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
, nmodule
)
37 nmodule
.ensure_java_files
38 var java_file
= nmodule
.java_file
39 assert java_file
!= null
41 java_file
.header
.add
(block
.code
)
44 redef fun compile_extern_method
(block
, m
, ccu
, nmodule
)
47 nmodule
.ensure_java_files
48 var java_file
= nmodule
.java_file
49 assert java_file
!= null
51 var mmodule
= nmodule
.mmodule
.as(not null)
52 var mclass_type
= m
.parent
.as(AClassdef).mclass
.mclass_type
53 var mmethodef
= m
.mpropdef
54 var mproperty
= m
.mpropdef
.mproperty
56 # C function calling the Java method through JNI
57 var fc
= new ExternCFunction(m
, mmodule
)
61 jmethodID java_meth_id;
63 // retrieve the current JVM
64 Sys sys = {{{mmodule.name}}}___Pointer_sys(NULL);
65 JNIEnv *nit_ffi_jni_env = {{{mmodule.name}}}___Sys_jni_env(sys);
67 // retrieve the implementation Java class
68 java_class = (*nit_ffi_jni_env)->FindClass(nit_ffi_jni_env, "{{{mmodule.impl_java_class_name}}}");
69 if (java_class == NULL) {
70 PRINT_ERROR("Nit FFI with Java error: failed to load class.\\n");
71 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
75 // register callbacks (only once per Nit module)
76 if (!nit_ffi_with_java_registered_natives) nit_ffi_with_java_register_natives(nit_ffi_jni_env, java_class);
79 # Retrieve the Java implementation function id
80 var java_fun_name
= mproperty
.build_cname
(mclass_type
, mmodule
, "___java_impl", long_signature
)
81 var jni_format
= mproperty
.build_jni_format
(mclass_type
, mmodule
)
83 // retreive the implementation static function
84 java_meth_id = (*nit_ffi_jni_env)->GetStaticMethodID(nit_ffi_jni_env, java_class, "{{{java_fun_name}}}", "{{{jni_format}}}");
85 if (java_meth_id == NULL) {
86 PRINT_ERROR("Nit FFI with Java error: Java implementation not found.\\n");
87 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
92 # Call the C Java implementation method from C
93 var signature
= mmethodef
.msignature
94 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
107 c_return_type
= mclass_type
.cname
110 if signature
.return_mtype
!= null then
111 var ret_mtype
= signature
.return_mtype
112 ret_mtype
= ret_mtype
.resolve_for
(mclass_type
, mclass_type
, mmodule
, true)
113 return_type
= signature
.return_mtype
114 c_return_type
= mclass_type
.cname
115 jni_signature_alt
= return_type
.jni_signature_alt
117 jni_signature_alt
= "Void"
123 for p
in signature
.mparameters
do params
.add
(p
.name
)
125 var cname
= "(*nit_ffi_jni_env)->CallStatic{jni_signature_alt}Method"
127 if return_type
!= null then
128 ccall
= "{return_type.jni_type} jni_res = {cname}({params.join(", ")});"
129 else ccall
= "{cname}({params.join(", ")});"
132 // execute implementation code
134 if ((*nit_ffi_jni_env)->ExceptionCheck(nit_ffi_jni_env)) {
135 PRINT_ERROR("Nit FFI with Java error: Exception after call.\\n");
136 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
141 if return_type
!= null then
142 fc
.exprs
.add
"\treturn {to_java_call_context.cast_from(return_type, "jni_res")};"
145 ccu
.add_exported_function
( fc
)
147 # Java implementation function in Java
148 var java_csig
= mproperty
.build_csignature
(mclass_type
, mmodule
, "___java_impl", long_signature
, java_call_context
)
149 nmodule
.java_file
.class_content
.add
"""
150 public static {{{java_csig}}} {
151 // from Nit FII at: {{{block.location}}}
157 redef fun compile_extern_class
(block
, m
, ccu
, nmodule
) do end
159 redef fun get_ftype
(block
, m
) do return new ForeignJavaType(block
.code
)
161 redef fun compile_to_files
(nmodule
, compdir
)
163 # Make sure we have a .java file
164 nmodule
.ensure_java_files
166 # Needed compiler and linker options
167 nmodule
.insert_compiler_options
169 # Enable linking C callbacks to java native methods
170 nmodule
.ensure_linking_callback_methods
(ffi_ccu
, self.callbacks
)
172 # Java implementation code
173 var java_file
= nmodule
.java_file
174 assert java_file
!= null
175 var extern_java_file
= java_file
.write_to_files
(compdir
)
176 nmodule
.ffi_files
.add
(extern_java_file
)
179 var callbacks
= new HashSet[NitniCallback] # HACK
180 var ffi_ccu
: CCompilationUnit # HACK
182 redef fun compile_callback
(callback
, nmodule
, mainmodule
, ccu
)
185 callbacks
.add callback
186 callback
.compile_callback_to_java
