Parsing - roybaer/sdcc-wiki GitHub Wiki

Table of Contents parsing sources what does it do input output

• happens inside SDCC.EXE

• sdcc/src/src/SDCC.lex
  • compiled using lex (flex?)
  • generates the lexer which is what recognizes groups of

characters as "words" (tokens)

• sdcc/src/src/SDCC.y
  • compiled using bison (alternative to yacc)
  • generates the parser which takes the output of the lexer and attempts to fit them into the defined grammar
• additional target dependent "hooks":
  • port->keywords for the "extra" port-dependent keywords
    • initialized usually in sdcc/src/src/[port]/main.c
    • passed via _ports in sdcc/src/src/SDCCmain.c
  • port->process_pragma
    • enables target-specific #pragma-s

• transforms C source into AST (annotated source tree or abstract source tree)
• flow: ???

• output from SDCPP preprocessor

• AST - a binary tree located in memory.
  • struct for it is defined in src/SDCCast.h.
  • use --dumptree compiler option to show what is in the tree