Difficultés à compiler lex / yacc avec du code C ++
Nov 14 2020
J'essaye de compiler lex.yy.c et y.tab.c avec du code C ++, voici le statut Make -
(base) rajatkmitra@spider:~/modeler> make
flex ./src/lex.l
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o main.o ./src/main.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o convertFloatToFixed.o ./src/convertFloatToFixed.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o convertProductFloatToFixed.o ./src/convertProductFloatToFixed.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o printer.o ./src/printer.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o vectorToString.o ./src/vectorToString.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o printFixedPointProduct.o ./src/printFixedPointProduct.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o fixedPointFormatter.o ./src/fixedPointFormatter.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o tokenize.o ./src/tokenize.cc
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o y.tab.o y.tab.c
bison -y -d ./src/bison.y
./src/bison.y: warning: 4 shift/reduce conflicts [-Wconflicts-sr]
g++ -I ./ -c -Wall -Wreorder -Wno-write-strings -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm -c -o lex.yy.o lex.yy.c
###############################################################################
# Building main.o convertFloatToFixed.o convertProductFloatToFixed.o printer.o vectorToString.o
printFixedPointProduct.o fixedPointFormatter.o tokenize.o y.tab.c lex.yy.c
###############################################################################
g++ -Wno-write-strings -I ./ main.o convertFloatToFixed.o convertProductFloatToFixed.o printer.o vectorToString.o printFixedPointProduct.o fixedPointFormatter.o tokenize.o y.tab.c lex.yy.c -o lynx -lm
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /tmp/cc8jVMLM.o: in function `yylex()':
lex.yy.c:(.text+0x343): undefined reference to `yyerror(char*)'
collect2: error: ld returned 1 exit status
make: *** [Makefile:71: lynx] Error 1
----Makefile----
####################################################################
# Library Paths
####################################################################
####################################################################
#Sources, use vpath and $CC/$LEX/$YACC should have arguments $<
#debug %make --just-print should show simulate make procedure
####################################################################
INCLUDE=-I ./
LEXSRC=lex.l
YACCSRC=bison.y
SRC=main.cc convertFloatToFixed.cc convertProductFloatToFixed.cc \
printer.cc vectorToString.cc printFixedPointProduct.cc fixedPointFormatter.cc \
tokenize.cc y.tab.c lex.yy.c
vpath %cc ./src
vpath %l ./src
vpath %y ./src
#####################################################################
#Compiler Settings
#####################################################################
OBJCC=$(SRC:.cc=.o) OBJC=$(SRC:.c=.o)
EXE=lynx
DEFINE=#-D _XOPEN_SOURCE
CFLAGS=$(INCLUDE) $(DEFINE) $(LIBPATH) -c -Wall -Wreorder -Wno-write-strings \ -Wno-unused-variable -Wno-unused-function -Wno-sign-compare -g -lm CXXFLAGS=$(CFLAGS)
CC=g++
LEX=flex
YACC=bison -y -d
######################################################################
#Build Rules
######################################################################
new: all
all:$(SRC) $(EXE)
# These dependency rules indicate that (1) lex.yy.o depends on
# lex.yy.c and y.tab.h and (2) lex.yy.o and y.tab.o depend on calc.h.
# Make uses the dependencies to figure out what rules must be run when
# a file has changed.
lex.yy.o: lex.yy.c y.tab.h
lex.yy.o y.tab.o:
## This rule will use yacc to generate the files y.tab.c and y.tab.h
## from our file $(YACCSRC).y y.tab.c y.tab.h: $(YACCSRC)
$(YACC) $<
## this is the make rule to use lex to generate the file lex.yy.c from
## our file $(LEXSRC).lex lex.yy.c: $(LEXSRC)
$(LEX) $<
## for lex.yy.c and y.tab.c
%.c.o:
$(CC) $(CFLAGS) $< -o $@
## all other C++ files
%.cc.o:
$(CC) $(CFLAGS) $< -o $@
$(EXE):$(OBJCC) $(OBJC) @echo \############################################################################### @echo \# Building $(OBJCC)
@echo \###############################################################################
$(CC) -Wno-write-strings $(INCLUDE) $(OBJCC) $(LIBPATH) $(LIB) -o $@ -lm
clean:
rm -rf $(EXE) *~ *.o lex.yy.c y.tab.h
Bon alors voici le fichier de grammaire bison.y
%{
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
int yylex();
void yyerror(const char *s);
/*|--------------------------
for global parsing
-----------------------------|*/
unsigned int attributeFlag;
%}
/*Possible types from lexer*/
%union {
int ival;
double fval;
const char *sval;
}
/*Possible tokens*/
%token KWREAL
%token <ival> INTEGER
%token <fval> FLOAT;
%token <sval> VARIABLE
/*associativity*/
%left GE LE EQ NE '>' '<'
%left '+' '-'
%left '*' '/'
%nonassoc UMINUS
/*parse rules*/
%%
description:
description decl_attributes {}
| description stmt_list {}
| description real_variable_decl {}
| decl_attributes {}
| stmt_list {}
| real_variable_decl {}
;
decl_attributes:
