Włączanie ostrzeżeń migracyjnych

Question

Przesyłam podstawę kodu 2.7.7 kodu scala do 2.8 i zastanawiałem się, czy była dostępna opcja kompilatora do wyświetlania powiadomień o migracji? Zostałem ukąszony przez zmianę zachowania dla zmiennych sekwencji, które miały następujące powiadomienie o migracji [1], jednak nie wyświetlają niczego podczas budowania projektu (mam już wycofane i niezaznaczone ostrzeżenia)

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

opcja: -Xmigration

Wprowadzanie scalac -help pokaże standardowe opcje kompilatora Scala.

Po wprowadzeniu scalac -X zostaną wyświetlone zaawansowane opcje.

Po wprowadzeniu scalac -Y zostaną wyświetlone opcje prywatne.

Answer 2

Jest to rozszerzona opcja, -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 
    ...