New SkRTConf macro SK_CONF_TRY_SET: no complaint on missing configuration

include/utils/SkRTConf.h

 /*
  * Copyright 2013 Google, Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkRTConf_DEFINED
 #define SkRTConf_DEFINED
@@ skipping 34 matching lines @@
 protected:
     void doPrint(char *s) const;
 
     T        fValue;
     T        fDefault;
     SkString fDescription;
 };
 
 #ifdef SK_DEVELOPER
 #define SK_CONF_DECLARE(confType, varName, confName, defaultValue, description) static SkRTConf<confType> varName(confName, defaultValue, description)
-#define SK_CONF_SET(confname, value) skRTConfRegistry().set(confname, value)
+#define SK_CONF_SET(confname, value) \

[reed1, 2013/11/06 15:02:21]

at some point we should clean-up the readability of this block of macros. add
whitespace? more std formatted comments?

+    skRTConfRegistry().set(confname, value, true)
+/* SK_CONF_TRY_SET() is like SK_CONF_SET(), but doesn't complain if
+   confname can't be found.  This is useful if the SK_CONF_DECLARE is
+   inside a source file whose linkage is dependent on the system. */
+#define SK_CONF_TRY_SET(confname, value) \
+    skRTConfRegistry().set(confname, value, false)
 #else
 #define SK_CONF_DECLARE(confType, varName, confName, defaultValue, description) static confType varName = defaultValue
 #define SK_CONF_SET(confname, value) (void) confname, (void) value
+#define SK_CONF_TRY_SET(confname, value) (void) confname, (void) value
 #endif
 
 /** \class SkRTConfRegistry
     A class that maintains a systemwide registry of all runtime configuration
     parameters.  Mainly used for printing them out and handling multiply-defined
     knobs.
 */
 
 class SkRTConfRegistry {
 public:
     SkRTConfRegistry();
     void printAll(const char *fname = NULL) const;
     void printNonDefault(const char *fname = NULL) const;
     const char *configFileLocation() const;
     void possiblyDumpFile() const;
     void validate() const;
-    template <typename T> void set(const char *confname, T value);
+    template <typename T> void set(const char *confname,
+                                   T value,
+                                   bool warnIfNotFound = true);
 #ifdef SK_SUPPORT_UNITTEST
     static void UnitTest();
 #endif
 private:
     template<typename T> friend class SkRTConf;
 
     void registerConf(SkRTConfBase *conf);
     template <typename T> bool parse(const char *name, T* value);
 
     SkTDArray<SkString *> fConfigFileKeys, fConfigFileValues;
@@ skipping 89 matching lines @@
     // static_cast here is okay because there's only one kind of child class.
     const SkRTConf<T> *child_pointer = static_cast<const SkRTConf<T> *>(conf);
     return child_pointer &&
            fName == child_pointer->fName &&
            fDescription == child_pointer->fDescription &&
            fValue == child_pointer->fValue &&
            fDefault == child_pointer->fDefault;
 }
 
 #endif