Add ObjC helpers for Any WKT.

- Capture the ObjC prefix used when generating the the file.
- Track the containing type on descriptors.
- Mark descriptors where the message class name got a suffix added to it.
- Expose a fullName property on Descriptors.
- Add helpers for packing/unpacking Any messages.
- Bump the ObjC runtime version number. Since we added methods and invoke them
  in the generated code, ensure the code is running against a matching version.
  Otherwise, someone could compile against headers, but run with a framework
  that is older and get unknown selector failures.  This should trip clearer
  messaging.

Fixes protocolbuffers#1674

objectivec/DevTools/compile_testing_protos.sh

@@ -93,6 +93,7 @@ compile_protos() {
 # sources can be generated from them.
 
 CORE_PROTO_FILES=(
+  src/google/protobuf/any_test.proto
   src/google/protobuf/unittest_arena.proto
   src/google/protobuf/unittest_custom_options.proto
   src/google/protobuf/unittest_enormous_descriptor.proto

objectivec/GPBBootstrap.h

@@ -99,4 +99,4 @@
 // regenerated.
 //
 // Meant to be used internally by generated code.
-#define GOOGLE_PROTOBUF_OBJC_GEN_VERSION 30001
+#define GOOGLE_PROTOBUF_OBJC_GEN_VERSION 30002

objectivec/GPBDescriptor.h

@@ -81,6 +81,13 @@ typedef NS_ENUM(uint8_t, GPBFieldType) {
 @property(nonatomic, readonly, getter=isWireFormat) BOOL wireFormat;
 /** The class of this message. */
 @property(nonatomic, readonly) Class messageClass;
+/** Containing message descriptor if this message is nested, or nil otherwise. */
+@property(readonly, nullable) GPBDescriptor *containingType;
+/**
+ * Fully qualified name for this message (package.message). Can be nil if the
+ * value is unable to be computed.
+ */
+@property(readonly, nullable) NSString *fullName;
 
 /**
  * Gets the field for the given number.
@@ -118,6 +125,8 @@ typedef NS_ENUM(uint8_t, GPBFieldType) {
 
 /** The package declared in the proto file. */
 @property(nonatomic, readonly, copy) NSString *package;
+/** The objc prefix declared in the proto file. */
+@property(nonatomic, readonly, copy, nullable) NSString *objcPrefix;
 /** The syntax of the proto file. */
 @property(nonatomic, readonly) GPBFileSyntax syntax;
 

objectivec/GPBDescriptor.m

@@ -42,8 +42,10 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdirect-ivar-access"
 
-// The address of this variable is used as a key for obj_getAssociatedObject.
+// The addresses of these variables are used as keys for objc_getAssociatedObject.
 static const char kTextFormatExtraValueKey = 0;
+static const char kParentClassNameValueKey = 0;
+static const char kClassNameSuffixKey = 0;
 
 // Utility function to generate selectors on the fly.
 static SEL SelFromStrings(const char *prefix, const char *middle,
@@ -215,10 +217,102 @@ - (void)setupExtensionRanges:(const GPBExtensionRange *)ranges count:(int32_t)co
   extensionRangesCount_ = count;
 }
 
+- (void)setupContainingMessageClassName:(const char *)msgClassName {
+  // Note: Only fetch the class here, can't send messages to it because
+  // that could cause cycles back to this class within +initialize if
+  // two messages have each other in fields (i.e. - they build a graph).
+  NSAssert(objc_getClass(msgClassName), @"Class %s not defined", msgClassName);
+  NSValue *parentNameValue = [NSValue valueWithPointer:msgClassName];
+  objc_setAssociatedObject(self, &kParentClassNameValueKey,
+                           parentNameValue,
+                           OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (void)setupMessageClassNameSuffix:(NSString *)suffix {
+  if (suffix.length) {
+    objc_setAssociatedObject(self, &kClassNameSuffixKey,
+                             suffix,
+                             OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+  }
+}
+
 - (NSString *)name {
   return NSStringFromClass(messageClass_);
 }
 
