fix(crashlytics): read SDK versions from LC_BUILD_VERSION (#16830)

Crashlytics/CHANGELOG.md

@@ -6,6 +6,8 @@
 - [fixed] Improved robustness in Firebase Sessions when parsing malformed
   settings from the server, including `null` values that could cause a crash
   when caching settings. (#16728)
+- [fixed] Fixed the app executable's minimum OS and SDK versions being recorded as `0.0.0` in
+  report metadata for apps targeting iOS 12, macOS 10.14, tvOS 12, watchOS 5, or later. (#16810)
 
 # 13.0.0
 - [fixed] Safely validate memory reads when executing `DW_OP_deref_size`

Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.m

@@ -311,6 +311,7 @@ static void FIRCLSPopulateImageDetailWithLoadCommand(uint32_t type,
     case LC_VERSION_MIN_IPHONEOS:
     case LC_VERSION_MIN_TVOS:
     case LC_VERSION_MIN_WATCHOS:
+    case LC_BUILD_VERSION:
       details->minSDK = FIRCLSMachOGetMinimumOSVersion(cmd);
       details->builtSDK = FIRCLSMachOGetLinkedSDKVersion(cmd);
       break;

Crashlytics/Crashlytics/Settings/Models/FIRCLSApplicationIdentifierModel.m

@@ -104,7 +104,8 @@
             uuid = FIRCLSMachOGetUUID(cmd);
 
             [executables setObject:FIRCLSUUIDToNSString(uuid) forKey:arch];
-          } else if (type == LC_VERSION_MIN_MACOSX || type == LC_VERSION_MIN_IPHONEOS) {
+          } else if (type == LC_VERSION_MIN_MACOSX || type == LC_VERSION_MIN_IPHONEOS ||
+                     type == LC_BUILD_VERSION) {
             self->_minimumSDK = FIRCLSMachOGetMinimumOSVersion(cmd);
             self->_builtSDK = FIRCLSMachOGetLinkedSDKVersion(cmd);
           }

Crashlytics/Shared/FIRCLSMachO/FIRCLSMachO.m

@@ -514,10 +514,18 @@ static FIRCLSMachOVersion FIRCLSMachOVersionFromEncoded(uint32_t encoded) {
 }
 
 FIRCLSMachOVersion FIRCLSMachOGetMinimumOSVersion(const struct load_command* cmd) {
+  if (cmd->cmd == LC_BUILD_VERSION) {
+    return FIRCLSMachOVersionFromEncoded(((const struct build_version_command*)cmd)->minos);
+  }
+
   return FIRCLSMachOVersionFromEncoded(((const struct version_min_command*)cmd)->version);
 }
 
 FIRCLSMachOVersion FIRCLSMachOGetLinkedSDKVersion(const struct load_command* cmd) {
+  if (cmd->cmd == LC_BUILD_VERSION) {
+    return FIRCLSMachOVersionFromEncoded(((const struct build_version_command*)cmd)->sdk);
+  }
+
   return FIRCLSMachOVersionFromEncoded(((const struct version_min_command*)cmd)->sdk);
 }
 

Crashlytics/Shared/FIRCLSMachO/FIRCLSMachOSlice.m

@@ -66,6 +66,7 @@
             case LC_VERSION_MIN_MACOSX:
             case LC_VERSION_MIN_WATCHOS:
             case LC_VERSION_MIN_TVOS:
+            case LC_BUILD_VERSION:
               self->_minimumOSVersion = FIRCLSMachOGetMinimumOSVersion(cmd);
               self->_linkedSDKVersion = FIRCLSMachOGetLinkedSDKVersion(cmd);
               break;

Crashlytics/UnitTests/FIRCLSApplicationIdentifierModelTests.m

@@ -0,0 +1,35 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#import "Crashlytics/Crashlytics/Settings/Models/FIRCLSApplicationIdentifierModel.h"
+
+#import <XCTest/XCTest.h>
+
+@interface FIRCLSApplicationIdentifierModelTests : XCTestCase
+
+@end
+
+@implementation FIRCLSApplicationIdentifierModelTests
+
+- (void)testReadsMinimumAndBuiltSDKVersionsOfExecutable {
+  // The test host is built with a current toolchain and deployment target, so its versions are
+  // described by LC_BUILD_VERSION rather than LC_VERSION_MIN_*.
+  FIRCLSApplicationIdentifierModel *model = [[FIRCLSApplicationIdentifierModel alloc] init];
+  XCTAssertNotNil(model);
+
+  XCTAssertNotEqualObjects(model.minimumSDKString, @"0.0.0");
+  XCTAssertNotEqualObjects(model.builtSDKString, @"0.0.0");
+}
+
+@end

