iwm@doc.ic.ac.uk (Ian Moor) (06/18/91)
gmd have produced a set of compiler writing tools in Modula-2, included in these is a Modula-2 to C translator, the distribution includes C sources produced by the translator for bootstrap purposes. I think I remember the documentation advising against program development using it -- i.e. it will translate correct code only. For uk readers, the tools are on the doc.ic archive, here is the README file from the distribution: ************************************************************************* * * * Compiler Construction Tool Box * * ============================== * * * * Copyright (c) 1989 by * * * * Gesellschaft fuer Mathematik und Datenverarbeitung * * (German National Research Center for Computer Science) * * Forschungsstelle fuer Programmstrukturen * * an der Universitaet Karlsruhe * * * * All rights reserved. GMD assumes no responsibility for the use * * or reliability of its software. * * * ************************************************************************* Direct requests, comments, questions, and error reports to: Josef Grosch GMD Forschungsstelle Vincenz-Priessnitz-Str. 1 D-7500 Karlsruhe 1 Phone: +721-662226 Email: grosch@gmdka.uucp or uunet!unido!gmdka!grosch Distribution Format: The compiler construction tool box is distributed on a DC300A data cartridge (streamer tape) or on a 1/2" magnetic tape (1600 bpi) in tar format. To read the tape use: tar -xvfb /dev/rst0 20 tar -xvb 20 or similar commands The directories and their contents are as follows: directory contents -------------------------------------------------- README this file Makefile sketches the compilation and installation of the tools rex Scanner Generator lalr LALR(1) Parser Generator ell Recursive Descent Parser Generator bnf Transforms Grammars from Extended BNF to Plain BNF struct Common Front-End of Lalr, Ell, and Bnf reuse Library of Reusable Modules specs Example Specifications for the Above Tools cg Common Program implementing Ast and Ag Ast = Generator for Abstract Syntax Trees Ag = Attribute Evaluator Generator l2r Transforms Lex input to Rex input y2l Transforms Yacc input to Lalr input hexa contains the scanner and parser tables of Rex and Struct (= front-end of Lalr, Ell, and Bnf) converted from binary to ascii hexadecimal representation bin shell scripts (my version) lib executables, table and data files (for SUN 3/SunOS 4.0) The names of the subdirectories indicate the following types of information: sub directory contents -------------------------------------------------- doc documentation, user's manual, manual pages suffix me : roff format, me macros suffix ps : postscript format suffix 1 : roff format, man macros src source files in Modula-2 mod source files in Modula-2 m2c source files in C (generated from the Modula-2 sources) c source files in C (hand-written) lib data files, module skeletons test test environment for a tool Installation: To compile and install the programs visit the directories listed below, look at the README file, and execute an appropriate make command. See also the Makefile at the global level. Source Language Modula-2: reuse/c reuse/mod rex/src struct/src bnf/src ell/src lalr/src struct/doc l2r y2l cg/src Source Language C: reuse/c reuse/m2c rex/m2c struct/m2c bnf/m2c ell/m2c lalr/m2c struct/doc l2r y2l cg/m2c Compiler Construction Tool Box ============================== Rex (Regular EXpression tool) is a scanner generator whose specifications are based on regular expressions and arbitrary semantic actions written in one of the target languages C or Modula-2. As scanners sometimes have to consider the context to unambiguously recognize a token the right context can be speci- fied by an additional regular expression and the left context can be handled by so-called start states. The generated scanners automatically compute the line and column position of the tokens and offer an efficient mechanism to normalize identifiers and keywords to upper or lower case letters. The scanners are table- driven and run at a speed of 180,000 to 195,000 lines per minute on a MC 68020 processor. Lalr is a LALR(1) parser generator accepting grammars writ- ten in extended BNF notation which may be augmented by semantic actions expressed by statements of the target language. The gen- erator provides a mechanism for S-attribution, that is syn- thesized attributes can be computed during parsing. In case of LR-conflicts unlike other tools Lalr provides not only informa- tion about an internal state consisting of a set of items but it prints a derivation tree which is much more useful to analyze the problem. Conflicts can be resolved by specifying precedence and associativity of operators and productions. The generated parsers include automatic error recovery, error messages, and error repair. The parsers are table-driven and run at a speed of 560,000 lines per minute. Currently parsers can be generated in the target languages