[ObjC] Deprecate GPBTextFormatForUnknownFieldSet().

`GPBTextFormatForMessage()` will contain any information for unknown fields.
And it clears the way for `GPBUnknownFieldSet` to eventually be deprecated
also.

PiperOrigin-RevId: 655184316

objectivec/GPBUnknownFieldSet.m

@@ -154,7 +154,10 @@ static void CopyWorker(__unused const void *key, const void *value, void *contex
 - (NSString *)description {
   NSMutableString *description =
       [NSMutableString stringWithFormat:@"<%@ %p>: TextFormat: {\n", [self class], self];
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
   NSString *textFormat = GPBTextFormatForUnknownFieldSet(self, @"  ");
+#pragma clang diagnostic pop
   [description appendString:textFormat];
   [description appendString:@"}"];
   return description;

objectivec/GPBUtilities.h

@@ -40,7 +40,9 @@ NSString *GPBTextFormatForMessage(GPBMessage *message, NSString *__nullable line
  * @return An NSString with the TextFormat of the unknown field set.
  **/
 NSString *GPBTextFormatForUnknownFieldSet(GPBUnknownFieldSet *__nullable unknownSet,
-                                          NSString *__nullable lineIndent);
+                                          NSString *__nullable lineIndent)
+    __attribute__((deprecated("Use GPBTextFormatForMessage will include the unknown fields, and "
+                              "GPBUnknownFieldSet it going away.")));
 
 /**
  * Checks if the given field number is set on a message.

objectivec/GPBUtilities.m

@@ -5,7 +5,7 @@
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 
-#import "GPBUtilities_PackagePrivate.h"
+#import "GPBUtilities.h"
 
 #import <objc/runtime.h>
 
@@ -15,6 +15,9 @@
 #import "GPBMessage_PackagePrivate.h"
 #import "GPBUnknownField.h"
 #import "GPBUnknownFieldSet.h"
+#import "GPBUnknownField_PackagePrivate.h"
+#import "GPBUnknownFields.h"
+#import "GPBUtilities_PackagePrivate.h"
 
 // Direct access is use for speed, to avoid even internally declaring things
 // read/write, etc. The warning is enabled in the project to ensure code calling
@@ -1929,6 +1932,78 @@ static void AppendTextFormatForMessageExtensionRange(GPBMessage *message, NSArra
   }  // for..in(activeExtensions)
 }
 
+static void AppendTextFormatForUnknownFields(GPBUnknownFields *ufs, NSMutableString *toStr,
+                                             NSString *lineIndent) {
+#if defined(DEBUG) && DEBUG
+  NSCAssert(!ufs.empty, @"Internal Error: No unknown fields to format.");
+#endif
+  // Extract the fields and sort them by field number. Use a stable sort and sort just by the field
+  // numbers, that way the output will still show the order the different types were added as well
+  // as maintaining the order within a give number/type pair (i.e. - repeated fields say in order).
+  NSMutableArray *sortedFields = [[NSMutableArray alloc] initWithCapacity:ufs.count];
+  for (GPBUnknownField *field in ufs) {
+    [sortedFields addObject:field];
+  }
+  [sortedFields
+      sortWithOptions:NSSortStable
+      usingComparator:^NSComparisonResult(GPBUnknownField *field1, GPBUnknownField *field2) {
+        int32_t fieldNumber1 = field1->number_;
+        int32_t fieldNumber2 = field2->number_;
+        if (fieldNumber1 < fieldNumber2) {
+          return NSOrderedAscending;
+        } else if (fieldNumber1 > fieldNumber2) {
+          return NSOrderedDescending;
+        } else {
+          return NSOrderedSame;
+        }
+      }];
+
+  NSString *subIndent = nil;
+
+  for (GPBUnknownField *field in sortedFields) {
+    int32_t fieldNumber = field->number_;
+    switch (field->type_) {
+      case GPBUnknownFieldTypeVarint:
+        [toStr appendFormat:@"%@%d: %llu\n", lineIndent, fieldNumber, field->storage_.intValue];
+        break;
+      case GPBUnknownFieldTypeFixed32:
+        [toStr appendFormat:@"%@%d: 0x%X\n", lineIndent, fieldNumber,
+                            (uint32_t)field->storage_.intValue];
+        break;
+      case GPBUnknownFieldTypeFixed64:
+        [toStr appendFormat:@"%@%d: 0x%llX\n", lineIndent, fieldNumber, field->storage_.intValue];
+        break;
+      case GPBUnknownFieldTypeLengthDelimited:
+        [toStr appendFormat:@"%@%d: ", lineIndent, fieldNumber];
+        AppendBufferAsString(field->storage_.lengthDelimited, toStr);
+        [toStr appendString:@"\n"];
+        break;
+      case GPBUnknownFieldTypeGroup: {
+        GPBUnknownFields *group = field->storage_.group;
+        if (group.empty) {
+          [toStr appendFormat:@"%@%d: {}\n", lineIndent, fieldNumber];
+        } else {
+          [toStr appendFormat:@"%@%d: {\n", lineIndent, fieldNumber];
+          if (subIndent == nil) {
+            subIndent = [lineIndent stringByAppendingString:@"  "];
+          }
+          AppendTextFormatForUnknownFields(group, toStr, subIndent);
+          [toStr appendFormat:@"%@}\n", lineIndent];
+        }
+      } break;
+      case GPBUnknownFieldTypeLegacy:
+#if defined(DEBUG) && DEBUG
+        NSCAssert(
+            NO,
+            @"Internal error: Shouldn't have gotten a legacy field type in the unknown fields.");
+#endif
+        break;
+    }
+  }
+  [subIndent release];
+  [sortedFields release];
+}
+
 static void AppendTextFormatForMessage(GPBMessage *message, NSMutableString *toStr,
                                        NSString *lineIndent) {
   GPBDescriptor *descriptor = [message descriptor];
@@ -1951,11 +2026,12 @@ static void AppendTextFormatForMessage(GPBMessage *message, NSMutableString *toS
     }
   }
 
