/* mucky.c MIPS uCompiler from KentuckY. */ #include #include #include "cgic.h" int haveinput = 0; char *prelab = "L"; int callerreg, calleereg; int scope = 0; int labnum = 0; /* next compiler-generated label */ int lexsym; int beginlab, endlab; /* for function begin/end code */ int gpoffset, fpoffset; /* for globals/locals */ int isleaf; /* is this a leaf procedure? */ int linestart = 0; /* start of current line */ #define DATABASE 0x10000000 #define INT 'a' #define IF 'b' #define ELSE 'c' #define WHILE 'd' #define RETURN 'e' #define FUNC 'f' #define WORD 'g' #define NUM 'h' #define DO 'i' #define VAR 'j' #define AFP 'k' #define ASP 'l' #define AGP 'm' #define SHORT 'n' #define CHAR 'o' #define RETVAL 'p' #define MULBY4 'q' #define MULBY2 'r' #define STRING 's' #define FOR 't' #define GOTO 'u' #define TARGET 'v' #define EQ 'A' #define NE 'B' #define GE 'C' #define LE 'D' #define SL 'E' #define PP 'F' #define MM 'G' #define OE 'H' #define XE 'I' #define AE 'J' #define PE 'K' #define ME 'L' #define TE 'M' #define DE 'N' #define RE 'O' #define OO 'P' #define AA 'Q' #define NEG 'R' #define SR 'S' #define MYEOF 'Z' #define MAXINPUT (1024*1024) char input[MAXINPUT]; int eof; int ipos; char *myname; /* name of this command */ int nextt; /* next token */ int lexnum; /* lexical number value */ int lexstr; /* lexical string ipos */ int lineno = 1; /* current line number */ #define STACKSIZE 64 int objsize[STACKSIZE]; int sp = 0; int highwater = 0; #define sym struct _sym sym { int ipos; int type; int scope; int base; int size; int dim; } symtab[513]; /* symbol table */ int symsp = 0; void expr(void); void decl(void); /* Reporting stuff... */ void html0(void) { register int i; cgiHeaderContentType("text/html"); fprintf(cgiOut, "\n" "\n" "EE380 MUCKY (MIPS uCompiler from KY)\n" "\n" "\n" "

EE380 MUCKY (MIPS uCompiler from KY)

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\n" "The C program that generated this page was written by\n" "Hank Dietz\n" "using the CGIC\n" "library to implement the CGI interface.\n" "

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\n" " $\"EE380\"\n"$ Computer Organization and Design.\n" "\n" "\n"); } int isnamechar(register int t) { return(((t >= '0') && (t <= '9')) || ((t >= 'A') && (t <= 'Z')) || ((t >= 'a') && (t <= 'z')) || (t == '_')); } char * namestring(register int ipos) { static char name[256]; register int i = 0; while (isnamechar(name[i] = input[ipos+i])) ++i; name[i] = 0; return(&(name[0])); } warn(fmt, a, b, c) char *fmt; int a, b, c; { fprintf(cgiOut, "#line %d: ", lineno); fprintf(cgiOut, fmt, a, b, c); fprintf(cgiOut, "\n"); } error(fmt, a, b, c) char *fmt; int a, b, c; { warn(fmt, a, b, c); fprintf(cgiOut, "#compilation terminated on this error\n" "\n" "

\n" ); html1(); exit(0); } /* Code generation stuff */ void incsp(void) { ++sp; } void decsp(void) { --sp; } #define prstr(s) pr(s, (sizeof(s)-1)) #define prop(s) { prtab(); prstr(s); prtab(); } void prchar(register int c) { putchar(c); } void prtab(void) { prchar('\t'); } void prcomma(void) { prchar(','); } void prnewline(void) { prchar('\n'); } void pr(register char *s, register int len) { while (--len >= 0) { prchar(*s); ++s; } } enum { ZERO, AT, V0, V1, A0, A1, A2, A3, T0, T1, T2, T3, T4, T5, T6, T7, S0, S1, S2, S3, S4, S5, S6, S7, T8, T9, K0, K1, GP, SP, FP, RA }; #define TOS (T0 + (sp-1)) #define NOS (T0 + (sp-2)) #define TMP (T0 + sp) char *regname[32] = { "0", "at", "v0", "v1", "a0", "a1", "a2", "a3", "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7", "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7", "t8", "t9", "k0", "k1", "gp", "sp", "fp", "ra" }; void prreg(register int r) { register char *s = regname[r]; prchar('$'); while (*s) { prchar(*s); ++s; } } void prrt(register int r) { prreg(r); } void prrs(register int r) { prreg(r); } void prrd(register int r) { prreg(r); } void primmed(register int r) { fprintf(cgiOut, "%d", r); } void prnum(register int n) { fprintf(cgiOut, "%d", n); } void mips_immed(register int rt, register int rs, register int immed) { prrt(rt); prcomma(); prrs(rs); prcomma(); primmed(immed); prnewline(); } void mips_offset(register int rt, register int rs, register int immed) { prrt(rt); prcomma(); prrs(rs); prcomma(); prchar('_'); prnum(immed); prnewline(); } void mips_3reg(register int rd, register int rs, register int rt) { prrt(rd); prcomma(); prrs(rs); prcomma(); prrs(rt); prnewline(); } void mips_ls(register int rt, register int immed, register int rs) { prrt(rt); prcomma(); primmed(immed); prchar('('); prrs(rs); prchar(')'); prnewline(); } void mips_lui(register int rt, register int immed) { prop("lui"); prrs(rt); prcomma(); primmed(immed); prnewline(); } void mips_addi(register int rt, register int rs, register int immed) { prop("addi"); mips_immed(rt, rs, immed); } void mips_ori(register int rt, register int rs, register int immed) { prop("ori"); mips_immed(rt, rs, immed); } void mips_xori(register int rt, register int rs, register int immed) { prop("xori"); mips_immed(rt, rs, immed); } void mips_beq(register int rt, register int rs, register int immed) { prop("beq"); mips_offset(rt, rs, immed); } void mips_bne(register int rt, register int rs, register int immed) { prop("bne"); mips_offset(rt, rs, immed); } void mips_jr(register int r) { prop("jr"); prreg(r); prnewline(); } void mips_space(register int n) { prstr("\t.space\t"); prnum(n); prnewline(); } void mips_or(register int rd, register int rs, register int rt) { prop("or"); mips_3reg(rd, rs, rt); } void mips_xor(register int rd, register int rs, register int rt) { prop("xor"); mips_3reg(rd, rs, rt); } void mips_and(register int rd, register int rs, register int rt) { prop("and"); mips_3reg(rd, rs, rt); } void mips_addu(register int rd, register int rs, register int rt) { prop("addu"); mips_3reg(rd, rs, rt); } void mips_subu(register int rd, register int rs, register int rt) { prop("subu"); mips_3reg(rd, rs, rt); } void mips_slt(register int rd, register int rs, register int rt) { prop("slt"); mips_3reg(rd, rs, rt); } void mips_sltu(register int rd, register int rs, register int rt) { prop("sltu"); mips_3reg(rd, rs, rt); } void mips_sllv(register int rd, register int rs, register int rt) { prop("sllv"); mips_3reg(rd, rs, rt); } void mips_srav(register int rd, register int rs, register int rt) { prop("srav"); mips_3reg(rd, rs, rt); } void mips_sw(register int rt, register int immed, register int rs) { prop("sw"); mips_ls(rt, immed, rs); } void mips_sh(register int rt, register int immed, register int rs) { prop("sh"); mips_ls(rt, immed, rs); } void mips_sb(register int rt, register int immed, register int rs) { prop("sb"); mips_ls(rt, immed, rs); } void mips_lw(register int rt, register int immed, register int rs) { prop("lw"); mips_ls(rt, immed, rs); } void mips_lh(register int rt, register