最近在跟着《深入理解Java虚拟机》复习 JVM 相关的知识，想再编译一下 JDK。因为之前有编译过 JDK8，因为版本较老，踩坑比较多；并且现在 Java 每半年一个大版本，新版本还没来得及了解就过时了，更别提去使用了，所以这次打算用 JDK11 来编译 OpenJDK12。
环境信息：
- 系统版本：MacOS 13.6.1 (22G313)
- boot jdk：idk-11.0.21
- Xcode 版本：15.0
源码下载
要编译 JDK，肯定要先有源码才能编译。源码从 Oracle 官网下载：https://hg.openjdk.org/jdk/jdk12，左边菜单选择方便的格式下载即可，开始我下载的是 zip，但是解压的时候总是会提示意料之外的文件结尾，解压不出来，所以就换了 tar 格式下载。
前置操作
freetype
OpenJDK 中用到 freetype 渲染，所以需要先安装好 freetype。
brew install freetype
ccache
ccache，是一个编译器缓存，该工具会高速缓存编译生成的信息，并在编译的特定部分使用高速缓存的信息。
brew install ccache
安装 JDK11
要得到梯子，首先要有个梯子。同样的道理，要编译出 JDK，首先得有个 JDK。只能通过低版本的 JDK 编译出高版本的 JDK，不能反过来。下载 JDK11 ，配置好环境变量，就不多赘述了。
编译
接下来就可以开始编译了，如果有过编译记录，先运行 make clean 和 make clean-dist 清空相关目录，然后在根目录运行 configure
./configure --disable-warnings-as-errors --with-debug-level=slowdebug --with-jvm-variants=server --enable-ccache
顺利的话会输出以下内容
====================================================
The existing configuration has been successfully updated in
/Users/lozhu/Documents/projects/jdk12-06222165c35f/build/macosx-x86_64-server-slowdebug
using configure arguments '--disable-warnings-as-errors --with-debug-level=slowdebug --with-jvm-variants=server --enable-ccache'.
Configuration summary:
* Debug level: slowdebug
* HS debug level: debug
* JVM variants: server
* JVM features: server: 'aot cds cmsgc compiler1 compiler2 dtrace epsilongc g1gc graal jfr jni-check jvmci jvmti management nmt parallelgc serialgc services shenandoahgc vm-structs'
* OpenJDK target: OS: macosx, CPU architecture: x86, address length: 64
* Version string: 12-internal+0-adhoc.root.jdk12-06222165c35f (12-internal)
Tools summary:
* Boot JDK: openjdk version "11.0.21" 2023-10-17 LTS OpenJDK Runtime Environment Microsoft-8519785 (build 11.0.21+9-LTS) OpenJDK 64-Bit Server VM Microsoft-8519785 (build 11.0.21+9-LTS, mixed mode) (at /opt/java/jdk-11.0.21+9/Contents/Home)
* Toolchain: clang (clang/LLVM from Xcode 15.0.1)
* C Compiler: Version 15.0.0 (at /usr/bin/clang)
* C++ Compiler: Version 15.0.0 (at /usr/bin/clang++)
Build performance summary:
* Cores to use: 8
* Memory limit: 16384 MB
* ccache status: Active (4.8.3)
WARNING: The result of this configuration has overridden an older
configuration. You *should* run 'make clean' to make sure you get a
proper build. Failure to do so might result in strange build problems.
然后运行 make images 进行编译，根据机器配置编译时间长短会有较大差异，2020款MacBook pro编译了15分钟。
Stopping sjavac server
Finished building target 'images' in configuration 'macosx-x86_64-server-slowdebug'
出现这个提示就说明编译成功了！编译出的 JDK 位于：./build/macosx-x86_64-server-slowdebug/jdk/bin 下，运行 ./java -version 可以看到自己编译出的 JDK 版本：
openjdk version "12-internal" 2019-03-19
OpenJDK Runtime Environment (slowdebug build 12-internal+0-adhoc.root.jdk12-06222165c35f)
OpenJDK 64-Bit Server VM (slowdebug build 12-internal+0-adhoc.root.jdk12-06222165c35f, mixed mode)
问题记录
问题1
./jdk12-06222165c35f/src/java.base/macosx/native/libosxsecurity/KeystoreImpl.m note: did not find header ‘JavaNativeFoundation.h’ in framework ‘JavaNativeFoundation’ (loaded from ‘/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.0.sdk/System/Library/Frameworks’)
解决
这个问题很明显，就是系统路径的问题，但是一直苦于不知道 JavaNativeFoundation 在哪里引入的，在这里卡了两三个小时，搜索了很多国内外的网站也没找到解决方案。最后是关掉电脑后用手机搜这个问题，在 CSDN 上搜到了一些之前没搜到的资料，虽然说问题不完全相同，但是算是同一个问题，提供了很大的帮助。
参考：macOS Catalina + Xcode 12 编译OpenJDK 14 错误解决
系统版本升级，一部分文件路径有变化。新的路径：/Library/Developer/CommandLineTools/SDKs/MacOSX14.sdk。
在 ./build/macosx-x86_64-server-slowdebug/spec.gmk 中搜索 SYSROOT_CFLAGS 和 SYSROOT_LDFLAGS ，注释掉这两个变量，新增下面的内容
SYSROOT_CFLAGS := -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
SYSROOT_LDFLAGS := -isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
BUILD_SYSROOT_CFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
BUILD_SYSROOT_LDFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
在 ./build/macosx-x86_64-server-slowdebug/buildjdk-spec.gmk 中搜索 SYSROOT_CFLAGS 和 SYSROOT_LDFLAGS ，注释掉这两个变量，新增下面的内容
BUILD_SYSROOT_CFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
BUILD_SYSROOT_LDFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
BUILD_SYSROOT_CFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
BUILD_SYSROOT_LDFLAGS:=-isysroot /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk -iframework /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks -F /Library/Developer/CommandLineTools/SDKs/MacOSX13.1.sdk/System/Library/Frameworks/JavaNativeFoundation.framework
问题2
assert 未定义
解决
直接将报错文件中有 assert 的行删除或者注释掉即可，只涉及一个文件，不到十行代码。
问题3
clang: error: SDK does not contain ‘libarclite’ at the path ‘/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/libarclite_macosx.a’; try increasing the minimum deployment target
解决
参考：iOS Xcode 升级Xcode15报错: SDK does not contain ‘libarclite‘ at the path ‘/Applications/Xcode.app/Con…
文件缺失，从 https://codeload.github.com/kamyarelyasi/Libarclite-Files/zip/refs/heads/main 下载 libarclite_macosx.a 文件，复制到 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/arc/ 路径下。这里有个问题就是，arc 路径需要自己创建，但是受系统权限限制，sudo 权限也创建不了这个目录，只能更改系统设置关闭 SIP。重启电脑，按住 ⌘ + R，进入保护模式后打开终端，输入命令：crsutil disable ，重启即可。要重新开启 SIP，命令为：crsutil enable
参考的链接里单词写错了，是 crsutil 不是 csrutil。