(nmodule
, ccu
)
192 # Pure java class source file
193 private var java_file
: nullable JavaClassTemplate = null
195 # Set up the templates of the Java implementation class
196 private fun ensure_java_files
198 if java_file
!= null then return
200 # Java implementation code
201 java_file
= new JavaClassTemplate(mmodule
.impl_java_class_name
)
204 # Compile C code to call JNI and link C callbacks implementations to Java extern methods
205 private fun ensure_linking_callback_methods
(ccu
: CCompilationUnit, callbacks
: Set[NitniCallback])
207 if callbacks
.is_empty
then
208 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 1;\n"
212 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 0;\n"
214 var jni_methods
= new Array[String]
215 for cb
in callbacks
do
216 jni_methods
.add_all
(cb
.jni_methods_declaration
(mmodule
.as(not null)))
219 var cf
= new CFunction("static void nit_ffi_with_java_register_natives(JNIEnv* env, jclass jclazz)")
221 nit_ffi_with_java_registered_natives = 1;
223 jint n_methods = {{{jni_methods.length}}};
224 JNINativeMethod methods[] = {
225 {{{jni_methods.join(",\n\t\t")}}}
227 jint res = (*env)->RegisterNatives(env, jclazz, methods, n_methods);
229 PRINT_ERROR("RegisterNatives failed\\n");
230 (*env)->ExceptionDescribe(env);
234 ccu
.add_local_function cf
237 # Tell the C compiler where to find jni.h and how to link with libjvm
238 private fun insert_compiler_options
240 mmodule
.c_compiler_options
= "{mmodule.c_compiler_options} -I $(JAVA_HOME)/include/"
241 mmodule
.c_linker_options
= "{mmodule.c_linker_options} -L $(JNI_LIB_PATH) -ljvm"
246 # Name of the generated Java class where to store all implementation methods of this module
247 # as well as generated callbacks.
248 private fun impl_java_class_name
: String do return "NitFFIWithJava_{name}"
251 redef class AExternPropdef
252 redef fun verify_nitni_callbacks
(toolcontext
)
256 var block
= n_extern_code_block
257 if block
!= null and block
.is_java
then
258 insert_articifial_callbacks
(toolcontext
)
262 # Insert additionnal explicit calls to get the current `JNIEnv`
264 # This forces declaration of callbacks to Nit. The callbacks will be available in Java
265 # but will be used mainly by the FFI itself.
267 # The developper can aso customize the JNIEnv used by the FFI by redefing `Sys::jni_env`.
268 private fun insert_articifial_callbacks
(toolcontext
: ToolContext)
270 var fcc
= foreign_callbacks
273 var modelbuilder
= toolcontext
.modelbuilder
274 var mmodule
= mpropdef
.mclassdef
.mmodule
277 var pointer_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Pointer")
278 assert pointer_class
!= null
279 var pointer_sys_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, pointer_class
.mclass_type
, "sys")
280 assert pointer_sys_meth
!= null and pointer_sys_meth
isa MMethod
282 var explicit_call
= new MExplicitCall(pointer_class
.mclass_type
, pointer_sys_meth
, mmodule
)
283 fcc
.callbacks
.add
(explicit_call
)
284 explicit_call
.fill_type_for
(fcc
, mmodule
)
287 var sys_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Sys")
288 assert sys_class
!= null
289 var sys_jni_env_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, sys_class
.mclass_type
, "jni_env")
290 assert sys_jni_env_meth
!= null
291 assert sys_jni_env_meth
isa MMethod
293 explicit_call
= new MExplicitCall(sys_class
.mclass_type
, sys_jni_env_meth
, mmodule
)
294 fcc
.callbacks
.add
(explicit_call
)
295 explicit_call
.fill_type_for
(fcc
, mmodule
)
299 redef class AExternCodeBlock
300 fun is_java
: Bool do return language_name
!= null and
301 language_name_lowered
== "java"
304 # Java class source template
305 class JavaClassTemplate
308 var java_class_name
: String
309 init(name
: String) do self.java_class_name
= name
311 var header
= new Template
312 var class_content
= new Template
314 fun write_to_files
(compdir
: String): ExternFile
316 var filename
= "{java_class_name}.java"
317 var filepath
= "{compdir}/{filename}"
319 write_to_file filepath
321 return new JavaFile(filename
)
328 add
"public class {java_class_name} \{\n"
334 # A generated Java source file, represent the corresponding Makefile rules
338 redef fun makefile_rule_name
do return "{filename.basename(".java")}.class"
339 redef fun makefile_rule_content
do return "javac {filename} -d ."
