source: CIVL/grammar/PreprocessorParser.g@ 173ff32

parser grammar PreprocessorParser;

/* Author: Stephen F. Siegel, University of Delaware
 * Last modified: June 1, 2012
 *
 * Grammar for C preprocessor.
 * This grammar describes a C source file before preprocessing.
 * It does not execute any preprocessor directives.
 * It simply represents the file in a structured way.
 *
 * See the C11 Standard, Sec. 6.10.
 *
 * This grammar uses the PreprocessorLexer, which has already
 * formed the preprocessor tokens.
 */

options {
   tokenVocab=PreprocessorLexer;
   output=AST;
}

/* "imaginary" tokens */
tokens {
        FILE;         // root node
        TEXT_BLOCK;   // a list of tokens
        PARAMLIST;    // x1,x2,x3
        EXPR;         // an expression used in a conditional (#if)
        SEQUENCE;     // true branch of conditional directive
        BODY;         // body of macro definition
}

@header
{
package edu.udel.cis.vsl.abc.preproc.common;
}

@members{
@Override
public void emitErrorMessage(String msg) { // don't try to recover!
    throw new RuntimeException(msg);
}
}

/**  The whole file consists of 1 block followed by EOF */
file            :       block EOF -> ^(FILE block? EOF)
                ;

/** A block is a sequence of directives and text blocks.
 *  A block may be empty.
 */
block           :       (directive | textblock)* ;

/** These are the various kind of preprocessor directives
 * specified in the C11 standard.   Each one whose name ends in
 * "block" is a complete block, so the "ifblock", for example,
 * contains everything up to and including the final "#endif".  
 *
 * Yes, a "nondirective" is a kind of directive.  That is what
 * C11 says.
 *
 */
directive       :       macrodef
                |       macroundef
                |       includeline
                |       pragmaline
                |       ifblock
                |       ifdefblock
                |       ifndefblock
                |       errorline
                |       lineline
                |       nondirectiveline
                ;

/** A textblock is a maximal sequence of text lines.  A
 * text line is any line that doesn't have a "#' as its first
 * non-whitespace character.   In the tree, the text block
 * just contains a sequence of all the tokens form all the lines
 * concatenated.  The white space tokens and newlines are included,
 * as are comments. */
textblock       :       (options {greedy=true;} : textline)+
                         -> ^(TEXT_BLOCK textline+) ;

textline        :       white* (nonPoundPpToken wpptoken*)? lineend ;

white           :       WS | COMMENT ;

wpptoken        :       pptoken | white ;

lineend         :       NEWLINE ;

macrodef        :       PDEFINE white+ i=identifier
                        ( paramlist macrobody -> ^(PDEFINE $i paramlist macrobody)
                        | lineend -> ^(PDEFINE $i ^(BODY))
                        | white macrobody -> ^(PDEFINE $i macrobody)
                        )
                ;

macrobody       :       white* 
                        ( t+=pptoken (t+=wpptoken* t+=pptoken)? white* lineend
                          -> ^(BODY $t+)
                        | lineend
                          -> ^(BODY)
                        )
                ;

paramlist       :       LPAREN white* 
                        ( RPAREN -> ^(PARAMLIST)
                        | identifier (white* COMMA white* identifier)* white* RPAREN
                          -> ^(PARAMLIST identifier+)
                        )
                ;

macroundef      :       PUNDEF white+ identifier white* lineend
                        -> ^(PUNDEF identifier)
                ;

includeline     :       PINCLUDE white* HEADER_NAME white* lineend
                        -> ^(PINCLUDE HEADER_NAME)
                ;

ifblock         :       PIF white* expr lineend block elseblock? endifline
                        -> ^(PIF expr ^(SEQUENCE block?) elseblock?)            
                ;

expr            :       ppdExpr (ppdExpr | white)* -> ^(EXPR ppdExpr+) ;

definedExpr     :       DEFINED WS!*
                        ( identifier
                        | LPAREN! WS!* identifier WS!* RPAREN!
                        )
                ;
                        
ppdExpr         :       pptoken | definedExpr ;

elseblock       :       simpleelseblock | elifblock ;

simpleelseblock :       PELSE white* lineend block -> ^(PELSE block?) ;

