1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2013-2014 Alexis Laferrière <alexis.laf@xymus.net>
5 # Licensed under the Apache License, Version 2.0 (the "License");
6 # you may not use this file except in compliance with the License.
7 # You may obtain a copy of the License at
9 # http://www.apache.org/licenses/LICENSE-2.0
11 # Unless required by applicable law or agreed to in writing, software
12 # distributed under the License is distributed on an "AS IS" BASIS,
13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 # See the License for the specific language governing permissions and
15 # limitations under the License.
17 # FFI support for the Java language
19 # TODO support callbacks to super and casts
24 import c_compiler_options
26 redef class FFILanguageAssignationPhase
27 var java_language
: FFILanguage = new JavaLanguage(self)
33 redef fun identify_language
(n
) do return n
.is_java
35 redef fun compile_module_block
(block
, ccu
, mmodule
)
37 mmodule
.ensure_java_files
38 var java_file
= mmodule
.java_file
39 assert java_file
!= null
41 if block
.is_inner_java
then
42 java_file
.class_content
.add
(block
.code
)
43 else java_file
.header
.add
(block
.code
)
46 redef fun compile_extern_method
(block
, m
, ccu
, mmodule
)
49 mmodule
.ensure_java_files
50 var java_file
= mmodule
.java_file
51 assert java_file
!= null
53 var mclass_type
= m
.parent
.as(AClassdef).mclass
.mclass_type
54 var mmethodef
= m
.mpropdef
55 var mproperty
= m
.mpropdef
.mproperty
57 # C function calling the Java method through JNI
58 var fc
= new ExternCFunction(m
, mmodule
)
62 jmethodID java_meth_id;
64 // retrieve the current JVM
65 Sys sys = Pointer_sys(NULL);
66 JNIEnv *nit_ffi_jni_env = Sys_jni_env(sys);
68 // retrieve the implementation Java class
69 java_class = Sys_load_jclass(sys, "{{{mmodule.impl_java_class_name}}}");
70 if (java_class == NULL) {
71 PRINT_ERROR("Nit FFI with Java error: failed to load class.\\n");
72 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
76 // register callbacks (only once per Nit module)
77 if (!nit_ffi_with_java_registered_natives) nit_ffi_with_java_register_natives(nit_ffi_jni_env, java_class);
80 # Retrieve the Java implementation function id
81 var java_fun_name
= mproperty
.build_cname
(mclass_type
, mmodule
, "___java_impl", long_signature
)
82 var jni_format
= mproperty
.build_jni_format
(mclass_type
, mmodule
)
84 // retreive the implementation static function
85 java_meth_id = (*nit_ffi_jni_env)->GetStaticMethodID(nit_ffi_jni_env, java_class, "{{{java_fun_name}}}", "{{{jni_format}}}");
86 if (java_meth_id == NULL) {
87 PRINT_ERROR("Nit FFI with Java error: Java implementation not found.\\n");
88 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
93 # Call the C Java implementation method from C
94 var signature
= mmethodef
.msignature
95 assert signature
!= null
99 var params
= new Array[String]
100 params
.add
"nit_ffi_jni_env"
101 params
.add
"java_class"
102 params
.add
"java_meth_id"
104 if mproperty
.is_init
then
105 jni_signature_alt
= mclass_type
.jni_signature_alt
106 return_type
= mclass_type
109 if signature
.return_mtype
!= null then
110 var ret_mtype
= signature
.return_mtype
111 ret_mtype
= ret_mtype
.resolve_for
(mclass_type
, mclass_type
, mmodule
, true)
112 return_type
= signature
.return_mtype
113 jni_signature_alt
= return_type
.jni_signature_alt
115 jni_signature_alt
= "Void"
120 for p
in signature
.mparameters
do
121 var param_mtype
= p
.mtype
122 param_mtype
= param_mtype
.resolve_for
(mclass_type
, mclass_type
, mmodule
, true)
123 params
.add
(to_java_call_context
