啓用遷移警告

Question

我將2.7.7 scala代碼庫移植到2.8版，並想知道是否有編譯器選項來顯示遷移通知？我被變化的行爲改變了，它具有以下遷移注意事項[1]，但是當我構建項目時（我已經棄用並且未經檢查的警告已啓用），它不會顯示任何東西。

1：@migration(2, 8, "As of 2.8, this operation creates a new map. To add an element as a\n"+ "side effect to an existing map and return that map itself, use +=." )

Answer 1

的選項是：-Xmigration

進入scalac -help將顯示Scala編譯器的標準選項。輸入scalac -X將顯示高級選項。

輸入scalac -Y將顯示私人選項。

Answer 2

這是一個擴展選項，-Xmigration。

~: scala -X 
Usage: scala <options> <source files> 
Possible advanced options include: 
    -Xassem-extdirs <dirs>   List of directories containing assemblies, defaults to `lib' 
    -Xassem-name <file>   Name of the output assembly (only relevant with -target:msil) 
    -Xassem-path <path>   List of assemblies referenced by the program (only relevant with -target:msil) 
    -Xcheck-null     Emit warning on selection of nullable reference 
    -Xcheckinit     Add runtime checks on field accessors. Uninitialized accesses result in an exception being thrown. 
    -Xdisable-assertions   Generate no assertions and assumptions 
    -Xelide-below     Generate calls to @elidable-marked methods only if method priority is greater than argument. 
    -Xexperimental     Enable experimental extensions 
    -Xfatal-warnings    Fail the compilation if there are any warnings. 
    -Xfuture      Turn on future language features 
    -Xgenerate-phase-graph <file> Generate the phase graphs (outputs .dot files) to fileX.dot 
    -Xlog-implicits    Show more info on why some implicits are not applicable 
    -Xmigration     Warn about constructs whose behavior may have changed between 2.7 and 2.8 
    -Xno-forwarders    Do not generate static forwarders in mirror classes 
    -Xno-uescape     Disables handling of \u unicode escapes 
    -Xnojline      Do not use JLine for editing 
    -Xplugin-disable:<plugin>  Disable a plugin 
    -Xplugin-list     Print a synopsis of loaded plugins 
    -Xplugin-require:<plugin>  Abort unless a plugin is available 
    -Xplugin:<file>    Load a plugin from a file 
    -Xpluginsdir <path>   Path to search compiler plugins 
    -Xprint-icode     Log internal icode to *.icode files 
    -Xprint-pos     Print tree positions (as offsets) 
    -Xprint-types     Print tree types (debugging option) 
    -Xprint:<phase>    Print out program after <phase> or "all" 
    -Xprompt      Display a prompt after each error (debugging option) 
    -Xresident      Compiler stays resident, files to compile are read from standard input 
    -Xscript <object>    Compile as a script, wrapping the code into object.main() 
    -Xshow-class <class>   Show class info 
    -Xshow-object <object>   Show object info 
    -Xshow-phases     Print a synopsis of compiler phases 
    -Xsource-reader <classname> Specify a custom method for reading source files 
    -Xsourcedir <directory>  When -target:msil, the source folder structure is mirrored in output directory. 
    -Xwarninit      Warn about possible changes in initialization semantics 
    -Y        Print a synopsis of private options 

Answer 3

% scala -X 
Usage: scala <options> <source files> 
Possible advanced options include: 
    ... 
    -Xmigration     Warn about constructs whose behavior may have changed between 2.7 and 2.8 
    ...