From 5757079cf72d426144f3f3bc7ff6e2c3bccab50d Mon Sep 17 00:00:00 2001 From: lemon Date: Tue, 13 Jun 2023 20:08:24 +0200 Subject: rename parse.c -> c.c --- c.c | 2626 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 2626 insertions(+) create mode 100644 c.c (limited to 'c.c') diff --git a/c.c b/c.c new file mode 100644 index 0000000..022ef8a --- /dev/null +++ b/c.c @@ -0,0 +1,2626 @@ +#include "parse.h" +#include "common.h" +#include "ir.h" + +static struct arena *tlarena; + +#define peek(Pr,Tk) lexpeek(Pr,Tk) + +void +initparser(struct parser *pr, const char *file) +{ + const char *error; + struct memfile *f; + + memset(pr, 0, sizeof *pr); + pr->fileid = openfile(&error, &f, file); + if (pr->fileid < 0) + fatal(NULL, "Cannot open %'s: %s", file, error); + pr->dat = f->p; + pr->ndat = f->n; +} + +static bool +match(struct parser *pr, struct token *tk, enum toktag t) +{ + if (peek(pr, NULL) == t) { + lex(pr, tk); + return 1; + } + return 0; +} + +static bool +expect(struct parser *pr, enum toktag t, const char *s) +{ + struct token tk; + if (!match(pr, &tk, t)) { + peek(pr, &tk); + if (aisprint(t)) tk.span.ex.len = tk.span.sl.len = 1; + error(&tk.span, "expected %'tt%s%s", t, s?" ":"",s ? s : ""); + return 0; + } + return 1; +} + +static struct token +expectdie(struct parser *pr, enum toktag t, const char *s) +{ + struct token tk; + if (!match(pr, &tk, t)) + fatal(&tk.span, "expected %'tt%s%s", t, s?" ":"",s ? s : ""); + return tk; +} + +enum declkind { + DTOPLEVEL, + DFUNCPARAM, + DFUNCVAR, + DFIELD, + DCASTEXPR, +}; + +struct decl { + union type ty; + uchar scls; + uchar qual : 2; + uchar isenum : 1; + struct span span; + const char *name; + union { + struct { ushort align; int id; }; + vlong value; + }; +}; + +struct declstate { + enum declkind kind; + union type base; + enum storageclass scls; + enum qualifier qual; + uint align; + bool more, varini, funcdef, tagdecl; + const char **pnames; + struct span *pspans; +}; + +static struct decl pdecl(struct declstate *st, struct parser *pr); +static struct decl *finddecl(struct parser *pr, const char *name); + +static bool +isdecltok(struct parser *pr) +{ + struct decl *decl; + struct token tk; + switch (peek(pr, &tk)) { + case TKWsigned: case TKWunsigned: case TKWshort: case TKWlong: + case TKWint: case TKWchar: case TKW_Bool: case TKWauto: + case TKWstruct: case TKWunion: case TKWenum: case TKWtypedef: + case TKWextern: case TKWstatic: case TKWinline: case TKW_Noreturn: + case TKWconst: case TKWvolatile: case TKWvoid: case TKWfloat: + case TKWdouble: case TKWregister: + return 1; + case TKIDENT: + return (decl = finddecl(pr, tk.s)) && decl->scls == SCTYPEDEF; + } + return 0; +} + + +/*******/ +/* ENV */ +/*******/ + +static struct decl envdeclsbuf[1<<10]; +static vec_of(struct decl) envdecls = VINIT(envdeclsbuf, arraylength(envdeclsbuf)); +struct tagged { + union type ty; + struct span span; +}; +static struct tagged envtaggedbuf[1<<10]; +static vec_of(struct tagged) envtagged = VINIT(envtaggedbuf, arraylength(envtaggedbuf)); +struct env { + struct env *up; + /* list of decls is implicitly envdecls[decl..ndecl] */ + ushort decl, ndecl; + /* ditto for envtagged[] */ + ushort tagged, ntagged; +}; +static struct env toplevel; + +static void +envdown(struct parser *pr, struct env *e) +{ + assert(pr->env->decl + pr->env->ndecl == envdecls.n); + assert(pr->env->tagged + pr->env->ntagged == envtagged.n); + e->decl = envdecls.n; + e->tagged = envtagged.n; + e->ndecl = e->ntagged = 0; + e->up = pr->env; + pr->env = e; +} + +static void +envup(struct parser *pr) +{ + struct env *env = pr->env; + assert(env->decl + env->ndecl == envdecls.n); + envdecls.n -= env->ndecl; + envtagged.n -= env->ntagged; + assert(env->up); + pr->env = env->up; +} + +static struct decl * +envadddecl(struct env *env, const struct decl *d) +{ + assert(env->decl + env->ndecl == envdecls.n); + vpush(&envdecls, *d); + ++env->ndecl; + return &envdecls.p[envdecls.n - 1]; +} + +/* iters in reversed order of insertion (most to least recent) */ +/* use like so: for (d = NULL; enviterdecl(&d, env);) ... */ +static inline bool +enviterdecl(struct decl **d, struct env *env) +{ + if (!env->ndecl) return 0; + if (!*d) *d = &envdecls.p[env->decl + env->ndecl - 1]; + else if (*d == &envdecls.p[env->decl]) return 0; + else --*d; + return 1; +} + +static struct tagged * +envaddtagged(struct env *env, union type ty, const struct span *span) +{ + struct tagged tagged = { ty, *span }; + assert(env->tagged + env->ntagged == envtagged.n); + vpush(&envtagged, tagged); + ++env->ntagged; + return &envtagged.p[envtagged.n - 1]; +} + +static inline bool +envitertagged(struct tagged **l, struct env *env) +{ + if (!env->ntagged) return 0; + if (!*l) *l = &envtagged.p[env->tagged + env->ntagged - 1]; + else if (*l == &envtagged.p[env->tagged]) return 0; + else --*l; + return 1; +} + +static bool +redeclarationok(const struct decl *old, const struct decl *new) +{ + if (old->scls != new->scls) return 0; + switch (old->scls) { + case SCTYPEDEF: + return old->ty.bits == new->ty.bits; + } + return 0; +} + +static struct decl * +putdecl(struct parser *pr, const struct decl *decl) +{ + struct decl *l; + for (l = NULL; enviterdecl(&l, pr->env);) { + if (decl->name == l->name && !redeclarationok(l, decl)) { + error(&decl->span, "incompatible redeclaration of '%s'", decl->name); + note(&l->span, "previously declared here"); + } + } + l = envadddecl(pr->env, decl); + return l; +} + +static struct decl * +finddecl(struct parser *pr, const char *name) +{ + struct env *e; + struct decl *l; + assert(name); + for (e = pr->env; e; e = e->up) { + for (l = NULL; enviterdecl(&l, e);) { + if (name == l->name) + return l; + } + } + return NULL; +} + +static union type +gettagged(struct parser *pr, struct span *span, enum typetag tt, const char *name, bool dodef) +{ + struct env *e; + struct tagged *l; + struct typedata td = {0}; + assert(name); + for (e = pr->env; e; e = e->up) { + for (l = NULL; envitertagged(&l, e);) { + if (name == ttypenames[typedata[l->ty.dat].id]) { + if (dodef && e != pr->env) + goto Break2; + *span = l->span; + return l->ty; + } + } + } +Break2: + if (tt == TYENUM) + return mktype(0); + td.t = tt; + return envaddtagged(pr->env, mktagtype(name, &td), span)->ty; +} + +static union type +deftagged(struct parser *pr, struct span *span, enum typetag tt, const char *name, union type ty) +{ + struct tagged *l; + struct typedata td = {0}; + assert(name); + for (l = NULL; envitertagged(&l, pr->env);) { + if (name == ttypenames[typedata[l->ty.dat].id]) { + *span = l->span; + return l->ty; + } + } + td.t = tt; + return envaddtagged(pr->env, ty.t ? ty : mktagtype(name, &td), span)->ty; +} + +/*******************/ +/*** EXPRESSIONS ***/ +/*******************/ + +/**********************/ +/* EXPR TYPE CHECKING */ +/**********************/ + +#define iszero(ex) ((ex).t == ENUMLIT && (ex).u == 0) + +static bool +islvalue(const struct expr *ex) +{ + if (ex->t == EGETF) return islvalue(ex->sub); + return ex->t == ESYM || ex->t == EDEREF; +} + +static union type /* 6.5.2.6 default argument promotions */ +argpromote(union type t) +{ + if (isint(t)) t.t = intpromote(t.t); + else if (t.t == TYFLOAT) t.t = TYDOUBLE; + else if (t.t == TYARRAY) return mkptrtype(typechild(t), t.flag & TFCHLDQUAL); + return t; +} + +static bool +assigncheck(union type t, const struct expr *src) +{ + if (assigncompat(t, typedecay(src->ty))) return 1; + if (t.t == TYPTR && iszero(*src)) return 1; + return 0; +} + +static void +incdeccheck(enum toktag tt, const struct expr *ex, const struct span *span) +{ + if (!isscalar(ex->ty)) + error(&ex->span, "invalid operand to %tt (%ty)", tt, ex->ty); + else if (!islvalue(ex)) + error(&ex->span, "operand to %tt is not an lvalue", tt); + else if (ex->ty.t == TYPTR && isincomplete(typechild(ex->ty))) + error(span, "arithmetic on pointer to incomplete type (%ty)", ex->ty); + else if (ex->ty.t == TYPTR && typechild(ex->ty).t == TYFUNC) + error(span, "arithmetic on function pointer (%ty)", ex->ty); +} + +static bool /* 6.5.4 Cast operators */ +castcheck(union type to, const struct expr *ex) +{ + union type src = ex->ty; + if (to.t == TYVOID) return 1; + if (isagg(to)) return 0; + if (to.bits == src.bits) return 1; + if (isarith(to) && isarith(src)) return 1; + if (isint(to) && isptrcvt(src)) return 1; + if (to.t == TYPTR && isint(src)) return 1; + if (to.t == TYPTR && isptrcvt(src)) return 1; + return 0; +} + +static union type /* 6.5.2.1 Array subscripting */ +subscriptcheck(const struct expr *ex, const struct expr *rhs, const struct span *span) +{ + union type ty; + if (ex->ty.t == TYPTR || ex->ty.t == TYARRAY) { + if (isincomplete(ty = typechild(ex->ty))) { + error(span, "cannot dereference pointer to incomplete type (%ty)", ty); + ty = mktype(TYINT); + } else if (ty.t == TYFUNC) { + error(span, "subscripted