.cast_to
(param_mtype
, p
.name
))
126 var cname
= "(*nit_ffi_jni_env)->CallStatic{jni_signature_alt}Method"
128 if return_type
!= null then
129 ccall
= "{return_type.jni_type} jni_res = {cname}({params.join(", ")});"
130 else ccall
= "{cname}({params.join(", ")});"
133 // execute implementation code
135 if ((*nit_ffi_jni_env)->ExceptionCheck(nit_ffi_jni_env)) {
136 PRINT_ERROR("Nit FFI with Java error: Exception after call.\\n");
137 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
141 (*nit_ffi_jni_env)->DeleteLocalRef(nit_ffi_jni_env, java_class);
144 if return_type
!= null then
145 fc
.exprs
.add
"\treturn {to_java_call_context.cast_from(return_type, "jni_res")};"
148 ccu
.add_exported_function
( fc
)
150 # Java implementation function in Java
151 var java_csig
= mproperty
.build_csignature
(mclass_type
, mmodule
, "___java_impl", long_signature
, java_call_context
)
152 mmodule
.java_file
.class_content
.add
"""
153 public static {{{java_csig}}} {
154 // from Nit FII at: {{{block.location}}}
160 redef fun compile_extern_class
(block
, m
, ccu
, mmodule
) do end
162 redef fun get_ftype
(block
, m
) do return new ForeignJavaType(block
.code
)
164 redef fun compile_to_files
(mmodule
, compdir
)
166 # Make sure we have a .java file
167 mmodule
.ensure_java_files
169 # Needed compiler and linker options
170 mmodule
.insert_compiler_options
172 # Enable linking C callbacks to java native methods
173 mmodule
.ensure_linking_callback_methods
(ffi_ccu
.as(not null), mmodule
.ffi_callbacks
[self])
175 # Java implementation code
176 var java_file
= mmodule
.java_file
177 assert java_file
!= null
178 var extern_java_file
= java_file
.write_to_files
(compdir
)
179 mmodule
.ffi_files
.add
(extern_java_file
)
182 var ffi_ccu
: nullable CCompilationUnit = null # HACK
184 redef fun compile_callback
(callback
, mmodule
, mainmodule
, ccu
)
187 callback
.compile_callback_to_java
(mmodule
, mainmodule
, ccu
)
193 # Pure java class source file
194 private var java_file
: nullable JavaClassTemplate = null
196 # Set up the templates of the Java implementation class
197 private fun ensure_java_files
199 if java_file
!= null then return
201 # Java implementation code
202 java_file
= new JavaClassTemplate(impl_java_class_name
)
205 # Compile C code to call JNI and link C callbacks implementations to Java extern methods
206 private fun ensure_linking_callback_methods
(ccu
: CCompilationUnit, callbacks
: Set[NitniCallback])
208 if callbacks
.is_empty
then
209 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 1;\n"
213 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 0;\n"
215 var jni_methods
= new Array[String]
216 for cb
in callbacks
do
217 jni_methods
.add_all
(cb
.jni_methods_declaration
(self))
220 var cf
= new CFunction("static void nit_ffi_with_java_register_natives(JNIEnv* env, jclass jclazz)")
222 nit_ffi_with_java_registered_natives = 1;
224 jint n_methods = {{{jni_methods.length}}};
225 JNINativeMethod methods[] = {
226 {{{jni_methods.join(",\n\t\t")}}}
228 jint res = (*env)->RegisterNatives(env, jclazz, methods, n_methods);
230 PRINT_ERROR("RegisterNatives failed\\n");
231 (*env)->ExceptionDescribe(env);
235 ccu
.add_local_function cf
238 # Tell the C compiler where to find jni.h and how to link with libjvm
239 private fun insert_compiler_options
241 c_compiler_options
= "{c_compiler_options} -I $(JAVA_HOME)/include/"
242 c_linker_options
= "{c_linker_options} -L $(JNI_LIB_PATH) -ljvm"
245 # Name of the generated Java class where to store all implementation methods of this module
246 # as well as generated callbacks.
