The vcgAST phase provides a way to graphically display the AST. This phase generates a specification of the AST that can be read by xvcg, a visualization tool that draws colored graphs. xvcg can display graphs on the screen and can save the graph in various formats, including PostScript. To visualize the AST for a program, foo.c, the vcgAST phase will produce the file foo.c.vcgast, which can then be visualized by xvcg as follows:
% xvcg foo.c.vcgast
If multiple input file names are given to C-Breeze, the output filename will be called combined.vcgast.
The output of this phase uses version 1.3 revision 3.17 running on Linux, but FreeBSD and MS Windows versions are also available. The tool has a number of useful features, including edge crossing reduction, subgraph folding, parameterized layouts, and rank assignment, many of which our phase does not exploit.