Move crash keys for command-line switches to components/crash so they can be set

components/crash/core/common/crash_keys.cc

Index: components/crash/core/common/crash_keys.cc
diff --git a/components/crash/core/common/crash_keys.cc b/components/crash/core/common/crash_keys.cc
index c0afc6a14bde0ef66ddd94777434472fa6ebdd56..5d0be35ea55114e257041fb67635e55abbd2661c 100644
--- a/components/crash/core/common/crash_keys.cc
+++ b/components/crash/core/common/crash_keys.cc
@@ -4,11 +4,16 @@
 
 #include "components/crash/core/common/crash_keys.h"
 
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/command_line.h"
 #include "base/debug/crash_logging.h"
 #include "base/format_macros.h"
+#include "base/logging.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
 
 namespace crash_keys {
 
@@ -25,6 +30,9 @@ const char kChannel[] = "channel";
 const char kNumVariations[] = "num-experiments";
 const char kVariations[] = "variations";
 
+const char kSwitch[] = "switch-%" PRIuS;
+const char kNumSwitches[] = "num-switches";
+
 const char kBug464926CrashKey[] = "bug-464926-info";
 
 #if defined(OS_MACOSX)
@@ -92,4 +100,74 @@ void SetVariationsList(const std::vector<std::string>& variations) {
   base::debug::SetCrashKeyValue(kVariations, variations_string);
 }
 
+void GetCrashKeysForCommandLineSwitches(
+    std::vector<base::debug::CrashKey>* keys) {
+  DCHECK(keys);
+  base::debug::CrashKey crash_key = { kNumSwitches, kSmallSize };
+  keys->push_back(crash_key);
+
+  // The fixed_keys names are string constants. Use static storage for
+  // formatted key names as well, since they will persist for the duration of
+  // the program.
+  static char formatted_keys[kSwitchesMaxCount][sizeof(kSwitch) + 1] = {{ 0 }};

[grt (UTC plus 2), 2015/11/27 18:51:21]

oh my. this is an accident waiting to happen. sizeof(kSwitch) is
platform-dependent (PRIuS could be any length). it just so happens that it's two
chars on all current platforms, but that's fragile. sigh. with the current
values, sizeof(kswitch) - 1 is really all the space that is needed. since you're
copying existing code, i'll just look the other way. you know, how about adding
this:
  static_assert(sizeof(formatted_keys[0]) >= 10,
                "insufficient space for \"switch-NN\"");

[Joe Mason, 2015/11/27 21:16:47]

Done.

+  const size_t formatted_key_len = sizeof(formatted_keys[0]);
+  for (size_t i = 0; i < kSwitchesMaxCount; ++i) {
+    // Name the keys using 1-based indexing.
+    int n = base::snprintf(formatted_keys[i], formatted_key_len, kSwitch,
+                           i + 1);
+    DCHECK_GT(n, 0);
+    base::debug::CrashKey crash_key = { formatted_keys[i], kSmallSize };
+    keys->push_back(crash_key);
+  }
+}
+
+namespace {
+
+bool PassThroughFilter(const std::string &) {
+  // By default do not reject any switches.
+  return false;
+}
+
+}  // namespace
+
+void SetSwitchesFromCommandLine(const base::CommandLine& command_line) {
+  SetSwitchesFromCommandLine(command_line, base::Bind(&PassThroughFilter));
+}
+
+void SetSwitchesFromCommandLine(const base::CommandLine& command_line,
+    const base::Callback<bool(const std::string &)>& skip_filter) {
+  const base::CommandLine::StringVector& argv = command_line.argv();
+
+  // Set the number of switches in case size > kNumSwitches.
+  base::debug::SetCrashKeyValue(kNumSwitches,
+      base::StringPrintf("%" PRIuS, argv.size() - 1));
+
+  size_t key_i = 1;  // Key names are 1-indexed.
+
+  // Go through the argv, skipping the exec path.
+  for (size_t i = 1; i < argv.size(); ++i) {
+#if defined(OS_WIN)
+    std::string switch_str = base::WideToUTF8(argv[i]);
+#else
+    std::string switch_str = argv[i];
+#endif
+
+    // Skip uninteresting switches.
+    if (skip_filter.Run(switch_str))
+      continue;
+
+    // Stop if there are too many switches.
+    if (i > crash_keys::kSwitchesMaxCount)

[grt (UTC plus 2), 2015/11/27 18:51:21]

i -> key_i

[Joe Mason, 2015/11/27 21:16:47]

Good catch! Fixed.

+      break;
+
+    std::string key = base::StringPrintf(kSwitch, key_i++);
+    base::debug::SetCrashKeyValue(key, switch_str);
+  }
+
+  // Clear any remaining switches.
+  for (; key_i <= kSwitchesMaxCount; ++key_i) {

[grt (UTC plus 2), 2015/11/27 18:51:21]

nit: omit braces. :-)

[Joe Mason, 2015/11/27 21:16:47]

Done.

+    base::debug::ClearCrashKey(base::StringPrintf(kSwitch, key_i));
+  }
+}
+
 }  // namespace crash_keys