[Mac] Log stack trace for CHECK in bug 97285.

base/mac/crash_logging.mm

Index: base/mac/crash_logging.mm
diff --git a/base/mac/crash_logging.mm b/base/mac/crash_logging.mm
index ce0db392a8239c9b991a9db35395fb1a81d6dfd2..3715be8f0881f086abf12846798cf6df765eca4f 100644
--- a/base/mac/crash_logging.mm
+++ b/base/mac/crash_logging.mm
@@ -4,8 +4,12 @@
 
 #include "base/mac/crash_logging.h"
 
+#include <algorithm>
+
 #import <Foundation/Foundation.h>
 
+#include "base/logging.h"
+
 namespace base {
 namespace mac {
 
@@ -28,6 +32,32 @@ void ClearCrashKey(NSString* key) {
     g_clear_key_func(key);
 }
 
+void SetCrashKeyFromAddresses(NSString* key,
+                              const void* const* addresses,
+                              size_t count) {
+  NSString* value = @"<null>";
+  if (addresses && count) {
+    static const size_t kBreakpadValueMax = 255;

[Nico, 2012/05/16 23:04:56]

Remove static, also below

[Scott Hess - ex-Googler, 2012/05/17 22:08:12]

Done.

+
+    // %p encodes 32-bit pointers as "0x" followed by up to 8 hex
+    // bytes.  Plus one byte for separating space.
+    static const size_t kMaxCount = kBreakpadValueMax / 11;

[Nico, 2012/05/16 23:04:56]

s/11/strlen("0xaabbccdd ")?

[Scott Hess - ex-Googler, 2012/05/17 22:08:12]

Rather than pile things higher and deeper, I revised the snippet to just track
the overall length and stop adding elements when it would become too long.

+    count = std::min(count, kMaxCount);
+
+    NSMutableArray* hexBacktrace = [NSMutableArray arrayWithCapacity:count];
+    for (size_t i = 0; i < count; ++i) {
+      NSString* s = [NSString stringWithFormat:@"%p", addresses[i]];
+      [hexBacktrace addObject:s];
+    }
+    value = [hexBacktrace componentsJoinedByString:@" "];
+
+    // Warn someone if this exceeds the breakpad limits.  Most likely
+    // a 64-bit compile.
+    DCHECK_LE(strlen([value UTF8String]), kBreakpadValueMax);
+  }
+  base::mac::SetCrashKeyValue(key, value);
+}
+
 ScopedCrashKey::ScopedCrashKey(NSString* key, NSString* value)
     : crash_key_([key retain]) {
   if (g_set_key_func)