B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998. 18  Home/Search   Document Not in Database   Summary   Related Articles   Check

....OASIS team [2] the abstract interpretation used is an adapted version of the analysis presented in [14] Despite its interesting precision, multithreaded programs can not be treated by this method. For our experiments, we used the multithreaded programs abstract interpretation proposed in Pangaea[16]. Pangaea is a framework aimed at analyzing Java programs for the generation of distributed applications. It deals with all the Java features, except for reflexion and dynamic class loading. It is available under the GPL, which permitted us to modify it to add the detection of activable objects. ....

A. Spiegel. Object graph analysis. Technical report, Freie Universitat Berlin, Germany, 1999.

....such as symbol tables can be encoded and compressed at varying degrees of sophistication. Our current implementation is a prototype written in Python consisting of roughly 40 modules handling grammars, syntax trees, and their encoding decoding. Our frontend is written in Java and uses Barat [5] for parsing Java programs. All information necessary to specify the AST s encoding and compression is condensed into one configuration file. The configuration file contains the AG augmented with additional information, e.g. on how to compress the symbol table. Given the availablity of our ....

B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998.

....in Python (version 1.5.2) Pyt] consisting of roughly 40 modules handling AGs, ASTs, and their compression decompression. In order to compare our compression results to other established methods we chose to compress Java programs. Our Java frontend is written in Java and uses the Barat framwork [BS98] for parsing. We devised an AG for Java, which is both suitable for easy generation from Barat s internal representation of Java programs and suitable to generate a dense encoding. A visitor for walking Barat s AST was then adapted to output a Lisp like textual representation of the AST according ....

Boris Bokowski and Andre Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, December 1998.

....the most specific visit( call is last. Thus one can group the handling of, say, all BranchInstructions into one single method. For debugging purposes it may even make sense to invent your own instructions. In a sophisticated code generator like the one used as a backend of the Barat framework [BS98] one often has to insert temporary nop (No operation) instructions. When examining the produced code it may be very difficult to track back where the nop was actually inserted. One could think of a derived nop2 instruction that contains additional debugging information. When the instruction list ....

.... has been applied: 4 Application areas There are many possible application areas for BCEL ranging from class browsers, profilers, byte code optimizers, and compilers to sophisticated run time analysis tools and extensions to the Java language [AFM97, MBL97] Compilers like the Barat compiler [BS98] use BCEL to implement a byte code generating back end. Other possible application areas are the static analysis of byte code [TK98] or examining the run time behavior of classes by inserting calls to profiling methods into the code. Further examples are extending Java with Eiffel like assertions ....

B. Bokowski and A. Spiegel. Barat -- A Front-End for Java. Technical report, Freie Universitat Berlin, 1998.

....optimization issue and not be used by the programmer to implement different Java semantics. Transferring objects by copy must not be applied if this changes the program s semantics. 5. 5 The Doorastha compilation and runtime system The Doorastha compilation system is based on the Barat framework [BS98] a tool for the static analysis of Java classes. Barat allows to decorate the nodes of the abstract syntax tree (AST) of a Java program with additional user defined attributes. The parser also allows to evaluate the contents of special comments starting with : and : respectively. We use ....

B. Bokowski and A. Spiegel. Barat -- A Front-End for Java. Technical report, Freie Universitat Berlin, 1998.

....or System.err is forwarded to the console host, i.e. the machine on which the main program has been started. Accordingly, all requests to read from System.in are forwarded to the console. 7. 9 The Doorastha compilation system The Doorastha compilation system is based on the Barat framework [BS98] a tool for the static analysis of Java classes. Barat allows to decorate the nodes of the abstract syntax tree (AST) of a Java program with additional user defined attributes. The AST can be traversed by user code using the Visitor design pattern [GHJV95] For every node there is a ....

B. Bokowski and A. Spiegel. Barat -- A Front-End for Java. Technical report, Freie Universitat Berlin, 1998.

....can be encoded and compressed at varying degrees of sophistication. 6 6.2 Preliminary Results Our current implementation is a prototype written in Python consisting of roughly 40 modules handling grammars, syntax trees, and their encoding decoding. Our frontend is written in Java and uses Barat [5] for parsing Java programs. All information necessary to specify the AST s encoding and compression is condensed into one configuration file. The configuration file contains the AG augmented with additional information, e.g. on how to compress the symbol table. Given the availability of our ....

B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998.

