decl.c

花了很长时间找了这么多c语言的编译器

 * This determines if another variable is being declared of the same type
 */
{       return st == star || st == id || st == openpa ||
                st == openbr;
}

void declenum(TABLE *table)
/*
 * declare enums
 */
{       SYM     *sp;
        TYP     *tp;
				char *nm;
        if( lastst == id) {
/* tagged */
                if((sp = search(nm = litlate(lastid),&tagtable)) == 0) {
                        sp = xalloc(sizeof(SYM));
                        sp->tp = xalloc(sizeof(TYP));
                        sp->tp->type = bt_enum;
                        sp->tp->size = 2;
                        sp->tp->lst.head = sp->tp->btp = 0;
                        sp->storage_class = sc_type;
                        sp->name = nm;
                        sp->tp->sname = sp->name;
												sp->tp->bits = sp->tp->startbit = -1;
#ifdef CPLUSPLUS
												/* tags are also typedefs in C++ */
												if (prm_cplusplus)
													insert(sp,active_table);
#endif
                        getsym();
                        if( lastst != begin)
                                generror(ERR_PUNCT,begin,skm_declend);
                        else    {
                                insert(sp,&tagtable);
                                getsym();
                                enumbody(table);
                                }
                        }
                else
                        getsym();
                head = sp->tp;
                }
        else    {
/* untagged */
                tp = xalloc(sizeof(TYP));
                tp->type = bt_enum;
                tp->lst.head = tp->btp = 0;
								tp->size = 2;
								tp->bits = tp->startbit = -1;
								tp->sname = 0;
                if( lastst != begin)
                        generror(ERR_PUNCT,begin,skm_declend);
                else    {
                        getsym();
                        enumbody(table);
                        }
                head = tp;
                }
}

void enumbody(TABLE *table)
/*
 * read the enumeration constants in
 */
{       long     evalue;
        SYM     *sp;
        evalue = 0;
        while(lastst == id) {
                sp = xalloc(sizeof(SYM));
                sp->value.i = evalue++;
                sp->name = litlate(lastid);
                sp->storage_class = sc_const;
                sp->tp = &stdconst;
                insert(sp,active_table);
                getsym();
								if (lastst == assign) {
										getsym();
										evalue = sp->value.i = intexpr(0);
										sp->value.i = evalue++;
										if (sp->value.i < SHRT_MIN || sp->value.i >SHRT_MAX)
											generror(ERR_CONSTTOOLARGE,0,0);
								}
                if( lastst == comma)
                        getsym();
                else if(lastst != end)
                        break;
                }
        needpunc(end,skm_declend);
}

void declstruct(TABLE *table, int ztype, int flags)
/*
 * declare a structure or union type
 */
{       SYM     *sp;
        TYP     *tp;
				char *nm = litlate(lastid);
        if(lastst == id) {
/* tagged */
                if((sp = search(nm,&tagtable)) == 0) {
/* if tag was never defined */
                        sp = xalloc(sizeof(SYM));
                        sp->name = nm;
                        sp->tp = xalloc(sizeof(TYP));
                        sp->tp->type = ztype;
                        sp->tp->lst.head = 0;
                        sp->storage_class = sc_type;
                        sp->tp->sname = sp->name;
												sp->tp->cflags = flags;
												sp->tp->uflags = UF_DEFINED;
												sp->tp->size = 0;
#ifdef CPLUSPLUS
												/* tags are also typedefs in C++ */
												if (prm_cplusplus)
													insert(sp,table);
#endif
                        getsym();
                        if(lastst != begin) {
                                insert(sp,&tagtable);
/*																if (lastst != semicolon)
																	generror(ERR_PUNCT,semicolon,skm_declend);
*/												}
                        else    {
                                insert(sp,&tagtable);
                                getsym();
                                structbody(sp->tp,sp->name,ztype);
                                }
                        }
                else {
/* Allow redefinition if it was forward declared */
                        getsym();
												if (lastst == begin) {
													getsym();
													if (sp->tp->size == 0) 
														structbody(sp->tp,sp->name,ztype);
													else {
														gensymerror(ERR_DUPSYM,sp->name);
														expskim(skm_declclosebr);
													}
												}
								}
								if (flags & (DF_CONST | DF_VOL))
									head = copytype(sp->tp,flags);
								else
                	head = sp->tp;
								head->bits = head->startbit = -1;
                }
        else    {
/* untagged */
                tp = xalloc(sizeof(TYP));
                tp->type = ztype;
								tp->cflags = flags;
								tp->uflags = UF_DEFINED;
                tp->sname = 0;
                tp->lst.head = 0;
								tp->bits = tp->startbit =-1;
                if( lastst != begin)
                       	generror(ERR_PUNCT,begin,skm_declend);
                else    {
                        getsym();
                        structbody(tp,tn_unnamed,ztype);
                        }
                head = tp;
                }
}

