This work area supports a demonstration of the superset C++ -grammar described in Chapter 5 of Ed Willink's thesis on Meta-Compilation -for C++. It contains working lex and yacc grammars that -enable C++ source to be lexically analysed, then syntactically -analysed without semantic knowlege. The lex and yacc grammar have -their action routines defined by macros in the hope that -reconfiguration may be possible without editing the grammars -directly. The dummy implementations of the yacc macros do nothing -other than count statements and diagnose the back-tracking -behaviour. Users may add their own syntactic level code. A proper -C++ parser needs semantic analysis as well, including correction -of minor misprses at the syntactic level. Semantic interpretaion -is provided by FOG -from which this demonstration is split off.
- -The work area is self-sufficient, requiring only lex -and yacc, or flex and bison.
- -The test grammar is a simple command line utility, for -analysing a single pre-processed source file -(use CC -E to run just the preprocessor on your source files)..
- -grammar [options] < source-file- -
The full set of command line options is:
- --c Recognise only C keywords - approximates C rather than C++ parsing - -m Display mark activity. - -n Echo line numbers. - -t Echo source line text. - -y Display yacc diagnostics.- -
On completion a three line diagnostic summarises the search -activity.
- -CxxSrc.tgz, CxxNtSrc.tgz -The source distribution kit including a Sun or NT executable.
- -CxxLexer.l A simple lexer for all C -and/or C++ tokens
- -CxxParser.y The parser, -automatically extracted from FogParser.y.
- -CxxToken.hxx, CxxToken.cxx A trivial class used by the -parser to represent each parsed token.
- -CxxLexing.hxx, CxxLexing.cxx Interface and -implementation of token creation routines for the lexer.
- -CxxParsing.hxx, CxxParsing.cxx Interface and -implementation of token manioulation routines for the parser.
- -CxxLexer.cpp, CxxParser.cpp, CxxToken.cpp -Degenerate compilation units for the above.
- -makefile, makefile.macros, -makefile.unix Unix build scripts
- -makefile.gmake, makefile.macros, grammar.dsw, -grammar.dsp NT build scripts and -DevStudio workspace and project
- -sun4o/grammar Built executable (on Unix)
- -Release/grammar.exe Built executable (on NT)
- -The code builds under Solaris 2.5 and with Sun C++ 4.2.
- -make sun- -
or Gnu egcs-1.0.2 release, with flex 2.3.7, bison 1.16
- -make gnu- -
The code builds under NT 4 and has been tested with DevStudio -V6 and cygwin 1.1.
- -You need cygwin, the latest version of which is available ftp://sunsite.org.uk:21/Mirrors/sourceware.cygnus.com/pub/cygwin/setup.exe
- -A slightly easier to install earlier version (used by the -author) is ftp://sunsite.org.uk:21/Mirrors/sourceware.cygnus.com/pub/cygwin/old/cygwin-b20/full.exe
- -Use a mirror site listed at http://sources.redhat.com/cygwin/mirrors.html.
- -The older cygwin is a simple standard NT installation - just -run full.exe (with administrator rights) and accept the default -installation paths (gnu tools build them in). The newer cygwin is -much smarter, doing automatic selective downloads - which the -author's firewall messes up.
- -You may want to make cygwin tools accessible from command -prompts so
- -Start->Settings->ControlPanel - System|Environment - Add Variable PATH - Value C:\cygwin\cygwin-b20\H-i586-cygwin32\BIN- -
You need to configure DevStudio to use cygwin.
- -In DevStudio:
- -Tools->Options->Directories - Show Directories For Executable files - Add C:\cygwin\bin- -
Then use winzip or gunzip to extract all of CxxNtSrc.tgz:
- -double click in Explorer on CxxNtSrc.tgz - Yes to decompress archive to temporary file - Wait a few moments - Actions...->Extract - All Files, to e.g. C:\CxxGrammar, use Folder names, Extract - Close Winzip- -
Double click in Explorer on grammar.dsw - If prompted to browse for a SourceSafe project Click No. - If prompted to attempt SourceSafe connection in another session click No. - Select your preferred configuration (Win32 Debug is default) - Select FileView|grammar Files->Targets->executable - <Ctrl>F7 - after a few seconds everything is built- -
DevStudio reports 0 errors and 1 warnings
- -Build : warning : failed to (or don't know how to) build 'C:\CxxGrammar\Targets\executable'- -
The warning is an artefact of fake build targets
- -Everything in DevStudio is compiled using a makefile.gmake -target which is selected for a <CTRL>F7 in the Workspace -window. Steer clear of the standard DevStudio F7 which builds all -targets: backup then clean then executables then realclean then -test etc. No harm is done but it takes a long time.
- -Last updated 28 July, 2001.
- -