ecj man page

ecj — the eclipse JDT Batch Compiler

Synopsis

ecj [OPTION]... [SOURCEFILE]... ...

Description

ecj is the batch compiler from Eclipse and is available as ecj.jar. Since 3.3, this jar also contains the support for jsr199 (Compiler API) and the support for jsr269 (Annotation processing). In order to use the annotations processing support, a 1.6 VM is required.

Options Summary

Here is a summary of all the options, grouped by type. Explanations are in the Options section.

ClassPath Options

-bootclasspath -cp|-classpath -extdirs -endorseddirs -sourcepath -d -encoding

Compliance Options

-target -1.3 -1.4 -1.5 -1.6 -1.7 -1.8 -source

Warning Options

-?:warn -help:warn -warn:... -nowarn -err:... -deprecation -properties

Debug Options

-g -preserveAllLocals -parameters

Annotation Processing Options

-Akey[=value] -proc:[only|none] -processor -processorpath -s -XprintProcessorInfo -XprintRounds -classNames

Ignored Options (for compatibility with javac options)

-J -X -O

Advanced Options

@<file> -maxProblems -log -Xemacs -proceedOnError -verbose -referenceInfo -progress -time -noExit -repeat -inlineJSR -enableJavaDoc -missingNullDefault

Helping Options

-? -help -v -version -showversion

Options

ClassPath Options

-bootclasspath <dir 1>;<dir 2>;...;<dir P>
This is a list of directories or jar files used to bootstrap the class files used by the compiler. By default the libraries of the running VM are used. Entries are separated by the platform path separator. Each directory or file can specify access rules for types between '[' and ']'. If no bootclasspath is specified, the compiler will infer it using the following system properties sun.boot.class.path, vm.boot.class.path or org.apache.harmony.boot.class.path in this order respectively
-cp|-classpath <dir 1>;dir2;...<dir P>
This is a list of directories or jar files used to compile the source files. The default value is the value of the property "java.class.path". Entries are separated by the platform path separator. Each directory or file can specify access rules for types between '[' and ']' (e.g. [-X] to forbid access to type X, [~X] to discourage access to type X, [+p/X:-p/*] to forbid access to all types in package p but allow access to p/X). The compiler follows the Class-Path clauses of jar files' manifests recursively and appends each referenced jar file to the end of the classpath, provided it is not on the classpath yet.
-extdirs <dir 1>;<dir 2>;...;<dir P>
This is a list of directories used to specify the location of extension zip/jar files. Entries are separated by the platform path separator.
-endorseddirs <dir 1>;<dir 2>;...;<dir P>
This is a list of directories used to specify the location of endorsed zip/jar files. Entries are separated by the platform path separator.
-sourcepath <dir 1>;<dir 2>;...;<dir P>
This is a list of directories used to specify the source files. Entries are separated by the platform path separator. Each directory can specify access rules for types between '[' and ']'.
-d <dir 1>|none
This is used to specify in which directory the generated .class files should be dumped. If it is omitted, no package directory structure is created. If you want to generate no .class file at all, use -d none.
-encoding <encoding name>

Specify default encoding for all source files. Custom encoding can also be specified on a per file basis by suffixing each input source file/folder name with [<encoding name>]. For example X.java[UTF-8] would specify the UTF-8 encoding for the compilation unit X.java located in the current user directory. If multiple default source file encodings are specified, the last one will be used.

For example: ... -encoding UTF-8 X.java[Cp1252] Y.java[UTF-16] Z.java ....
All source files will be read using UTF-8 encoding (this includes Z.java). X.java will be read using Cp1252 encoding and Y.java will be read using UTF-16 encoding.

... -encoding UTF-8 -encoding UTF-16 ....
All source files will be read using UTF-16 encoding. The -encoding option for UTF-8 is ignored.