247 private fun impl_java_class_name
: String do return "Nit_{name}"
250 redef class AMethPropdef
251 redef fun verify_nitni_callbacks
(toolcontext
)
255 var block
= n_extern_code_block
256 if block
!= null and block
.is_java
then
257 insert_artificial_callbacks
(toolcontext
)
261 # Insert additional explicit calls to get the current `JNIEnv`
263 # This forces declaration of callbacks to Nit. The callbacks will be available in Java
264 # but will be used mainly by the FFI itself.
266 # The developer can also customize the JNIEnv used by the FFI by redefining `Sys::jni_env`.
267 private fun insert_artificial_callbacks
(toolcontext
: ToolContext)
269 var fcc
= foreign_callbacks
271 var modelbuilder
= toolcontext
.modelbuilder
272 var mmodule
= mpropdef
.mclassdef
.mmodule
274 # We use callbacks from the C FFI since they will be called from generated C
275 var c_language_visitor
= toolcontext
.ffi_language_assignation_phase
.as(FFILanguageAssignationPhase).c_language
276 if not mmodule
.ffi_callbacks
.keys
.has
(c_language_visitor
) then
277 mmodule
.ffi_callbacks
[c_language_visitor
] = new HashSet[NitniCallback]
281 var pointer_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Pointer")
282 assert pointer_class
!= null
283 var pointer_sys_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, pointer_class
.mclass_type
, "sys")
284 assert pointer_sys_meth
!= null and pointer_sys_meth
isa MMethod
286 var explicit_call
= new MExplicitCall(pointer_class
.mclass_type
, pointer_sys_meth
, mmodule
)
287 fcc
.callbacks
.add
(explicit_call
)
288 mmodule
.ffi_callbacks
[c_language_visitor
].add
(explicit_call
)
291 var sys_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Sys")
292 assert sys_class
!= null
293 var sys_jni_env_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, sys_class
.mclass_type
, "jni_env")
294 if sys_jni_env_meth
== null or not sys_jni_env_meth
isa MMethod then
295 toolcontext
.error
(self.location
, "Java FFI error: you must import the `java` module when using the FFI with Java")
299 explicit_call
= new MExplicitCall(sys_class
.mclass_type
, sys_jni_env_meth
, mmodule
)
300 fcc
.callbacks
.add
(explicit_call
)
301 mmodule
.ffi_callbacks
[c_language_visitor
].add
(explicit_call
)
304 var sys_jni_load_jclass_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, sys_class
.mclass_type
, "load_jclass")
305 assert sys_jni_load_jclass_meth
!= null
306 assert sys_jni_load_jclass_meth
isa MMethod
308 explicit_call
= new MExplicitCall(sys_class
.mclass_type
, sys_jni_load_jclass_meth
, mmodule
)
309 fcc
.callbacks
.add
(explicit_call
)
310 mmodule
.ffi_callbacks
[c_language_visitor
].add
(explicit_call
)
311 explicit_call
.fill_type_for
(fcc
, mmodule
)
315 redef class AExternCodeBlock
316 # Is this code block in Java?
317 fun is_java
: Bool do return is_default_java
or (parent
isa AModule and is_inner_java
)
319 # Is this code block in Java, with the default mode? (On module blocks it targets the file header)
320 private fun is_default_java
: Bool do return language_name
!= null and
321 language_name_lowered
== "java"
323 # Is this code block in Java, and for a module block to generate in the class?
324 private fun is_inner_java
: Bool do return language_name
!= null and
325 language_name_lowered
== "java inner"
328 # Java class source template
329 class JavaClassTemplate
332 var java_class_name
: String
334 var header
= new Template
335 var class_content
= new Template
337 fun write_to_files
(compdir
: String): ExternFile
339 var filename
= "{java_class_name}.java"
340 var filepath
= "{compdir}/{filename}"
342 write_to_file filepath
344 return new JavaFile(filename
)
351 add
"public class {java_class_name} \{\n"
357 # A generated Java source file, represent the corresponding Makefile rules
361 redef fun makefile_rule_name
do return "{filename.basename(".java")}.class"
362 redef fun makefile_rule_content
do return "javac {filename.basename("")} -d ."