attribute {}
| decl_attributes attribute {}
;
attribute:
open_attribute several_attribute_assignments close_attribute
real_variable_decl
{
attributeFlag = 0;
}
;
open_attribute:
'(' '*' {attributeFlag = 1;}
;
close_attribute:
'*' ')' {}
;
several_attribute_assignments:
integer_assignment {}
| continued_attribute_assignments integer_assignment {}
;
continued_attribute_assignments:
integer_assignment ',' {}
| continued_attribute_assignments integer_assignment ',' {}
;
real_variable_decl:
KWREAL VARIABLE ';'
{
}
;
stmt_list:
stmt { }
| stmt_list stmt { }
;
stmt:
VARIABLE '=' expr ';' {printf("%s\n\n",$1); }
| integer_assignment ';' { }
;
integer_assignment:
VARIABLE '=' INTEGER
{
if(attributeFlag==1){
if(strcmp($1, "S")==0){ //attrContainer.isSigned = $3;
}else if(strcmp($1, "IB")==0){ //attrContainer.intBits = $3;
}else if(strcmp($1, "FB")==0){ //attrContainer.fracBits = $3;
}
}
}
;
expr:
VARIABLE { printf("%s\n",$1); } | FLOAT { printf("%f\n",$1); }
| '-' expr %prec UMINUS { }
| expr '+' expr { }
| expr '-' expr { }
| expr '*' expr { }
| expr '/' expr { }
| expr '<' expr { }
| expr '>' expr { }
| expr GE expr { }
| expr LE expr { }
| expr NE expr { }
| expr EQ expr { }
| '(' expr ')' { }
;
%%
/*|-----------------------------------------------------
Parsing Functions
-----------------------------------------------------|*/
/*Definition of yyerror*/
void yyerror(const char *s)
{
extern int yylineno; // defined and maintained in lex.c
extern char *yytext; // defined and maintained in lex.c
printf("ERROR: %s on line %d\n", yytext, yylineno);
}
et le lexer -
%{
#include <stdlib.h>
#include <stdio.h>
#include "y.tab.h"
void yyerror(char *);
%}
%%
"real" return KWREAL;
[a-zA-Z][a-zA-Z]* {
//yylval.sval= *yytext - 'a';
yylval.sval = strdup(yytext);
return VARIABLE;
}
0 {
yylval.ival = atoi(yytext);
return INTEGER;
}
[1-9][0-9]* {
yylval.ival = atoi(yytext);
return INTEGER;
}
(([0-9]*\.[0-9]*)([eE][-+]?[0-9]+)?) {
yylval.fval = atof(yytext);
return FLOAT;
}
[-()<>=+*/;,{}.] {
return *yytext;
}
">=" return GE;
"<=" return LE;
"==" return EQ;
"!=" return NE;
#[^\n]* { /* Discard preprocessor comments. */ }
"//"[^\n]* { /* Discard c99 comments. */ }
[ \t\n]+ ; /* ignore whitespace */
. yyerror("Unknown character");
%%
int yywrap(void) {
return 1;
}
C'est la routine principale main.cc
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
/*------------------------------------------------
Front end parser
------------------------------------------------*/
extern void yyparse(void);
extern FILE *yyin;
int main(int argc, char **argv)
{
/*------------------------
parse the file
------------------------*/
/*open file handle to a file of interest*/
if(argc < 2){
printf("Usage: main <filename> \n");
exit(-1);
}
yyin = fopen(argv[1],"r");
if(yyin==NULL){
printf("Could not open file !\n");
exit(-1);
}
/*Parse the design*/
do{
yyparse();
}while(!feof(yyin));
}
Alors voilà! J'ai ajouté l'exemple minimal reproductible. Quand je compile tout avec g ++, je finis par obtenir une erreur de l'éditeur de liens qui ne trouve pas la routine yyerror () dans yylex ()
g++ -Wno-write-strings -I ./ y.tab.o lex.yy.o main.o -o lynx -lm -lfl -
std = c ++ 11 /usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: lex.yy.o: dans function yylex()': /home/rajatkmitra/modeler/minimal/lex.l:46: undefined reference to yyerror (char *) '/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: / usr / lib64 / gcc /x86_64-suse-linux/7/../../../../lib64/libfl.so: référence non définie à `yylex 'collect2: erreur: ld a renvoyé 1 état de sortie make: *** [Makefile: 68: lynx] Erreur 1
Changes Made to get this environment to work -
(1) Compile ALL sources including the output from lex and yacc with g++
(2) yyerror arguments are (char *s) and NOT (const char *s)
(2) do not link with -lfl as this is not not required with g++
Réponses
rici Nov 15 2020 at 00:00
Voici un exemple minimal qui montre le problème:
fichier: yyerror.c
#include <iostream>
void yyerror(const char* msg) {
std::cout << msg;
}
fichier: main.c
void yyerror(char* msg);
int main(void) {
char* msg[] = "Hello, world";
yyerror(msg);
}
Essayez de construire
$ g++ -Wall -o main main.c yyerror.c
/tmp/cc4xbjus.o: In function `main':
main.c:(.text+0x5f): undefined reference to `yyerror(char*)'
collect2: error: ld returned 1 exit status
Notez que la déclaration de yyerrorin main.cest différente de la définition de yyerrorin yyerror.c. Puisque vous compilez ces fichiers en C ++, ceci est important: en C ++, les noms de fonctions peuvent être surchargés avec différents types d'arguments et leur const char*type d'argument est différent de char*. Donc, les deux fichiers ne peuvent pas être liés avec succès: la surcharge de yyerrordéclaré dans main.cn'est définie nulle part.
Bien que vous ne yyerrormontriez pas la déclaration de vous placée dans votre fichier lexer, je suppose que c'est le même que mon exemple, basé sur le message d'erreur généré par le compilateur. Le message d'erreur indique le nom complet (y compris les types d'argument) de la fonction qui ne peut pas être liée.