/* $NetBSD: decl.c,v 1.411 2024/11/30 10:43:48 rillig Exp $ */ /* * Copyright (c) 1996 Christopher G. Demetriou. All Rights Reserved. * Copyright (c) 1994, 1995 Jochen Pohl * All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Jochen Pohl for * The NetBSD Project. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #if HAVE_NBTOOL_CONFIG_H #include "nbtool_config.h" #endif #include #if defined(__RCSID) __RCSID("$NetBSD: decl.c,v 1.411 2024/11/30 10:43:48 rillig Exp $"); #endif #include #include #include #include #include "lint1.h" const char unnamed[] = ""; /* shared type structures for arithmetic types and void */ static type_t typetab[NTSPEC]; /* value of next enumerator during declaration of enum types */ int enumval; /* * Points to the innermost element of a stack that contains information about * nested declarations, such as struct declarations, function prototypes, * local variables. */ decl_level *dcs; #ifdef DEBUG static inline void debug_func_dcs(const char *func) { debug_printf("%s: ", func); debug_dcs(); } #else #define debug_func_dcs(func) debug_noop() #endif void init_decl(void) { dcs = xcalloc(1, sizeof(*dcs)); dcs->d_kind = DLK_EXTERN; dcs->d_last_dlsym = &dcs->d_first_dlsym; if (!pflag) { for (size_t i = 0; i < NTSPEC; i++) { if (ttab[i].tt_rank_kind != RK_NONE) ttab[i].tt_rank_value = ttab[i].tt_size_in_bits; } ttab[BOOL].tt_rank_value = 1; } if (Tflag) { ttab[BOOL].tt_is_integer = false; ttab[BOOL].tt_is_uinteger = false; ttab[BOOL].tt_is_arithmetic = false; } /* struct, union, enum, ptr, array and func are not shared. */ for (int i = (int)SIGNED; i < (int)STRUCT; i++) typetab[i].t_tspec = (tspec_t)i; } /* * Returns a shared type structure for arithmetic types and void. The returned * type must not be modified; use block_dup_type or expr_dup_type if necessary. */ type_t * gettyp(tspec_t t) { lint_assert((int)t < (int)STRUCT); /* TODO: make the return type 'const' */ return &typetab[t]; } type_t * block_dup_type(const type_t *tp) { type_t *ntp = block_zero_alloc(sizeof(*ntp), "type"); // Keep referring to the same subtype, struct, union, enum, params. *ntp = *tp; debug_step("%s '%s'", __func__, type_name(ntp)); return ntp; } /* Duplicate a type, free the allocated memory after the expression. */ type_t * expr_dup_type(const type_t *tp) { type_t *ntp = expr_zero_alloc(sizeof(*ntp), "type"); // Keep referring to the same subtype, struct, union, enum, params. *ntp = *tp; debug_step("%s: '%s'", __func__, type_name(ntp)); return ntp; } /* * Return the unqualified version of the type. The returned type is freed at * the end of the current expression. * * See C99 6.2.5p25. */ type_t * expr_unqualified_type(const type_t *tp) { type_t *ntp = expr_zero_alloc(sizeof(*ntp), "type"); // Keep referring to the same subtype, struct, union, enum, params. *ntp = *tp; ntp->t_const = false; ntp->t_volatile = false; /* * In case of a struct or union type, the members should lose their * qualifiers as well, but that would require a deep copy of the struct * or union type. This in turn would defeat the type comparison in * types_compatible, which simply tests whether 'tp1->u.sou == * tp2->u.sou'. */ debug_step("%s: '%s'", __func__, type_name(ntp)); return ntp; } /* * Returns whether the type is 'void' or an incomplete array, struct, union * or enum. */ bool is_incomplete(const type_t *tp) { tspec_t t = tp->t_tspec; if (t == VOID) return true; if (t == ARRAY) return tp->t_incomplete_array; if (is_struct_or_union(t)) return tp->u.sou->sou_incomplete; if (t == ENUM) return tp->u.enumer->en_incomplete; return false; } void