void structbody(TYP *tp,char  *name,int ztype)
/*
 * read in the structure/union elements and calculate the total size
 */
{       int     slc;
        slc = 0;
        tp->val_flag = 1;
				tp->uflags &= ~UF_CANASSIGN;
        while( lastst != end) {
								int flags=0;
                if(ztype == bt_struct)
                        slc += declare2(&tp->lst,sc_member,ztype,flags,slc);
                else
                        slc = imax(slc,declare2(&tp->lst,sc_member,ztype,flags,0));
								if (tp->lst.tail->tp->type == bt_ref)
									genclasserror(ERR_REFNOCONS,name,tp->lst.tail->name);
								tp->lst.tail->tp->uflags |= UF_DEFINED;
                }
				if (!prm_packing)
        	tp->size = (slc+strucadd)&strucmod;
				else
					tp->size = slc;
        getsym();
}
void check_used(void)
/*
 * At the end of compilition we check for some common cases where 
 * module-scoped variables are either missing or unused
 */
{
				int i;
				SYM *sp;
					for (i=0; i < HASHTABLESIZE; i++) {
						if ((sp=(SYM *) globalhash[i]) != 0) {
							while (sp) {
								if (sp->storage_class == sc_static)
									if (sp->tp->uflags & UF_USED) {
										if (sp->tp->type == bt_func)
											gensymerror(ERR_NOSTATICFUNC,sp->name);
									}
									else
										if (sp->tp->type == bt_ifunc || sp->tp->type == bt_func)
											gensymerror(ERR_FUNCUNUSED,sp->name);
										else
											gensymerror(ERR_STATICSYMUNUSED,sp->name);
								sp = sp->next;
							}
						}
					}
				sp = tagtable.head;
				while (sp) {
					if (sp->tp->size == 0) 
						gensymerror(ERR_NEVERSTRUCT,sp->name);
					sp = sp->next;
				}
}
void compile(void)
/*
 * Main compiler routine
 */
{       while(lastst != eof) {
                dodecl(sc_global);
								if (lastst != eof) {
									generror(ERR_DECLEXPECT,0,0);
									getsym();
								}
        }
        flush_peep();
				dumplits();
				initrundown();
				dumpstartups();
				check_used();
				putexterns();
}