340 redef fun add_to_jar
do return true
343 # Context in pure Java code
344 private class JavaCallContext
347 redef fun name_mtype
(mtype
) do return mtype
.java_type
350 # Context in C, when call are from normal C to JNI
351 private class ToJavaCallContext
354 redef fun cast_to
(mtype
, name
) do return "({mtype.jni_type})({name})"
355 redef fun cast_from
(mtype
, name
) do return "({mtype.cname})({name})"
356 redef fun name_mtype
(mtype
) do return mtype
.jni_type
359 # Context in C, when call are from JNI to normal C
360 private class FromJavaCallContext
363 redef fun cast_to
(mtype
, name
) do return "({mtype.cname})({name})"
364 redef fun cast_from
(mtype
, name
) do return "({mtype.jni_type})({name})"
365 redef fun name_mtype
(mtype
) do return mtype
.jni_type
368 # Foreign type attach to Nit extern Java classes
369 class ForeignJavaType
372 var java_type
: String
373 init (java_type
: String) do self.java_type
= java_type
376 redef class NitniCallback
377 # Compile C and Java code to implement this callback
378 fun compile_callback_to_java
(nmodule
: AModule, ccu
: CCompilationUnit) do end
380 # Returns the list of C functions to link with extern Java methods, as required
381 # to enable this callback from Java code.
383 # Return used by `AModule::ensure_linking_callback_methods`
385 # TODO we return an Array to support cast and other features like that
386 fun jni_methods_declaration
(from_module
: MModule): Array[String] do return new Array[String]
389 redef class MExplicitCall
390 redef fun compile_callback_to_java
(nmodule
, ccu
)
392 var mproperty
= mproperty
393 assert mproperty
isa MMethod
394 var mmodule
= nmodule
.mmodule
.as(not null)
396 # In C, indirection implementing the Java extern methods
397 var csignature
= mproperty
.build_c_implementation_signature
(recv_mtype
, mmodule
, "___indirect", long_signature
, from_java_call_context
)
398 var cf
= new CFunction("JNIEXPORT {csignature}")
399 cf
.exprs
.add
"\t{mproperty.build_ccall(recv_mtype, mmodule, null, long_signature, from_java_call_context, null)}\n"
400 ccu
.add_local_function cf
402 # In Java, declare the extern method as a private static local method
403 var java_signature
= mproperty
.build_csignature
(recv_mtype
, mmodule
, null, short_signature
, java_call_context
)
404 nmodule
.java_file
.class_content
.add
"private native static {java_signature};\n"
407 redef fun jni_methods_declaration
(from_mmodule
)
409 var mproperty
= mproperty
410 assert mproperty
isa MMethod
412 var java_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, null, short_signature
)
413 var jni_format
= mproperty
.build_jni_format
(recv_mtype
, from_mmodule
)
414 var c_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, "___indirect", long_signature
)
416 return ["""{"{{{java_name}}}", "{{{jni_format}}}", {{{c_name}}}}"""]
424 # * Primitives common to both languages use their Java primitive type
425 # * Nit extern Java classes are reprensented by their full Java type
426 # * Other Nit objects are represented by `long` in Java. It holds the
427 # pointer to the underlying C structure.
428 # TODO create static Java types to store and hide the pointer
429 private fun java_type
: String do return "long"
431 # JNI type name (in C)
433 # So this is a C type, usually defined in `jni.h`
434 private fun jni_type
: String do return "jlong"
436 # JNI short type name (for signatures)
438 # Is used by `MMethod::build_jni_format` to pass a Java method signature
439 # to the JNI function `GetStaticMetodId`.
