RFR: Module constraints on targets

[Paul Sandoz]

Hi Chris,

Looks good.

Paul.

On Oct 11, 2012, at 6:37 PM, Chris Hegarty <chris.hegarty at oracle.com> wrote:

> 
> This is a proposal to fulfill the 'module constraints on targets' requirement [1]. Essentially, support setting OS and Arch values on module-files and libraries. It meets the common use-cases, like installing platform specific modules into the wrong module library, when cross compiling, etc..
> 
> 1) Extend the Jigsaw module-file format [2] (jmod) to accommodate Operating System and Architecture values in the module header.
> 
> ModuleFileHeader {
>    u4 magic;          // FileConstants.MAGIC
>    u2 type;           // FileConstants.Type.MODULE_FILE
>    u2 major;          // FileConstants.ModuleFile.MAJOR_VERSION
>    u2 minor;          // FileConstants.ModuleFile.MINOR_VERSION
>    u8 csize;          // Size of entire file, compressed
>    u8 usize;          // Space required for uncompressed contents
>                       // (upper bound; need not be exact)
>    u2 sections;       // Number of following sections
>    u2 hashType;       // One of FileConstants.ModuleFile.HashType
>                       // (applies to all hashes in this file)
>    u2 hashLength;     // Length of following hash
>    b* hash;           // Hash of entire file (except this hash)
>    u2 osLength;       // Length of following Operating System, in bytes <<< ADDED
>    b* os;             // Operating System, in Java-modified UTF-8 <<< ADDED
>    u2 archLength;     // Length of following Architecture, in bytes <<< ADDED
>    b* arch;           // Architecture, in Java-modified UTF-8  <<< ADDED
> }
> 
> The os and arch values are Java-modified UTF-8 strings, representing the Operating System and Architecture where the module-file/library is intended to be deployed.
> 
> A value of 0 is a valid value for both osLength and archLength. This effectively means that these values are unset, and the module-file/library is agnostic of Operating System and Architecture. It should be considered a candidate for any module library.
> 
> 2) Update CLIs
> 
> Both jmod and jpkg need to be updated to support passing of os and arch values during creation.
> 
> Define two new arguments -os, -arch for both jmod and jpkg. These arguments are optional. If specified, can only be specified once. For example:
> 
> ./bin/jmod create -L m.lib -os linux -arch x64
> 
> ./bin/jmod id -L m.lib
> path /export/chris/repos/jigsaw/constraints/test/m.lib
> version 0.1
> os: linux
> arch: x64
> 
> ./bin/jmod install -L m.lib jigsaw-pkgs/jmod/jdk.logging at 8-ea.jmod
> java.io.IOException: Module architecture [linux-i586] does not match library [linux-x64]
> org.openjdk.jigsaw.cli.Command$Exception: java.io.IOException: Module architecture [linux-i586] does not match library [linux-x64]
> 	at org.openjdk.jigsaw.cli.Librarian$Install.go(Librarian.java:230)
> 	at org.openjdk.jigsaw.cli.Librarian$Install.go(Librarian.java:189)
> 	at org.openjdk.jigsaw.cli.Command.run(Command.java:100)
>  .....
> 
> 
> 3) Update the build to produce images and module-files that are
> $PLATFORM and $ARCH specific ( matching the bundles ).
> 
> Webrev:
>  http://cr.openjdk.java.net/~chegar/jigsaw/constraints.00/webrev/
> 
> 
> -Chris.
> 
> [1] http://openjdk.java.net/projects/jigsaw/doc/draft-java-module-system-requirements-12#module-constraints-on-targets
> [2] http://cr.openjdk.java.net/~mr/jigsaw/notes/module-file-format/