dcs_add_function_specifier(function_specifier fs) { if (fs == FS_INLINE) { if (dcs->d_inline) /* duplicate '%s' */ warning(10, "inline"); dcs->d_inline = true; } if (fs == FS_NORETURN) dcs->d_noreturn = true; debug_func_dcs(__func__); } void dcs_add_storage_class(scl_t sc) { if (dcs->d_type != NULL || dcs->d_abstract_type != NO_TSPEC || dcs->d_sign_mod != NO_TSPEC || dcs->d_rank_mod != NO_TSPEC) /* storage class after type is obsolescent */ warning(83); if (dcs->d_scl == NO_SCL) dcs->d_scl = sc; else if ((dcs->d_scl == EXTERN && sc == THREAD_LOCAL) || (dcs->d_scl == THREAD_LOCAL && sc == EXTERN)) dcs->d_scl = EXTERN; /* ignore thread_local */ else if ((dcs->d_scl == STATIC && sc == THREAD_LOCAL) || (dcs->d_scl == THREAD_LOCAL && sc == STATIC)) dcs->d_scl = STATIC; /* ignore thread_local */ else dcs->d_multiple_storage_classes = true; debug_func_dcs(__func__); } /* Merge the signedness into the abstract type. */ static tspec_t merge_signedness(tspec_t t, tspec_t s) { if (s == SIGNED) return t == CHAR ? SCHAR : t; if (s != UNSIGN) return t; return t == CHAR ? UCHAR : t == SHORT ? USHORT : t == INT ? UINT : t == LONG ? ULONG : t == LLONG ? ULLONG : t; } /* * Called if a list of declaration specifiers contains a typedef name * and other specifiers (except struct, union, enum, typedef name). */ static type_t * typedef_error(type_t *td, tspec_t t) { tspec_t t2 = td->t_tspec; if ((t == SIGNED || t == UNSIGN) && (t2 == CHAR || t2 == SHORT || t2 == INT || t2 == LONG || t2 == LLONG)) { if (allow_c90) /* modifying typedef with '%s'; only qualifiers... */ warning(5, tspec_name(t)); td = block_dup_type(gettyp(merge_signedness(t2, t))); td->t_typedef = true; return td; } if (t == SHORT && (t2 == INT || t2 == UINT)) { /* modifying typedef with '%s'; only qualifiers allowed */ warning(5, "short"); td = block_dup_type(gettyp(t2 == INT ? SHORT : USHORT)); td->t_typedef = true; return td; } if (t != LONG) goto invalid; tspec_t lt; if (t2 == INT) lt = LONG; else if (t2 == UINT) lt = ULONG; else if (t2 == LONG) lt = LLONG; else if (t2 == ULONG) lt = ULLONG; else if (t2 == FLOAT) lt = DOUBLE; else if (t2 == DOUBLE) lt = LDOUBLE; else if (t2 == DCOMPLEX) lt = LCOMPLEX; else goto invalid; /* modifying typedef with '%s'; only qualifiers allowed */ warning(5, "long"); td = block_dup_type(gettyp(lt)); td->t_typedef = true; return td; invalid: dcs->d_invalid_type_combination = true; debug_func_dcs(__func__); return td; } /* * Remember the type, modifier or typedef name returned by the parser in the * top element of the declaration stack. This information is used in * dcs_end_type to build the type used for all declarators in this declaration. * * If tp->t_typedef is true, the type comes from a previously defined typename. * Otherwise, it comes from a type specifier (int, long, ...) or a * struct/union/enum tag. */ void dcs_add_type(type_t *tp) { if (tp->t_typedef) { /*- * something like "typedef int a; int a b;" * This should not happen with current grammar. */ lint_assert(dcs->d_type == NULL); lint_assert(dcs->d_abstract_type == NO_TSPEC); lint_assert(dcs->d_sign_mod == NO_TSPEC); lint_assert(dcs->d_rank_mod == NO_TSPEC); dcs->d_type = tp; debug_func_dcs(__func__); return; } tspec_t t = tp->t_tspec; if (t == STRUCT || t == UNION || t == ENUM) { /* something like "int struct a ..." */ if (dcs->d_type != NULL || dcs->d_abstract_type != NO_TSPEC || dcs->d_rank_mod != NO_TSPEC || dcs->d_sign_mod != NO_TSPEC) { dcs->d_invalid_type_combination = true; dcs->d_abstract_type = NO_TSPEC; dcs->d_sign_mod = NO_TSPEC; dcs->d_rank_mod = NO_TSPEC; } dcs->d_type = tp; debug_func_dcs(__func__); return; } if (dcs->d_type != NULL && !dcs->d_type->t_typedef) { /* something like "struct a int" */ dcs->d_invalid_type_combination = true; debug_func_dcs(__func__); return; } if (t == COMPLEX) { if (dcs->d_complex_mod == FLOAT) t = FCOMPLEX; else if (dcs->d_complex_mod == DOUBLE) t = DCOMPLEX; else { /* invalid type for _Complex */ error(308); t = DCOMPLEX; /* just as a fallback */ } dcs->d_complex_mod = NO_TSPEC; } if (t == LONG && dcs->d_rank_mod == LONG) { /* "long long" or "long ... long" */ t = LLONG; dcs->d_rank_mod = NO_TSPEC; if (!suppress_longlong) /* %s does not support 'long long' */ c99ism(265, allow_c90 ? "C90" : "traditional C"); } if (dcs->d_type != NULL && dcs->d_type->t_typedef) { /* something like "typedef int a; a long ..." */ dcs->d_type = typedef_error(dcs->d_type, t); return; } /* now it can be only a combination of arithmetic types and void */ if (t == SIGNED || t == UNSIGN) { if (dcs->d_sign_mod != NO_TSPEC) dcs->d_invalid_type_combination = true; dcs->d_sign_mod = t; } else if (t == SHORT || t == LONG || t == LLONG) { if (dcs->d_rank_mod != NO_TSPEC) dcs->d_invalid_type_combination = true; dcs->d_rank_mod = t; } else if (t == FLOAT || t == DOUBLE) { if (dcs->d_rank_mod == NO_TSPEC || dcs->d_rank_mod == LONG) { if (dcs->d_complex_mod != NO_TSPEC || (t == FLOAT && dcs->d_rank_mod == LONG)) dcs->d_invalid_type_combination = true; dcs->d_complex_mod = t; } else { if (dcs->d_abstract_type != NO_TSPEC) dcs->d_invalid_type_combination = true; dcs->d_abstract_type = t; } } else if (t == PTR) { dcs->d_type = tp; } else { if (dcs->d_abstract_type != NO_TSPEC) dcs->d_invalid_type_combination = true; dcs->d_abstract_type = t; } debug_func_dcs(__func__); } static void set_first_typedef(type_t *tp, sym_t *sym) { tspec_t t = tp->t_tspec; if (is_struct_or_union(t) && tp->u.sou->sou_first_typedef == NULL) tp->u.sou->sou_first_typedef = sym; if (t == ENUM && tp->u.enumer->en_first_typedef == NULL) tp->u.enumer->en_first_typedef = sym; debug_printf("%s: ", __func__); debug_type(tp); } static unsigned int bit_fields_width(const sym_t **mem, bool *named) { unsigned int width = 0; unsigned int align = 0; while (*mem != NULL && (*mem)->s_type->t_bitfield) { if ((*mem)->s_name != unnamed) *named = true; width += (*mem)->s_type->t_bit_field_width; unsigned mem_align = alignment((*mem)->s_type); if (mem_align > align) align = mem_align; *mem = (*mem)->s_next; } unsigned align_in_bits = align * CHAR_BIT; return (width + align_in_bits - 1) & -align_in_bits; } static void pack_struct_or_union(type_t *tp) { if (!is_struct_or_union(tp->t_tspec)) { /* attribute '%s' ignored for '%s' */ warning(326, "packed", type_name(tp)); return; } unsigned int bits = 0; bool named = false; for (const sym_t *mem = tp->u.sou->sou_first_member; mem != NULL; mem = mem->s_next) { // TODO: Maybe update mem->u.s_member.sm_offset_in_bits. if (mem->s_type->t_bitfield) { bits += bit_fields_width(&mem, &named); if (mem == NULL) break; } unsigned int mem_bits = type_size_in_bits(mem->s_type); if (tp->t_tspec == STRUCT) bits += mem_bits; else if (mem_bits > bits) bits = mem_bits; } tp->u.sou->sou_size_in_bits = bits; } void dcs_add_alignas(tnode_t *tn) { dcs->d_mem_align = to_int_constant(tn, true); if (dcs->d_type != NULL && is_struct_or_union(dcs->d_type->t_tspec)) // FIXME: The type must not be modified. dcs->d_type->u.sou->sou_align = dcs->d_mem_align; debug_func_dcs(__func__); } void dcs_add_packed(void) { if (dcs->d_type == NULL) dcs->d_packed = true; else pack_struct_or_union(dcs->d_type); debug_func_dcs(__func__); } void