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}}}");
70 // register callbacks (only once per Nit module)
71 if (!nit_ffi_with_java_registered_natives) nit_ffi_with_java_register_natives(nit_ffi_jni_env, java_class);
74 # Retrieve the Java implementation function id
75 var java_fun_name
= mproperty
.build_cname
(mclass_type
, mmodule
, "___java_impl", long_signature
)
76 var jni_format
= mproperty
.build_jni_format
(mclass_type
, mmodule
)
78 // retreive the implementation static function
79 java_meth_id = (*nit_ffi_jni_env)->GetStaticMethodID(nit_ffi_jni_env, java_class, "{{{java_fun_name}}}", "{{{jni_format}}}");
80 if (java_meth_id == NULL) {
81 fprintf(stderr, "Nit FFI with Java error: Java implementation not found.\\n");
82 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
87 # Call the C Java implementation method from C
88 var signature
= mmethodef
.msignature
89 assert signature
!= null
94 var params
= new Array[String]
95 params
.add
"nit_ffi_jni_env"
96 params
.add
"java_class"
97 params
.add
"java_meth_id"
99 if mproperty
.is_init
then
100 jni_signature_alt
= mclass_type
.jni_signature_alt
101 return_type
= mclass_type
102 c_return_type
= mclass_type
.cname
105 if signature
.return_mtype
!= null then
106 var ret_mtype
= signature
.return_mtype
107 ret_mtype
= ret_mtype
.resolve_for
(mclass_type
, mclass_type
, mmodule
, true)
108 return_type
= signature
.return_mtype
109 c_return_type
= mclass_type
.cname
110 jni_signature_alt
= return_type
.jni_signature_alt
112 jni_signature_alt
= "Void"
118 for p
in signature
.mparameters
do params
.add
(p
.name
)
120 var cname
= "(*nit_ffi_jni_env)->CallStatic{jni_signature_alt}Method"
122 if return_type
!= null then
123 ccall
= "{return_type.jni_type} jni_res = {cname}({params.join(", ")});"
124 else ccall
= "{cname}({params.join(", ")});"
127 // execute implementation code
129 if ((*nit_ffi_jni_env)->ExceptionCheck(nit_ffi_jni_env)) {
130 fprintf(stderr, "Nit FFI with Java error: Exception after call.\\n");
131 (*nit_ffi_jni_env)->ExceptionDescribe(nit_ffi_jni_env);
136 if return_type
!= null then
137 fc
.exprs
.add
"\treturn {to_java_call_context.cast_from(return_type, "jni_res")};"
140 ccu
.add_exported_function
( fc
)
142 # Java implementation function in Java
143 var java_csig
= mproperty
.build_csignature
(mclass_type
, mmodule
, "___java_impl", long_signature
, java_call_context
)
144 nmodule
.java_file
.class_content
.add
"""
145 public static {{{java_csig}}} {
146 // from Nit FII at: {{{block.location}}}
152 redef fun compile_extern_class
(block
, m
, ccu
, nmodule
) do end
154 redef fun get_ftype
(block
, m
) do return new ForeignJavaType(block
.code
)
156 redef fun compile_to_files
(nmodule
, compdir
)
158 # Make sure we have a .java file
159 nmodule
.ensure_java_files
161 # Needed compiler and linker options
162 nmodule
.insert_compiler_options
164 # Enable linking C callbacks to java native methods
165 nmodule
.ensure_linking_callback_methods
(ffi_ccu
, self.callbacks
)
167 # Java implementation code
168 var java_file
= nmodule
.java_file
169 assert java_file
!= null
170 var extern_java_file
= java_file
.write_to_files
(compdir
)
171 nmodule
.ffi_files
.add
(extern_java_file
)
174 var callbacks
= new HashSet[NitniCallback] # HACK
175 var ffi_ccu
: CCompilationUnit # HACK
177 redef fun compile_callback
(callback
, nmodule
, mainmodule
, ccu
)
180 callbacks
.add callback
181 callback
.compile_callback_to_java
(nmodule
, ccu
)
187 # Pure java class source file
188 private var java_file
: nullable JavaClassTemplate = null
190 # Set up the templates of the Java implementation class
191 private fun ensure_java_files
193 if java_file
!= null then return
195 # Java implementation code
196 java_file
= new JavaClassTemplate(mmodule
.impl_java_class_name
)
199 # Compile C code to call JNI and link C callbacks implementations to Java extern methods
