scc

Simple C99 Compiler
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commit fdbf2edecf2f3eba01c23eee08375d66162e7cce
parent 3183b71d83817fd0ad0566889a941b69844e8451
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Wed, 12 Aug 2015 17:27:12 +0200

Remove declarator0()

This function was needed because declarator() had some
process and data that disable it to be recursive.
All the data and process are moved to dodcl(),
which simplify the code and avoid the problem
with sym->u.pars incorrect assignations.

Diffstat:
cc1/cc1.h | 3+--
cc1/decl.c | 256++++++++++++++++++++++++++++++++++++++++++++-----------------------------------
2 files changed, 143 insertions(+), 116 deletions(-)

diff --git a/cc1/cc1.h b/cc1/cc1.h @@ -110,8 +110,7 @@ enum { enum { FTN = 1, PTR, - ARY, - PARS + ARY }; /* namespaces */ diff --git a/cc1/decl.c b/cc1/decl.c @@ -1,6 +1,7 @@ #include <inttypes.h> #include <setjmp.h> +#include <stdarg.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -11,30 +12,85 @@ #define NOSCLASS 0 -struct dcldata { - unsigned char op; - unsigned short nelem; - unsigned char ndcl; - void *data; +struct declarators { + unsigned char nr; + struct declarator { + unsigned char op; + unsigned short nelem; + Symbol *sym; + Type **tpars; + Symbol **pars; + } d [NR_DECLARATORS]; }; -static struct dcldata * -queue(struct dcldata *dp, unsigned op, short nelem, void *data) +struct decl { + unsigned ns; + int sclass; + Symbol *sym; + Symbol **pars; + Type *type; + Type *parent; +}; + +static void +push(struct declarators *dp, unsigned op, ...) { + va_list va; unsigned n; + struct declarator *p; - if ((n = dp->ndcl) == NR_DECLARATORS) + va_start(va, op); + if ((n = dp->nr++) == NR_DECLARATORS) error("too much declarators"); - dp->op = op; - dp->nelem = nelem; - dp->data = data; - ++dp; - dp->ndcl = n+1; - return dp; + p = &dp->d[n]; + + p->op = op; + switch (op) { + case ARY: + p->nelem = va_arg(va, unsigned); + break; + case FTN: + p->nelem = va_arg(va, unsigned); + p->tpars = va_arg(va, Type **); + p->pars = va_arg(va, Symbol **); + break; + case IDEN: + p->sym = va_arg(va, Symbol *); + break; + } +} + +static bool +pop(struct declarators *dp, struct decl *dcl) +{ + struct declarator *p; + + if (dp->nr == 0) + return 0; + + p = &dp->d[--dp->nr]; + if (p->op == IDEN) { + dcl->sym = p->sym; + return 1; + } + if (dcl->type->op == FTN) { + /* + * constructor applied to a + * function. We don't need + * the parameter symbols anymore. + */ + free(dcl->pars); + popctx(); + dcl->pars = NULL; + } + if (p->op == FTN) + dcl->pars = p->pars; + dcl->type = mktype(dcl->type, p->op, p->nelem, p->tpars); + return 1; } -static struct dcldata * -arydcl(struct dcldata *dp) +static void +arydcl(struct declarators *dp) { Node *np = NULL; TINT n; @@ -49,13 +105,14 @@ arydcl(struct dcldata *dp) n = (np == NULL) ? 0 : np->sym->u.i; freetree(np); - return queue(dp, ARY, n, NULL); + push(dp, ARY, n); } static Symbol * -parameter(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) +parameter(struct decl *dcl) { - Type *funtp = data; + Symbol *sym = dcl->sym; + Type *funtp = dcl->parent, *tp = dcl->type; size_t n = funtp->n.elem; char *name = sym->name; @@ -64,7 +121,7 @@ parameter(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) if (n == -1) error("'void' must be the only parameter"); - switch (sclass) { + switch (dcl->sclass) { case STATIC: case EXTERN: case AUTO: @@ -81,7 +138,7 @@ parameter(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) case VOID: if (n != 0) error("incorrect void parameter"); - if (sclass) + if (dcl->sclass) error("void as unique parameter may not be qualified"); funtp->n.elem = -1; return NULL; @@ -108,17 +165,17 @@ parameter(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) } static Symbol *dodcl(int rep, - Symbol *(*fun)(Symbol *, Type *, unsigned, int, Type *), + Symbol *(*fun)(struct decl *), unsigned ns, Type *type); -static struct dcldata * -fundcl(struct dcldata *dp) +static void +fundcl(struct declarators *dp) { Type type = {.n = {.elem = -1}, .pars = NULL}; Symbol *syms[NR_FUNPARAM], **sp; size_t size; - void *pars = NULL; + Symbol *pars = NULL; pushctx(); expect('('); @@ -137,21 +194,18 @@ fundcl(struct dcldata *dp) pars = memcpy(xmalloc(size), syms, size); } } - dp = queue(dp, PARS, 0, pars); - dp = queue(dp, FTN, type.n.elem, type.pars); - - return dp; + push(dp, FTN, type.n.elem, type.pars, pars); } -static struct dcldata *declarator0(struct dcldata *dp, unsigned ns); +static void declarator(struct declarators *dp, unsigned ns); -static struct dcldata * -directdcl(struct dcldata *dp, unsigned ns) +static void +directdcl(struct declarators *dp, unsigned ns) { Symbol *sym; if (accept('(')) { - dp = declarator0(dp, ns); + declarator(dp, ns); expect(')'); } else { if (yytoken == IDEN || yytoken == TYPEIDEN) { @@ -160,20 +214,20 @@ directdcl(struct dcldata *dp, unsigned ns) } else { sym = newsym(ns); } - dp = queue(dp, IDEN, 0, sym); + push(dp, IDEN, sym); } for (;;) { switch (yytoken) { - case '(': dp = fundcl(dp); break; - case '[': dp = arydcl(dp); break; - default: return dp; + case '(': fundcl(dp); break; + case '[': arydcl(dp); break; + default: return; } } } -static struct dcldata* -declarator0(struct dcldata *dp, unsigned ns) +static void +declarator(struct declarators *dp, unsigned ns) { unsigned n; @@ -182,52 +236,10 @@ declarator0(struct dcldata *dp, unsigned ns) /* nothing */; } - dp = directdcl(dp, ns); + directdcl(dp, ns); while (n--) - dp = queue(dp, PTR, 0, NULL); - - return dp; -} - -static Symbol * -declarator(Type *tp, unsigned ns, Type **otp) -{ - struct dcldata data[NR_DECLARATORS+1]; - struct dcldata *bp; - Symbol *osym, *sym, **pars = NULL; - char *name; - - data[0].ndcl = 0; - for (bp = declarator0(data, ns); bp-- > data; ) { - switch (bp->op) { - case IDEN: - sym = bp->data; - break; - case PARS: - pars = bp->data; - break; - default: - if (pars) { - /* - * constructor applied to a function. We don't - * need the parameter symbols anymore. - */ - free(pars); - popctx(); - pars = NULL; - } - tp = mktype(tp, bp->op, bp->nelem, bp->data); - break; - } - } - /* - * FIXME: This assignation can destroy pars of a previous definition - */ - if (pars) - sym->u.pars = pars; - *otp = tp; - return sym; + push(dp, PTR); } static Type *structdcl(void), *enumdcl(void); @@ -312,8 +324,16 @@ specifier(int *sclass) return_type: if (sclass) *sclass = cls; - if (!tp && spec) - tp = ctype(type, sign, size); + if (!tp) { + if (spec) { + tp = ctype(type, sign, size); + } else { + if (curctx != GLOBALCTX) + unexpected(); + warn("type defaults to 'int' in declaration"); + tp = inttype; + } + } return tp; invalid_type: @@ -439,56 +459,61 @@ enumdcl(void) } static Symbol * -type(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) +type(struct decl *dcl) { - if (sclass) + Symbol *sym = dcl->sym; + + if (dcl->sclass) error("class storage in type name"); if (sym->name) error("unexpected identifier in type name"); - sym->type = tp; + sym->type = dcl->type; return sym; } static Symbol * -field(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) +field(struct decl *dcl) { - Type *funtp = data; - size_t n = funtp->n.elem; + Symbol *sym = dcl->sym; char *name = sym->name; + Type *structp = dcl->parent, *tp = dcl->type; + size_t n = structp->n.elem; if (!name) { sym->type = tp; warn("empty declaration"); return sym; } - if (sclass) + if (dcl->sclass) error("storage class in struct/union field"); if (tp->op == FTN) error("invalid type in struct/union"); if (!tp->defined) error("field '%s' has incomplete type", name); - if ((sym = install(ns, sym)) == NULL) + if ((sym = install(dcl->ns, sym)) == NULL) error("duplicated member '%s'", name); sym->type = tp; sym->flags |= ISFIELD; if (n++ == NR_FUNPARAM) error("too much fields in struct/union"); - funtp->pars = xrealloc(funtp->pars, n); - funtp->pars[n-1] = tp; - funtp->n.elem = n; + structp->pars = xrealloc(structp->pars, n); + structp->pars[n-1] = tp; + structp->n.elem = n; return sym; } static Symbol * -identifier(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) +identifier(struct decl *dcl) { + Symbol *sym = dcl->sym; + Type *tp = dcl->type; char *name = sym->name; short flags; - Symbol *osym; + int sclass = dcl->sclass; if (!name) { sym->type = tp; @@ -513,11 +538,11 @@ identifier(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) sym = install(NS_IDEN, sym); ++curctx; } else { - sym = install(NS_IDEN, osym = sym); + sym = install(NS_IDEN, sym); } if (sym == NULL) { - sym = osym; + sym = dcl->sym; flags = sym->flags; if (!eqtype(sym->type, tp)) error("conflicting types for '%s'", name); @@ -572,6 +597,7 @@ identifier(Symbol *sym, Type *tp, unsigned ns, int sclass, Type *data) } } + sym->u.pars = dcl->pars; sym->flags = flags; sym->type = tp; @@ -603,25 +629,27 @@ static_after_non: } static Symbol * -dodcl(int rep, - Symbol *(*fun)(Symbol *, Type *, unsigned, int, Type *), - unsigned ns, - Type *data) +dodcl(int rep, Symbol *(*fun)(struct decl *), unsigned ns, Type *parent) { Symbol *sym; - Type *base, *tp; - int sclass; + Type *base; + struct decl dcl; + struct declarators stack; - if ((base = specifier(&sclass)) == NULL) { - if (curctx != GLOBALCTX) - unexpected(); - warn("type defaults to 'int' in declaration"); - base = inttype; - } + dcl.ns = ns; + dcl.parent = parent; + base = specifier(&dcl.sclass); do { - sym = declarator(base, ns, &tp); - sym = (*fun)(sym, tp, ns, sclass, data); + stack.nr = 0; + dcl.pars = NULL; + dcl.type = base; + + declarator(&stack, ns); + + while (pop(&stack, &dcl)) + /* nothing */; + sym = (*fun)(&dcl); } while (rep && accept(',')); return sym;