dcs_set_used(void) { dcs->d_used = true; debug_func_dcs(__func__); } /* * Remember a qualifier that is part of the declaration specifiers (and not the * declarator). The remembered qualifier is used by dcs_end_type for all * declarators. */ void dcs_add_qualifiers(type_qualifiers qs) { add_type_qualifiers(&dcs->d_qual, qs); debug_func_dcs(__func__); } void begin_declaration_level(decl_level_kind kind) { decl_level *dl = xcalloc(1, sizeof(*dl)); dl->d_enclosing = dcs; dl->d_kind = kind; dl->d_last_dlsym = &dl->d_first_dlsym; dcs = dl; debug_enter(); debug_dcs_all(); } void end_declaration_level(void) { debug_dcs_all(); decl_level *dl = dcs; dcs = dl->d_enclosing; lint_assert(dcs != NULL); switch (dl->d_kind) { case DLK_STRUCT: case DLK_UNION: case DLK_ENUM: /* * Symbols declared in (nested) structs or enums are part of * the next level (they are removed from the symbol table if * the symbols of the outer level are removed). */ if ((*dcs->d_last_dlsym = dl->d_first_dlsym) != NULL) dcs->d_last_dlsym = dl->d_last_dlsym; break; case DLK_OLD_STYLE_PARAMS: /* * All symbols in dcs->d_first_dlsym are introduced in * old-style parameter declarations (it's not clean, but * possible). They are appended to the list of symbols declared * in an old-style parameter identifier list or a new-style * parameter type list. */ if (dl->d_first_dlsym != NULL) { *dl->d_last_dlsym = dcs->d_func_proto_syms; dcs->d_func_proto_syms = dl->d_first_dlsym; } break; case DLK_ABSTRACT: /* * Append all symbols declared in the abstract declaration to * the list of symbols declared in the surrounding declaration * or block. * * XXX I'm not sure whether they should be removed from the * symbol table now or later. */ if ((*dcs->d_last_dlsym = dl->d_first_dlsym) != NULL) dcs->d_last_dlsym = dl->d_last_dlsym; break; case DLK_AUTO: check_usage(dl); /* FALLTHROUGH */ case DLK_PROTO_PARAMS: /* usage of parameters will be checked by end_function() */ symtab_remove_level(dl->d_first_dlsym); break; case DLK_EXTERN: /* there is nothing around an external declaration */ /* FALLTHROUGH */ default: lint_assert(/*CONSTCOND*/false); } free(dl); debug_leave(); } /* * Set flag d_asm in all declaration stack elements up to the outermost one. * * This is used to mark compound statements which have, possibly in nested * compound statements, asm statements. For these compound statements, no * warnings about unused or uninitialized variables are printed. * * There is no need to clear d_asm in decl_level structs with context AUTO, as * these structs are freed at the end of the compound statement. But it must be * cleared in the outermost decl_level struct, which has context EXTERN. This * could be done in dcs_begin_type and would work for C90, but not for C99 or * C++ (due to mixed statements and declarations). Thus, we clear it in * global_clean_up_decl. */ void dcs_set_asm(void) { for (decl_level *dl = dcs; dl != NULL; dl = dl->d_enclosing) dl->d_asm = true; debug_step("%s", __func__); debug_dcs_all(); } void dcs_begin_type(void) { debug_enter(); // keep d_kind dcs->d_abstract_type = NO_TSPEC; dcs->d_complex_mod = NO_TSPEC; dcs->d_sign_mod = NO_TSPEC; dcs->d_rank_mod = NO_TSPEC; dcs->d_scl = NO_SCL; dcs->d_type = NULL; dcs->d_redeclared_symbol = NULL; // keep d_sou_size_in_bits // keep d_sou_align dcs->d_mem_align = 0; dcs->d_qual = (type_qualifiers) { .tq_const = false }; dcs->d_inline = false; dcs->d_multiple_storage_classes = false; dcs->d_invalid_type_combination = false; dcs->d_nonempty_decl = false; dcs->d_no_type_specifier = false; // keep d_asm