200 private fun ensure_linking_callback_methods
(ccu
: CCompilationUnit, callbacks
: Set[NitniCallback])
202 if callbacks
.is_empty
then
203 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 1;\n"
207 ccu
.body_decl
.add
"static int nit_ffi_with_java_registered_natives = 0;\n"
209 var jni_methods
= new Array[String]
210 for cb
in callbacks
do
211 jni_methods
.add_all
(cb
.jni_methods_declaration
(mmodule
.as(not null)))
214 var cf
= new CFunction("static void nit_ffi_with_java_register_natives(JNIEnv* env, jclass jclazz)")
216 nit_ffi_with_java_registered_natives = 1;
218 jint n_methods = {{{jni_methods.length}}};
219 JNINativeMethod methods[] = {
220 {{{jni_methods.join(",\n\t\t")}}}
222 jint res = (*env)->RegisterNatives(env, jclazz, methods, n_methods);
224 fprintf(stderr, "RegisterNatives failed\\n");
225 (*env)->ExceptionDescribe(env);
229 ccu
.add_local_function cf
232 # Tell the C compiler where to find jni.h and how to link with libjvm
233 private fun insert_compiler_options
235 mmodule
.c_compiler_options
= "{mmodule.c_compiler_options} -I $(JAVA_HOME)/include/"
236 mmodule
.c_linker_options
= "{mmodule.c_linker_options} -L $(JNI_LIB_PATH) -ljvm"
241 # Name of the generated Java class where to store all implementation methods of this module
242 # as well as generated callbacks.
243 private fun impl_java_class_name
: String do return "NitFFIWithJava_{name}"
246 redef class AExternPropdef
247 redef fun verify_nitni_callbacks
(toolcontext
)
251 var block
= n_extern_code_block
252 if block
!= null and block
.is_java
then
253 insert_articifial_callbacks
(toolcontext
)
257 # Insert additionnal explicit calls to get the current `JNIEnv`
259 # This forces declaration of callbacks to Nit. The callbacks will be available in Java
260 # but will be used mainly by the FFI itself.
262 # The developper can aso customize the JNIEnv used by the FFI by redefing `Sys::jni_env`.
263 private fun insert_articifial_callbacks
(toolcontext
: ToolContext)
265 var fcc
= foreign_callbacks
268 var modelbuilder
= toolcontext
.modelbuilder
269 var mmodule
= mpropdef
.mclassdef
.mmodule
272 var pointer_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Pointer")
273 assert pointer_class
!= null
274 var pointer_sys_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, pointer_class
.mclass_type
, "sys")
275 assert pointer_sys_meth
!= null and pointer_sys_meth
isa MMethod
277 var explicit_call
= new MExplicitCall(pointer_class
.mclass_type
, pointer_sys_meth
, mmodule
)
278 fcc
.callbacks
.add
(explicit_call
)
279 explicit_call
.fill_type_for
(fcc
, mmodule
)
282 var sys_class
= modelbuilder
.try_get_mclass_by_name
(self, mmodule
, "Sys")
283 assert sys_class
!= null
284 var sys_jni_env_meth
= modelbuilder
.try_get_mproperty_by_name2
(self, mmodule
, sys_class
.mclass_type
, "jni_env")
285 assert sys_jni_env_meth
!= null
286 assert sys_jni_env_meth
isa MMethod
288 explicit_call
= new MExplicitCall(sys_class
.mclass_type
, sys_jni_env_meth
, mmodule
)
289 fcc
.callbacks
.add
(explicit_call
)
290 explicit_call
.fill_type_for
(fcc
, mmodule
)
294 redef class AExternCodeBlock
295 fun is_java
: Bool do return language_name
!= null and
296 language_name_lowered
== "java"
299 # Java class source template
300 class JavaClassTemplate
303 var java_class_name
: String
304 init(name
: String) do self.java_class_name
= name
306 var header
= new Template
307 var class_content
= new Template
309 fun write_to_files
(compdir
: String): ExternFile
311 var filename
= "{java_class_name}.java"
312 var filepath
= "{compdir}/{filename}"
314 write_to_file filepath
316 return new JavaFile(filename
)
323 add
"public class {java_class_name} \{\n"
329 # A generated Java source file, represent the corresponding Makefile rules
333 redef fun makefile_rule_name
do return "{filename.basename(".java")}.class"
334 redef fun makefile_rule_content
do return "javac {filename} -d ."