....written in Python [Pyt] consisting of roughly 40 modules handling AGs, ASTs, and their compression decompression. In order to compare our compression results to other established methods we chose to compress Java programs. Our Java frontend is written in Java and uses the Barat framework [BS98] for parsing. We devised an AG for Java, which is 6 Note that conventional symbol tables can conveniently be expressed as some kind of AST with the appropriate string nodes. 8 both suitable for easy generation from Barat s internal representation of Java programs and suitable to generate a ....

Boris Bokowski and Andre Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, December 1998.

....ways of compressing, maintaining, and accessing lists of constants. 3 Implementation and Results Our current implementation is a prototype written in Python consisting of roughly 40 modules handling AGs, ASTs, and their compression decompression. Our frontend is written in Java and uses Barat [BS98] for parsing Java programs. We devised an AG for Java, which is both suitable for easy generation from Barat s internal representation of Java programs and suitable to generate a dense encoding. According to this AG, Barat generates a Lisp like textual representation of the AST. The textual ....

Boris Bokowski and Andre Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, December 1998.

....can be encoded and compressed at varying degrees of sophistication. 6 6.2 Preliminary Results Our current implementation is a prototype written in Python consisting of roughly 40 modules handling grammars, syntax trees, and their encoding decoding. Our frontend is written in Java and uses Barat [5] for parsing Java programs. All information necessary to specify the AST s encoding and compression is condensed into one configuration file. The configuration file contains the AG augmented with additional information, e.g. on how to compress the symbol table. Given the availablity of our ....

B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998.

....in that it deals with individual objects, not only the types of those objects. Although the latter is usually sufficient for common compiler optimizations, such as static binding of method invocations, it is not enough for distributing programs. We have described the algorithm in detail elsewhere [13] and must confine ourselves to a brief overview here. The result of our algorithm is a graph, the nodes of which represent the run time objects of the program. There are three kinds of edges between these nodes: creation edges, reference edges, and usage edges. We say that an object a uses an ....

....object graph, in all places where an object a knows an object b, and the type graph indicates that there is a usage relation between the corresponding types. The algorithm s complexity is cubic in the size of the program except for pathological cases that do not occur in real world programs (see [13] for a complete discussion) We have implemented the algorithm completely and tested it on a range of non trivial example programs with up to 10,000 lines of code. For none of these, the algorithm took longer than several minutes to complete; for typical parallel applications, results are obtained ....

Andre Spiegel. Object graph analysis. Technical Report B-99-11, Freie Universitat Berlin, July 1999.

....to targets somewhere within the byte code. Obviously, this makes them candidates for playing an InstructionTargeter role, too. For debugging purposes it may even make sense to invent your own instructions. In a sophisticated code generator like the one used as a backend of the Barat framework [BS98] one often has to insert temporary nop (No operation) instructions. When examining the produced code it may be very difficult to track back where the nop was actually inserted. One could think of a derived nop2 instruction that contains additional debugging information. When the instruction list ....

.... has been applied: 4 Application areas There are many possible application areas for JAVACLASS ranging from class browsers, profilers, byte code optimizers, and compilers to sophisticated run time analysis tools and extensions to the Java language [AFM97, MBL97] Compilers like the Barat compiler [BS98] use JAVACLASS to implement a byte code generating back end. Other possible application areas are the static analysis of byte code [TK98] or examining the run time behavior of classes by inserting calls to profiling methods into the code. Further examples are extending Java with Eiffel like ....

B. Bokowski and A. Spiegel. Barat -- A Front-End for Java. Technical report, Freie Universitat Berlin, 1998.

....direction. The authors acknowledge, however, that their analysis algorithm has not been able to produce convincing results for real programs yet. We believe that some of the problems responsible for that are dealt more easily with in our own approach; a more elaborate discussion can be found in [8]. What further distinguishes our work from both projects is that Pangaea handles other distribution concepts than mere placement and replication decisions (see previous section) Pangaea does also not depend on any particular distribution platform, it rather provides an abstraction mechanism that ....

....in that it deals with individual objects, not only the types of those objects. Although the latter is usually sufficient for common compiler optimizations, such as static binding of method invocations, it is not enough for distributing programs. We have described the algorithm in detail elsewhere [8] and must confine ourselves to a rough overview here. The result of our algorithm is a graph, the nodes of which represent the run time objects of the program. There are three kinds of edges between these nodes: creation edges, reference edges, and usage edges. We say that an object a uses an ....

Andre Spiegel. Object graph analysis. Technical Report B-99-11, Freie Universitat Berlin, July 1999.

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B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998. 18

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B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998. 18

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B. Bokowski and A. Spiegel. Barat -- A front-end for Java. Technical Report B-98-09, Freie Universitat Berlin, Dec. 1998. 18

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