dcs->d_packed = false; dcs->d_used = false; dcs->d_noreturn = false; // keep d_tag_type dcs->d_func_params = NULL; dcs->d_func_def_pos = (pos_t){ NULL, 0, 0 }; // keep d_first_dlsym // keep d_last_dlsym dcs->d_func_proto_syms = NULL; // keep d_enclosing debug_func_dcs(__func__); } static void dcs_adjust_storage_class(void) { if (dcs->d_kind == DLK_EXTERN) { if (dcs->d_scl == REG || dcs->d_scl == AUTO) { /* illegal storage class */ error(8); dcs->d_scl = NO_SCL; } } else if (dcs->d_kind == DLK_OLD_STYLE_PARAMS || dcs->d_kind == DLK_PROTO_PARAMS) { if (dcs->d_scl != NO_SCL && dcs->d_scl != REG) { /* only 'register' is valid as storage class ... */ error(9); dcs->d_scl = NO_SCL; } } } /* * Merge the declaration specifiers from dcs into dcs->d_type. * * See C99 6.7.2 "Type specifiers". */ static void dcs_merge_declaration_specifiers(void) { tspec_t t = dcs->d_abstract_type; tspec_t c = dcs->d_complex_mod; tspec_t s = dcs->d_sign_mod; tspec_t l = dcs->d_rank_mod; type_t *tp = dcs->d_type; if (tp != NULL) { lint_assert(t == NO_TSPEC); lint_assert(s == NO_TSPEC); lint_assert(l == NO_TSPEC); return; } if (t == NO_TSPEC && s == NO_TSPEC && l == NO_TSPEC && c == NO_TSPEC) dcs->d_no_type_specifier = true; if (t == NO_TSPEC && s == NO_TSPEC && (l == NO_TSPEC || l == LONG)) t = c; if (t == NO_TSPEC) t = INT; if (s == NO_TSPEC && t == INT) s = SIGNED; if (l != NO_TSPEC && t == CHAR) { dcs->d_invalid_type_combination = true; l = NO_TSPEC; } if (l == LONG && t == FLOAT) { l = NO_TSPEC; t = DOUBLE; if (allow_c90) /* use 'double' instead of 'long float' */ warning(6); } if ((l == LONG && t == DOUBLE) || t == LDOUBLE) { l = NO_TSPEC; t = LDOUBLE; } if (t == LDOUBLE && !allow_c90) /* 'long double' is illegal in traditional C */ warning(266); if (l == LONG && t == DCOMPLEX) { l = NO_TSPEC; t = LCOMPLEX; } if (t != INT && t != CHAR && (s != NO_TSPEC || l != NO_TSPEC)) { dcs->d_invalid_type_combination = true; l = s = NO_TSPEC; } if (l != NO_TSPEC) t = l; dcs->d_type = gettyp(merge_signedness(t, s)); debug_func_dcs(__func__); } static void dcs_align(unsigned int, unsigned int); /* Create a type in 'dcs->d_type' from the information gathered in 'dcs'. */ void dcs_end_type(void) { dcs_merge_declaration_specifiers(); if (dcs->d_multiple_storage_classes) /* only one storage class allowed */ error(7); if (dcs->d_invalid_type_combination) /* illegal type combination */ error(4); dcs_adjust_storage_class(); if (dcs->d_qual.tq_const && dcs->d_type->t_const && !dcs->d_type->t_typeof) { lint_assert(dcs->d_type->t_typedef); /* typedef already qualified with '%s' */ warning(68, "const"); } if (dcs->d_qual.tq_volatile && dcs->d_type->t_volatile && !dcs->d_type->t_typeof) { lint_assert(dcs->d_type->t_typedef); /* typedef already qualified with '%s' */ warning(68, "volatile"); } if (dcs->d_qual.tq_const || dcs->d_qual.tq_volatile) { dcs->d_type = block_dup_type(dcs->d_type); dcs->d_type->t_const |= dcs->d_qual.tq_const; dcs->d_type->t_volatile |= dcs->d_qual.tq_volatile; } unsigned align = dcs->d_mem_align; if (align > 0 && dcs->d_type->t_tspec == STRUCT) { dcs_align(align, 0); dcs->d_type->u.sou->sou_align = align; unsigned align_in_bits = align * CHAR_SIZE; dcs->d_type->u.sou->sou_size_in_bits = (dcs->d_type->u.sou->sou_size_in_bits + align_in_bits - 1) & -align_in_bits; } debug_dcs(); debug_leave(); } /* * Return the length of a type in bits. For bit-fields, return the length of * the underlying storage type. * * Printing a message if the outermost dimension of an array is 0 must * be done by the caller. All other problems are reported by this function * if