value is pointer to function"); + ty = mktype(TYINT); + } + } else { + error(&ex->span, "subscripted value is not pointer-convertible (%ty)", ex->ty); + ty = mktype(TYINT); + } + if (!isint(rhs->ty)) + error(&rhs->span, "array subscript is not integer (%ty)", rhs->ty); + return ty; +} + +static void /* 6.5.3.4 The sizeof operator */ +sizeofcheck(const struct span *span, union type ty) +{ + if (isincomplete(ty)) + error(span, "cannot apply sizeof to incomplete type (%ty)", ty); + else if (ty.t == TYFUNC) + error(span, "cannot apply sizeof to function type (%ty)", ty); +} + +static bool /* 6.5.8 Relational operators */ +relationalcheck(const struct expr *a, const struct expr *b) +{ + union type t1 = a->ty, t2 = b->ty; + if (isarith(t1) && isarith(t2)) return 1; + if (isptrcvt(t1) && isptrcvt(t2)) { + t1 = typedecay(t1); + t2 = typedecay(t2); + return t1.dat == t2.dat; + } + return 0; +} + +static bool +isnullpo(const struct expr *ex) /* match '0' or '(void *) 0' */ +{ + static const union type voidptr = {{ TYPTR, .flag = TFCHLDPRIM, .child = TYVOID }}; + if (ex->t == ECAST && ex->ty.bits == voidptr.bits) + ex = ex->sub; + return iszero(*ex); +} + +static bool /* 6.5.9 Equality operators */ +equalitycheck(const struct expr *a, const struct expr *b) +{ + union type t1 = a->ty, t2 = b->ty; + if (isarith(t1) && isarith(t2)) return 1; + if (isptrcvt(t1) && isptrcvt(t2)) { + t1 = typedecay(t1); + t2 = typedecay(t2); + return t1.dat == t2.dat || typechild(t1).t == TYVOID || typechild(t2).t == TYVOID; + } + if (isptrcvt(t1) && isnullpo(b)) return 1; + return isptrcvt(t2) && isnullpo(a); +} + +static union type /* 6.5.15 Conditional operator */ +condtype(const struct expr *a, const struct expr *b) +{ + union type t1 = typedecay(a->ty), t2 = typedecay(b->ty), s1, s2; + if (isarith(t1) && isarith(t2)) return cvtarith(t1, t2); + if (t1.bits == t2.bits) return t1; + if (t1.t == TYPTR && t2.t == TYPTR) { + s1 = typechild(t1); + s2 = typechild(t2); + if (s1.bits == s2.bits || s2.t == TYVOID || s1.t == TYVOID) { + return mkptrtype(s1.t == TYVOID ? s1 : s2, (t1.flag | t2.flag) & TFCHLDQUAL); + } + } + if (t1.t == TYPTR && isnullpo(b)) return t1; + if (isnullpo(a) && t2.t == TYPTR) return t2; + return mktype(0); +} + +static void +bintypeerr(const struct span *span, enum toktag tt, union type lhs, union type rhs) +{ + error(span, "bad operands to %tt (%ty, %ty)", tt, lhs, rhs); +} + +enum binopclass { /* binary operator type-checking classes */ + BCSET = 1<<7, /* is a (compound) assignment operator? */ + BCSEQ = 1, BCADDITIVE, BCARITH, BCINT, BCSHFT, BCEQL, BCCMP, BCLOG, +}; + +/* table indexed by binary op token; + * containing precedence level, expression kind and type-checking class */ +static const struct { uchar prec, t, k; } bintab[] = { + ['*'] = {13, EMUL, BCARITH}, + ['/'] = {13, EDIV, BCARITH}, + ['%'] = {13, EREM, BCINT}, + ['+'] = {12, EADD, BCADDITIVE}, + ['-'] = {12, ESUB, BCADDITIVE}, + [TKSHL] = {11, ESHL, BCSHFT}, + [TKSHR] = {11, ESHR, BCSHFT}, + ['<'] = {10, ELTH, BCCMP}, + ['>'] = {10, EGTH, BCCMP}, + [TKLTE] = {10, ELTE, BCCMP}, + [TKGTE] = {10, EGTE, BCCMP}, + [TKEQU] = {9, EEQU, BCEQL}, + [TKNEQ] = {9, ENEQ, BCEQL}, + ['&'] = {8, EBAND, BCINT}, + ['^'] = {7, EXOR, BCINT}, + ['|'] = {6, EBIOR, BCINT}, + [TKLOGAND] = {5, ELOGAND, BCLOG}, + [TKLOGIOR] = {4, ELOGIOR, BCLOG}, + ['?'] = {3, ECOND}, /* not actually a binop (special cased) */ + ['='] = {2, ESET, BCSET}, + [TKSETADD] = {2, ESETADD, BCSET|BCADDITIVE}, [TKSETSUB] = {2, ESETSUB, BCSET|BCADDITIVE}, + [TKSETMUL] = {2, ESETMUL, BCSET|BCARITH}, [TKSETDIV] = {2, ESETDIV, BCSET|BCARITH}, + [TKSETREM] = {2, ESETREM, BCSET|BCINT}, [TKSETAND] = {2, ESETAND, BCSET|BCINT}, + [TKSETIOR] = {2, ESETIOR, BCSET|BCINT}, [TKSETXOR] = {2, ESETXOR, BCSET|BCINT}, + [TKSETSHL] = {2, ESETSHL, BCSET|BCSHFT}, [TKSETSHR] = {2, ESETSHR, BCSET|BCSHFT}, + [','] = {1, ESEQ, BCSEQ} +}; + +static union type +bintypecheck(const struct span *span, enum toktag tt, struct expr *lhs, struct expr *rhs) +{ + enum binopclass k = bintab[tt].k; + union type ty = lhs->ty; + + assert(k); + if (k & BCSET) { + if (!islvalue(lhs)) + error(&lhs->span, "left-hand-side of assignment is not an lvalue"); + else if (lhs->qual & QCONST) + error(&lhs->span, "cannot assign to const-qualified lvalue (%tq)", ty, lhs->qual); + else if (isincomplete(ty)) + error(&lhs->span, "cannot assign to incomplete type (%ty)", ty); + else if (ty.t == TYARRAY) + error(&lhs->span, "cannot assign to array type (%ty)", ty); + else if (ty.t == TYFUNC) + error(&lhs->span, "cannot assign to function designator (%ty)", lhs->ty); + } + switch (k &~ BCSET) { + case 0: + if (isagg(ty) && !(lhs->qual & QCONST) && typedata[ty.dat].anyconst) + error(&lhs->span, "cannot assign to aggregate with const-qualified member"); + if (!assigncheck(ty, rhs)) + goto Error; + break; + case BCSEQ: + ty = rhs->ty; + break; + case BCADDITIVE: + if (tt == '+' && isptrcvt(rhs->ty)) { + /* int + ptr -> ptr + int (for convenience) */ + const struct expr swaptmp = *lhs; + *lhs = *rhs; + *rhs = swaptmp; + ty = lhs->ty; + } + if (isarith(ty) && isarith(rhs->ty)) { + /* num +/- num */ + ty = cvtarith(ty, rhs->ty); + assert(ty.t); + } else if ((ty.t == TYPTR || ty.t == TYARRAY) && isint(rhs->ty)) { + /* ptr +/- int */ + union type pointee = typechild(ty); + if (isincomplete(pointee)) + error(span, "arithmetic on pointer to incomplete type (%ty)", ty); + else if (pointee.t == TYFUNC) + error(span, "arithmetic on function pointer (%ty)", ty); + ty = typedecay(ty); + } else if (tt == '-' && isptrcvt(ty) && isptrcvt(rhs->ty)) { + /* ptr - ptr */ + union type pointee1 = typechild(typedecay(ty)), + pointee2 = typechild(typedecay(rhs->ty)); + if (isincomplete(pointee1)) + error(span, "arithmetic on pointer to incomplete type (%ty)", ty); + else if (pointee1.t == TYFUNC) + error(span, "arithmetic on function pointer (%ty)", lhs->ty); + else if (pointee1.bits != pointee2.bits) { + error(span, "arithmetic on incompatible pointer types (%ty, %ty)", + ty, rhs->ty); + } + ty = mktype(targ_ptrdifftype); + } else goto Error; + break; + case BCARITH: + ty = cvtarith(ty, rhs->ty); + if (!ty.t) { + ty.t = TYINT; + Error: + bintypeerr(span, tt, lhs->ty, rhs->ty); + } + break; + case BCINT: + if (!isint(ty) || !isint(rhs->ty)) + goto Error; + ty = cvtarith(ty, rhs->ty); + assert(ty.t); + break; + case BCSHFT: /* 6.5.7 Bitwise shift operators */ + if (!isint(ty) || !isint(rhs->ty)) + goto Error; + ty.t = intpromote(ty.t); + assert(ty.t); + break; + case BCEQL: + if (!equalitycheck(lhs, rhs)) + goto Error; + ty = mktype(TYINT); + break; + case BCCMP: + if (!relationalcheck(lhs, rhs)) + goto Error; + ty = mktype(TYINT); + break; + case BCLOG: /* 6.5.13-14 Logical AND/OR operator */ + if (!isscalar(ty) || !isscalar(rhs->ty)) + goto Error; + ty = mktype(TYINT); + break; + } + return (k & BCSET) || !ty.t ? lhs->ty : ty; +} + +/****************/ +/* EXPR PARSING */ +/****************/ + +#define mkexpr(t_,span_,ty_,...) ((struct expr){.t=(t_), .ty=(ty_), .span=(span_), __VA_ARGS__}) + +static struct expr * +exprdup(struct parser *pr, const struct expr *e) +{ + return memcpy(alloc(&pr->exarena, sizeof *e, 0), e, sizeof *e); +} +static struct expr * +exprdup2(struct parser *pr, const struct expr *e1, const struct expr *e2) +{ + struct expr *r = alloc(&pr->exarena, 2*sizeof *r, 0); + r[0] = *e1, r[1] = *e2; + return r; +} + +static struct expr expr(struct parser *pr); +static struct expr commaexpr(struct parser *pr); + +static struct expr /* 6.5.2.2 Function calls */ +callexpr(struct parser *pr, const struct span *span_, const struct expr *callee) +{ + struct token tk; + struct expr ex, arg; + struct span span = callee->span; + union type ty = callee->ty; + const struct typedata *td = &typedata[ty.dat]; + struct expr argbuf[10]; + vec_of(struct expr) args = VINIT(argbuf, arraylength(argbuf)); + bool spanok = joinspan(&span.ex, span_->ex); + bool printsig = 0; + + if (callee->t == ESYM && !callee->ty.t) { /* implicit function decl.. */ + const char *name = (void *)callee->sym; + struct decl decl = { + ty = mkfntype(mktype(TYINT), 0, NULL, NULL, /* kandr */ 1, 0), + .scls = SCEXTERN, .span = callee->span, .name = name + }; + warn(&callee->span, "call to undeclared function '%s'", name); + ((struct expr *)callee)->sym = putdecl(pr, &decl); + td = &typedata[ty.dat]; + } + + if (ty.t == TYPTR) /* auto-deref when calling a function pointer */ + ty = typechild(ty); + if (ty.t != TYFUNC) error(&callee->span, "calling a value of type '%ty'", callee->ty); + if (!match(pr, &tk, ')')) for (;;) { + arg = expr(pr); + spanok = spanok && joinspan(&span.ex, callee->span.ex); + if (ty.t == TYFUNC && args.n == td->nmemb && !td->variadic && !td->kandr) { + error(&arg.span, "too many args to function taking %d params", td->nmemb); + printsig = 1; + } + if (ty.t == TYFUNC && args.n < td->nmemb && !td->kandr) { + if (!assigncheck(td->param[args.n], &arg)) { + error(&arg.span, "arg #%d of type '%ty' is incompatible with '%ty'", + args.n+1, arg.ty, td->param[args.n]); + printsig = 1; + } + } + vpush(&args, arg); + peek(pr, &tk); + if (match(pr, &tk, ',')) { + spanok = spanok && joinspan(&span.ex, tk.span.ex); + } else if (expect(pr, ')', "or ',' after arg")) { + break; + } + } + if (!spanok || !joinspan(&span.ex, tk.span.ex)) span = *span_; + + if (!td->variadic && !td->kandr && args.n < td->nmemb) { + error(&tk.span, "not enough args to function taking %d param%s", + td->nmemb, td->nmemb != 1 ? "s" : ""); + printsig = 1; + } + if (printsig) note(&callee->span, "function signature is %ty", ty); + + ex = mkexpr(ECALL, span, ty.t == TYFUNC ? td->ret : ty, .narg = args.n, + .sub = alloc(&pr->exarena, (args.n+1)*sizeof(struct expr), 0)); + ex.sub[0] = *callee; + memcpy(ex.sub+1, args.p, args.n*sizeof(struct expr)); + vfree(&args); + return ex; +} + +static inline int +tkprec(int tt) +{ + return ((uint)tt < arraylength(bintab)) ? bintab[tt].prec : 0; +} + +static struct expr +exprparse(struct parser *pr, int prec) +{ + struct token tk, tk2; + struct span span; + struct expr ex, rhs, tmp; + struct decl *decl; + union type ty; + int opprec; + enum exprkind ek; + struct { + struct span span; + union { + union type ty; /* cast type */ + struct { + uchar t0; /* t == 0 */ + short tt; /* token */ + }; + }; + } unops[4]; + int nunop = 0; + +Unary: + switch (lex(pr, &tk)) { + /* unary operators (gather) */ + case '+': case '-': case '~': case '!': + case '*': case '&': case TKINC: case TKDEC: + Unops: + unops[nunop].span = tk.span; + unops[nunop].t0 = 0; + unops[nunop].tt = tk.t; + if (++nunop >= arraylength(unops)) { + ex = exprparse(pr, 999); + break; + } + goto Unary; + + /* base exprs */ + case TKNUMLIT: + case TKCHRLIT: + ex = mkexpr(ENUMLIT, tk.span, mktype(0), ); + if (!(ty.t = parsenumlit(&ex.u, &ex.f, &tk, 0))) + error(&tk.span, "bad number literal %'tk", &tk); + ex.ty.t = ty.t ? ty.t : TYINT; + break; + case TKSTRLIT: + ex = mkexpr(ESTRLIT, tk.span, + mkarrtype(mktype(TYCHAR), 0, tk.len+1), .s = { (uchar *)tk.s, tk.len }); + break; + case TKIDENT: + decl = finddecl(pr, tk.s); + if (!decl) { + if (lexpeek(pr, NULL) == '(') { /* implicit function decl? */ + ex = mkexpr(ESYM, tk.span, mktype(0), .sym = (void *)tk.s); + } else { + error(&tk.span, "undeclared identifier %'tk", &tk); + ex = mkexpr(ESYM, tk.span, mktype(TYINT), .sym = NULL); + } + } else if (decl->scls == SCTYPEDEF) { + error(&tk.span, "unexpected typename %'tk (expected expression)", &tk); + ex = mkexpr(ESYM, tk.span, decl->ty, .sym = NULL); + } else if (decl->isenum) { + ex = mkexpr(ENUMLIT, tk.span, decl->ty, .i = decl->value); + } else { + ex = mkexpr(ESYM, tk.span, decl->ty, .qual = decl->qual, .sym = decl); + } + break; + + /* might be unary op or primary expr */ + case '(': + if (!isdecltok(pr)) { /* (expr) */ + ex = commaexpr(pr); + expect(pr, ')', NULL); + break; + } else { /* (type) expr */ + struct declstate st = { DCASTEXPR }; + struct decl decl = pdecl(&st, pr); + expect(pr, ')', NULL); + assert(decl.ty.t); + unops[nunop].span = tk.span; + unops[nunop].ty = decl.ty; + if (++nunop >= arraylength(unops)) { + ex = exprparse(pr, 999); + break; + } + goto Unary; + } + case TKWsizeof: + span = tk.span; + if (!match(pr, NULL, '(')) /* sizeof expr */ + goto Unops; + else if (isdecltok(pr)) { /* sizeof (type) */ + struct declstate st = { DCASTEXPR }; + ty = pdecl(&st, pr).ty; + } else { /* sizeof (expr) */ + ty = commaexpr(pr).ty; + } + peek(pr, &tk); + if (expect(pr, ')', NULL)) + joinspan(&span.ex, tk.span.ex); + sizeofcheck(&span, ty); + ex = mkexpr(ENUMLIT, span, mktype(targ_sizetype), .u = typesize(ty)); + break; + default: + fatal(&tk.span, "expected expression (near %'tk)", &tk); + } + + /* postfix operators */ +Postfix: + switch (peek(pr, &tk)) { + default: break; + case TKINC: + case TKDEC: + lex(pr, &tk); + span = ex.span; + if (!joinspan(&span.ex, tk.span.ex)) span = tk.span; + incdeccheck(tk.t, &ex, &span); + ex = mkexpr(tk.t == TKINC ? EPOSTINC : EPOSTDEC, span, ex.ty, .sub = exprdup(pr, &ex)); + goto Postfix; + case '[': /* a[subscript] */ + lex(pr, NULL); + rhs = commaexpr(pr); + span = ex.span; + if (!joinspan(&span.ex, tk.span.ex) || !joinspan(&span.ex, ex.span.ex) + || (peek(pr, &tk2), !joinspan(&span.ex, tk.span.ex))) + span = tk.span; + expect(pr, ']', NULL); + + if (isint(ex.ty) && isptrcvt(rhs.ty)) { + /* swap idx[ptr] -> ptr[idx] */ + tmp = ex; + ex = rhs; + rhs = tmp; + } + + ty = subscriptcheck(&ex, &rhs, &span); + assert(ty.t); + if (!iszero(rhs)) { + tmp.sub = exprdup2(pr, &ex, &rhs); + tmp.t = EADD; + tmp.span = span; + tmp.ty = typedecay(ex.ty); + } + tmp.sub = exprdup(pr, iszero(rhs) ? &ex : &tmp); + tmp.span = span; + tmp.t = EDEREF; + tmp.qual = ex.ty.flag & TFCHLDQUAL; + tmp.ty = ty; + ex = tmp; + goto Postfix; + case '(': /* call(args) */ + lex(pr, &tk); + span = ex.span; + ex = callexpr(pr, &span, &ex); + goto Postfix; + case TKARROW: + if (ex.ty.t != TYPTR && ex.ty.t != TYARRAY) + error(&ex.span, "operand to -> is not a pointer (%ty)", ex.ty); + else + ex = mkexpr(EDEREF, ex.span, typechild(ex.ty), .qual = ex.ty.flag & TFCHLDQUAL, + .sub = exprdup(pr, &ex)); + /* fallthru */ + case '.': + lex(pr, &tk); + span = ex.span; + peek(pr, &tk2); /* field name */ + if (!expect(pr, TKIDENT, NULL)) tk2.s = ""; + if (!joinspan(&span.ex, tk.span.ex) || !joinspan(&span.ex, tk2.span.ex)) + span = tk.span; + if (!isagg(ex.ty)) { + error(&span, "member access operand is not an aggregate (%ty)%s", ex.ty, + ex.ty.t == TYPTR && isagg(typechild(ex.ty)) ? "; did you mean to use '->'?" : ""); + } else { + struct fielddata fld = {.t = mktype(TYINT)}; + if (*tk2.s && !getfield(&fld, ex.ty, tk2.s)) + error(&span, "'%ty' has no such field: '%s'", ex.ty, tk2.s); + if (ex.t == EGETF && ex.qual == fld.qual) { /* accumulate */ + ex.span = span; + ex.ty = fld.t; + ex.fld.off += fld.off; + ex.fld.bitoff = fld.bitoff; + ex.fld.bitsiz = fld.bitsiz; + } else { + ex = mkexpr(EGETF, span, fld.t, .qual = ex.qual | fld.qual, .sub = exprdup(pr, &ex), + .fld = { fld.off, fld.bitsiz, fld.bitoff }); + } + } + goto Postfix; + } + + /* unary operators (process) */ + while (nunop-- > 0) { + span = unops[nunop].span; + joinspan(&span.ex, ex.span.ex); + if (unops[nunop].t0 == 0) { + switch (unops[nunop].tt) { + case '+': + ek = EPLUS; + goto Alu; + case '-': + ek = ENEG; + goto Alu; + case '~': + ek = ECOMPL; + goto Alu; + case '!': + ek = ELOGNOT; + Alu: + ty = ek == ELOGNOT ? mktype(TYINT) : cvtarith(ex.ty, ex.ty); + if (!ty.t || (ek == ECOMPL && !isint(ty))) { + error(&tk.span, "invalid operand to %'tk (%ty)", &tk, ex.ty); + ty = mktype(TYINT); + } + ex = mkexpr(ek, span, ty, .sub = exprdup(pr, &ex)); + break; + case TKINC: case TKDEC: + ty = ex.ty; + incdeccheck(tk.t, &ex, &span); + ex = mkexpr(unops[nunop].tt == TKINC ? EPREINC : EPREDEC, span, ty, + .sub = exprdup(pr, &ex)); + break; + case '*': + if (ex.ty.t == TYPTR || ex.ty.t == TYARRAY) { + ty = typechild(ex.ty); + if (isincomplete(ty)) { + error(&span, "cannot dereference pointer to incomplete type (%ty)", ty); + ty = mktype(TYINT); + } + } else { + error(&span, "invalid operand to unary * (%ty)", ex.ty); + ty = mktype(TYINT); + } + ex = mkexpr(EDEREF, span, ty, .qual = ex.ty.flag & TFCHLDQUAL, + .sub = exprdup(pr, &ex)); + break; + case '&': + if (!islvalue(&ex)) + error(&span, "operand to unary & is not an lvalue"); + if (ex.t == EGETF && ex.fld.bitsiz) + error(&span, "cannot take address of bitfield"); + ex = mkexpr(EADDROF, span, mkptrtype(ex.ty, ex.qual), .sub = exprdup(pr, &ex)); + break; + case TKWsizeof: + sizeofcheck(&span, ex.ty); + ex = mkexpr(ENUMLIT, span, mktype(targ_sizetype), .u = typesize(ex.ty)); + break; + default: assert(0); + } + } else { /* cast */ + ty = unops[nunop].ty; + if (!castcheck(ty, &ex)) + error(&span, "cannot cast value of type '%ty' to '%ty'", ex.ty, ty); + ex = mkexpr(ECAST, span, ty, .sub = exprdup(pr, &ex)); + } + } + + /* binary operators */ + while ((opprec = tkprec(peek(pr, &tk))) >= prec) { + lex(pr, &tk); + ek = bintab[tk.t].t; + if (ek != ECOND) { + bool leftassoc = (bintab[tk.t].k & BCSET) == 0; /* only the assignment operators are right-associative */ + /* ex OP rhs */ + span.sl = tk.span.sl; + span.ex = ex.span.ex; + rhs = exprparse(pr, opprec + leftassoc); + if (!joinspan(&span.ex, tk.span.ex) || !joinspan(&span.ex, rhs.span.ex)) + span.ex = tk.span.ex; + ty = bintypecheck(&span, tk.t, &ex, &rhs); + assert(ty.t); + ex = mkexpr(ek, span, ty, .sub = exprdup2(pr, &ex, &rhs)); + } else { + /* ex ? tmp : rhs */ + struct expr *sub; + span.sl = tk.span.sl; + span.ex = ex.span.ex; + if (!isscalar(ex.ty)) + error(&ex.span, "?: condition is not a scalar type (%ty)", ex.ty); + tmp = commaexpr(pr); + joinspan(&tk.span.ex, tmp.span.ex); + expect(pr, ':', NULL); + rhs = expr(pr); + if (!joinspan(&span.ex, tk.span.ex) || !joinspan(&span.ex, tmp.span.ex) + || !joinspan(&span.ex, rhs.span.ex)) + span.ex = tk.span.ex; + ty = condtype(&tmp, &rhs); + if (!ty.t) { + error(&span, "bad operands to conditional expression (%ty, %ty)", tmp.ty, rhs.ty); + ty = tmp.ty; + } + sub = alloc(&pr->exarena, 3 * sizeof*sub, 0); + sub[0] = ex, sub[1] = tmp, sub[2] = rhs; + ex = mkexpr(ECOND, span, ty, .sub = sub); + } + } + + return ex; +} + +static struct expr +expr(struct parser *pr) +{ + return exprparse(pr, 2); /* non-comma expr */ +} + +static struct expr +commaexpr(struct parser *pr) +{ + return exprparse(pr, 1); +} + +/*********/ +/* -> IR */ +/*********/ + +static union ref expraddr(struct function *, const struct expr *); +static union ref compileexpr(struct function *, const struct expr *, bool discard); +static inline union ref +exprvalue(struct function *fn, const struct expr *ex) +{ + return compileexpr(fn, ex, /*discard*/ 0); +} +static inline void +expreffects(struct function *fn, const struct expr *ex) +{ + compileexpr(fn, ex, /*discard*/ 1); +} + + +static void +structcopy(struct function *fn, union type ty, union ref dst, union ref src) +{ + union irtype typ = mkirtype(ty); + addinstr(fn, mkarginstr(typ, dst)); + addinstr(fn, mkarginstr(typ, src)); + addinstr(fn, mkintrin(INstructcopy, 0, 2)); +} + +static union ref +structreturn(struct function *fn, const struct expr *src) +{ + return expraddr(fn, src); +} + +static union ref compilecall(struct function *fn, const struct expr *ex); + +static union ref +expraddr(struct function *fn, const struct expr *ex) +{ + struct decl *decl; + union ref r; + struct instr ins = {0}; + + switch (ex->t) { + case ESYM: + decl = ex->sym; + assert(decl != NULL); + switch (decl->scls) { + case SCAUTO: case SCREGISTER: + return mkref(RTMP, decl->id); + case SCEXTERN: case SCNONE: + return mksymref(decl->name); + case SCSTATIC: + assert(!"nyi"); + break; + default: + assert(0); + } + break; + case ESTRLIT: + return mkdatref(ex->s.n+1, /*align*/ 1, ex->s.p, ex->s.n, /*deref*/0); + case EDEREF: + return exprvalue(fn, ex->sub); + case EGETF: + r = expraddr(fn, ex->sub); + assert(ex->fld.bitsiz == 0); + if (ex->fld.off == 0) return r; + ins.cls = KPTR; + ins.op = Oadd; + ins.l = r; + ins.r = mkintcon(KI4, ex->fld.off); + return addinstr(fn, ins); + case ESET: + assert(isagg(ex->ty)); + r = expraddr(fn, &ex->sub[1]); + structcopy(fn, ex->ty, expraddr(fn, &ex->sub[0]), r); + return r; + case ESEQ: + expreffects(fn, &ex->sub[0]); + return expraddr(fn, &ex->sub[1]); + case ECALL: + assert(isagg(ex->ty)); + return compilecall(fn, ex); + default: + assert(!"lvalue?>"); + } + +} + +static union ref +genload(struct function *fn, union type t, union ref ref) +{ + struct instr ins = {0}; + + assert(isscalar(t)); + ins.cls = type2cls[t.t]; + switch (typesize(t)) { + case 1: ins.op = issigned(t) ? Oloads1 : Oloadu1; break; + case 2: ins.op = issigned(t) ? Oloads2 : Oloadu2; break; + case 4: ins.op = isflt(t) ? Oloadf4 : issigned(t) ? Oloads4 : Oloadu4; break; + case 8: ins.op = isflt(t) ? Oloadf8 : Oloadi8; break; + default: assert(0); + } + ins.l = ref; + return addinstr(fn, ins); +} + +static union ref +genstore(struct function *fn, union type t, union ref ptr, union ref val) +{ + struct instr ins = {0}; + + assert(isscalar(t)); + switch (typesize(t)) { + case 1: ins.op = Ostore1; break; + case 2: ins.op = Ostore2; break; + case 4: ins.op = Ostore4; break; + case 8: ins.op = Ostore8; break; + default: assert(0); + } + ins.l = ptr; + ins.r = val; + return addinstr(fn, ins); +} + +static union ref +cvt(struct function *fn, enum typetag to, enum typetag from, union ref ref) +{ + enum irclass kto = type2cls[to], kfrom = type2cls[from]; + struct instr ins = {0}; + if (kto == kfrom && to != TYBOOL) return ref; + if (ref.t == RICON && kto < KF4) return ref; + + ins.cls = kto; + ins.l = ref; + if (kisflt(kto) || kisflt(kfrom)) { + if (ref.t == RICON) { + assert(kisflt(kto) && kisint(kfrom)); + return mkfltcon(kto, kto == KF4 ? (float)ref.i : (double)ref.i); + } + if (kisflt(kto) && kfrom == KI4) ins.op = issignedt(from) ? Ocvts4f : Ocvtu4f; + else if (to == TYBOOL && kisflt(kfrom)) ins.op = Oneq, ins.r = mkfltcon(kfrom, 0.0); + else if (kisflt(kto) && kfrom == KI8) ins.op = issignedt(from) ? Ocvts8f : Ocvtu8f; + else if (kto == KF8 && kfrom == KF4) ins.op = Ocvtf4f8; + else if (kto == KF4 && kfrom == KF8) ins.op = Ocvtf8f4; + else if (kfrom == KF4) ins.op = issignedt(to) ? Ocvtf4s : Ocvtf4u; + else if (kfrom == KF8) ins.op = issignedt(to) ? Ocvtf8s : Ocvtf8u; + else assert(0); + } else { + if (to == TYBOOL) { + if (from == TYBOOL) return ref; + if (ref.t == RTMP) + /* these instrs already have output range of [0,1] */ + if (instrtab[ref.i].op == Onot || oiscmp(instrtab[ref.i].op)) + return ref; + ins.op = Oneq, ins.r = ZEROREF; + } + else if (kfrom == KI4 && issignedt(from)) ins.op = Oexts4; + else if (kfrom == KI4) ins.op = Oextu4; + else if (ref.t == RXCON && kfrom == KI8) return mkintcon(KI4, (int)(conht[ref.i].i8)); + else ins.op = Ocopy; + } + return addinstr(fn, ins); +} + +static union ref +narrow(struct function *fn, enum irclass to, enum typetag tt, union ref ref) +{ + struct instr ins = {0}; + assert(isscalart(tt)); + if (targ_primsizes[tt] >= cls2siz[to]) return ref; + ins.cls = to; + if (isfltt(tt)) { + assert(to == KF4 && tt == TYDOUBLE); + ins.op = Ocvtf8f4; + } else { + static const enum op ext[5][2] = { + [1] = {Oextu1, Oexts1}, [2] = {Oextu2, Oexts2}, [4] = {Oextu4, Oexts4} + }; + ins.op = ext[targ_primsizes[tt]][issignedt(tt)]; + } + ins.l = ref; + return addinstr(fn, ins); +} + +union ref +genptroff(struct function *fn, enum op op, uint siz, union ref ptr, + enum typetag tt, union ref idx) +{ + uint cls = type2cls[targ_sizetype]; + union ref off; + assert(siz); + + idx = cvt(fn, targ_sizetype, tt, idx); + if (siz == 1) off = idx; + else if (idx.t == RICON) + off = mkintcon(cls, idx.i * siz); + else if (ispo2(siz)) + off = addinstr(fn, + mkinstr(Oshl, cls, .l = idx, .r = mkintcon(cls, ilog2(siz)))); + else + off = addinstr(fn, + mkinstr(Omul, cls, .l = idx, .r = mkintcon(cls, siz))); + assert(in_range(op, Oadd, Osub)); + return addinstr(fn, mkinstr(op, KPTR, .l = ptr, .r = off)); +} + +union ref +genptrdiff(struct function *fn, uint siz, union ref a, union ref b) +{ + uint cls = type2cls[targ_ptrdifftype]; + assert(siz > 0); + a = addinstr(fn, mkinstr(Osub, cls, .l = a, .r = b)); + if (siz == 1) return a; + else if ((siz & (siz-1)) == 0) /* is power of 2 */ + return addinstr(fn, mkinstr(Osar, cls, a, mkintcon(cls, ilog2(siz)))); + else + return addinstr(fn, mkinstr(Odiv, cls, a, mkintcon(cls, siz))); +} + +/* used to emit the jumps in an in if (), while (), etc condition */ +static void +condjump(struct function *fn, const struct expr *ex, struct block *tr, struct block *fl) +{ + struct block *next, *next2; +Loop: + while (ex->t == ESEQ) { + expreffects(fn, &ex->sub[0]); + ex = &ex->sub[1]; + } + if (ex->t == ELOGAND) { + next = newblk(fn); + condjump(fn, &ex->sub[0], next, fl); + useblk(fn, next); + ex = &ex->sub[1]; + goto Loop; + } else if (ex->t == ELOGIOR) { + next = newblk(fn); + condjump(fn, &ex->sub[0], tr, next); + useblk(fn, next); + ex = &ex->sub[1]; + goto Loop; + } else if (ex->t == ECOND) { + next = newblk(fn); + next2 = newblk(fn); + condjump(fn, &ex->sub[0], next, next2); + useblk(fn, next); + condjump(fn, &ex->sub[1], tr, fl); + useblk(fn, next2); + condjump(fn, &ex->sub[2], tr, fl); + } else if (ex->t == ELOGNOT) { + Negate: + /* swap tr,fl */ + next = tr; + tr = fl; + fl = next; + ex = &ex->sub[0]; + goto Loop; + } else if (ex->t == EEQU && isnullpo(&ex->sub[1])) { /* == 0 */ + goto Negate; + } else if (ex->t == ENEQ && isnullpo(&ex->sub[1])) { /* != 0 */ + ex = &ex->sub[0]; + goto Loop; + } else { + putcondbranch(fn, exprvalue(fn, ex), tr, fl); + } +} + +struct condphis { + vec_of(struct block *) blk; + vec_of(union ref) ref; +}; + +static void +condexprrec(struct function *fn, const struct expr *ex, struct condphis *phis, + int boolcon, struct block *end, struct block *zero) +{ + struct block *tr, *fl, *next; + union ref r; + while (ex->t == ESEQ) { + expreffects(fn, &ex->sub[0]); + ex = &ex->sub[1]; + } + if (ex->t == ELOGAND) { + next = newblk(fn); + condexprrec(fn, &ex->sub[0], phis, 0, next, end); + useblk(fn, next); + condexprrec(fn, &ex->sub[1], phis, -2, end, zero); + } else if (ex->t == ELOGIOR) { + next = newblk(fn); + condexprrec(fn, &ex->sub[0], phis, 1, end, next); + useblk(fn, next); + condexprrec(fn, &ex->sub[1], phis, -2, end, zero); + } else if (ex->t == ECOND) { + tr = newblk(fn); + fl = newblk(fn); + condjump(fn, &ex->sub[0], tr, fl); + useblk(fn, tr); + condexprrec(fn, &ex->sub[1], phis, -1, end, zero); + useblk(fn, fl); + condexprrec(fn, &ex->sub[2], phis, -1, end, zero); + } else { + r = exprvalue(fn, ex); + vpush(&phis->blk, fn->curblk); + if (boolcon == -2) + r = cvt(fn, TYBOOL, ex->ty.t, r); + if (boolcon >= 0) + vpush(&phis->ref, mkintcon(KI4, boolcon)); + else + vpush(&phis->ref, r); + if (zero) { + putcondbranch(fn, r, end, zero); + } else { + assert(boolcon < 0); + putbranch(fn, end); + } + } +} + +static union ref +compilecall(struct function *fn, const struct expr *ex) +{ + struct instr ins = {0}; + struct expr *sub = ex->sub; + const struct typedata *td = &typedata[sub[0].ty.dat]; + struct instr insnsbuf[10]; + vec_of(struct instr) insns = VINIT(insnsbuf, arraylength(insnsbuf)); + + ins.op = Ocall; + if (isagg(ex->ty)) { + ins.cls = KPTR; + } else { + assert(isscalar(ex->ty) || ex->ty.t == TYVOID); + ins.cls = type2cls[ex->ty.t]; + } + ins.l = exprvalue(fn, &sub[0]); + for (int i = 0; i < ex->narg; ++i) { + struct expr *arg = &sub[i+1]; + union type ty = i < td->nmemb ? td->param[i] : argpromote(arg->ty); + union ref r = cvt(fn, ty.t, arg->ty.t, exprvalue(fn, arg)); + vpush(&insns, mkarginstr(mkirtype(ty), r)); + } + for (int i = 0; i < insns.n; ++i) + addinstr(fn, insns.p[i]); + vfree(&insns); + ins.r = mkcallarg(mkirtype(ex->ty), ex->narg, td->variadic ? td->nmemb : td->kandr ? 