDescription *descr);
 bool DescribeAddressIfStack(uptr addr, uptr access_size);
 
+struct GlobalAddressDescription {
+  uptr addr;
+  // Assume address is close to at most four globals.
+  static const int kMaxGlobals = 4;
+  __asan_global globals[kMaxGlobals];
+  u32 reg_sites[kMaxGlobals];
+  u8 size;
+};
+
+bool GetGlobalAddressInformation(uptr addr, GlobalAddressDescription *descr);
+bool DescribeAddressIfGlobal(uptr addr, uptr access_size, const char *bug_type);
+
 }  // namespace __asan

compiler-rt/lib/asan/asan_globals.cc

@@ -25,6 +25,7 @@
 #include "sanitizer_common/sanitizer_mutex.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
+#include "sanitizer_common/sanitizer_symbolizer.h"
 
 namespace __asan {
 
@@ -123,18 +124,6 @@ int GetGlobalsForAddress(uptr addr, Global *globals, u32 *reg_sites,
   return res;
 }
 
-bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr) {
-  Global g = {};
-  if (GetGlobalsForAddress(addr, &g, nullptr, 1)) {
-    internal_strncpy(descr->name, g.name, descr->name_size);
-    descr->region_address = g.beg;
-    descr->region_size = g.size;
-    descr->region_kind = "global";
-    return true;
-  }
-  return false;
-}
-
 enum GlobalSymbolState {
   UNREGISTERED = 0,
   REGISTERED = 1
@@ -279,6 +268,46 @@ void StopInitOrderChecking() {
   }
 }
 
+static bool IsASCII(unsigned char c) { return /*0x00 <= c &&*/ c <= 0x7F; }
+
+const char *MaybeDemangleGlobalName(const char *name) {
+  // We can spoil names of globals with C linkage, so use an heuristic
+  // approach to check if the name should be demangled.
+  bool should_demangle = false;
+  if (name[0] == '_' && name[1] == 'Z')
+    should_demangle = true;
+  else if (SANITIZER_WINDOWS && name[0] == '\01' && name[1] == '?')
+    should_demangle = true;
+
+  return should_demangle ? Symbolizer::GetOrInit()->Demangle(name) : name;
+}
+
+// Check if the global is a zero-terminated ASCII string. If so, print it.
+void PrintGlobalNameIfASCII(InternalScopedString *str, const __asan_global &g) {
+  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
+    unsigned char c = *(unsigned char *)p;
+    if (c == '\0' || !IsASCII(c)) return;
+  }
+  if (*(char *)(g.beg + g.size - 1) != '\0') return;
+  str->append("  '%s' is ascii string '%s'\n", MaybeDemangleGlobalName(g.name),
+              (char *)g.beg);
+}
+
+static const char *GlobalFilename(const __asan_global &g) {
+  const char *res = g.module_name;
+  // Prefer the filename from source location, if is available.
+  if (g.location) res = g.location->filename;
+  CHECK(res);
+  return res;
+}
+
+void PrintGlobalLocation(InternalScopedString *str, const __asan_global &g) {
+  str->append("%s", GlobalFilename(g));
+  if (!g.location) return;
+  if (g.location->line_no) str->append(":%d", g.location->line_no);
+  if (g.location->column_no) str->append(":%d", g.location->column_no);
+}
+
 } // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1