elifblock       :       c=PELIF white* expr lineend block elseblock? 
                        ->
                        ^($c ^($c expr ^(SEQUENCE block?) elseblock?))
                ;

ifdefblock      :       PIFDEF white* identifier white* lineend
                        block elseblock? endifline
                        -> ^(PIFDEF identifier ^(SEQUENCE block?) elseblock?)
                ;

ifndefblock     :       PIFNDEF white* identifier white* lineend
                        block elseblock? endifline
                        -> ^(PIFNDEF identifier ^(SEQUENCE block) elseblock?)
                ;

endifline       :       PENDIF white* lineend ;

pragmaline      :       PRAGMA wpptoken* lineend -> ^(PRAGMA wpptoken* lineend) ;

errorline       :       PERROR wpptoken* lineend -> ^(PERROR wpptoken*) ;

lineline        :       PLINE wpptoken* lineend -> ^(PLINE wpptoken*) ;

nondirectiveline
                :       HASH wpptoken* lineend -> ^(HASH wpptoken*) ;

/* A "preprocessor token" as defined in the C11 Standard. */
pptoken         :       HEADER_NAME
                |       identifier
                |       pp_number
                |       CHARACTER_CONSTANT
                |       STRING_LITERAL
                |       punctuator
                |       OTHER
                ;

/* Any preprocessor token other than '#' */
nonPoundPpToken :       HEADER_NAME
                |       identifier
                |       pp_number
                |       CHARACTER_CONSTANT
                |       STRING_LITERAL
                |       nonPoundPunctuator
                |       OTHER
                ;
                
/* An "identifier" for the preprocessor is any C IDENTIFIER or C keyword: */
/* Added for CIVL-C: any CIVL-C keyword */

identifier      :       IDENTIFIER | c_keyword ;

c_keyword       :       AUTO | BREAK | CASE | CHAR | CONST | CONTINUE | DEFAULT
                |       DO | DOUBLE | ELSE | ENUM | EXTERN | FLOAT | FOR | GOTO
                |       IF | INLINE | INT | LONG | REGISTER | RESTRICT | RETURN
                |       SHORT | SIGNED | SIZEOF | STATIC | STRUCT | SWITCH | TYPEDEF
                |       UNION | UNSIGNED | VOID | VOLATILE | WHILE | ALIGNAS | ALIGNOF
                |       ATOMIC | BOOL | COMPLEX | GENERIC | IMAGINARY | NORETURN
                |       STATICASSERT | THREADLOCAL
                |       ASSERT | ASSUME | CHOOSE | COLLECTIVE | INPUT | INVARIANT
                |       OUTPUT | PROC | SPAWN | WAIT | WHEN | COLLECTIVE
                ;

punctuator      :       nonPoundPunctuator | HASH ;

/* a "pp_number" is any PP_NUMBER, INTEGER_CONSTANT, or FLOATING_CONSTANT */
pp_number       :       INTEGER_CONSTANT | FLOATING_CONSTANT | PP_NUMBER ;

/* Any punctuator other than '#' */
nonPoundPunctuator
                :       AMPERSAND
                |       AND
                |       ARROW
                |       ASSIGN
                |       BITANDEQ
                |       BITOR
                |       BITOREQ
                |       BITXOR
                |       BITXOREQ
                |       COLON
                |       COMMA
                |       DIV
                |       DIVEQ
                |       DOT
                |       ELLIPSIS
                |       EQUALS
                |       GT
                |       GTE
                |       HASHHASH
                |       LCURLY
                |       LPAREN
                |       LSQUARE
                |       LT
                |       LTE
                |       MINUSMINUS
                |       MOD
                |       MODEQ
                |       NEQ
                |       NOT
                |       OR
                |       PLUS
                |       PLUSEQ
                |       PLUSPLUS
                |       QMARK
                |       RCURLY
                |       RPAREN
                |       RSQUARE
                |       SEMI
                |       SHIFTLEFT
                |       SHIFTLEFTEQ
                |       SHIFTRIGHT
                |       SHIFTRIGHTEQ
                |       STAR
                |       STAREQ
                |       SUB
                |       SUBEQ
                |       TILDE
                ;