440 private fun jni_format
: String do return "J"
442 # Type name appearing within JNI function names.
444 # Used by `JavaLanguage::compile_extern_method` when calling JNI's `CallStatic*Method`.
445 # This strategy is used by JNI to type the return of callbacks to Java.
446 private fun jni_signature_alt
: String do return "Long"
449 redef class MClassType
452 var ftype
= mclass
.ftype
453 if ftype
isa ForeignJavaType then return ftype
.java_type
454 if mclass
.name
== "Bool" then return "boolean"
455 if mclass
.name
== "Char" then return "char"
456 if mclass
.name
== "Int" then return "int"
457 if mclass
.name
== "Float" then return "double"
463 var ftype
= mclass
.ftype
464 if ftype
isa ForeignJavaType then return "jobject"
465 if mclass
.name
== "Bool" then return "jboolean"
466 if mclass
.name
== "Char" then return "jchar"
467 if mclass
.name
== "Int" then return "jint"
468 if mclass
.name
== "Float" then return "jdouble"
474 var ftype
= mclass
.ftype
475 if ftype
isa ForeignJavaType then return "L{ftype.java_type.replace('.', "/").replace(' ', "")};"
476 if mclass
.name
== "Bool" then return "Z"
477 if mclass
.name
== "Char" then return "C"
478 if mclass
.name
== "Int" then return "I"
479 if mclass
.name
== "Float" then return "D"
483 redef fun jni_signature_alt
485 var ftype
= mclass
.ftype
486 if ftype
isa ForeignJavaType then return "Object"
487 if mclass
.name
== "Bool" then return "Bool"
488 if mclass
.name
== "Char" then return "Char"
489 if mclass
.name
== "Int" then return "Int"
490 if mclass
.name
== "Float" then return "Double"
496 # Returns the JNI signature format of this Nit method
498 # Example: a Nity signature `(Bool, Int, Float, JavaString)` is represented by
499 # the JNI format `(ZIDLjava/lang/string;)V"
500 private fun build_jni_format
(recv_mtype
: MClassType, from_mmodule
: MModule): String
502 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
503 var msignature
= mmethoddef
.msignature
504 var format
= new Array[String]
509 if not self.is_init
then format
.add recv_mtype
.jni_format
512 for p
in msignature
.mparameters
do
513 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
514 format
.add param_mtype
.jni_format
520 format
.add recv_mtype
.jni_format
522 var return_mtype
= msignature
.return_mtype
523 if return_mtype
!= null then
524 format
.add return_mtype
.jni_format
528 return format
.join
("")
531 # Similar to `build_c_signature` but adapted to create the signature expected by JNI for C functions
532 # implementing Java extern methods.
534 # Is used to generate FFI callbacks to Nit at `MExplicitCall::compile_callback_to_java`.
535 private fun build_c_implementation_signature
(recv_mtype
: MClassType, from_mmodule
: MModule,
536 suffix
: nullable String, length
: SignatureLength, call_context
: CallContext): String
538 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
539 var signature
= mmethoddef
.msignature
540 assert signature
!= null
544 creturn_type
= call_context
.name_mtype
(recv_mtype
)
545 else if signature
.return_mtype
!= null then
546 var ret_mtype
= signature
.return_mtype
547 ret_mtype
= ret_mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
548 creturn_type
= call_context
.name_mtype
(ret_mtype
)
550 creturn_type
= "void"
553 var cname
= build_cname
(recv_mtype
, from_mmodule
, suffix
, length
)
555 var cparams
= new List[String]
558 cparams
.add
"JNIEnv *env"
559 cparams
.add
"jclass clazz"
561 if not self.is_init
then
562 cparams
.add
"{call_context.name_mtype(recv_mtype)} recv"
564 for p
in signature
.mparameters
do
565 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
566 cparams
.add
"{call_context.name_mtype(param_mtype)} {p.name}"
569 return "{creturn_type} {cname}( {cparams.join(", ")} )"
573 private fun java_call_context
: JavaCallContext do return new JavaCallContext
574 private fun to_java_call_context
: ToJavaCallContext do return new ToJavaCallContext
575 private fun from_java_call_context
: FromJavaCallContext do return new FromJavaCallContext