int immed, register int rs) { prop("lh"); mips_ls(rt, immed, rs); } void mips_lb(register int rt, register int immed, register int rs) { prop("lb"); mips_ls(rt, immed, rs); } void mips_text(void) { prstr("\t.text\n"); } void mips_data(int n) { prstr("\t.data\t"); prnum(n); prchar('\n'); } void mips_j(register char *s) { prop("j"); while (*s) { prchar(*s); ++s; } prnewline(); } void mips_j_(register int n) { prop("j"); prchar('_'); prnum(n); prnewline(); } void mips_jal_(register char *s) { prop("jal"); prchar('_'); while (*s) { prchar(*s); ++s; } prnewline(); } void mips_syscall(void) { prstr("\tsyscall\n"); } void mips_globl(register char *s) { prstr("\t.globl\t"); while (*s) { prchar(*s); ++s; } prnewline(); } void mips_globl_(register char *s) { prstr("\t.globl\t_"); while (*s) { prchar(*s); ++s; } prnewline(); } void mips_label(register char *s) { while (*s) { prchar(*s); ++s; } prstr(":\n"); } void mips_label_(register int n) { prchar('_'); prnum(n); prstr(":\n"); } void mips_prelabel(register char *s) { prchar('_'); while (*s) { prchar(*s); ++s; } prstr(":\n"); } void pushnum(register int n) { incsp(); /* Try to optimize immediate handling... ori immediate doesn't sign extend, addi immediate does */ if ((n & 0xffff8000) == 0xffff8000) { mips_addi(TOS, 0, n); } else if ((n & 0xffff0000) == 0) { mips_ori(TOS, 0, n); } else if ((n & 0x0000ffff) == 0) { mips_lui(TOS, ((n >> 16) & 0xffff)); } else { mips_lui(TOS, ((n >> 16) & 0xffff)); mips_ori(TOS, TOS, (n & 0xffff)); } objsize[sp-1] = 0; } void pushgpoff(register int off) { incsp(); mips_addi(TOS, GP, off); objsize[sp-1] = 0; } void pushfpoff(register int off) { incsp(); mips_addi(TOS, FP, off); objsize[sp-1] = 0; } void pushdup(void) { incsp(); mips_or(TOS, NOS, 0); objsize[sp-1] = objsize[sp-2]; } void pusharg(register int argno) { incsp(); mips_or(TOS, (A0 + argno), 0); objsize[sp-1] = 0; } void lval(register int size) { objsize[sp-1] = size; } void loadtos(void) { /* Need both TOS loaded from memory? */ switch (objsize[sp-1]) { case 0: return; case 1: mips_lb(TOS, 0, TOS); break; case 2: mips_lh(TOS, 0, TOS); break; case 4: mips_lw(TOS, 0, TOS); break; default: error("cannot load %d-byte object", objsize[sp-1]); } objsize[sp-1] = 0; } void loadnostos(void) { /* Need either NOS or TOS loaded from memory? */ decsp(); loadtos(); incsp(); loadtos(); } void loadnos(void) { /* Need NOS loaded from memory? */ decsp(); loadtos(); incsp(); } void setarg(register int argno) { loadtos(); mips_or((A0 + argno), TOS, 0); decsp(); } void pushop(register int op) { switch (op) { case NEG: loadtos(); mips_subu(TOS, 0, TOS); break; case '!': loadtos(); mips_sltu(TOS, 0, TOS); break; case '~': loadtos(); mips_xori(TOS, TOS, -1); break; case MULBY4: loadtos(); mips_addu(TOS, TOS, TOS); mips_addu(TOS, TOS, TOS); break; case MULBY2: loadtos(); mips_addu(TOS, TOS, TOS); break; case AFP: loadtos(); mips_addu(TOS, TOS, FP); break; case ASP: loadtos(); mips_addu(TOS, TOS, SP); break; case AGP: loadtos(); mips_addu(TOS, TOS, GP); break; case RETVAL: loadtos(); mips_or(V0, TOS, 0); decsp(); break; case '+': loadnostos(); mips_addu(NOS, NOS, TOS); decsp(); break; case '-': loadnostos(); mips_subu(NOS, NOS, TOS); decsp(); break; case SL: loadnostos(); mips_sllv(NOS, NOS, TOS); decsp(); break; case SR: loadnostos(); mips_srav(NOS, NOS, TOS); decsp(); break; case LE: loadnostos(); mips_slt(TMP, TOS, NOS); /* GT */ mips_slt(NOS, NOS, TOS); /* LT */ mips_or(TMP, NOS, TMP); /* NE */ mips_xori(TMP, TMP, 1); /* EQ */ mips_or(NOS, NOS, TMP); decsp(); break; case '<': loadnostos(); mips_slt(NOS, NOS, TOS); decsp(); break; case GE: loadnostos(); mips_slt(TMP, NOS, TOS); /* LT */ mips_slt(NOS, TOS, NOS); /* GT */ mips_or(TMP, NOS, TMP); /* NE */ mips_xori(TMP, TMP, 1); /* EQ */ mips_or(NOS, NOS, TMP); decsp(); break; case '>': loadnostos(); mips_slt(NOS, TOS, NOS); decsp(); break; case EQ: loadnostos(); mips_xor(NOS, NOS, TOS); /* NE */ mips_sltu(NOS, 0, NOS); mips_xori(TMP, TMP, 1); decsp(); break; case NE: loadnostos(); mips_xor(NOS, NOS, TOS); /* NE */ mips_sltu(NOS, 0, NOS); decsp(); break; case '&': loadnostos(); mips_and(NOS, NOS, TOS); decsp(); break; case '^': loadnostos(); mips_xor(NOS, NOS, TOS); decsp(); break; case '|': loadnostos(); mips_or(NOS, NOS, TOS); decsp(); break; default: error("cannot yet handle op (%c)", op); } } void store(register int prop) { /* Store TOS into NOS */ loadtos(); switch (objsize[sp-2]) { case 0: error("lvalue required"); case 1: mips_sb(TOS, 0, NOS); break; case 2: mips_sh(TOS, 0, NOS); break; case 4: mips_sw(TOS, 0, NOS); break; default: error("cannot store %d-byte object", objsize[sp-2]); } if (prop) { /* Just in case we have x=(y=z)... Strictly speaking, x=(y=z) sets x=((typeof(y))z), but I don't think we have to be that precise here */ mips_or(NOS, TOS, 0); decsp(); objsize[sp-1] = 0; } else { decsp(); decsp(); } } void jump(register int a) { /* Compiler-generated labels are nearby... so use a branch instead */ mips_j_(a); } void jumpf(register int a) { loadtos(); mips_beq(TOS, 0, a); decsp(); } void jumpt(register int a) { loadtos(); mips_bne(TOS, 0, a); decsp(); } void label(register int a) { mips_label_(a); } void ghoto(register char *s) { mips_j(s); } void target(register char *s) { mips_prelabel(s); } void startup(void) { mips_text(); mips_globl("main"); mips_globl_("exit"); mips_globl_("print_int"); mips_globl_("print_string"); mips_label("main"); mips_lui(GP, ((DATABASE >> 16) & 0xffff)); mips_jal_("main"); mips_label("_exit"); mips_ori(V0, 0, 10); mips_syscall(); mips_label("_print_int"); mips_ori(V0, 0, 1); mips_syscall(); mips_jr(RA); mips_label("_print_string"); mips_ori(V0, 0, 4); mips_syscall(); mips_jr(RA); } void call(register int mysym) { register char *n = namestring(symtab[mysym].ipos); register int i; /* We're not a leaf procedure.... */ isleaf = 0; /* Save registers */ if (sp > 0) { mips_addi(SP, SP, -4*(TOS-T0+1)); for (i=T0; i<=TOS; ++i) { mips_sw(i, -4*(i-T0), SP); } } /* Call the function */ mips_jal_(n); /* Restore registers */ if (sp > 0) { for (i=T0; i<=TOS; ++i) { mips_lw(i, -4*(i-T0), SP); } mips_addi(SP, SP, 4*(TOS-T0+1)); } /* Copy the return value to someplace useful */ incsp(); mips_or(TOS, V0, 0); objsize[sp-1] = 0; } void funcbegin(register int mysym) { register char *n = namestring(symtab[mysym].ipos); fpoffset = -4; highwater = 0; beginlab = labnum++; endlab = labnum++; /* For now, functions always return an int */ symtab[mysym].type = FUNC; symtab[mysym].base = -4; symtab[mysym].size = 4; symtab[mysym].dim = 1; ++scope; /* So far, we could be a leaf procedure.... */ isleaf = 1; mips_text(); mips_globl_(n); label(beginlab); } void funcend(register int mysym) { register char *n = namestring(symtab[mysym].ipos); /* For now, functions always return an int */ symtab[mysym].type = FUNC; symtab[mysym].base = -4; symtab[mysym].size = 4; symtab[mysym].dim = 1; /* Now the common end return code... but special-case leaf procedures */ if ((isleaf == 0) || (highwater != 0)) { /* Not a leaf; do full stack frame... Stack looks like: [old fp] [ret addr] [locals] we do this here because that's when we know how much space we need for locals... */ /* Add space for fp and return address */ highwater += 8; label(endlab); mips_lw(RA, -4, FP); /* ra = fp[-4] */ mips_or(SP, FP, 0); /* sp = fp */ mips_lw(FP, 0, SP); /* fp = old fp */ mips_addi(SP, SP, 4); /* sp = old sp */ mips_jr(RA); /* return */ mips_prelabel(n); mips_addi(SP, SP, -highwater); /* sp -= highwater */ mips_sw(FP, highwater-4, SP); /* sp[highwater-4] = fp */ mips_addi(FP, SP, highwater-4); /* fp = &(sp[highwater-4]) */ mips_sw(RA, -4, FP); /* fp[-4] = ra */ } else { /* A leaf without locals... */ label(endlab); mips_jr(RA); /* return */ mips_prelabel(n); } jump(beginlab); --scope; } void def(register int mysym) { register char *n = namestring(symtab[mysym].ipos); register int asize; /* Objects always are 4-byte word alligned... */ asize = (((symtab[mysym].size * symtab[mysym].dim) + 3) & ~3); symtab[mysym].type = VAR; if ((symtab[mysym].scope = scope) == 0) { /* Offset from $gp */ symtab[mysym].base = gpoffset; gpoffset += asize; mips_data(DATABASE + symtab[mysym].base); mips_globl(n); mips_label(n); mips_space(asize); } else { /* Offset from $fp */ fpoffset -= asize; symtab[mysym].base = fpoffset; if (highwater < -fpoffset) { highwater = -fpoffset; } } } int defstr(register int spos) { register int num; register int asize; mips_data(DATABASE + gpoffset); asize = 0; while (input[++spos] != '"') { if (++asize > 1) { if ((asize & 7) == 1) { prnewline(); prstr("\t.byte\t"); } else { prstr(", "); } } else { prstr("\t.byte\t"); } if (input[spos] == '\\') { switch (input[++spos]) { case 't': fprintf(cgiOut, "%3d", '\t'); break; case 'n': fprintf(cgiOut, "%3d", '\n'); break; case 'r': fprintf(cgiOut, "%3d", '\r'); break; case 'b': fprintf(cgiOut, "%3d", '\b'); break; case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': num = (input[spos] - '0'); while ((input[spos+1] >= '0') && (input[spos+1] <= '7')) { num *= 8; num += (input[++spos] - '0'); } fprintf(cgiOut, "%3d", num); break; default: fprintf(cgiOut, "%3d", input[spos]); } } else { fprintf(cgiOut, "%3d", input[spos]); } } ++asize; fprintf(cgiOut, "\n" "\t.byte\t0\n" "\n" "\t.text\n"); /* Make size a multiple of 4 bytes for allignment... */ asize = ((asize + 3) & ~3); gpoffset += asize; return(DATABASE + gpoffset - asize); } /* Lexicals... */ int prefixis(register char *p) { register int i = 0; for (;;) { register int t = p[i]; if (t == 0) { ipos += i; return(1); } if (t != input[ipos + i]) { return(0); } ++i; } } int nameis(register char *p) { register int i = 0; for (;;) { register int t = p[i]; if (!isnamechar(t)) { if (!isnamechar(input[ipos + i])) { ipos += i; return(1); } else { return(0); } } if (t != input[ipos + i]) { return(0); } ++i; } } int lexhelp(void) { register int base = 10; again: /* Recognize all the non-name stuff */ switch (input[ipos]) { /* Handle whitespace, etc. */ case '\n': #ifdef NOTNOW fprintf(cgiOut, "#line\t%d:\t", lineno); while (linestart <= ipos) { putchar(input[linestart]); ++linestart; } #endif ++lineno; /* Fall through... */ case ' ': case '\t': case '\r': ++ipos; goto again; case '\000': return(MYEOF); /* Handling of punctuation... */ case '=': case '!': case '<': case '>': case '+': case '-': case '~': case '*': case '/': case '%': case '|': case '&': if (prefixis("==")) return(EQ); if (prefixis("!