RFR: 8347831: Re-examine version check when cross linking

[Erik Joelsson]

On Wed, 5 Nov 2025 17:41:44 GMT, Henry Jen <henryjen at openjdk.org> wrote:

> This PR include build changes from @magicus and jlink change to verify the build signature.
> 
> Tested with local builds for MacOS and Linux as below shows that cross linking with same build is working while linking with different build failed with error message.
> 
> ❯ export JAVA_HOME=./build/macosx-x86_64-server-fastdebug/images/jdk-bundle/jdk-26.jdk/Contents/Home
>                                                                                                                                                                  
> ❯ java --version
> openjdk 26-internal 2026-03-17
> OpenJDK Runtime Environment (fastdebug build 26-internal-adhoc.hjen.JDK-8347831)
> OpenJDK 64-Bit Server VM (fastdebug build 26-internal-adhoc.hjen.JDK-8347831, mixed mode, sharing)
>                                                                                                                                                                  
> ❯ jlink --version                                                                       
> 26-internal
>                                                                                                                                                                  
> ❯ jlink --module-path ./build/linux-x86_64-server-release/images/jdk/jmods --add-modules java.base --output linux                                                                                                                                        
>                                                                                                                                                                  
> ❯ jlink --add-modules java.base --output macos
>                                                             
> ❯ jlink --module-path ~/linux/jdk-25.0.1/jmods --add-modules java.base --output linux25    
> Error: jlink build N/A-26-internal-adhoc.hjen.JDK-8347831-2026-03-17 does not match target java.base build N/A
>                                                                                                                                                                  
> ❯ jlink --module-path /Library/Java/JavaVirtualMachines/jdk-25.jdk/Contents/Home/jmods --add-modules java.base --output macos25 
> Error: jlink build N/A-26-internal-adhoc.hjen.JDK-8347831-2026-03-17 does not match target java.base build N/A

I'm not thrilled about the code duplication between Gensrc.gmk in java.base and and jdk.jlink. I think this should be extracted out into a common file in some way. Having 2 copies of the template file also seems suboptimal.

make/modules/java.base/Gensrc.gmk line 129:

> 127: RELEASE_FILE_VARDEPS := $(COMPANY_NAME) $(VERSION_STRING) $(VERSION_DATE)
> 128: RELEASE_FILE_VARDEPS_FILE := $(call DependOnVariable, RELEASE_FILE_VARDEPS, \
> 129:   $(SUPPORT_OUTPUTDIR)/gensrc/$(MODULE)/jlink_release_txt.vardeps)

Continuation indentation should be 4 spaces (see https://openjdk.org/groups/build/doc/code-conventions.html).

make/modules/java.base/Gensrc.gmk line 134:

> 132:   SOURCE_FILES := $(RELEASE_FILE_TEMPLATE), \
> 133:   OUTPUT_FILE := $(RELEASE_FILE_TARGET), \
> 134:   REPLACEMENTS := \

Continuation indentation 4 spaces.

make/modules/java.base/Gensrc.gmk line 140:

> 138: ))
> 139: 
> 140: $(OUTPUT_FILE): $(RELEASE_FILE_VARDEPS_FILE)

There is no variable `OUTPUT_FILE` defined. I think this should be `$(BUILD_RELEASE_FILE)`.

-------------

PR Review: https://git.openjdk.org/jdk/pull/28155#pullrequestreview-3423620882
PR Review Comment: https://git.openjdk.org/jdk/pull/28155#discussion_r2495596212
PR Review Comment: https://git.openjdk.org/jdk/pull/28155#discussion_r2495596793
PR Review Comment: https://git.openjdk.org/jdk/pull/28155#discussion_r2495599114