363 redef fun add_to_jar
do return true
366 # Context in pure Java code
367 private class JavaCallContext
370 redef fun name_mtype
(mtype
) do return mtype
.java_type
373 # Context in C, when call are from normal C to JNI
374 private class ToJavaCallContext
377 redef fun cast_to
(mtype
, name
) do return "({mtype.jni_type})({name})"
378 redef fun cast_from
(mtype
, name
) do return "({mtype.cname})({name})"
379 redef fun name_mtype
(mtype
) do return mtype
.jni_type
382 # Context in C, when call are from JNI to normal C
383 private class FromJavaCallContext
386 redef fun cast_to
(mtype
, name
) do return "({mtype.cname})({name})"
387 redef fun cast_from
(mtype
, name
) do return "({mtype.jni_type})({name})"
388 redef fun name_mtype
(mtype
) do return mtype
.jni_type
391 # Foreign type attach to Nit extern Java classes
392 class ForeignJavaType
395 var java_type
: String
398 redef class NitniCallback
399 # Compile C and Java code to implement this callback
400 fun compile_callback_to_java
(mmodule
: MModule, mainmodule
: MModule, ccu
: CCompilationUnit) do end
402 # Returns the list of C functions to link with extern Java methods, as required
403 # to enable this callback from Java code.
405 # Return used by `MModule::ensure_linking_callback_methods`
407 # TODO we return an Array to support cast and other features like that
408 fun jni_methods_declaration
(from_module
: MModule): Array[String] do return new Array[String]
411 redef class MExplicitCall
412 redef fun compile_callback_to_java
(mmodule
, mainmodule
, ccu
)
414 var mproperty
= mproperty
415 assert mproperty
isa MMethod
417 # In C, indirection implementing the Java extern methods
418 var csignature
= mproperty
.build_c_implementation_signature
(recv_mtype
, mmodule
, "___indirect", long_signature
, from_java_call_context
)
419 var cf
= new CFunction("JNIEXPORT {csignature}")
420 cf
.exprs
.add
"\t{mproperty.build_ccall(recv_mtype, mainmodule, null, long_signature, from_java_call_context, null)}\n"
421 ccu
.add_local_function cf
423 # In Java, declare the extern method as a private static local method
424 var java_signature
= mproperty
.build_csignature
(recv_mtype
, mainmodule
, null, short_signature
, java_call_context
)
425 mmodule
.java_file
.class_content
.add
"private native static {java_signature};\n"
428 redef fun jni_methods_declaration
(from_mmodule
)
430 var mproperty
= mproperty
431 assert mproperty
isa MMethod
433 var java_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, null, short_signature
)
434 var jni_format
= mproperty
.build_jni_format
(recv_mtype
, from_mmodule
)
435 var c_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, "___indirect", long_signature
)
437 return ["""{"{{{java_name}}}", "{{{jni_format}}}", {{{c_name}}}}"""]
445 # * Primitives common to both languages use their Java primitive type
446 # * Nit extern Java classes are represented by their full Java type
447 # * Other Nit objects are represented by `int` in Java. It holds the
448 # pointer to the underlying C structure.
449 # TODO create static Java types to store and hide the pointer
450 private fun java_type
: String do return "int"
452 # JNI type name (in C)
454 # So this is a C type, usually defined in `jni.h`
455 private fun jni_type
: String do return "jint"
457 # JNI short type name (for signatures)
459 # Is used by `MMethod::build_jni_format` to pass a Java method signature
460 # to the JNI function `GetStaticMetodId`.
461 private fun jni_format
: String do return "I"
463 # Type name appearing within JNI function names.
465 # Used by `JavaLanguage::compile_extern_method` when calling JNI's `CallStatic*Method`.
466 # This strategy is used by JNI to type the return of callbacks to Java.
467 private fun jni_signature_alt
: String do return "Int"
470 redef class MClassType
473 var ftype
= mclass
.ftype
474 if ftype
isa ForeignJavaType then return ftype
.java_type
.