335 redef fun add_to_jar
do return true
338 # Context in pure Java code
339 private class JavaCallContext
342 redef fun name_mtype
(mtype
) do return mtype
.java_type
345 # Context in C, when call are from normal C to JNI
346 private class ToJavaCallContext
349 redef fun cast_to
(mtype
, name
) do return "({mtype.jni_type})({name})"
350 redef fun cast_from
(mtype
, name
) do return "({mtype.cname})({name})"
351 redef fun name_mtype
(mtype
) do return mtype
.jni_type
354 # Context in C, when call are from JNI to normal C
355 private class FromJavaCallContext
358 redef fun cast_to
(mtype
, name
) do return "({mtype.cname})({name})"
359 redef fun cast_from
(mtype
, name
) do return "({mtype.jni_type})({name})"
360 redef fun name_mtype
(mtype
) do return mtype
.jni_type
363 # Foreign type attach to Nit extern Java classes
364 class ForeignJavaType
367 var java_type
: String
368 init (java_type
: String) do self.java_type
= java_type
371 redef class NitniCallback
372 # Compile C and Java code to implement this callback
373 fun compile_callback_to_java
(nmodule
: AModule, ccu
: CCompilationUnit) do end
375 # Returns the list of C functions to link with extern Java methods, as required
376 # to enable this callback from Java code.
378 # Return used by `AModule::ensure_linking_callback_methods`
380 # TODO we return an Array to support cast and other features like that
381 fun jni_methods_declaration
(from_module
: MModule): Array[String] do return new Array[String]
384 redef class MExplicitCall
385 redef fun compile_callback_to_java
(nmodule
, ccu
)
387 var mproperty
= mproperty
388 assert mproperty
isa MMethod
389 var mmodule
= nmodule
.mmodule
.as(not null)
391 # In C, indirection implementing the Java extern methods
392 var csignature
= mproperty
.build_c_implementation_signature
(recv_mtype
, mmodule
, "___indirect", long_signature
, from_java_call_context
)
393 var cf
= new CFunction("JNIEXPORT {csignature}")
394 cf
.exprs
.add
"\t{mproperty.build_ccall(recv_mtype, mmodule, null, long_signature, from_java_call_context, null)}\n"
395 ccu
.add_local_function cf
397 # In Java, declare the extern method as a private static local method
398 var java_signature
= mproperty
.build_csignature
(recv_mtype
, mmodule
, null, short_signature
, java_call_context
)
399 nmodule
.java_file
.class_content
.add
"private native static {java_signature};\n"
402 redef fun jni_methods_declaration
(from_mmodule
)
404 var mproperty
= mproperty
405 assert mproperty
isa MMethod
407 var java_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, null, short_signature
)
408 var jni_format
= mproperty
.build_jni_format
(recv_mtype
, from_mmodule
)
409 var c_name
= mproperty
.build_cname
(recv_mtype
, from_mmodule
, "___indirect", long_signature
)
411 return ["""{"{{{java_name}}}", "{{{jni_format}}}", {{{c_name}}}}"""]
419 # * Primitives common to both languages use their Java primitive type
420 # * Nit extern Java classes are reprensented by their full Java type
421 # * Other Nit objects are represented by `int` in Java. It holds the
422 # pointer to the underlying C structure.
423 # TODO create static Java types to store and hide the pointer
424 private fun java_type
: String do return "int"
426 # JNI type name (in C)
428 # So this is a C type, usually defined in `jni.h`
429 private fun jni_type
: String do return "jint"
431 # JNI short type name (for signatures)
433 # Is used by `MMethod::build_jni_format` to pass a Java method signature
434 # to the JNI function `GetStaticMetodId`.
435 private fun jni_format
: String do return "I"
437 # Type name appearing within JNI function names.
439 # Used by `JavaLanguage::compile_extern_method` when calling JNI's `CallStatic*Method`.