Crashlytics/UnitTests/FIRCLSBinaryImageTests.m

@@ -0,0 +1,61 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "Crashlytics/Crashlytics/Components/FIRCLSBinaryImage.h"
+
+#import <Foundation/Foundation.h>
+#import <XCTest/XCTest.h>
+
+#include "Crashlytics/Crashlytics/Helpers/FIRCLSFile.h"
+
+@interface FIRCLSBinaryImageTests : XCTestCase
+
+@end
+
+@implementation FIRCLSBinaryImageTests
+
+- (void)testRecordMainExecutableIncludesMinimumAndBuiltSDKVersions {
+  // The test host is built with a current toolchain and deployment target, so its versions are
+  // described by LC_BUILD_VERSION rather than LC_VERSION_MIN_*.
+  NSString *path =
+      [NSTemporaryDirectory() stringByAppendingPathComponent:@"executable_test.clsrecord"];
+  [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
+
+  FIRCLSFile file;
+  if (!FIRCLSFileInitWithPath(&file, [path fileSystemRepresentation], false)) {
+    XCTFail(@"Failed to open %@", path);
+    return;
+  }
+  XCTAssertTrue(FIRCLSBinaryImageRecordMainExecutable(&file));
+  FIRCLSFileClose(&file);
+
+  NSData *data = [NSData dataWithContentsOfFile:path];
+  XCTAssertNotNil(data);
+  if (!data) {
+    return;
+  }
+
+  NSDictionary *record = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil];
+  NSDictionary *executable = record[@"executable"];
+  XCTAssertNotNil(executable);
+
+  XCTAssertNotNil(executable[@"minimum_sdk_version"]);
+  XCTAssertNotNil(executable[@"built_sdk_version"]);
+  XCTAssertNotEqualObjects(executable[@"minimum_sdk_version"], @"0.0.0");
+  XCTAssertNotEqualObjects(executable[@"built_sdk_version"], @"0.0.0");
+
+  [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
+}
+
+@end

Crashlytics/UnitTests/FIRCLSMachO/FIRCLSMachOTests.m

@@ -277,6 +277,36 @@
   XCTAssertEqual((uint32_t)0, version.bugfix, @"");
 }
 
+- (void)testReadVersionsFromBuildVersionLoadCommand {
+  // Binaries built for iOS 12, macOS 10.14, tvOS 12, watchOS 5 or later carry LC_BUILD_VERSION
+  // instead of LC_VERSION_MIN_*.
+  struct build_version_command command = {0};
+  command.cmd = LC_BUILD_VERSION;
+  command.cmdsize = sizeof(command);
+  command.platform = PLATFORM_IOS;
+  command.minos = 0x000F0200;  // 15.2.0
+  command.sdk = 0x001A0501;    // 26.5.1
+
+  FIRCLSMachOVersion version = FIRCLSMachOGetMinimumOSVersion((const struct load_command*)&command);
+  XCTAssertEqual((uint32_t)15, version.major);
+  XCTAssertEqual((uint32_t)2, version.minor);
+  XCTAssertEqual((uint32_t)0, version.bugfix);
+
+  version = FIRCLSMachOGetLinkedSDKVersion((const struct load_command*)&command);
+  XCTAssertEqual((uint32_t)26, version.major);
+  XCTAssertEqual((uint32_t)5, version.minor);
+  XCTAssertEqual((uint32_t)1, version.bugfix);
+}
+
+- (void)testRunningSliceReadsMinimumOSAndSDKVersions {
+  // The test host is built with a current toolchain and deployment target, so its versions are
+  // described by LC_BUILD_VERSION.
+  FIRCLSMachOSlice* slice = [FIRCLSMachOSlice runningSlice];
+
+  XCTAssertGreaterThan(slice.minimumOSVersion.major, (uint32_t)0);
+  XCTAssertGreaterThan(slice.linkedSDKVersion.major, (uint32_t)0);
+}
+
 - (void)testReadx86_64Section {
   NSString* path = [[self resourcePath] stringByAppendingPathComponent:@"x86_64-executable"];
   struct FIRCLSMachOFile file;