... -encoding Cp1252 /foo/bar/X.java[UTF-16] /foo/bar[UTF-8] ....
All source files will be read using Cp1252 encoding. X.java is the only file inside the /foo/bar directory to be read using the encoding UTF-16. All other files in that directory will use UTF-8 encoding.

Compliance Options

-target 1.1 to 1.8 (or 8, 8.0, etc.)

This specifies the .class file target setting. The possible value are:
1.1 (major version: 45 minor: 3)
1.2 (major version: 46 minor: 0)
1.3 (major version: 47 minor: 0)
1.4 (major version: 48 minor: 0)
1.5, 5 or 5.0 (major version: 49 minor: 0)
1.6, 6 or 6.0 (major version: 50 minor: 0)
1.7, 7 or 7.0 (major version: 51 minor: 0)
1.8, 8 or 8.0 (major version: 52 minor: 0)

Defaults are:
1.1 in -1.3 mode
1.2 in -1.4 mode
1.5 in -1.5 mode
1.6 in -1.6 mode
1.7 in -1.7 mode
1.8 in -1.8 mode clcd1.1 can be used to generate the StackMap attribute.

-1.3
Set compliance level to 1.3. Implicit -source 1.3 -target 1.1.
-1.4
Set compliance level to 1.4 (default). Implicit -source 1.3 -target 1.2.
-1.5
Set compliance level to 1.5. Implicit -source 1.5 -target 1.5.
-1.6
Set compliance level to 1.6. Implicit -source 1.6 -target 1.6.
-1.7
Set compliance level to 1.7. Implicit -source 1.7 -target 1.7.
-1.8
Set compliance level to 1.8. Implicit -source 1.8 -target 1.8.
-source 1.1 to 1.8 (or 8, 8.0, etc.)

This is used to specify the source level expected by the compiler. The possible value are:
1.3
1.4
1.5, 5 or 5.0
1.6, 6 or 6.0
1.7, 7 or 7.0
1.8, 8 or 8.0

Defaults are:
1.3 in -1.3 mode
1.3 in -1.4 mode
1.5 in -1.5 mode
1.6 in -1.6 mode
1.7 in -1.7 mode
1.8 in -1.8 mode
In 1.4, assert is treated as a keyword. In 1.5 and 1.6, enum and assert are treated as keywords.

Warning Options

-?:warn -help:warn
Display advanced warning options
-warn:...

Specify the set of enabled warnings.
-warn:none disable all warnings
-warn:<warning tokens separated by ,> enable exactly the listed warnings
-warn:+<warning tokens separated by ,> enable additional warnings
-warn:-<warning tokens separated by ,> disable specific warnings

Examples:

-warn:unusedLocal,deprecation
enables only the given two warning options and disables all the other options

-warn:-unusedLocal,deprecation,+fallthrough
disables unusedLocal and deprecation, enables fallthrough, and leaves the other warning options untouched

The first column below shows the default state for an option. A mark "+/-" indicates that an option covers several fine grained warning variants, some of which are enabled by default, others disabled. This means that specifying the given option with "+" will enable more warnings than the default, and specifying "-" disables some that are enabled by default.

+/- allDeadCode dead code including trivial if (DEBUG) check

+/- allDeprecation deprecation even inside deprecated code

allJavadoc invalid or missing Javadoc

allOver-ann all missing @Override annotations (superclass and superinterfaces)

all-static-method all method can be declared as static warnings

assertIdentifier occurrence of assert used as identifier

boxing autoboxing conversion

charConcat when a char array is used in a string concatenation without being converted explicitly to a string

compareIdentical comparing identical expressions

conditionAssign possible accidental boolean assignment

constructorName method with constructor name

deadCode dead code excluding trivial if (DEBUG) check

dep-ann missing @Deprecated annotation

+/- deprecation usage of deprecated type or member outside deprecated code

discouraged use of types matching a discouraged access rule

emptyBlock undocumented empty block

enumIdentifier occurrence of enum used as identifier

enumSwitch incomplete enum switch

enumSwitchPedantic report missing enum switch cases even in the presence of a default case

fallthrough possible fall-through case

fieldHiding field hiding another variable

finalBound type parameter with final bound

finally finally block not completing normally

forbidden use of types matching a forbidden access rule

hashCode missing hashCode() method when overriding equals()