C and Modula-2. Ell is a LL(1) parser generator accepting the same specifi- cation language as Lalr except that the grammars must obey the LL(1) property. It is possible to evaluate an L-attribution during parsing. The generated parsers include automatic error recovery, error messages, and error repair like Lalr. The parsers are implemented following the recursive descent method and reach a speed of 810,000 lines per minute. The possible tar- get languages are again C and Modula-2. Ast - A Generator for Abstract Syntax Trees - generates abstract data types (program modules) to handle trees - the trees may be attributed - besides trees graphs are handled as well - nodes may be associated with arbitrary many attributes of arbitrary type - specifications are based on extended context-free grammars - common notation for concrete and abstract syntax - as well as for attributed trees and graphs - an extension mechanism provides single inheritance - trees are stored as linked records - generates efficient program modules - generates modules in Modula-2 or C - provides many tree operations (procedures): - node constructors combine aggregate notation and storage management - ascii graph reader and writer - binary graph reader and writer - reversal of lists - top down and bottom up traversal - interactive graph browser Ag - An Attribute Evaluator Generator - processes ordered attribute grammars (OAGs) - processes higher order attribute grammars (HAGs) - operates on abstract syntax - is based on tree modules generated by Ast - the tree structure is fully known - terminals and nonterminals may have arbitrary many attributes - attributes can have any target language type - allows tree-valued attributes - differentiates input and output attributes - allows attributes local to rules - allows to eliminate chain rules - offers an extension mechanism (single inheritance) - attributes are denoted by unique selector names instead of nonterminal names with subscripts - attribute computations are expressed in the target language - attribute computations are written in a functional style - attribute computations can call external functions - non-functional statements and side-effects are possible - allows to write compact, modular, and readable specifications - AGs can consist of several modules - the context-free grammar is specified only once - checks an AG for completeness of the attribute computations - checks for unused attributes - checks an AG for the classes SNC, DNC, OAG, LAG, and SAG - the evaluators are directly coded using recursive procedures - generates efficient evaluators - generates evaluators in Modula-2 (or C) A comparison of the above tools with the corresponding UNIX tools shows that significant improvements in terms of error handling as well as efficiency have been achieved: Rex generated scanners are 4 times faster than those of LEX. Lalr generated parsers are 2-3 times faster than those of YACC. Ell generated parsers are 4 times faster than those of YACC. The input languages of the tools are improvements of the LEX and YACC inputs. The tools also understand LEX and YACC syntax with the help of the preprocessors l2r and y2l. The tool box is publicly copyable. It has been developed since 1987. It has been tested by generating scanners and parsers for e. g. Pascal, Modula, Oberon, Ada and found stable. The tool box is implemented in Modula-2. It has been developed using our own Modula-2 compiler called MOCKA on a MC 68020 based UNIX workstation. It has been ported to the SUN workstation and been compiled successfully using the SUN Modula-2 compiler. The tools also run on VAX/BSD UNIX and VAX/ULTRIX machines. This should assure a reasonable level of portability for the Modula-2 code. Meanwhile the sources exist in C, too. I would be pleased to send the programs to everybody that is interested. To minimize the costs (at least for me) I suggest to send a blank SUN streamer tape. 1/2" magtapes are possible, too. I will return the tape with the sources organized as a UNIX file tree (tar format). The tape will contain user manuals (troff format) for each tool. References: 1. J. Grosch, `Generators for High-Speed Front-Ends', LNCS, 371, 81-92 (Oct. 1988), Springer Verlag. 2. W. M. Waite, J. Grosch and F. W. Schroeer, `Three Compiler Specifications', GMD-Studie Nr. 166, GMD Forschungsstelle an der Universitaet Karlsruhe, Aug. 1989. 3. J. Grosch, `Efficient Generation of Lexical Analysers', Software-Practice & Experience, 19, 1089-1103 (Nov. 1989). -- Ian W Moor Internet: iwm@doc.ic.ac.uk JANET: iwm@uk.ac.ic.doc Department of Computing, That which you call a crime when one man does it, Imperial College. you call government when done by many. 180 Queensgate London SW7 UK.
david@oahu.cs.ucla.edu (David Dantowitz) (06/28/91)
The gmd tools work VERY well and have saved us uncounted translation time. -- David Dantowitz david@cs.ucla.edu Singing Barbershop when I'm not computing...