void dodecl(int defclass)
/*
 * Declarations come here, ALWAYS
 */
{
				SYM *sp;
				int flags = 0;
				long val;
				char *nm;
				cbautoinithead = 0;
        for(;;) {
						ispascal = FALSE;
            switch(lastst) {
								case semicolon:
												getsym();
												break;
								case kw_typedef:
												getsym();
												if (defclass == sc_global)
													declare(&gsyms,sc_type,bt_struct, 0);
												else
													declare(&lsyms,sc_type,bt_struct, 0);
												break;
                case kw_register:
                        if( defclass != sc_auto || flags & DF_VOL) {
                          gensymerror(ERR_ILLCLASS,lastid);
                        	getsym();
												}
												else  {
                        	getsym();
          	                  declare(&lsyms,sc_autoreg,bt_struct,flags | DF_AUTOREG);
												};
										break;
                case id:
										if (defclass == sc_auto)
												if (!(((sp = search(nm = litlate(lastid),&gsyms)) != 0 && sp->storage_class == sc_type)
												     || ((sp = search(nm,&lsyms)) != 0 && sp->storage_class == sc_type)))
													return;
								case kw_volatile:
								case kw_const:
                case kw_char: case kw_int: case kw_short: case kw_unsigned:
                case kw_long: case kw_struct: case kw_union: case kw_signed:
                case kw_enum: case kw_void:
                case kw_float: case kw_double:
                    if( defclass == sc_global)
                            declare(&gsyms,sc_global,bt_struct,flags | DF_GLOBAL);
                    else if( defclass == sc_auto)
                            declare(&lsyms,sc_auto,bt_struct,flags);
                    else
                        declare(&lsyms,sc_auto,bt_struct,flags);
                    break;
                case kw_static:
                        if( defclass == sc_member) {
                           gensymerror(ERR_ILLCLASS,lastid);
														getsym();
														break;
												}
												getsym();
												if( defclass == sc_auto)
														declare(&lsyms,sc_static,bt_struct,flags | DF_GLOBAL);
												else
														declare(&gsyms,sc_static,bt_struct,flags | DF_GLOBAL);
                        break;
                case kw_extern: {
												int thismangle = FALSE;
                        getsym();
#ifdef CPLUSPLUS
												if (prm_cplusplus && lastst == sconst) {
													if (!strcmp(laststr,Cstr)) {
														mangleflag = FALSE;
														manglelevel++;
														getsym();
														if (lastst == begin) {
															getsym();
														  thismangle = FALSE;
														}
														else thismangle = TRUE;
													}
												}
#endif
                        if( defclass == sc_member) {
                            gensymerror(ERR_ILLCLASS,lastid);
														break;
												}
                        ++global_flag;
                        declare(&gsyms,sc_external,bt_struct,flags);
                        --global_flag;
												if (thismangle && !--manglelevel)
													mangleflag = TRUE;
												}
                        break;
								case end:
#ifdef CPLUSPLUS
												if (prm_cplusplus && manglelevel) {
													mangleflag = (!--manglelevel);
													getsym();
													continue;
												}
#endif
												return;
								case kw__interrupt:
												intflag = 1;
												flags |= DF_INT;
												getsym();
												continue;
								case kw__abs:
												++global_flag;
												getsym();
												if (lastst != openpa) {
													generror(ERR_PUNCT,openpa,0);
												}
												else {
													getsym();
													val = intexpr(0);
													if (lastst != closepa)
														generror(ERR_PUNCT,closepa,skm_declclosepa);
												}
												getsym();
												declare2(&gsyms,sc_abs,bt_struct,flags,val);
												--global_flag;
												break;
                default:
                        return;
                }
						flags = 0;
						intflag = 0;
            }
}
void doargdecl(int defclass, char *names[], int *nparms, TABLE *table, int isinline)
/*
 * Function arguments are declared here
 */
{
				SYM *sp;
				int flags = isinline ? DF_FUNCPARMS : 0;
        for(;;) {
            switch(lastst) {
								case ellipse: {
									sprintf(declid,"**ELLIPSE%d**",pcount++);
									sp = xalloc(sizeof(SYM));
									sp->name = litlate(declid);
                  sp->storage_class = sc_auto;
									sp->tp = maketype(bt_ellipse,0);
									sp->tp->uflags |= UF_DEFINED | UF_USED;
									insert(sp,table);
									if (ispascal)
										generror(ERR_PASCAL_NO_ELLIPSE,0,0);
									getsym();
									goto exit;
								}
								case kw_const:
								case id:
                case kw_char: case kw_int: case kw_short: case kw_unsigned:
                case kw_long: case kw_struct: case kw_union: case kw_signed:
                case kw_enum: case kw_void:
                case kw_float: case kw_double:
                    declare(table,sc_auto,bt_struct,flags);
                    break;
                case kw_static:
								case kw_auto:
								case kw_register:
                        gensymerror(ERR_ILLCLASS,lastid);
                        getsym();
												continue;
                default:
												goto exit;
                }
							if (isinline) {
								names[(*nparms)++] = litlate(declid);
							}
						
				flags &= ~DF_CONST;
				}
exit:
#ifdef CPLUSPLUS
		if (prm_cplusplus) {
			SYM *sp = table->head;
			int found = FALSE;
			while (sp) {
				if (sp->defalt)
					found = TRUE;
				else 
					if (found)
						gensymerror(ERR_MISSINGDEFAULT,sp->name);
				sp = sp->next;
			}
		}
#endif
}