name is not NULL. */ int length_in_bits(const type_t *tp, const char *name) { if (tp == NULL) return -1; unsigned int elem = 1; while (tp->t_tspec == ARRAY) { elem *= tp->u.dimension; tp = tp->t_subt; } if (is_struct_or_union(tp->t_tspec)) { if (is_incomplete(tp) && name != NULL) /* '%s' has incomplete type '%s' */ error(31, name, type_name(tp)); return (int)(elem * tp->u.sou->sou_size_in_bits); } if (tp->t_tspec == ENUM && is_incomplete(tp) && name != NULL) /* incomplete enum type '%s' */ warning(13, name); lint_assert(tp->t_tspec != FUNC); unsigned int elsz = size_in_bits(tp->t_tspec); /* * Workaround until the type parser (see add_function, add_array, * add_pointer) does not construct the invalid intermediate declaration * 'void b[4]' for the legitimate declaration 'void *b[4]'. */ if (sytxerr > 0 && elsz == 0) elsz = CHAR_SIZE; lint_assert(elsz > 0); return (int)(elem * elsz); } unsigned int alignment(const type_t *tp) { /* Super conservative so that it works for most systems. */ unsigned worst_align = 2 * LONG_SIZE / CHAR_SIZE; while (tp->t_tspec == ARRAY) tp = tp->t_subt; tspec_t t = tp->t_tspec; unsigned a; if (is_struct_or_union(t)) a = tp->u.sou->sou_align; else { lint_assert(t != FUNC); if ((a = size_in_bits(t) / CHAR_SIZE) == 0) a = 1; else if (a > worst_align) a = worst_align; } lint_assert(a >= 1); return a; } /* * Concatenate two lists of symbols by s_next. Used by declarations of * struct/union/enum elements and parameters. */ sym_t * concat_symbols(sym_t *l1, sym_t *l2) { if (l1 == NULL) return l2; sym_t *l = l1; while (l->s_next != NULL) l = l->s_next; l->s_next = l2; return l1; } /* * Check if the type of the given symbol is valid. * * Invalid types are: * - arrays of incomplete types or functions * - functions returning arrays or functions * - void types other than type of function or pointer */ void check_type(sym_t *sym) { type_t **tpp = &sym->s_type; tspec_t to = NO_TSPEC; while (*tpp != NULL) { type_t *tp = *tpp; tspec_t t = tp->t_tspec; /* * If this is the type of an old-style function definition, a * better warning is printed in begin_function(). */ if (t == FUNC && !tp->t_proto && !(to == NO_TSPEC && sym->s_osdef)) { /* TODO: Make this an error in C99 mode as well. */ if (!allow_trad && !allow_c99 && hflag) /* function declaration is not a prototype */ warning(287); } if (to == FUNC) { if (t == FUNC || t == ARRAY) { /* function returns illegal type '%s' */ error(15, type_name(tp)); *tpp = block_derive_type( t == FUNC ? *tpp : (*tpp)->t_subt, PTR); return; } if (tp->t_const || tp->t_volatile) { /* TODO: Make this a warning in C99 mode as well. */ if (!allow_trad && !allow_c99) { /* XXX or better allow_c90? */ /* function cannot return const... */ warning(228); } } } else if (to == ARRAY) { if (t == FUNC) { /* array of function is illegal */ error(16); *tpp = gettyp(INT); return; } if (t == ARRAY && tp->u.dimension == 0) { /* null dimension */ error(17); return; } if (t == VOID) { /* illegal use of 'void' */ error(18); *tpp = gettyp(INT); } /* * No need to check for incomplete types here as * length_in_bits already does this. */ } else if (to == NO_TSPEC && t == VOID) { if (dcs->d_kind == DLK_PROTO_PARAMS) { if (sym->s_scl != ABSTRACT) { lint_assert(sym->s_name != unnamed); /* void parameter '%s' cannot ... */ error(61, sym->s_name); *tpp = gettyp(INT); } } else if (dcs->d_kind == DLK_ABSTRACT) { /* ok */ } else if (sym->s_scl != TYPEDEF) { /* void type for '%s' */ error(19, sym->s_name); *tpp = gettyp(INT); } } if (t == VOID && to != PTR) { if (tp->t_const || tp->t_volatile) { /* inappropriate