0 : -1); + return addinstr(fn, ins); +} + +/* the naive way to generate something like a ? b : c ? d : e, uses multiple phis, + * this code reduces such nested conditional expressions into one phi */ +static union ref +condexprvalue(struct function *fn, const struct expr *ex) +{ + struct block *blkbuf[8]; + union ref refbuf[8]; + struct condphis phis = { VINIT(blkbuf, arraylength(blkbuf)), + VINIT(refbuf, arraylength(refbuf))}; + struct block *dst = newblk(fn); + union ref r; + condexprrec(fn, ex, &phis, -1, dst, NULL); + useblk(fn, dst); + r = addphi(fn, type2cls[ex->ty.t], phis.blk.p, phis.ref.p, phis.blk.n); + vfree(&phis.blk); + vfree(&phis.ref); + return r; +} + +static union ref +compileexpr(struct function *fn, const struct expr *ex, bool discard) +{ + union type ty; + union ref r, q; + enum irclass cls = type2cls[ex->ty.t]; + struct instr ins = {0}; + int swp = 0; + struct expr *sub; + + eval((struct expr *)ex, EVFOLD); + sub = ex->sub; + + if (ex->ty.t != TYVOID && !isscalar(ex->ty)) + /* fn & array designators evaluate to their address; + * so do aggregates for the purpose of code generation */ + return expraddr(fn, ex); + switch (ex->t) { + case ENUMLIT: + if (discard) return NOREF; + if (isflt(ex->ty)) + return mkfltcon(cls, ex->f); + return mkintcon(cls, ex->i); + case ESYM: + if (discard && !(ex->qual & QVOLATILE)) return NOREF; + return genload(fn, ex->ty, expraddr(fn, ex)); + case EGETF: + if (discard && !(ex->qual & QVOLATILE)) return NOREF; + return genload(fn, ex->ty, expraddr(fn, ex)); + case ECAST: + if (ex->ty.t == TYVOID) { + expreffects(fn, sub); + return NOREF; + } + /* fallthru */ + case EPLUS: + r = compileexpr(fn, sub, discard); + if (discard) return NOREF; + return cvt(fn, ex->ty.t, sub->ty.t, r); + case ENEG: + ins.op = Oneg; + goto Unary; + case ECOMPL: + ins.op = Onot; + Unary: + ins.l = compileexpr(fn, sub, discard); + if (discard) return NOREF; + ins.l = cvt(fn, ex->ty.t, sub->ty.t, ins.l); + ins.cls = cls; + return addinstr(fn, ins); + case ELOGNOT: + for (; sub->t == ELOGNOT; ex = sub, sub = sub->sub) + swp ^= 1; + ins.op = Oequ + swp; + ins.l = compileexpr(fn, sub, discard); + if (discard) return NOREF; + ins.l = cvt(fn, ex->ty.t, sub->ty.t, ins.l); + ins.r = mkintcon(cls, 0); + ins.cls = cls; + return addinstr(fn, ins); + case EDEREF: + discard &= (ex->qual & QVOLATILE) == 0; + r = compileexpr(fn, sub, discard); + if (discard) return NOREF; + return genload(fn, ex->ty, r); + case EADDROF: + return expraddr(fn, sub); + case EMUL: + ins.op = isunsigned(ex->ty) ? Oumul : Omul; + goto BinArith; + case EDIV: + ins.op = isunsigned(ex->ty) ? Oudiv : Odiv; + goto BinArith; + case EREM: + ins.op = issigned(ex->ty) ? Orem : Ourem; + goto BinArith; + case EBAND: + ins.op = Oand; + goto BinArith; + case EXOR: + ins.op = Oxor; + goto BinArith; + case EBIOR: + ins.op = Oior; + goto BinArith; + case ESHL: + ins.op = Oshl; + goto BinArith; + case ESHR: + ins.op = issigned(ex->ty) ? Osar : Oslr; + goto BinArith; + case ESUB: + ins.op = Osub; + goto BinArith; + case EADD: + ins.op = Oadd; + BinArith: + ins.l = compileexpr(fn, &sub[0], discard); + ins.r = compileexpr(fn, &sub[1], discard); + if (discard) return NOREF; + if (ins.op == Osub && isptrcvt(sub[0].ty) && isptrcvt(sub[1].ty)) { + /* ptr - ptr */ + return genptrdiff(fn, typesize(typechild(sub[0].ty)), ins.l, ins.r); + } else if ((ins.op != Oadd && ins.op != Osub) || cls != KPTR) { + /* num OP num */ + ins.l = cvt(fn, ex->ty.t, sub[0].ty.t, ins.l); + ins.r = cvt(fn, ex->ty.t, sub[1].ty.t, ins.r); + } else { + assert(isptrcvt(sub[0].ty)); + /* ptr +/- num */ + return genptroff(fn, ins.op, typesize(typechild(sub[0].ty)), ins.l, sub[1].ty.t, ins.r); + } + ins.cls = cls; + return addinstr(fn, ins); + case EPOSTINC: + case EPOSTDEC: + ins.op = ex->t == EPOSTINC ? Oadd : Osub; + ins.cls = cls; + r = expraddr(fn, sub); + ins.l = genload(fn, sub->ty, r); + if (ex->ty.t == TYPTR) + ins.r = mkintcon(KI4, typesize(typechild(ex->ty))); + else + ins.r = mkref(RICON, 1); + genstore(fn, sub->ty, r, addinstr(fn, ins)); + return ins.l; + case EPREINC: + case EPREDEC: + ins.op = ex->t == EPREINC ? Oadd : Osub; + ins.cls = cls; + r = expraddr(fn, sub); + ins.l = genload(fn, sub->ty, r); + if (ex->ty.t == TYPTR) + ins.r = mkintcon(KI4, typesize(typechild(ex->ty))); + else + ins.r = mkref(RICON, 1); + q = addinstr(fn, ins); + genstore(fn, sub->ty, r, q); + if (discard) return NOREF; + return narrow(fn, cls, ex->ty.t, q); + case EEQU: + ins.op = Oequ; + goto Cmp; + case ENEQ: + ins.op = Oneq; + goto Cmp; + case ELTH: + ins.op = Olth; + goto Cmp; + case ELTE: + ins.op = Olte; + goto Cmp; + case EGTH: + ins.op = Ogth; + goto Cmp; + case EGTE: + ins.op = Ogte; + Cmp: + ty = cvtarith(sub[0].ty, sub[1].ty); + if (!ty.t) ty.t = TYPTR; + if (isunsigned(ty) && in_range(ins.op, Olth, Olte)) + ins.op += Oulth - Olth; + ins.l = compileexpr(fn, &sub[0], discard); + ins.r = compileexpr(fn, &sub[1], discard); + if (discard) return NOREF; + ins.l = cvt(fn, ty.t, sub[0].ty.t, ins.l); + ins.r = cvt(fn, ty.t, sub[1].ty.t, ins.r); + ins.cls = cls; + return addinstr(fn, ins); + case ESET: + assert(isscalar(ex->ty)); + q = cvt(fn, sub[0].ty.t, sub[1].ty.t, exprvalue(fn, &sub[1])); + r = expraddr(fn, &sub[0]); + genstore(fn, ex->ty, r, q); + if (discard) return NOREF; + return narrow(fn, cls, sub[0].ty.t, q); + case ESETMUL: + ins.op = isunsigned(ex->ty) ? Oumul : Omul; + goto Compound; + case ESETDIV: + ins.op = isunsigned(ex->ty) ? Oudiv : Odiv; + goto Compound; + case ESETREM: + ins.op = issigned(ex->ty) ? Orem : Ourem; + goto Compound; + case ESETAND: + ins.op = Oand; + goto Compound; + case ESETXOR: + ins.op = Oxor; + goto Compound; + case ESETIOR: + ins.op = Oior; + goto Compound; + case ESETSHL: + ins.op = Oshl; + goto Compound; + case ESETSHR: + ins.op = issigned(ex->ty) ? Osar : Oslr; + goto Compound; + case ESETSUB: + ins.op = Osub; + goto Compound; + case ESETADD: + ins.op = Oadd; + Compound: + r = expraddr(fn, &sub[0]); + ty = in_range(ex->t, ESETSHL, ESETSHR) ? mktype(intpromote(ex->ty.t)) + : cvtarith(sub[0].ty, sub[1].ty); + ins.cls = cls; + ins.l = genload(fn, ex->ty, r); + ins.r = exprvalue(fn, &sub[1]); + if ((ins.op != Oadd && ins.op != Osub) || cls != KPTR) { + ins.l = cvt(fn, ty.t, sub[0].ty.t, ins.l); + ins.r = cvt(fn, ex->ty.t, sub[1].ty.t, ins.r); + q = addinstr(fn, ins); + } else { + q = genptroff(fn, ins.op, typesize(typechild(ex->ty)), ins.l, sub[1].ty.t, ins.r); + } + genstore(fn, ex->ty, r, q); + if (discard) return NOREF; + return narrow(fn, cls, ex->ty.t, q); + case ECALL: + r = compilecall(fn, ex); + if (isint(ex->ty)) + return narrow(fn, cls, ex->ty.t, r); + return r; + case ECOND: + if (ex->ty.t == TYVOID) { + struct block *tr, *fl, *end; + condjump(fn, &sub[0], tr = newblk(fn), fl = newblk(fn)); + useblk(fn, tr); + expreffects(fn, &sub[1]); + end = newblk(fn); + putbranch(fn, end); + useblk(fn, fl); + expreffects(fn, &sub[2]); + putbranch(fn, end); + useblk(fn, end); + return NOREF; + } + /* fallthru */ + case ELOGAND: + case ELOGIOR: + return condexprvalue(fn, ex); + case ESEQ: + expreffects(fn, &sub[0]); + return compileexpr(fn, &sub[1], discard); + default: assert(!"nyi expr"); + } +} + +static void +stmtterm(struct parser *pr) +{ + expect(pr, ';', "to terminate previous statement"); +} + +static void block(struct parser *pr, struct function *fn); + +static bool /* return 1 if stmt is terminating (all codepaths return) */ +stmt(struct parser *pr, struct function *fn) +{ + struct block *tr, *fl, *end, *begin; + struct expr ex; + union ref r; + bool terminates = 0; + const bool doemit = fn->curblk; + +#define