compiler-rt/lib/asan/asan_report.cc

@@ -187,101 +187,6 @@ static void PrintZoneForPointer(uptr ptr, uptr zone_ptr,
 
 // ---------------------- Address Descriptions ------------------- {{{1
 
-static bool IsASCII(unsigned char c) {
-  return /*0x00 <= c &&*/ c <= 0x7F;
-}
-
-static const char *MaybeDemangleGlobalName(const char *name) {
-  // We can spoil names of globals with C linkage, so use an heuristic
-  // approach to check if the name should be demangled.
-  bool should_demangle = false;
-  if (name[0] == '_' && name[1] == 'Z')
-    should_demangle = true;
-  else if (SANITIZER_WINDOWS && name[0] == '\01' && name[1] == '?')
-    should_demangle = true;
-
-  return should_demangle ? Symbolizer::GetOrInit()->Demangle(name) : name;
-}
-
-// Check if the global is a zero-terminated ASCII string. If so, print it.
-static void PrintGlobalNameIfASCII(InternalScopedString *str,
-                                   const __asan_global &g) {
-  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
-    unsigned char c = *(unsigned char*)p;
-    if (c == '\0' || !IsASCII(c)) return;
-  }
-  if (*(char*)(g.beg + g.size - 1) != '\0') return;
-  str->append("  '%s' is ascii string '%s'\n", MaybeDemangleGlobalName(g.name),
-              (char *)g.beg);
-}
-
-static const char *GlobalFilename(const __asan_global &g) {
-  const char *res = g.module_name;
-  // Prefer the filename from source location, if is available.
-  if (g.location)
-    res = g.location->filename;
-  CHECK(res);
-  return res;
-}
-
-static void PrintGlobalLocation(InternalScopedString *str,
-                                const __asan_global &g) {
-  str->append("%s", GlobalFilename(g));
-  if (!g.location)
-    return;
-  if (g.location->line_no)
-    str->append(":%d", g.location->line_no);
-  if (g.location->column_no)
-    str->append(":%d", g.location->column_no);
-}
-
-static void DescribeAddressRelativeToGlobal(uptr addr, uptr size,
-                                            const __asan_global &g) {
-  InternalScopedString str(4096);
-  Decorator d;
-  str.append("%s", d.Location());
-  if (addr < g.beg) {
-    str.append("%p is located %zd bytes to the left", (void *)addr,
-               g.beg - addr);
-  } else if (addr + size > g.beg + g.size) {
-    if (addr < g.beg + g.size)
-      addr = g.beg + g.size;
-    str.append("%p is located %zd bytes to the right", (void *)addr,
-               addr - (g.beg + g.size));
-  } else {
-    // Can it happen?
-    str.append("%p is located %zd bytes inside", (void *)addr, addr - g.beg);
-  }
-  str.append(" of global variable '%s' defined in '",
-             MaybeDemangleGlobalName(g.name));
-  PrintGlobalLocation(&str, g);
-  str.append("' (0x%zx) of size %zu\n", g.beg, g.size);
-  str.append("%s", d.EndLocation());
-  PrintGlobalNameIfASCII(&str, g);
-  Printf("%s", str.data());
-}
-
-static bool DescribeAddressIfGlobal(uptr addr, uptr size,
-                                    const char *bug_type) {
-  // Assume address is close to at most four globals.
-  const int kMaxGlobalsInReport = 4;
-  __asan_global globals[kMaxGlobalsInReport];
-  u32 reg_sites[kMaxGlobalsInReport];
-  int globals_num =
-      GetGlobalsForAddress(addr, globals, reg_sites, ARRAY_SIZE(globals));
-  if (globals_num == 0)
-    return false;
-  for (int i = 0; i < globals_num; i++) {
-    DescribeAddressRelativeToGlobal(addr, size, globals[i]);
-    if (0 == internal_strcmp(bug_type, "initialization-order-fiasco") &&
-        reg_sites[i]) {
-      Printf("  registered at:\n");
-      StackDepotGet(reg_sites[i]).Print();
-    }
-  }
-  return true;
-}
-
 bool ParseFrameDescription(const char *frame_descr,
                            InternalMmapVector<StackVarDescr> *vars) {
   CHECK(frame_descr);

compiler-rt/lib/asan/asan_report.h

@@ -37,7 +37,11 @@ struct AddressDescription {
 // them to "globals" array.
 int GetGlobalsForAddress(uptr addr, __asan_global *globals, u32 *reg_sites,
                          int max_globals);
-bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr);
+
+const char *MaybeDemangleGlobalName(const char *name);
+void PrintGlobalNameIfASCII(InternalScopedString *str, const __asan_global &g);
+void PrintGlobalLocation(InternalScopedString *str, const __asan_global &g);
+
 // The following functions prints address description depending
 // on the memory type (shadow/heap/stack/global).
 bool ParseFrameDescription(const char *frame_descr,