=")) return(NE); if (prefixis(">=")) return(GE); if (prefixis("<=")) return(LE); if (prefixis("<<")) return(SL); if (prefixis("++")) return(PP); if (prefixis("--")) return(MM); if (prefixis("|=")) return(OE); if (prefixis("^=")) return(XE); if (prefixis("&=")) return(AE); if (prefixis("+=")) return(PE); if (prefixis("-=")) return(ME); if (prefixis("*=")) return(TE); if (prefixis("/=")) return(DE); if (prefixis("%=")) return(RE); if (prefixis("||")) return(OO); if (prefixis("&&")) return(AA); /* Fall through... */ case ',': case '?': case ':': case '{': case '}': case '^': case '[': case ']': case '(': case ')': case ';': return(input[ipos++]); /* Handling of numbers... */ case '0': base = 8; switch (input[++ipos]) { case 'b': base = 2; ++ipos; break; case 'x': base = 16; ++ipos; break; } case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': lexnum = 0; for (;;) { register int t = input[ipos]; if ((t >= '0') && (t <= '9')) { t -= '0'; } else if (((t |= ('a'-'A')) >= 'a') && (t <= 'f')) { t -= ('a' - 10); } else { return(NUM); } if (t >= base) { error("invalid digit"); } lexnum = (lexnum * base) + t; ++ipos; } case '\'': ++ipos; lexnum = input[ipos++]; if (input[ipos++] != '\'') { error("ill-formed character constant"); } return(NUM); case '"': lexstr = ipos; do { ++ipos; if (input[ipos] == 0) { error("string ends in end of input"); } } while ((input[ipos] != '"') || (input[ipos-1] == '\\')); ++ipos; return(STRING); default: if (!isnamechar(input[ipos])) { error("illegal character 0x%02x (%c)", input[ipos], input[ipos]); ++ipos; goto again; } } /* Must be a name... */ if (nameis("int")) return(INT); if (nameis("short")) return(SHORT); if (nameis("char")) return(CHAR); if (nameis("if")) return(IF); if (nameis("else")) return(ELSE); if (nameis("while")) return(WHILE); if (nameis("do")) return(DO); if (nameis("return")) return(RETURN); if (nameis("for")) return(FOR); if (nameis("goto")) return(GOTO); /* Find it in the symbol table */ for (lexsym=(symsp-1); lexsym>=0; --lexsym) { if (nameis(&(input[symtab[lexsym].ipos]))) { return(symtab[lexsym].type); } } /* Make a new symbol table entry */ symtab[lexsym = (symsp++)].ipos = ipos; nameis(&(input[ipos])); return(symtab[lexsym].type = ((input[ipos] == ':') ? TARGET : WORD)); } int lex(void) { nextt = lexhelp(); return(nextt); } int match(register int t) { if (nextt == t) { lex(); return(1); } return(0); } int assume(register int t) { if (!match(t)) { warn("missing %c assumed", t); return(0); } return(1); } /* Parsing... */ void memaddr(register int mysym) { /* Base address */ if (symtab[mysym].scope != 0) { pushfpoff(symtab[mysym].base); } else { pushgpoff(symtab[mysym].base); } lex(); if (match('[')) { /* subscripted */ expr(); /* Index value */ assume(']'); /* Multiply by element size */ switch (symtab[mysym].size) { case 2: pushop(MULBY2); break; case 1: break; default: pushop(MULBY4); } pushop('+'); /* Add to base address */ } lval(symtab[mysym].size); } void unary(void) { register int mysym; register int args = 0; switch (nextt) { case PP: lex(); unary(); pushdup(); pushnum(1); pushop('+'); store(1); break; case MM: lex(); unary(); pushdup(); pushnum(-1); pushop('+'); store(1); break; case '(': lex(); expr(); assume(')'); break; case '-': lex(); unary(); pushop(NEG); break; case '!': lex(); unary(); pushop('!'); break; case '~': lex(); unary(); pushop('~'); break; case VAR: memaddr(lexsym); break; case WORD: symtab[lexsym].type = FUNC; symtab[lexsym].base = 0; /* Fall through... */ case FUNC: /* Function call */ mysym = lexsym; lex(); if (!match('(')) { error("undefined variable %s", namestring(symtab[mysym].ipos)); } args = 0; while (!match(')')) { expr(); setarg(args++); match(','); } call(mysym); break; case NUM: pushnum(lexnum); lex(); break; case STRING: pushnum(defstr(lexstr)); lex(); break; default: error("malformed expression"); } /* Suffix operation */ switch (nextt) { case PP: lex(); pushdup(); loadnos(); pushdup(); pushnum(1); pushop('+'); store(0); break; case MM: lex(); pushdup(); loadnos(); pushdup(); pushnum(1); pushop('+'); store(0); break; } } void mul(void) { register int t; unary(); for (;;) { switch (nextt) { case '*': case '/': case '%': t = nextt; lex(); unary(); pushop(t); default: return; } } } void add(void) { register int t; mul(); for (;;) { switch (nextt) { case '+': case '-': t = nextt; lex(); mul(); pushop(t); default: return; } } } void slsr(void) { register int t; add(); for (;;) { switch (nextt) { case SL: case SR: t = nextt; lex(); add(); pushop(t); default: return; } } } void leltgegt(void) { register int t; slsr(); for (;;) { switch (nextt) { case LE: case '<': case GE: case '>': t = nextt; lex(); slsr(); pushop(t); default: return; } } } void eqne(void) { register int t; leltgegt(); for (;;) { switch (nextt) { case EQ: case NE: t = nextt; lex(); leltgegt(); pushop(t); default: return; } } } void and(void) { eqne(); while (match('&')) { eqne(); pushop('&'); } } void xor(void) { and(); while (match('^')) { and(); pushop('^'); } } void or(void) { xor(); while (match('|')) { xor(); pushop('|'); } } void andand(void) { register int lab; or(); if (match(AA)) { lab = labnum; labnum += 3; do { jumpf(lab); ++labnum; or(); } while (match(AA)); jumpt(lab+1); label(lab); pushnum(0); decsp(); jump(lab+2); label(lab+1); pushnum(1); label(lab+2); } } void oror(void) { register int lab; andand(); if (match(OO)) { lab = labnum; labnum += 3; do { jumpt(lab); ++labnum; andand(); } while (match(OO)); jumpf(lab+1); label(lab); pushnum(1); decsp(); jump(lab+2); label(lab+1); pushnum(0); label(lab+2); } } void cond(void) { register int lab; oror(); if (match('?')) { lab = labnum; labnum += 2; jumpf(lab); expr(); decsp(); jump(lab+1); assume(':'); label(lab); cond(); label(lab+1); } } void assign(void) { register int t; cond(); switch (nextt) { case '=': lex(); assign(); store(1); break; case OE: lex(); pushdup(); assign(); pushop('|'); store(1); break; case XE: lex(); pushdup(); assign(); pushop('^'); store(1); break; case AE: lex(); pushdup(); assign(); pushop('&'); store(1); break; case PE: lex(); pushdup(); assign(); pushop('+'); store(1); break; case ME: lex(); pushdup(); assign(); pushop('-'); store(1); break; case TE: lex(); pushdup(); assign(); pushop('*'); store(1); break; case DE: lex(); pushdup(); assign(); pushop('/'); store(1); break; case RE: lex(); pushdup(); assign(); pushop('%'); store(1); break; } } void expr(void) { assign(); while (match(',')) { decsp(); assign(); } } int newsym(void) { /* Create a new symbol table entry */ register int mysym; switch (nextt) { case WORD: mysym = lexsym; break; case VAR: case FUNC: if (scope == symtab[lexsym].scope) { warn("redefinition of identifier"); } symtab[mysym = (symsp++)].ipos = symtab[lexsym].ipos; break; default: error("ill-formed declaration of %s", namestring(symtab[mysym].ipos)); } lex(); symtab[mysym].scope = scope; return(mysym); } void stat(void) { register int scopesymsp, scopeoffset; register int lab; register int mysym; switch (nextt) { case '{': lex(); scopesymsp = symsp; scopeoffset = fpoffset; decl(); while (!match('}')) { stat(); } symsp = scopesymsp; fpoffset = scopeoffset; break; case IF: lex(); expr(); lab = labnum; labnum += 2; jumpf(lab); stat(); if (nextt == ELSE) { lex(); jump(lab+1); label(lab); stat(); label(lab+1); } else { label(lab); } break; case FOR: lex(); assume('('); lab = labnum; labnum += 4; if (!match(';')) { expr(); decsp(); match(';'); } label(lab); if (!match(';')) { expr(); jumpf(lab+1); match(';'); } jump(lab+2); label(lab+3); if (!match(')')) { expr(); decsp(); match(')'); } jump(lab); label(lab+2); stat(); jump(lab+3); label(lab+1); break; case WHILE: lex(); lab = labnum; labnum += 2; label(lab); expr(); jumpf(lab+1); stat(); jump(lab); label(lab+1); break; case DO: lex(); lab = (labnum++); label(lab); stat(); if (match(WHILE)) { error("do missing while"); } expr(); assume(';'); jumpt(lab); break; case RETURN: lex(); if (nextt != ';') { expr(); pushop(RETVAL); } match(';'); break; case GOTO: lex(); ghoto(namestring(symtab[newsym()].ipos)); --symsp; break; case TARGET: target(namestring(symtab[symsp-1].ipos)); --symsp; lex(); assume(':'); break; case ';': lex(); break; default: expr(); assume(';'); decsp(); break; } } int ctype(void) { switch (nextt) { case INT: lex(); return(4); case SHORT: lex(); return(2); case CHAR: lex(); return(1); case WORD: if (scope == 0) { warn("missing int keyword assumed"); return(4); } } return(0); } void decl(void) { register int scopeoffset; register int mysym, argsym; register int size, args; while ((size = ctype()) != 0) { moredecls: mysym = newsym(); symtab[mysym].size = size; switch (nextt) { case '[': lex(); symtab[mysym].type = VAR; if (nextt != NUM) { error("non-constant dim for %s", namestring(symtab[mysym].ipos)); } symtab[mysym].dim = lexnum; def(mysym); lex(); assume(']'); if (match(',')) goto moredecls; assume(';'); break; case ';': symtab[mysym].dim = 1; def(mysym); lex(); break; case ',': symtab[mysym].dim = 1; def(mysym); lex(); goto moredecls; case '(': if (scope != 0) { error("nested definition of function %s", namestring(symtab[mysym].ipos)); } lex(); funcbegin(mysym); args = 0; while ((size = ctype()) != 0) { argsym = newsym(); symtab[argsym].type = VAR; symtab[argsym].size = 4; symtab[argsym].dim = 1; def(argsym); /* Copy arg from register to local */ pushnum(symtab[argsym].base); pushop(AFP); lval(4); pusharg(args++); store(0); if (match('[')) { error("array arguments currently not supported"); } match(','); } if (!match(')')) { warn("missing ) in function argument declaration"); } stat(); funcend(mysym); break; default: error("declaration missing ; or argument list"); } } } int cgiMain(void) { input[0] = 0; cgiFormInteger("haveinput", &haveinput, 0); cgiFormString("input", &(input[0]), (sizeof(input)-1)); html0(); if (haveinput) { fprintf(cgiOut, "The following MIPS assembly code (for spim) was generated:\n" "

\n"
			);
		eof = 0;
		while (input[eof]) ++eof;
		ipos = 0;
		nextt = lex();
		startup();
		decl();
		fprintf(cgiOut,
"

\n" ); } html1(); }