EMITS if (doemit && !nerror) + + switch (peek(pr, NULL)) { + case '{': + lex(pr, NULL); + { + struct env e; + envdown(pr, &e); + block(pr, fn); + envup(pr); + } + break; + case ';': + lex(pr, NULL); + break; + case TKWif: + lex(pr, NULL); + expect(pr, '(', NULL); + ex = commaexpr(pr); + expect(pr, ')', NULL); + if (!isscalar(ex.ty)) + error(&ex.span, "'if' condition is not a scalar (%ty)", ex.ty); + tr = fl = end = NULL; + EMITS { + tr = newblk(fn); + fl = newblk(fn); + condjump(fn, &ex, tr, fl); + useblk(fn, tr); + } + terminates = stmt(pr, fn); + if (!match(pr, NULL, TKWelse)) { + end = fl; + EMITS if (!terminates) putbranch(fn, end); + terminates = 0; + } else { + EMITS { + if (!terminates) putbranch(fn, end = newblk(fn)); + useblk(fn, fl); + } + terminates &= stmt(pr, fn); + EMITS { + if (fn->curblk) putbranch(fn, end); + } + } + EMITS if (!terminates) useblk(fn, end); + break; + case TKWwhile: + lex(pr, NULL); + expect(pr, '(', NULL); + ex = commaexpr(pr); + expect(pr, ')', NULL); + if (!isscalar(ex.ty)) + error(&ex.span, "'while' condition is not a scalar (%ty)", ex.ty); + tr = begin = end = NULL; + EMITS { + begin = newblk(fn); + putbranch(fn, begin); + useblk(fn, begin); + condjump(fn, &ex, tr = newblk(fn), end = newblk(fn)); + useblk(fn, tr); + } + terminates = stmt(pr, fn); + EMITS { + if (!terminates) putbranch(fn, begin); + useblk(fn, end); + } + break; + case TKWdo: + lex(pr, NULL); + begin = end = NULL; + EMITS { + putbranch(fn, begin = newblk(fn)); + useblk(fn, begin); + } + terminates = stmt(pr, fn); + expect(pr, TKWwhile, NULL); + expect(pr, '(', NULL); + ex = commaexpr(pr); + expect(pr, ')', NULL); + if (!isscalar(ex.ty)) + error(&ex.span, "'while' condition is not a scalar (%ty)", ex.ty); + stmtterm(pr); + EMITS { + end = newblk(fn); + if (!terminates) condjump(fn, &ex, begin, end); + useblk(fn, end); + } + break; + case TKWreturn: + lex(pr, NULL); + if (fn->retty.t != TYVOID) { + ex = commaexpr(pr); + if (!assigncheck(fn->retty, &ex)) { + error(&ex.span, + "cannot return '%ty' value from function with return type '%ty'", + ex.ty, fn->retty); + } + EMITS { + if (isscalar(fn->retty)) + r = cvt(fn, fn->retty.t, ex.ty.t, exprvalue(fn, &ex)); + else + r = structreturn(fn, &ex); + putreturn(fn, r, NOREF); + } + } else { + EMITS putreturn(fn, NOREF, NOREF); + } + stmtterm(pr); + break; + default: + ex = commaexpr(pr); + stmtterm(pr); + EMITS expreffects(fn, &ex); + break; + } + freearena(pr->exarena); + return fn->curblk == NULL; +} + +static void +block(struct parser *pr, struct function *fn) +{ + struct token tk; + const bool doemit = fn->curblk; + + while (!match(pr, &tk, '}')) { + if (isdecltok(pr)) { /* decl */ + struct expr ini; + struct declstate st = { DFUNCVAR }; + do { + struct decl decl = pdecl(&st, pr); + if (decl.name) { + static int staticid; + bool put = 0; + + switch (decl.scls) { + case SCSTATIC: + decl.id = ++staticid; + break; + case SCNONE: + decl.scls = SCAUTO; + case SCAUTO: + case SCREGISTER: + if (isincomplete(decl.ty) || decl.ty.t == TYFUNC) { + error(&decl.span, + "declaring variable '%s' with %s type '%ty'", + decl.name, decl.ty.t == TYFUNC ? "function" : "incomplete", + decl.ty); + goto Err; + } + EMITS { + decl.id = addinstr(fn, mkalloca(typesize(decl.ty), typealign(decl.ty))).i; + } + if (st.varini) { + putdecl(pr, &decl); + put = 1; + ini = expr(pr); + pdecl(&st, pr); + if (!assigncheck(decl.ty, &ini)) { + struct span span = decl.span; + joinspan(&span.ex, ini.span.ex); + error(&span, "cannot initialize '%ty' variable with '%ty'", + decl.ty, ini.ty); + } + EMITS { + if (isagg(decl.ty)) + structcopy(fn, decl.ty, mkref(RTMP, decl.id), expraddr(fn, &ini)); + else + genstore(fn, decl.ty, mkref(RTMP, decl.id), exprvalue(fn, &ini)); + } + } + break; + case SCTYPEDEF: break; + case SCEXTERN: break; + default: assert(0); + } + Err: + if (!put) putdecl(pr, &decl); + } + } while (st.more); + } else { + stmt(pr, fn); + } + } + pr->fnblkspan = tk.span; +} + +static void +function(struct parser *pr, struct function *fn, const char **pnames, const struct span *pspans) +{ + const struct typedata *td = &typedata[fn->fnty.dat]; + const bool doemit = fn->curblk; + struct env e; + envdown(pr, &e); + + /* emit Oparam instructions */ + EMITS { + for (int i = 0; i < td->nmemb; ++i) { + union irtype pty = mkirtype(td->param[i]); + union ref r = addinstr(fn, mkinstr(Oparam, pty.isagg ? KPTR : pty.cls, + mkref(RICON, i), mktyperef(pty))); + assert(r.t == RTMP && r.i == i); + } + } + /* add parameters to symbol table and create prologue (arguments) block */ + for (int i = 0; i < td->nmemb; ++i) { + if (pnames[i]) { + struct decl arg = { .ty = td->param[i], .qual = tdgetqual(td->quals, i), + .name = pnames[i], .scls = SCAUTO, .span = pspans[i] }; + EMITS { + if (isscalar(arg.ty)) { + arg.id = addinstr(fn, mkalloca(typesize(arg.ty), typealign(arg.ty))).i; + genstore(fn, arg.ty, mkref(RTMP, arg.id), mkref(RTMP, i)); + } else { + arg.id = addinstr(fn, mkinstr(Ocopy, KPTR, mkref(RTMP, i))).i; + } + } + putdecl(pr, &arg); + } else if (ccopt.cstd < STDC23) { + warn(&pspans[i], "missing name of parameter #%d", i+1); + } + } + /* end prologue */ + EMITS { + struct block *blk; + putbranch(fn, blk = newblk(fn)); + useblk(fn, blk); + } + block(pr, fn); + envup(pr); + if (fn->curblk) { + if (!strcmp(fn->name, "main") && fn->retty.t == TYINT) { + /* implicit return 0 for main function */ + putreturn(fn, ZEROREF, NOREF); + } else { + if (fn->retty.t != TYVOID && !nerror) { + warn(&pr->fnblkspan, "non-void function may not return a value"); + } + putreturn(fn, NOREF, NOREF); + } + } +} + +/********/ +/* DECL */ +/********/ + +static union type +buildagg(struct parser *pr, enum typetag tt, const char *name, int id) +{ + struct token tk; + union type t; + struct span flexspan; + struct namedfield fbuf[32]; + vec_of(struct namedfield) fld = VINIT(fbuf, arraylength(fbuf)); + struct typedata td = {tt}; + bool isunion = tt == TYUNION; + const char *tag = isunion ? "union" : "struct"; + + while (!match(pr, &tk, '}')) { + struct declstate st = { DFIELD }; + do { + struct decl decl = pdecl(&st, pr); + if (fld.n && td.flexi) { + td.flexi = 0; + error(&flexspan, "flexible array member is not at end of struct"); + } + if (!isunion && decl.ty.t == TYARRAY && !typearrlen(decl.ty)) { + td.flexi = 1; + flexspan = decl.span; + } else if (isincomplete(decl.ty)) { + error(&decl.span, "field has incomplete type (%ty)", decl.ty); + } else if (decl.ty.t == TYFUNC) { + error(&decl.span, "field has function type (%ty)", decl.ty); + } + if (decl.ty.t) { + uint align = typealign(decl.ty); + uint siz = typesize(decl.ty); + uint off = isunion ? 0 : alignup(td.siz, align); + struct namedfield f = { decl.name, { decl.ty, off, .qual = decl.qual }}; + if (!decl.name) { + if (!isagg(decl.ty) || ttypenames[typedata[decl.ty.dat].id]) { + warn(&decl.span, "declaration does not declare anything"); + continue; + } else if (ccopt.cstd < STDC11 && ccopt.pedant) { + warn(&decl.span, "anonymous %s in %M is an extension", + decl.ty.t == TYUNION ? "union" : "struct"); + } + } + vpush(&fld, f); + td.anyconst |= decl.qual & QCONST; + if (isagg(decl.ty)) { + td.anyconst |= typedata[decl.ty.dat].anyconst; + if (typedata[decl.ty.dat].flexi) + error(&decl.span, "nested aggregate has flexible array member"); + } + if (isunion) + td.siz = td.siz < siz ? siz : td.siz; + else + td.siz = off + siz; + td.align = td.align < align ? align : td.align; + } + } while (st.more); + } + if (td.flexi && ccopt.cstd < STDC99 && ccopt.pedant) + warn(&flexspan, "flexible array member in %M is an extension"); + if (fld.n == 0) { + struct namedfield dummy = { "", { mktype(TYCHAR), 0 }}; + error(&tk.span, "%s cannot have zero members", tag); + vpush(&fld, dummy); + td.siz = td.align = 1; + } + td.siz = alignup(td.siz, td.align); + td.fld = fld.p; + td.nmemb = fld.n; + if (id != -1) + t = completetype(name, id, &td); + else + t = mktagtype(name, &td); + vfree(&fld); + return t; +} + +static inline void +inttyminmax(vlong *min, uvlong *max, enum typetag tt) +{ + uint bits = 8*targ_primsizes[tt]; + *min = isunsignedt(tt) ? 