+- (GPBDescriptor *)containingType {
+  NSValue *parentNameValue =
+      objc_getAssociatedObject(self, &kParentClassNameValueKey);
+  if (!parentNameValue) {
+    return nil;
+  }
+  const char *parentName = [parentNameValue pointerValue];
+  Class parentClass = objc_getClass(parentName);
+  NSAssert(parentClass, @"Class %s not defined", parentName);
+  return [parentClass descriptor];
+}
+
+- (NSString *)fullName {
+  NSString *className = NSStringFromClass(self.messageClass);
+  GPBFileDescriptor *file = self.file;
+  NSString *objcPrefix = file.objcPrefix;
+  if (objcPrefix && ![className hasPrefix:objcPrefix]) {
+    NSAssert(0,
+             @"Class didn't have correct prefix? (%@ - %@)",
+             className, objcPrefix);
+    return nil;
+  }
+  GPBDescriptor *parent = self.containingType;
+
+  NSString *name = nil;
+  if (parent) {
+    NSString *parentClassName = NSStringFromClass(parent.messageClass);
+    // The generator will add _Class to avoid reserved words, drop it.
+    NSString *suffix = objc_getAssociatedObject(parent, &kClassNameSuffixKey);
+    if (suffix) {
+      if (![parentClassName hasSuffix:suffix]) {
+        NSAssert(0,
+                 @"ParentMessage class didn't have correct suffix? (%@ - %@)",
+                 className, suffix);
+        return nil;
+      }
+      parentClassName =
+          [parentClassName substringToIndex:(parentClassName.length - suffix.length)];
+    }
+    NSString *parentPrefix = [parentClassName stringByAppendingString:@"_"];
+    if (![className hasPrefix:parentPrefix]) {
+      NSAssert(0,
+               @"Class didn't have the correct parent name prefix? (%@ - %@)",
+               parentPrefix, className);
+      return nil;
+    }
+    name = [className substringFromIndex:parentPrefix.length];
+  } else {
+    name = [className substringFromIndex:objcPrefix.length];
+  }
+
+  // The generator will add _Class to avoid reserved words, drop it.
+  NSString *suffix = objc_getAssociatedObject(self, &kClassNameSuffixKey);
+  if (suffix) {
+    if (![name hasSuffix:suffix]) {
+      NSAssert(0,
+               @"Message class didn't have correct suffix? (%@ - %@)",
+               name, suffix);
+      return nil;
+    }
+    name = [name substringToIndex:(name.length - suffix.length)];
+  }
+
+  NSString *prefix = (parent != nil ? parent.fullName : file.package);
+  NSString *result;
+  if (prefix.length > 0) {
+    result = [NSString stringWithFormat:@"%@.%@", prefix, name];
+  } else {
+    result = name;
+  }
+  return result;
+}
+
 - (id)copyWithZone:(NSZone *)zone {
 #pragma unused(zone)
   return [self retain];
@@ -255,12 +349,26 @@ - (GPBOneofDescriptor *)oneofWithName:(NSString *)name {
 
 @implementation GPBFileDescriptor {
   NSString *package_;
+  NSString *objcPrefix_;
   GPBFileSyntax syntax_;
 }
 
 @synthesize package = package_;
+@synthesize objcPrefix = objcPrefix_;
 @synthesize syntax = syntax_;
 
+- (instancetype)initWithPackage:(NSString *)package
+                     objcPrefix:(NSString *)objcPrefix
+                         syntax:(GPBFileSyntax)syntax {
+  self = [super init];
+  if (self) {
+    package_ = [package copy];
+    objcPrefix_ = [objcPrefix copy];
+    syntax_ = syntax;
+  }
+  return self;
+}
+
 - (instancetype)initWithPackage:(NSString *)package
                          syntax:(GPBFileSyntax)syntax {
   self = [super init];
@@ -273,6 +381,7 @@ - (instancetype)initWithPackage:(NSString *)package
 
 - (void)dealloc {
   [package_ release];
+  [objcPrefix_ release];
   [super dealloc];
 }
 
@@ -416,6 +525,9 @@ - (instancetype)initWithFieldDescription:(void *)description
     // Extra type specific data.
     if (isMessage) {
       const char *className = coreDesc->dataTypeSpecific.className;
+      // Note: Only fetch the class here, can't send messages to it because
+      // that could cause cycles back to this class within +initialize if
+      // two messages have each other in fields (i.e. - they build a graph).
       msgClass_ = objc_getClass(className);
       NSAssert(msgClass_, @"Class %s not defined", className);
     } else if (dataType == GPBDataTypeEnum) {

objectivec/GPBDescriptor_PackagePrivate.h

@@ -165,10 +165,15 @@ typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
       firstHasIndex:(int32_t)firstHasIndex;
 - (void)setupExtraTextInfo:(const char *)extraTextFormatInfo;
 - (void)setupExtensionRanges:(const GPBExtensionRange *)ranges count:(int32_t)count;
+- (void)setupContainingMessageClassName:(const char *)msgClassName;
+- (void)setupMessageClassNameSuffix:(NSString *)suffix;
 
 @end
 
 @interface GPBFileDescriptor ()
+- (instancetype)initWithPackage:(NSString *)package
+                     objcPrefix:(NSString *)objcPrefix
+                         syntax:(GPBFileSyntax)syntax;
 - (instancetype)initWithPackage:(NSString *)package
                          syntax:(GPBFileSyntax)syntax;
 @end

objectivec/GPBWellKnownTypes.h

@@ -37,15 +37,32 @@
 #endif
 
 #if GPB_USE_PROTOBUF_FRAMEWORK_IMPORTS
+ #import <Protobuf/Any.pbobjc.h>
  #import <Protobuf/Duration.pbobjc.h>
  #import <Protobuf/Timestamp.pbobjc.h>
 #else
+ #import "google/protobuf/Any.pbobjc.h"
  #import "google/protobuf/Duration.pbobjc.h"
  #import "google/protobuf/Timestamp.pbobjc.h"
 #endif
 