475 replace
('/', ".").replace
('$', ".").replace
(' ', "").replace
('\n',"")
476 if mclass
.name
== "Bool" then return "boolean"
477 if mclass
.name
== "Char" then return "char"
478 if mclass
.name
== "Int" then return "long"
479 if mclass
.name
== "Float" then return "double"
485 var ftype
= mclass
.ftype
486 if ftype
isa ForeignJavaType then return "jobject"
487 if mclass
.name
== "Bool" then return "jboolean"
488 if mclass
.name
== "Char" then return "jchar"
489 if mclass
.name
== "Int" then return "jlong"
490 if mclass
.name
== "Float" then return "jdouble"
496 var ftype
= mclass
.ftype
497 if ftype
isa ForeignJavaType then
498 var jni_type
= ftype
.java_type
.
499 replace
('.', "/").replace
(' ', "").replace
('\n', "")
501 # Remove parameters of generic types
503 var i
= jni_type
.last_index_of
('<')
505 var j
= jni_type
.index_of_from
('>', i
)
507 print
"Error: missing closing '>' in extern Java type of \"{mclass.name}\
""
510 jni_type
= jni_type
.substring
(0, i
) +
511 jni_type
.substring
(j
+1, jni_type
.length
)
515 return "L{jni_type};"
517 if mclass
.name
== "Bool" then return "Z"
518 if mclass
.name
== "Char" then return "C"
519 if mclass
.name
== "Int" then return "J"
520 if mclass
.name
== "Float" then return "D"
524 redef fun jni_signature_alt
526 var ftype
= mclass
.ftype
527 if ftype
isa ForeignJavaType then return "Object"
528 if mclass
.name
== "Bool" then return "Boolean"
529 if mclass
.name
== "Char" then return "Char"
530 if mclass
.name
== "Int" then return "Long"
531 if mclass
.name
== "Float" then return "Double"
537 # Returns the JNI signature format of this Nit method
539 # Example: a Nity signature `(Bool, Int, Float, JavaString)` is represented by
540 # the JNI format `(ZIDLjava/lang/string;)V"
541 private fun build_jni_format
(recv_mtype
: MClassType, from_mmodule
: MModule): String
543 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
544 var msignature
= mmethoddef
.msignature
545 var format
= new Array[String]
550 if not self.is_init
then format
.add recv_mtype
.jni_format
553 for p
in msignature
.mparameters
do
554 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
555 format
.add param_mtype
.jni_format
561 format
.add recv_mtype
.jni_format
563 var return_mtype
= msignature
.return_mtype
564 if return_mtype
!= null then
565 return_mtype
= return_mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
566 format
.add return_mtype
.jni_format
570 return format
.join
("")
573 # Similar to `build_c_signature` but adapted to create the signature expected by JNI for C functions
574 # implementing Java extern methods.
576 # Is used to generate FFI callbacks to Nit at `MExplicitCall::compile_callback_to_java`.
577 private fun build_c_implementation_signature
(recv_mtype
: MClassType, from_mmodule
: MModule,
578 suffix
: nullable String, length
: SignatureLength, call_context
: CallContext): String
580 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
581 var signature
= mmethoddef
.msignature
582 assert signature
!= null
586 creturn_type
= call_context
.name_mtype
(recv_mtype
)
587 else if signature
.return_mtype
!= null then
588 var ret_mtype
= signature
.return_mtype
589 ret_mtype
= ret_mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
590 creturn_type
= call_context
.name_mtype
(ret_mtype
)
592 creturn_type
= "void"
595 var cname
= build_cname
(recv_mtype
, from_mmodule
, suffix
, length
)
597 var cparams
= new List[String]
600 cparams
.add
"JNIEnv *env"
601 cparams
.add
"jclass clazz"
603 if not self.is_init
then
604 cparams
.add
"{call_context.name_mtype(recv_mtype)} recv"
606 for p
in signature
.mparameters
do
607 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
608 cparams
.add
"{call_context.name_mtype(param_mtype)} {p.name}"
611 return "{creturn_type} {cname}( {cparams.join(", ")} )"
615 private fun java_call_context
: JavaCallContext do return new JavaCallContext
616 private fun to_java_call_context
: ToJavaCallContext do return new ToJavaCallContext
617 private fun from_java_call_context
: FromJavaCallContext do return new FromJavaCallContext