+/- hiding macro for fieldHiding, localHiding, maskedCatchBlock, and typeHiding

includeAssertNull raise null warnings for variables that got tainted in an assert expression

indirectStatic indirect reference to static member

inheritNullAnnot consider null annotations as being inherited from an overridden method to any overriding methods

intfAnnotation annotation type used as super interface

intfNonInherited interface non-inherited method compatibility

intfRedundant find redundant superinterfaces

invalidJavadoc macro to toggle the 'malformed Javadoc comments' option and all its sub-options listed below

invalidJavadocTag report invalid Javadoc tags in Javadoc comments.

invalidJavadocTagDep report invalid deprecated references in Javadoc tag arguments

invalidJavadocTagNotVisible report invalid non-visible references in Javadoc tag arguments

invalidJavadocVisibility(<visibility>) specify visibility modifier ("public", "protected" or "private") for malformed Javadoc tag warnings. Usage example: invalidJavadocVisibility(public)

javadoc invalid Javadoc

localHiding local variable hiding another variable

maskedCatchBlock hidden catch block

missingJavadocTags macro to toggle the 'missing Javadoc tags' option and all its sub-options listed below

missingJavadocTagsMethod report missing Javadoc tags for a method's type parameters

missingJavadocTagsOverriding report missing Javadoc tags in overriding methods

missingJavadocTagsVisibility(<visibility>) specify visibility modifier ("public", "protected" or "private") for missing Javadoc tags warnings. Usage example: missingJavadocTagsVisibility(public)

missingJavadocComments macro to toggle the 'missing Javadoc comments' option and all its sub-options listed below

missingJavadocCommentsOverriding report missing Javadoc comments in overriding methods

missingJavadocCommentsVisibility(<visibility>) specify visibility modifier ("public", "protected" or "private") for missing Javadoc comments warnings. Usage example: missingJavadocCommentsVisibility(public)

nls non-nls string literals (lacking of tags //$NON-NLS-<n>)

noEffectAssign assignment with no effect

nonnullNotRepeated nonnull parameter annotation from overridden method is not repeated in an overriding method. Is effective only with the nullAnnot option enabled.

+/- null potential missing or redundant null check

nullAnnot enable annotation based null analysis. If desired, the annotation types to be interpreted by the compiler can be specified by appending (nullable|nonnull|nonnullbydefault), where each annotation type is specified using its fully qualified name. Usage example: nullAnnot(p.Nullable|p.NonNull|p.NonNullByDefault)

Enabling this option enables all null-annotation related sub-options. These can be individually controlled using options listed below

nullAnnotConflict report conflicts between null annotation specified and nullness inferred. Is effective only with the nullAnnot option enabled.

nullAnnotRedundant report redundant specification of null annotation. Is effective only with the nullAnnot option enabled.

nullDereference missing null check

nullUncheckedConversion report unchecked conversion from unannotated type to @NonNull type. Is effective only with the nullAnnot option enabled.

over-ann missing @Override annotation (superclass only)

paramAssign assignment to a parameter

pkgDefaultMethod attempt to override package-default method

raw usage a of raw type (instead of a parameterized type)