 NS_ASSUME_NONNULL_BEGIN
 
+#pragma mark - Errors
+
+/** NSError domain used for errors. */
+extern NSString *const GPBWellKnownTypesErrorDomain;
+
+/** Error code for NSError with GPBWellKnownTypesErrorDomain. */
+typedef NS_ENUM(NSInteger, GPBWellKnownTypesErrorCode) {
+  /** The type_url could not be computed for the requested GPBMessage class. */
+  GPBWellKnownTypesErrorCodeFailedToComputeTypeURL = -100,
+  /** type_url in a Any doesn’t match that of the requested GPBMessage class. */
+  GPBWellKnownTypesErrorCodeTypeURLMismatch = -101,
+};
+
+#pragma mark - GPBTimestamp
+
 /**
  * Category for GPBTimestamp to work with standard Foundation time/date types.
  **/
@@ -77,6 +94,8 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+#pragma mark - GPBDuration
+
 /**
  * Category for GPBDuration to work with standard Foundation time type.
  **/
@@ -96,4 +115,110 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+#pragma mark - GPBAny
+
+/**
+ * Category for GPBAny to help work with the message within the object.
+ **/
+@interface GPBAny (GBPWellKnownTypes)
+
+/**
+ * Convenience method to create a GPBAny containing the serialized message.
+ * This uses type.googleapis.com/ as the type_url's prefix.
+ *
+ * @param message  The message to be packed into the GPBAny.
+ * @param errorPtr Pointer to an error that will be populated if something goes
+ *                 wrong.
+ *
+ * @return A newly configured GPBAny with the given message, or nil on failure.
+ */
++ (nullable instancetype)anyWithMessage:(nonnull GPBMessage *)message
+                                  error:(NSError **)errorPtr;
+
+/**
+ * Convenience method to create a GPBAny containing the serialized message.
+ *
+ * @param message       The message to be packed into the GPBAny.
+ * @param typeURLPrefix The URL prefix to apply for type_url.
+ * @param errorPtr      Pointer to an error that will be populated if something
+ *                      goes wrong.
+ *
+ * @return A newly configured GPBAny with the given message, or nil on failure.
+ */
++ (nullable instancetype)anyWithMessage:(nonnull GPBMessage *)message
+                          typeURLPrefix:(nonnull NSString *)typeURLPrefix
+                                  error:(NSError **)errorPtr;
+
+/**
+ * Initializes a GPBAny to contain the serialized message. This uses
+ * type.googleapis.com/ as the type_url's prefix.
+ *
+ * @param message  The message to be packed into the GPBAny.
+ * @param errorPtr Pointer to an error that will be populated if something goes
+ *                 wrong.
+ *
+ * @return A newly configured GPBAny with the given message, or nil on failure.
+ */
+- (nullable instancetype)initWithMessage:(nonnull GPBMessage *)message
+                                   error:(NSError **)errorPtr;
+
+/**
+ * Initializes a GPBAny to contain the serialized message.
+ *
+ * @param message       The message to be packed into the GPBAny.
+ * @param typeURLPrefix The URL prefix to apply for type_url.
+ * @param errorPtr      Pointer to an error that will be populated if something
+ *                      goes wrong.
+ *
+ * @return A newly configured GPBAny with the given message, or nil on failure.
+ */
+- (nullable instancetype)initWithMessage:(nonnull GPBMessage *)message
+                           typeURLPrefix:(nonnull NSString *)typeURLPrefix
+                                   error:(NSError **)errorPtr;
+
+/**
+ * Packs the serialized message into this GPBAny. This uses
+ * type.googleapis.com/ as the type_url's prefix.
+ *
+ * @param message  The message to be packed into the GPBAny.
+ * @param errorPtr Pointer to an error that will be populated if something goes
+ *                 wrong.
+ *
+ * @return Whether the packing was successful or not.
+ */
+- (BOOL)packWithMessage:(nonnull GPBMessage *)message
+                  error:(NSError **)errorPtr;
+
+/**
+ * Packs the serialized message into this GPBAny.
+ *
+ * @param message       The message to be packed into the GPBAny.
+ * @param typeURLPrefix The URL prefix to apply for type_url.
+ * @param errorPtr      Pointer to an error that will be populated if something
+ *                      goes wrong.
+ *
+ * @return Whether the packing was successful or not.
+ */
+- (BOOL)packWithMessage:(nonnull GPBMessage *)message
+          typeURLPrefix:(nonnull NSString *)typeURLPrefix
+                  error:(NSError **)errorPtr;
+
+/**
+ * Unpacks the serialized message as if it was an instance of the given class.
+ *
+ * @note When checking type_url, the base URL is not checked, only the fully
+ *       qualified name.
+ *
+ * @param messageClass The class to use to deserialize the contained message.
+ * @param errorPtr     Pointer to an error that will be populated if something
+ *                     goes wrong.
+ *
+ * @return An instance of the given class populated with the contained data, or
+ *         nil on failure.
+ */
+- (nullable GPBMessage *)unpackMessageClass:(Class)messageClass
+                                      error:(NSError **)errorPtr;
+
+@end
+
 NS_ASSUME_NONNULL_END