-  NSString *unknownFieldsStr = GPBTextFormatForUnknownFieldSet(message.unknownFields, lineIndent);
+  GPBUnknownFields *ufs = [[GPBUnknownFields alloc] initFromMessage:message];
-  if ([unknownFieldsStr length] > 0) {
+  if (ufs.count > 0) {
     [toStr appendFormat:@"%@# --- Unknown fields ---\n", lineIndent];
-    [toStr appendString:unknownFieldsStr];
+    AppendTextFormatForUnknownFields(ufs, toStr, lineIndent);
   }
+  [ufs release];
 }
 
 NSString *GPBTextFormatForMessage(GPBMessage *message, NSString *lineIndent) {

objectivec/Tests/GPBUtilitiesTests.m

@@ -6,17 +6,16 @@
 // https://developers.google.com/open-source/licenses/bsd
 
 #import <XCTest/XCTest.h>
-
-#import "GPBUtilities_PackagePrivate.h"
-
 #import <objc/runtime.h>
 
-#import "GPBTestUtilities.h"
-
 #import "GPBDescriptor.h"
 #import "GPBDescriptor_PackagePrivate.h"
 #import "GPBMessage.h"
+#import "GPBTestUtilities.h"
+#import "GPBUnknownField.h"
 #import "GPBUnknownField_PackagePrivate.h"
+#import "GPBUtilities.h"
+#import "GPBUtilities_PackagePrivate.h"
 
 #import "objectivec/Tests/MapUnittest.pbobjc.h"
 #import "objectivec/Tests/Unittest.pbobjc.h"
@@ -168,6 +167,54 @@
   [expected release];
 }
 
+- (void)testTextFormatUnknownFields {
+  GPBUnknownFields *ufs = [[[GPBUnknownFields alloc] init] autorelease];
+  [ufs addFieldNumber:100 varint:5];
+  [ufs addFieldNumber:100 varint:4];
+  [ufs addFieldNumber:10 varint:1];
+  [ufs addFieldNumber:300 fixed32:0x50];
+  [ufs addFieldNumber:300 fixed32:0x40];
+  [ufs addFieldNumber:10 fixed32:0x10];
+  [ufs addFieldNumber:200 fixed64:0x5000];
+  [ufs addFieldNumber:200 fixed64:0x4000];
+  [ufs addFieldNumber:10 fixed64:0x1000];
+  [ufs addFieldNumber:10 lengthDelimited:DataFromCStr("foo")];
+  [ufs addFieldNumber:10 lengthDelimited:DataFromCStr("bar")];
+  GPBUnknownFields *group = [ufs addGroupWithFieldNumber:150];
+  [group addFieldNumber:2 varint:2];
+  [group addFieldNumber:1 varint:1];
+  group = [ufs addGroupWithFieldNumber:150];
+  [group addFieldNumber:1 varint:1];
+  [group addFieldNumber:3 fixed32:0x3];
+  [group addFieldNumber:2 fixed64:0x2];
+  TestEmptyMessage *message = [TestEmptyMessage message];
+  [message mergeUnknownFields:ufs extensionRegistry:nil];
+
+  NSString *expected = @"# --- Unknown fields ---\n"
+                       @"10: 1\n"
+                       @"10: 0x10\n"
+                       @"10: 0x1000\n"
+                       @"10: \"foo\"\n"
+                       @"10: \"bar\"\n"
+                       @"100: 5\n"
+                       @"100: 4\n"
+                       @"150: {\n"
+                       @"  1: 1\n"
+                       @"  2: 2\n"
+                       @"}\n"
+                       @"150: {\n"
+                       @"  1: 1\n"
+                       @"  2: 0x2\n"
+                       @"  3: 0x3\n"
+                       @"}\n"
+                       @"200: 0x5000\n"
+                       @"200: 0x4000\n"
+                       @"300: 0x50\n"
+                       @"300: 0x40\n";
+  NSString *result = GPBTextFormatForMessage(message, nil);
+  XCTAssertEqualObjects(expected, result);
+}
+
 - (void)testSetRepeatedFields {
   TestAllTypes *message = [TestAllTypes message];