TINY+语法分析（完全）

/****************************************************/ /* File: tm.c */ /* The TM ("Tiny Machine") computer */ /* Compiler Construction: Principles and Practice */ /* Kenneth C. Louden */ /****************************************************/ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #ifndef TRUE #define TRUE 1 #endif #ifndef FALSE #define FALSE 0 #endif /******* const *******/ #define IADDR_SIZE 1024 /* increase for large programs */ #define DADDR_SIZE 1024 /* increase for large programs */ #define NO_REGS 8 #define PC_REG 7 #define LINESIZE 121 #define WORDSIZE 20 /******* type *******/ typedef enum { opclRR, /* reg operands r,s,t */ opclRM, /* reg r, mem d+s */ opclRA /* reg r, int d+s */ } OPCLASS; typedef enum { /* RR instructions */ opHALT, /* RR halt, operands are ignored */ opIN, /* RR read into reg(r); s and t are ignored */ opOUT, /* RR write from reg(r), s and t are ignored */ opADD, /* RR reg(r) = reg(s)+reg(t) */ opSUB, /* RR reg(r) = reg(s)-reg(t) */ opMUL, /* RR reg(r) = reg(s)*reg(t) */ opDIV, /* RR reg(r) = reg(s)/reg(t) */ opRRLim, /* limit of RR opcodes */ /* RM instructions */ opLD, /* RM reg(r) = mem(d+reg(s)) */ opST, /* RM mem(d+reg(s)) = reg(r) */ opRMLim, /* Limit of RM opcodes */ /* RA instructions */ opLDA, /* RA reg(r) = d+reg(s) */ opLDC, /* RA reg(r) = d ; reg(s) is ignored */ opJLT, /* RA if reg(r)<0 then reg(7) = d+reg(s) */ opJLE, /* RA if reg(r)<=0 then reg(7) = d+reg(s) */ opJGT, /* RA if reg(r)>0 then reg(7) = d+reg(s) */ opJGE, /* RA if reg(r)>=0 then reg(7) = d+reg(s) */ opJEQ, /* RA if reg(r)==0 then reg(7) = d+reg(s) */ opJNE, /* RA if reg(r)!=0 then reg(7) = d+reg(s) */ opRALim /* Limit of RA opcodes */ } OPCODE; typedef enum { srOKAY, srHALT, srIMEM_ERR, srDMEM_ERR, srZERODIVIDE } STEPRESULT; typedef struct { int iop ; int iarg1 ; int iarg2 ; int iarg3 ; } INSTRUCTION; /******** vars ********/ int iloc = 0 ; int dloc = 0 ; int traceflag = FALSE; int icountflag = FALSE; INSTRUCTION iMem [IADDR_SIZE]; int dMem [DADDR_SIZE]; int reg [NO_REGS]; char * opCodeTab[] = {"HALT","IN","OUT","ADD","SUB","MUL","DIV","????", /* RR opcodes */ "LD","ST","????", /* RM opcodes */ "LDA","LDC","JLT","JLE","JGT","JGE","JEQ","JNE","????" /* RA opcodes */ }; char * stepResultTab[] = {"OK","Halted","Instruction Memory Fault", "Data Memory Fault","Division by 0" }; char pgmName[20]; FILE *pgm ; char in_Line[LINESIZE] ; int lineLen ; int inCol ; int num ; char word[WORDSIZE] ; char ch ; int done ; /********************************************/ int opClass( int c ) { if ( c <= opRRLim) return ( opclRR ); else if ( c <= opRMLim) return ( opclRM ); else return ( opclRA ); } /* opClass */ /********************************************/ void writeInstruction ( int loc ) { printf( "%5d: ", loc) ; if ( (loc >= 0) && (loc < IADDR_SIZE) ) { printf("%6s%3d,", opCodeTab[iMem[loc].iop], iMem[loc].iarg1); switch ( opClass(iMem[loc].iop) ) { case opclRR: printf("%1d,%1d", iMem[loc].iarg2, iMem[loc].iarg3); break; case opclRM: case opclRA: printf("%3d(%1d)", iMem[loc].iarg2, iMem[loc].iarg3); break; } printf ("\n") ; } } /* writeInstruction */ /********************************************/ void getCh (void) { if (++inCol < lineLen) ch = in_Line[inCol] ; else ch = ' ' ; } /* getCh */ /********************************************/ int nonBlank (void) { while ((inCol < lineLen) && (in_Line[inCol] == ' ') ) inCol++ ; if (inCol < lineLen) { ch = in_Line[inCol] ; return TRUE ; } else { ch = ' ' ; return FALSE ; } } /* nonBlank */ /********************************************/ int getNum (void) { int sign; int term; int temp = FALSE; num = 0 ; do { sign = 1; while ( nonBlank() && ((ch == '+') || (ch == '-')) ) { temp = FALSE ; if (ch == '-') sign = - sign ; getCh(); } term = 0 ; nonBlank(); while (isdigit(ch)) { temp = TRUE ; term = term * 10 + ( ch - '0' ) ; getCh(); } num = num + (term * sign) ; } while ( (nonBlank()) && ((ch == '+') || (ch == '-')) ) ; return temp; } /* getNum */ /********************************************/ int getWord (void) { int temp = FALSE; int length = 0; if (nonBlank ()) { while (isalnum(ch)) { if (length < WORDSIZE-1) word [length++] = ch ; getCh() ; } word[length] = '\0'; temp = (length != 0); } return temp; } /* getWord */ /********************************************/ int skipCh ( char c ) { int temp = FALSE; if ( nonBlank() && (ch == c) ) { getCh(); temp = TRUE; } return temp; } /* skipCh */ /********************************************/ int atEOL(void) { return ( ! nonBlank ()); } /* atEOL */ /********************************************/ int error( char * msg, int lineNo, int instNo) { printf("Line %d",lineNo); if (instNo >= 0) printf(" (Instruction %d)",instNo); printf(" %s\n",msg); return FALSE; } /* error */ /********************************************/ int readInstructions (void) { OPCODE op; int arg1, arg2, arg3; int loc, regNo, lineNo; for (regNo = 0 ; regNo < NO_REGS ; regNo++) reg[regNo] = 0 ; dMem[0] = DADDR_SIZE - 1 ; for (loc = 1 ; loc < DADDR_SIZE ; loc++) dMem[loc] = 0 ; for (loc = 0 ; loc < IADDR_SIZE ; loc++) { iMem[loc].iop = opHALT ; iMem[loc].iarg1 = 0 ; iMem[loc].iarg2 = 0 ; iMem[loc].iarg3 = 0 ; } lineNo = 0 ; while (! feof(pgm)) { fgets( in_Line, LINESIZE-2, pgm ) ; inCol = 0 ; lineNo++; lineLen = strlen(in_Line)-1 ; if (in_Line[lineLen]=='\n') in_Line[lineLen] = '\0' ; else in_Line[++lineLen] = '\0'; if ( (nonBlank()) && (in_Line[inCol] != '*') ) { if (! getNum()) return error("Bad location", lineNo,-1); loc = num; if (loc > IADDR_SIZE) return error("Location too large",lineNo,loc); if (! skipCh(':')) return error("Missing colon", lineNo,loc); if (! getWord ()) return error("Missing opcode", lineNo,loc); op = opHALT ; while ((op < opRALim) && (strncmp(opCodeTab[op], word, 4) != 0) ) op++ ; if (strncmp(opCodeTab[op], word, 4) != 0) return error("Illegal opcode", lineNo,loc); switch ( opClass(op) ) { case opclRR : /***********************************/ if ( (! getNum ()) || (num < 0) || (num >= NO_REGS) ) return error("Bad first register", lineNo,loc); arg1 = num; if ( ! skipCh(',')) return error("Missing comma", lineNo, loc); if ( (! getNum ()) || (num < 0) || (num >= NO_REGS) ) return error("Bad second register", lineNo, loc); arg2 = num; if ( ! skipCh(',')) return error("Missing comma", lineNo,loc); if ( (! getNum ()) || (num < 0) || (num >= NO_REGS) ) return error("Bad third register", lineNo,loc); arg3 = num; break; case opclRM : case opclRA : /***********************************/ if ( (! getNum ()) || (num < 0) || (num >= NO_REGS) ) return error("B