0 : -(1ll << (bits - 1)); + *max = isunsignedt(tt) ? ~0ull >> (64 - bits) : (1ll << (bits - 1)) - 1; +} + +/* the backing type of enum (without a C23 fixed backing type) is int or the + * smallest-rank type that all the enumerators fit in, or if it doesn't exist, + * then the biggest signed type. the type of enumeration constants is the type of + * its defining expression when present or the type of the previous enumerator + * or in case of overflow the smallest type that fits (previous value + 1) + * this isn't strictly conforming since pre C23 enums are pretty loosely defined, + * and this is similar to existing compiler's de-facto behaviour (though gcc + * prefers to use unsigned types when possible). should add support for -fshort-enums + */ +static union type +buildenum(struct parser *pr, const char *name, const struct span *span) +{ + struct token tk; + vlong tymin, minv = 0; + uvlong tymax, maxv = 0; + struct typedata td = {TYENUM, .backing = TYINT}; + union type ty = mktype(td.backing); + struct span maxvspan; + vlong iota = 0; + bool somelonglong = 0; + + inttyminmax(&tymin, &tymax, td.backing); + while (!match(pr, &tk, '}')) { + struct decl decl = {0}; + peek(pr, &tk); + expect(pr, TKIDENT, NULL); + if (match(pr, NULL, '=') || (peek(pr, NULL) == TKNUMLIT && !expect(pr, '=', NULL))) { + struct expr ex = expr(pr); + if (eval(&ex, EVINTCONST)) { + iota = ex.i; + if (ex.ty.t != ty.t) + inttyminmax(&tymin, &tymax, ex.ty.t); + ty = ex.ty; + } else { + error(&ex.span, "enum value is not an integer constant"); + } + } else if (tk.t != TKIDENT) { + lex(pr, NULL); + continue; + } + while (issigned(ty) ? (iota > (vlong)tymax || iota < tymin) : iota > tymax) + inttyminmax(&tymin, &tymax, ++ty.t); + somelonglong |= ty.t >= TYVLONG; + if ((isunsigned(ty) || iota > 0) && iota > maxv) + maxv = iota, maxvspan = tk.span; + else if (issigned(ty) && iota < minv) + minv = iota; + + decl.name = tk.s; + decl.ty = ty; + decl.isenum = 1; + decl.value = iota++; + putdecl(pr, &decl); + if (!match(pr, &tk, ',')) { + if (expect(pr, '}', "or `,'")) + break; + else lex(pr, NULL); + } + } + + td.backing = 0; + for (int t = TYINT; t <= TYUVLONG; ++t) { + inttyminmax(&tymin, &tymax, t); + if (minv >= tymin && maxv <= tymax) { + td.backing = t; + break; + } + } + if (!td.backing) { + td.backing = !somelonglong && ccopt.cstd == STDC89 && ccopt.pedant ? TYLONG : TYVLONG; + warn(&maxvspan, "enumerators exceed range of enum's backing type (%ty)", mktype(td.backing)); + } + if (td.backing >= TYVLONG && !somelonglong && ccopt.cstd == STDC89 && ccopt.pedant) + warn(span, "enum backing type is '%ty' in %M", mktype(td.backing)); + + ty = mktagtype(name, &td); + ty.backing = td.backing; + return ty; +} + +static union type +tagtype(struct parser *pr, enum toktag kind) +{ + struct token tk; + union type t; + struct span span; + enum typetag tt = kind == TKWenum ? TYENUM : kind == TKWstruct ? TYSTRUCT : TYUNION; + const char *tag = NULL; + + peek(pr, &tk); + if (match(pr, &tk, TKIDENT)) + tag = tk.s; + span = tk.span; + if (!match(pr, NULL, '{')) { + if (!tag) { + error(&tk.span, "expected %tt name or '{'", kind); + return mktype(0); + } + t = gettagged(pr, &span, tt, tag, /* def? */ peek(pr, NULL) == ';'); + if (tt == TYENUM && !t.t) { + error(&tk.span, "cannot forward-declare enum"); + return mktype(TYINT); + } + } else { + if (tt != TYENUM) { + if (tag) { + t = deftagged(pr, &span, tt, tag, mktype(0)); + if (t.t != tt || !isincomplete(t)) { + if (t.t != tt) + error(&tk.span, + "defining tagged type %'tk as %tt clashes with previous definition", + &tk, kind); + else + error(&tk.span, "redefinition of '%tt %s'", kind, tag, mktype(0)); + note(&span, "previous definition:"); + } + } + t = buildagg(pr, tt, tag, tag ? typedata[t.dat].id : -1); + } else { + t = buildenum(pr, tag, &span); + if (tag) deftagged(pr, &span, TYENUM, tag, t); + } + } + + if (t.t != tt) { + error(&tk.span, "declaring tagged type %'tk as %tt clashes with previous definition", + &tk, kind); + note(&span, "previous definition:"); + } + return t; +} + +static void +declspec(struct declstate *st, struct parser *pr) +{ + struct token tk; + struct decl *decl; + enum arith { + KSIGNED = 1<<0, + KUNSIGNED = 1<<1, + KBOOL = 1<<2, + KCHAR = 1<<3, + KSHORT = 1<<4, + KLONG = 1<<5, + KLONGLONG = 1<<6, + KINT = 1<<7, + KFLOAT = 1<<8, + KDOUBLE = 1<<9, + } arith = 0; + struct span span = {0}; + + for (;;) { + peek(pr, &tk); + switch (tk.t) { + case TKWconst: + st->qual |= QCONST; + break; + case TKWvolatile: + st->qual |= QVOLATILE; + break; + case TKW_Noreturn: + st->qual |= QNORETURN; + break; + case TKWinline: + st->qual |= QINLINE; + break; + case TKWvoid: + st->base = mktype(TYVOID); + break; + case TKWsigned: + arith |= KSIGNED; + break; + case TKWunsigned: + arith |= KUNSIGNED; + break; + case TKW_Bool: + case TKWbool: + if (arith & KBOOL) goto Dup; + arith |= KBOOL; + break; + case TKWchar: + if (arith & KCHAR) { + Dup: + error(&tk.span, "duplicate %tk specifier", &tk); + } + arith |= KCHAR; + break; + case TKWshort: + arith |= KSHORT; + break; + case TKWlong: + if ((arith & (KLONG | KLONGLONG)) == KLONG) + arith = (arith &~ KLONG) | KLONGLONG; + else if ((arith & (KLONG | KLONGLONG)) == 0) + arith |= KLONG; + else + error(&tk.span, "too long"); + break; + case TKWint: + if (arith & KINT) goto Dup; + arith |= KINT; + break; + case TKWfloat: + if (arith & KFLOAT) goto Dup; + arith |= KFLOAT; + break; + case TKWdouble: + if (arith & KDOUBLE) goto Dup; + arith |= KDOUBLE; + break; + case TKWenum: + case TKWstruct: + case TKWunion: + lex(pr, &tk); + st->base = tagtype(pr, tk.t); + st->tagdecl = 1; + if (!span.ex.len) span.ex = tk.span.ex; + joinspan(&span.ex, tk.span.ex); + goto End; + case TKIDENT: + if (!st->base.t && !arith && (decl = finddecl(pr, tk.s)) + && decl->scls == SCTYPEDEF) { + st->base = decl->ty; + break; + } + /* fallthru */ + default: + if (!span.ex.len) span.ex = tk.span.ex; + goto End; + case TKW_BitInt: case TKW_Complex: + case TKW_Decimal128: case TKW_Decimal32: + case TKW_Decimal64: case TKW_Imaginary: + error(&tk.span, "%'tk is unsupported", &tk); + arith = arith ? arith : KINT; + } + if (!span.ex.len) span.ex = tk.span.ex; + joinspan(&span.ex, tk.span.ex); + lex(pr, &tk); + if (st->base.t) break; + } +End: + if (st->base.t && arith) { + /* combining arith type specifiers and other types */ + Bad: + error(&span, "invalid declaration specifier"); + st->base = mktype(TYINT); + } else if (!st->base.t && arith) { + enum typetag t; + ioflush(&bstderr); + if (arith == KFLOAT) + t = TYFLOAT; + else if (arith == KDOUBLE) + t = TYDOUBLE; + else if (arith == (KLONG | KDOUBLE)) { + t = TYLDOUBLE; + error(&span, "`long double' is unsupported"); + } else if (arith == KBOOL) + t = TYBOOL; + else if (arith == KCHAR) + t = TYCHAR; + else if (arith == (KSIGNED | KCHAR)) + t = TYSCHAR; + else if (arith == (KUNSIGNED | KCHAR)) + t = TYUCHAR; + else if ((arith & ~KINT & ~KSIGNED) == KSHORT) + t = TYSHORT; + else if ((arith & ~KINT) == (KUNSIGNED | KSHORT)) + t = TYUSHORT; + else if ((arith & ~KINT & ~KSIGNED) == 0) + t = TYINT; + else if ((arith & ~KINT) == KUNSIGNED) + t = TYUINT; + else if ((arith & ~KINT & ~KSIGNED) == KLONG) + t = TYLONG; + else if ((arith & ~KINT) == (KUNSIGNED | KLONG)) + t = TYULONG; + else if ((arith & ~KINT & ~KSIGNED) == KLONGLONG) + t = TYVLONG; + else if ((arith & ~KINT) == (KUNSIGNED | KLONGLONG)) + t = TYUVLONG; + else + goto Bad; + st->base = mktype(t ? t : TYINT); + } else if (!st->base.t && ccopt.cstd < STDC23) { + warn(&span, "type implicitly declared as int"); + st->base = mktype(TYINT); + } else if (!st->base.t) + fatal(&span, "expected declaration type specifier"); +} + +/* circular doubly linked list used to parse declarators */ +static struct decllist { + struct decllist *prev, *next; + uchar t; /* TYPTR, TYARRAY or TYFUNC */ + union { + uchar qual; /* TYPTR */ + uint len; /* TYARRAY */ + struct { /* TYFUNC */ + union type *param; + const char **pnames; + struct span *pspans; + uchar *pqual; + short npar; + bool kandr : 1, variadic : 1; + }; + }; + struct span span; +} decltmp[64], *declfreelist; +static union type declparamtmp[16]; +static const char *declpnamestmp[16]; +static struct span declpspanstmp[16]; +static uchar declpqualtmp[tdqualsiz(16)]; + +static void +declinsert(struct decllist *list, const struct decllist *node) +{ + struct decllist *pnode = declfreelist; + if (!pnode) fatal(NULL, "too many nested declarators"); + declfreelist = declfreelist->next; + *pnode = *node; + pnode->next = list->next; + pnode->prev = list; + list->next->prev = pnode; + list->next = pnode; +} + +static int +sclass(struct parser *pr, struct span *span) +{ + struct token tk; + int sc = 0, first = 1; + for (;; lex(pr, &tk)) { + switch (peek(pr, &tk)) { + case TKWtypedef: sc |= SCTYPEDEF; break; + case TKWextern: sc |= SCEXTERN; break; + case TKWstatic: sc |= SCSTATIC; break; + case TKWauto: sc |= SCAUTO; break; + case TKWregister: sc |= SCREGISTER; break; + case TKWthread_local: + case TKW_Thread_local: + sc |= SCTHREADLOCAL; break; + default: return sc; + } + if (first) *span = tk.span; + else joinspan(&span->ex, tk.span.ex); + first = 0; + } +} + +static int +cvqual(struct parser *pr) +{ + struct token tk; + int q = 0; + while (match(pr, &tk, TKWconst) || match(pr, &tk, TKWvolatile)) + q |= tk.t == TKWconst ? QCONST : QVOLATILE; + return q; +} + +static void +decltypes(struct parser *pr, struct decllist *list, const char **name, struct span *span) { + struct token tk; + struct decllist *ptr, node; + + while (match(pr, &tk, '*')) { + node.t = TYPTR; + node.qual = cvqual(pr); + node.span = tk.span; + declinsert(list, &node); + } + ptr = list->next; + switch (peek(pr, &tk)) { + case '(': + lex(pr, &tk); + if (isdecltok(pr)) { + goto Func; + } else if (match(pr, &tk, ')')) { + /* T () is K&R func proto */ + node.span = tk.span; + node.t = TYFUNC; + node.param = NULL; + node.pqual = NULL; + node.pnames = NULL; + node.variadic = 0; + node.kandr = 1; + node.npar = 0; + declinsert(ptr->prev, &node); + break; + } else { + decltypes(pr, list, name, span); + expect(pr, ')', NULL); + } + break; + case TKIDENT: + if (!name) + error(&tk.span, "unexpected identifier in type name"); + else { + *name = tk.s; + *span = tk.span; + } + lex(pr, &tk); + break; + default: + *span = tk.span; + if (name) + *name = NULL; + } + for (;;) { + if (match(pr, &tk, '[')) { + node.span = tk.span; + uint n = 0; + if (!match(pr, &tk, ']')) { + struct expr ex = expr(pr); + if (!eval(&ex, EVINTCONST)) { + error(&ex.span, "array length is not an integer constant"); + } else if (typesize(ex.ty) < 8 && ex.i < 0) { + error(&ex.span, "array length is negative"); + } else if (ex.u > (1ull << (8*sizeof n)) - 1) { + error(&ex.span, "array too long (%ul)", ex.u); + } else if (ex.u == 0) { + error(&ex.span, "array cannot have zero length"); + } else { + n = ex.u; + } + peek(pr, &tk); + joinspan(&node.span.ex, tk.span.ex); + expect(pr, ']', NULL); + } + node.t = TYARRAY; + node.len = n; + declinsert(ptr->prev, &node); + } else if (match(pr, &tk, '(')) Func: { + static int depth = 0; + vec_of(union type) params = {0}; + vec_of(uchar) qual = {0}; + vec_of(const char *) names = {0}; + vec_of(struct span) spans = {0}; + bool anyqual = 0; + + if (depth++ == 0) { + vinit(¶ms, declparamtmp, arraylength(declparamtmp)); + vinit(&qual, declpqualtmp, arraylength(declpqualtmp)); + vinit(&names, declpnamestmp, arraylength(declpnamestmp)); + vinit(&spans, declpspanstmp, arraylength(declpspanstmp)); + } + node.span = tk.span; + node.kandr = 0; + node.variadic = 0; + + while (!match(pr, &tk, ')')) { + struct declstate st = { DFUNCPARAM }; + struct decl decl; + if (match(pr, &tk, TKDOTS)) { + node.variadic = 1; + expect(pr, ')', NULL); + break; + } + decl = pdecl(&st, pr); + decl.ty = typedecay(decl.ty); + vpush(¶ms, decl.ty); + vpush(&names, decl.name); + vpush(&spans, decl.span); + if (decl.qual) { + anyqual = 1; + while (qual.n < tdqualsiz(params.n)) vpush(&qual, 0); + tdsetqual(qual.p, params.n-1, decl.qual); + } + if (isincomplete(decl.ty)) { + if (params.n > 1 || decl.ty.t != TYVOID || decl.qual || decl.name) { + error(&decl.span, + "function parameter #%d has incomplete type (%tq)", + params.n, decl.ty, tdgetqual(qual.p, params.n-1)); + } + } + joinspan(&node.span.ex, tk.span.ex); + if (!match(pr, &tk, ',')) { + expect(pr, ')', NULL); + break; + } + } + --depth; + node.kandr = params.n == 0 && ccopt.cstd < STDC23; + if (params.n == 1 && params.p[0].t == TYVOID && !qual.n && !names.p[0]) { /* (void) */ + vfree(¶ms); + vfree(&names); + vfree(&spans); + } else if (params.n && params.p[0].t == TYVOID && !qual.n && !names.p[0]) { + error(&node.span, "function parameter #1 has incomplete type (%tq)", + params.p[0], tdgetqual(qual.p, 0)); + } + node.t = TYFUNC; + node.param = params.n ? params.p : NULL; + node.pqual = anyqual ? qual.p : NULL; + node.pnames = params.n ? names.p : NULL; + node.pspans = params.n ? spans.p : NULL; + node.npar = params.n; + declinsert(ptr->prev, &node); + } else break; + } +} + +static struct decl +declarator(struct declstate *st, struct parser *pr) { + struct decl decl = { st->base, st->scls, st->qual, st->align }; + struct decllist list = { &list, &list }, *l; + static bool inidecltmp = 0; + if (!inidecltmp) { + inidecltmp = 1; + for (int i = 0; i < arraylength(decltmp); ++i) { + decltmp[i].next = declfreelist; + declfreelist = &decltmp[i]; + } + } + + decltypes(pr, &list, st->kind == DCASTEXPR ? NULL : &decl.name, &decl.span); + if (!decl.name && st->kind != DCASTEXPR && st->kind != DFUNCPARAM) { + if (list.prev == &list) lex(pr, NULL); + error(&decl.span, "expected `(', `*' or identifier"); + } + for (l = list.prev; l != &list; l = l->prev) { + switch (l->t) { + case TYPTR: + decl.ty = mkptrtype(decl.ty, decl.qual); + decl.qual = l->qual; + break; + case TYARRAY: + if (isincomplete(decl.ty)) + error(&l->span, "array has incomplete element type (%ty)", decl.ty); + else if (decl.ty.t == TYFUNC) + error(&l->span, "array has element has function type (%ty)", decl.ty); + decl.ty = mkarrtype(decl.ty, decl.qual, l->len); + decl.qual = 0; + break; + case TYFUNC: + if (decl.ty.t == TYFUNC) + error(&decl.span, "function cannot return function type (%ty)", decl.ty); + else if (decl.ty.t == TYARRAY) + error(&decl.span, "function cannot return array type", decl.ty); + else if (decl.ty.t != TYVOID && isincomplete(decl.ty)) + error(&decl.span, "function cannot return incomplete type (%ty)", decl.ty); + decl.ty = mkfntype(decl.ty, l->npar, l->param, l->pqual, l->kandr, l->variadic); + if (l->param != declparamtmp) free(l->param); + if (l->pqual != declpqualtmp) free(l->pqual); + if (l->prev == &list && l->npar) { /* last */ + st->pnames = alloc(&pr->fnarena, l->npar * sizeof(char *), 0); + st->pspans = alloc(&pr->fnarena, l->npar * sizeof(struct span), 0); + memcpy(st->pnames, l->pnames, l->npar * sizeof(char *)); + memcpy(st->pspans, l->pspans, l->npar * sizeof(struct span)); + } + if (l->pnames != declpnamestmp) free(l->pnames); + if (l->pspans != declpspanstmp) free(l->pspans); + decl.qual = 0; + break; + } + + l->next = declfreelist; + declfreelist = l; + } + + return decl; +} + +static struct decl +pdecl(struct declstate *st, struct parser *pr) { + struct token tk; + struct decl decl; + bool iniallowed = st->kind != DFIELD && st->kind != DFUNCPARAM && st->kind != DCASTEXPR; + bool first = 0; + + if (st->varini) { + memset(&decl, 0, sizeof decl); + goto AfterVarIni; + } + + if (!st->base.t) { + first = 1; + st->scls = sclass(pr, &tk.span); + if (popcnt(st->scls) > 1) + error(&tk.span, "invalid combination of storage class specifiers"); + else { + int allowed; + switch (st->kind) { + case DTOPLEVEL: allowed = SCTYPEDEF | SCEXTERN | SCSTATIC | SCTHREADLOCAL; break; + case DCASTEXPR: allowed = 0; break; + case DFIELD: allowed = 0; break; + case DFUNCPARAM: allowed = 0; break; + case DFUNCVAR: + allowed = SCTYPEDEF | SCREGISTER | SCAUTO | SCEXTERN | SCSTATIC | SCTHREADLOCAL; + break; + default: assert(0); + } + if ((st->scls & allowed) != st->scls) + error(&tk.span, "this storage class is not allowed in this context"); + st->scls &= allowed; + } + declspec(st, pr); + } + + if (first && st->tagdecl && match(pr, &tk, ';')) { + decl = (struct decl) { st->base, st->scls, st->qual, st->align, tk.span }; + return decl; + } + decl = declarator(st, pr); + + if (iniallowed && match(pr, &tk, '=')) { + st->varini = 1; + return decl; + } else if (first && decl.ty.t == TYFUNC && match(pr, &tk, '{')) { + st->funcdef = 1; + return decl; + } + +AfterVarIni: + st->varini = 0; + st->more = 0; + if (st->kind != DCASTEXPR && st->kind != DFUNCPARAM) { + if (match(pr, &tk, ',')) + st->more = 1; + else expect(pr, st->kind == DFUNCPARAM ? ')' : ';', "or `,'"); + } + + return decl; +} + +void +parse(struct parser *pr) +{ + struct token tk[1]; + + if (!pr->env) pr->env = &toplevel; + if (!tlarena) { + enum { N = 1<<12 }; + static union { char m[sizeof(struct arena) + N]; struct arena *_align; } amem[3]; + + tlarena = (void *)amem[0].m; + tlarena->cap = N; + pr->fnarena = (void *)amem[1].m; + pr->fnarena->cap = N; + pr->exarena = (void *)amem[2].m; + pr->exarena->cap = N; + } + + putdecl(pr, &(struct decl) { mktype(TYVALIST), SCTYPEDEF, .name = intern("__builtin_va_list") }); + + while (peek(pr, tk) != TKEOF) { + struct expr ini; + struct declstate st = { DTOPLEVEL, }; + do { + int nerr = nerror; + struct decl decl = pdecl(&st, pr); + + if (nerror != nerr) { + if (st.varini) { + (void)expr(pr); + pdecl(&st, pr); + } + continue; + } + if (st.funcdef) { + const struct typedata *td = &typedata[decl.ty.dat]; + struct function fn = { pr->fnarena, decl.name, .globl = decl.scls != SCSTATIC }; + fn.fnty = decl.ty; + fn.retty = td->ret; + putdecl(pr, &decl); + irinit(&fn); + function(pr, &fn, st.pnames, st.pspans); + if (!nerror && ccopt.dbg.p) + irdump(&fn); + irfini(&fn); + } else if (decl.name) { + putdecl(pr, &decl); + if (st.varini) { + ini = expr(pr); + pdecl(&st, pr); + if (!assigncheck(decl.ty, &ini)) + error(&ini.span, "cannot initialize %ty with %ty", decl.ty, ini.ty); + if (!eval(&ini, EVSTATICINI)) + error(&ini.span, "cannot evaluate expression statically"); + } + if (ccopt.dbg.p) efmt("var %s : %tq\n", decl.name, decl.ty, decl.qual); + } else { + if (ccopt.dbg.p) efmt("type %ty\n", decl.ty); + } + freearena(pr->fnarena); + freearena(pr->exarena); + } while (st.more); + } +} + +/* vim:set ts=3 sw=3 expandtab: */ -- cgit v1.2.3