440 # This strategy is used by JNI to type the return of callbacks to Java.
441 private fun jni_signature_alt
: String do return "Int"
444 redef class MClassType
447 var ftype
= mclass
.ftype
448 if ftype
isa ForeignJavaType then return ftype
.java_type
449 if mclass
.name
== "Bool" then return "boolean"
450 if mclass
.name
== "Char" then return "char"
451 if mclass
.name
== "Int" then return "int"
452 if mclass
.name
== "Float" then return "double"
458 var ftype
= mclass
.ftype
459 if ftype
isa ForeignJavaType then return "jobject"
460 if mclass
.name
== "Bool" then return "jboolean"
461 if mclass
.name
== "Char" then return "jchar"
462 if mclass
.name
== "Int" then return "jint"
463 if mclass
.name
== "Float" then return "jdouble"
469 var ftype
= mclass
.ftype
470 if ftype
isa ForeignJavaType then return "L{ftype.java_type.replace('.', "/").replace(' ', "")};"
471 if mclass
.name
== "Bool" then return "Z"
472 if mclass
.name
== "Char" then return "C"
473 if mclass
.name
== "Int" then return "I"
474 if mclass
.name
== "Float" then return "D"
478 redef fun jni_signature_alt
480 var ftype
= mclass
.ftype
481 if ftype
isa ForeignJavaType then return "Object"
482 if mclass
.name
== "Bool" then return "Bool"
483 if mclass
.name
== "Char" then return "Char"
484 if mclass
.name
== "Int" then return "Int"
485 if mclass
.name
== "Float" then return "Double"
491 # Returns the JNI signature format of this Nit method
493 # Example: a Nity signature `(Bool, Int, Float, JavaString)` is represented by
494 # the JNI format `(ZIDLjava/lang/string;)V"
495 private fun build_jni_format
(recv_mtype
: MClassType, from_mmodule
: MModule): String
497 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
498 var msignature
= mmethoddef
.msignature
499 var format
= new Array[String]
504 if not self.is_init
then format
.add recv_mtype
.jni_format
507 for p
in msignature
.mparameters
do
508 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
509 format
.add param_mtype
.jni_format
515 format
.add recv_mtype
.jni_format
517 var return_mtype
= msignature
.return_mtype
518 if return_mtype
!= null then
519 format
.add return_mtype
.jni_format
523 return format
.join
("")
526 # Similar to `build_c_signature` but adapted to create the signature expected by JNI for C functions
527 # implementing Java extern methods.
529 # Is used to generate FFI callbacks to Nit at `MExplicitCall::compile_callback_to_java`.
530 private fun build_c_implementation_signature
(recv_mtype
: MClassType, from_mmodule
: MModule,
531 suffix
: nullable String, length
: SignatureLength, call_context
: CallContext): String
533 var mmethoddef
= lookup_first_definition
(from_mmodule
, recv_mtype
)
534 var signature
= mmethoddef
.msignature
535 assert signature
!= null
539 creturn_type
= call_context
.name_mtype
(recv_mtype
)
540 else if signature
.return_mtype
!= null then
541 var ret_mtype
= signature
.return_mtype
542 ret_mtype
= ret_mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
543 creturn_type
= call_context
.name_mtype
(ret_mtype
)
545 creturn_type
= "void"
548 var cname
= build_cname
(recv_mtype
, from_mmodule
, suffix
, length
)
550 var cparams
= new List[String]
553 cparams
.add
"JNIEnv *env"
554 cparams
.add
"jclass clazz"
556 if not self.is_init
then
557 cparams
.add
"{call_context.name_mtype(recv_mtype)} recv"
559 for p
in signature
.mparameters
do
560 var param_mtype
= p
.mtype
.resolve_for
(recv_mtype
, recv_mtype
, from_mmodule
, true)
561 cparams
.add
"{call_context.name_mtype(param_mtype)} {p.name}"
564 return "{creturn_type} {cname}( {cparams.join(", ")} )"
568 private fun java_call_context
: JavaCallContext do return new JavaCallContext
569 private fun to_java_call_context
: ToJavaCallContext do return new ToJavaCallContext
570 private fun from_java_call_context
: FromJavaCallContext do return new FromJavaCallContext