+/- resource (potentially) unsafe usage of resource of type Closeable

semicolon unnecessary semicolon or empty statement

serial missing serialVersionUID

specialParamHiding constructor or setter parameter hiding another field

+/- static-access macro for indirectStatic and staticReceiver

static-method an instance method that could be as a static method

staticReceiver if a non static receiver is used to get a static field or call a static method

super overriding a method without making a super invocation

suppress enable @SuppressWarnings

switchDefault switch statement lacking a default case

syncOverride missing synchronized in synchronized method override

syntacticAnalysis perform syntax-based null analysis for fields

syntheticAccess when performing synthetic access for innerclass

tasks enable support for tasks tags in source code

typeHiding type parameter hiding another type

unavoidableGenericProblems report even unavoidable type safety problems due to raw APIs

unchecked unchecked type operation

unnecessaryElse unnecessary else clause

unqualifiedField unqualified reference to field

+/- unused macro for unusedImport, unusedLabel, unusedLocal, unusedPrivate, unusedThrown, unusedTypeArgs, and unusedTypeParameter

unusedAllocation allocating an object that is not used

unusedArgument unused method parameter (deprecated option; use unusedParam instead)

unusedImport unused import reference

unusedLabel unused label

unusedLocal unused local variable

unusedParam unused method parameter

unusedParamImplementing unused parameter for implementing method

unusedParamIncludeDoc unused parameter documented in a Javadoc comment tag

unusedParamOverriding unused parameter for overriding method

unusedPrivate unused private member declaration

unusedThrown unused declared thrown exception

unusedThrownIncludeDocComment unused declared thrown exception documented in a Javadoc comment tag

unusedThrownExemptExceptionThrowable report unused declared thrown exception but exempt Exception and Throwable

unusedThrownWhenOverriding unused declared thrown exception in overriding method

unusedTypeArgs unused type arguments for method and constructor

unusedTypeParameter unused type parameter

uselessTypeCheck unnecessary cast/instanceof operation

varargsCast varargs argument need explicit cast

+/- warningToken unhandled or unused warning token in @SuppressWarnings

-nowarn
No warning (equivalent to -warn:none)
-err:...

Specify the set of enabled warnings that are converted to errors.
E.g.
-err:unusedLocal,deprecation
unusedLocal and deprecation warnings will be converted to errors. All other warnings are still reported as warnings.

-err:<warning tokens separated by ,> convert exactly the listed warnings to errors
-err:+<warning tokens separated by ,> convert additional warnings to errors
-err:-<warning tokens separated by ,> remove specific warnings from being converted to errors

-deprecation
Equivalent to -warn:+deprecation.
-properties <file>

Set warnings/errors option based on the properties file contents. This option can be used with -nowarn, -err:.. or -warn:.. options, but the last one on the command line sets the options to be used.

The properties file contents can be generated by setting project specific settings on an existing java project and using the file in .settings/org.eclipse.jdt.core.prefs file as a properties file, or a simple text file that is defined entry/value pairs using the constants defined in the org.eclipse.jdt.core.JavaCore class. Of those constants declared in this class, all options starting with "org.eclipse.jdt.core.compiler." are interpreted by the batch compiler.

...
org.eclipse.jdt.core.compiler.problem.annotationSuperInterface=warning
org.eclipse.jdt.core.compiler.problem.assertIdentifier=warning
org.eclipse.jdt.core.compiler.problem.autoboxing=ignore
...

To ensure that a property file has the same effect when used in the IDE and for the batch compiler, use of the -properties option will change the defaults for a few options:

-g default changed to all enabled
-preserveAllLocals default changed to enabled
-enableJavadoc default changed to enabled
error/warning forbidden default changed to error

Debug Options

-g[:none|:lines,vars,source]
Set the debug attributes level
-g All debug info (equivalent to -g:lines,vars,source)
-g:none No debug info
-g:[lines,vars,source] Selective debug info
Not specifying this option is equivalent to setting -g:lines,source.
-preserveAllLocals
Explicitly request the compiler to preserve all local variables (for debug purpose). If omitted, the compiler will remove unused locals.
-parameters
Explicitly request the compiler to preserve information about the formal parameters of a method (such as their names) to be accessed from reflection libraries, annotation processing, code weaving, and in the debugger. This option is supported from target level 1.8 and later. Annotation processing options (require a 1.6 VM or above and are used only if the compliance is 1.6)

Annotation Processing Options

-Akey[=value]
Annotation processors options that are passed to annotation processors. key is made of identifiers separated by dots
-proc:[only|none]
If -proc:only is specified, the annotation processors will run but no compilation will be performed. If -proc:none is specified, annotation processors will not be discovered or run; compilation will proceed as if no annotation processors were found. By default the compiler must search the classpath for annotation processors, so specifying -proc:none may speed compilation if annotation processing is not required.
-processor <class1[,class2,...]>
Qualified class names of annotation processors to run. If specified, the normal processor discovery process will be skipped.
-processorpath <dir 1>;<dir 2>;...;<dir P>
A list of directories or jar files which will be searched for annotation processors. Entries are separated by the platform path separator. If not specified, the classpath will be searched instead.
-s <dir>
The directory where generated source files will be created.
-XprintProcessorInfo
Print information about which annotations and which elements a processor is asked to process
-XprintRounds
Print information about annotation processing rounds
-classNames <class1[,class2,...]>
Qualified names of binary types that need to be processed

Ignored Options (for compatibility with javac options)

-J<option>
Pass option to the virtual machine
-X<option>
Specify non-standard option. -Xemacs is not ignored.
-X
Print non-standard options and exit
-O
Optimize for execution time

Advanced Options

@<file>
Read command-line arguments from file
-maxProblems <n>
Max number of problems per compilation unit (100 by default)
-log <filename>
Specify a log file in which all output from the compiler will be dumped. This is really useful if you want to debug the batch compiler or get a file which contains all errors and warnings from a batch build. If the extension is .xml, the generated log will be an xml file.
-genericsignature
Explicitly request the compiler to preserve information about generic signature of lambda expressions.
-Xemacs
Use emacs style to present errors and warnings locations into the console and regular text logs. XML logs are unaffected by this option. With this option active, the message:
2. WARNING in /workspace/X.java
(at line 8)...
is presented as:
/workspace/X.java:8: warning: The method...
-proceedOnError[:Fatal]
Keep compiling in spite of errors, dumping class files with problem methods or problem types. This is recommended only if you want to be able to run your application even if you have remaining errors. With ":Fatal", all optional errors are treated as fatal and this leads to code that will abort if an error is reached at runtime. Without ":Fatal", optional errors don't prevent the proper code generation and the produced .class files can be run without a problem.
-verbose
Print accessed/processed compilation units in the console or the log file if specified.
-referenceInfo
Compute reference info. This is useful only if connected to the builder. The reference infos are useless otherwise.
-progress
Show progress (only in -log mode).
-time
Display speed information.
-noExit
Do not call System.exit(n) at end of compilation (n=0 if no error).
-repeat <n>
Repeat compilation process <n> times (perf analysis).
-inlineJSR
Inline JSR bytecode (implicit if target >= 1.5).
-enableJavadoc
Consider references inside Javadoc. The Javadoc options are effective only when this option is enabled.
-missingNullDefault
When annotation based null analysis is enabled (using "nullAnnot", above), this option will raise a warning whenever there is no default annotation on a package or a type.
-annotationpath
When annotation based null analysis is enabled (using "nullAnnot", above), this option defines locations where to find external annotations to support annotation-based null analysis. The value of this options is a list of directories or zip files. Entries are separated by the platform path separator. The special name CLASSPATH will cause lookup of external annotations from the classpath and sourcepath.

Helping Options

-? -help
Display the help message.
-v -version
Display the build number of the compiler. This is very useful to report a bug.
-showversion
Display the build number of the compiler and continue. This is very useful to report a bug.

See Also

<http://help.eclipse.org/topic/org.eclip…>

Bugs

To report bugs, use <https://bugs.eclipse.org/bugs/enter_bug…>

Author

For details on Eclipse committers, see <http://www.eclipse.org/committers/>

Info

10 August 2015