qualifiers with 'void' */ warning(69); tp->t_const = tp->t_volatile = false; } } tpp = &tp->t_subt; to = t; } } /* * In traditional C, the only portable type for bit-fields is unsigned int. * * In C90, the only allowed types for bit-fields are int, signed int and * unsigned int (3.5.2.1). There is no mention of implementation-defined * types. * * In C99, the only portable types for bit-fields are _Bool, signed int and * unsigned int (6.7.2.1p4). In addition, C99 allows "or some other * implementation-defined type". */ static void check_bit_field_type(sym_t *dsym, type_t **inout_tp, tspec_t *inout_t) { type_t *tp = *inout_tp; tspec_t t = *inout_t; if (t == CHAR || t == UCHAR || t == SCHAR || t == SHORT || t == USHORT || t == ENUM) { if (!suppress_bitfieldtype) { /* TODO: Make this an error in C99 mode as well. */ if (!allow_trad && !allow_c99) { type_t *btp = block_dup_type(tp); btp->t_bitfield = false; /* bit-field type '%s' invalid in C90 or ... */ warning(273, type_name(btp)); } else if (pflag) { type_t *btp = block_dup_type(tp); btp->t_bitfield = false; /* nonportable bit-field type '%s' */ warning(34, type_name(btp)); } } } else if (t == INT && dcs->d_sign_mod == NO_TSPEC) { if (pflag && !suppress_bitfieldtype) { /* bit-field of type plain 'int' has ... */ warning(344); } } else if (!(t == INT || t == UINT || t == BOOL || (is_integer(t) && (suppress_bitfieldtype || allow_gcc)))) { type_t *btp = block_dup_type(tp); btp->t_bitfield = false; /* illegal bit-field type '%s' */ warning(35, type_name(btp)); unsigned int width = tp->t_bit_field_width; dsym->s_type = tp = block_dup_type(gettyp(t = INT)); if ((tp->t_bit_field_width = width) > size_in_bits(t)) tp->t_bit_field_width = size_in_bits(t); *inout_t = t; *inout_tp = tp; } } static void check_bit_field(sym_t *dsym, tspec_t *inout_t, type_t **inout_tp) { check_bit_field_type(dsym, inout_tp, inout_t); type_t *tp = *inout_tp; tspec_t t = *inout_t; unsigned int t_width = size_in_bits(t); if (tp->t_bit_field_width > t_width) { /* illegal bit-field size: %d */ error(36, (int)tp->t_bit_field_width); tp->t_bit_field_width = t_width; } else if (tp->t_bit_field_width == 0 && dsym->s_name != unnamed) { /* zero size bit-field */ error(37); tp->t_bit_field_width = t_width; } if (dsym->s_scl == UNION_MEMBER) { /* bit-field in union is very unusual */ warning(41); dsym->s_type->t_bitfield = false; dsym->s_bitfield = false; } } /* Aligns the next structure member as required. */ static void dcs_align(unsigned int member_alignment, unsigned int bit_field_width) { if (member_alignment > dcs->d_sou_align) dcs->d_sou_align = member_alignment; unsigned align_in_bits = member_alignment * CHAR_SIZE; unsigned offset = (dcs->d_sou_size_in_bits + align_in_bits - 1) & -align_in_bits; if (bit_field_width == 0 || dcs->d_sou_size_in_bits + bit_field_width > offset) dcs->d_sou_size_in_bits = offset; debug_func_dcs(__func__); } /* Add a member to the struct or union type that is being built in 'dcs'. */ static void dcs_add_member(sym_t *mem) { type_t *tp = mem->s_type; unsigned int union_size = 0; if (dcs->d_kind == DLK_UNION) { union_size = dcs->d_sou_size_in_bits; dcs->d_sou_size_in_bits = 0; } if (mem->s_bitfield) { dcs_align(alignment(tp), tp->t_bit_field_width); // XXX: Why round down? mem->u.s_member.sm_offset_in_bits = dcs->d_sou_size_in_bits - dcs->d_sou_size_in_bits % size_in_bits(tp->t_tspec); tp->t_bit_field_offset = dcs->d_sou_size_in_bits - mem->u.s_member.sm_offset_in_bits; dcs->d_sou_size_in_bits += tp->t_bit_field_width; } else { unsigned int align = dcs->d_mem_align > 0 ? dcs->d_mem_align : alignment(tp); dcs_align(align, 0); mem->u.s_member.sm_offset_in_bits = dcs->d_sou_size_in_bits; dcs->d_sou_size_in_bits += type_size_in_bits(tp); } if (union_size > dcs->d_sou_size_in_bits) dcs->d_sou_size_in_bits = union_size; debug_func_dcs(__func__); } sym_t * declare_unnamed_member(void) { sym_t *mem = block_zero_alloc(sizeof(*mem), "sym"); mem->s_name = unnamed; mem->s_kind = SK_MEMBER; mem->s_scl = dcs->d_kind == DLK_STRUCT ? STRUCT_MEMBER : UNION_MEMBER; mem->s_block_level = -1; mem->s_type = dcs->d_type; mem->u.s_member.sm_containing_type = dcs->d_tag_type->u.sou; dcs_add_member(mem); suppress_bitfieldtype = false; return mem; } sym_t * declare_member(sym_t *dsym) { lint_assert(is_member(dsym)); sym_t *rdsym = dcs->d_redeclared_symbol; if (rdsym != NULL) { debug_sym("rdsym: ", rdsym, "\n"); lint_assert(is_member(rdsym)); if (dsym->u.s_member.sm_containing_type == rdsym->u.s_member.sm_containing_type) { /* duplicate member name '%s' */ error(33, dsym->s_name); symtab_remove_forever(rdsym); } } check_type(dsym); type_t *tp = dsym->s_type; tspec_t t = tp->t_tspec; if (dsym->s_bitfield) check_bit_field(dsym, &t, &tp); else if (t == FUNC) { /* function illegal in structure or union */ error(38); dsym->s_type = tp = block_derive_type(tp, t = PTR); } /* * bit-fields of length 0 are not warned about because length_in_bits * does not return the length of the bit-field but the length of the * type the bit-field is packed in (it's ok) */ int sz = length_in_bits(dsym->s_type, dsym->s_name); if (sz == 0 && t == ARRAY && dsym->s_type->u.dimension == 0) /* zero-sized array '%s' in struct requires C99 or later */ c99ism(39, dsym->s_name); dcs_add_member(dsym); check_function_definition(dsym, false); suppress_bitfieldtype = false; return dsym; } sym_t * set_bit_field_width(sym_t *dsym, int bit_field_width) { if (dsym == NULL) { dsym = block_zero_alloc(sizeof(*dsym), "sym"); dsym->s_name = unnamed; dsym->s_kind = SK_MEMBER; dsym->s_scl = STRUCT_MEMBER; dsym->s_type = gettyp(UINT); dsym->s_block_level = -1; lint_assert(dcs->d_tag_type->u.sou != NULL); dsym->u.s_member.sm_containing_type = dcs->d_tag_type->u.sou; } dsym->s_type = block_dup_type(dsym->s_type); dsym->s_type->t_bitfield = true; dsym->s_type->t_bit_field_width = bit_field_width; dsym->s_bitfield = true; debug_sym("set_bit_field_width: ", dsym, "\n"); return dsym; } void add_type_qualifiers(type_qualifiers *dst, type_qualifiers src) { if (src.tq_const && dst->tq_const) /* duplicate '%s' */ warning(10, "const"); if (src.tq_volatile && dst->tq_volatile) /* duplicate '%s' */ warning(10, "volatile"); dst->tq_const = dst->tq_const | src.tq_const; dst->tq_restrict = dst->tq_restrict | src.tq_restrict; dst->tq_volatile = dst->tq_volatile | src.tq_volatile; dst->tq_atomic = dst->tq_atomic | src.tq_atomic; debug_step("%s: '%s'", __func__, type_qualifiers_string(*dst)); } qual_ptr * append_qualified_pointer(qual_ptr *p1, qual_ptr *p2) { qual_ptr *tail = p2; while (tail->p_next != NULL) tail = tail->p_next; tail->p_next = p1; return p2; } static type_t * block_derive_pointer(type_t *stp, bool is_const, bool is_volatile) { type_t *tp = block_derive_type(stp, PTR); tp->t_const = is_const; tp->t_volatile = is_volatile; debug_step("%s: '%s'", __func__, type_name(tp)); return tp; } sym_t * add_pointer(sym_t *decl, qual_ptr *p) { debug_dcs(); type_t **tpp = &decl->s_type; lint_assert(*tpp != NULL); while (*tpp != dcs->d_type) { tpp = &(*tpp)->t_subt; lint_assert(*tpp != NULL); } while (p != NULL) { *tpp = block_derive_pointer(dcs->d_type, p->qualifiers.tq_const, p->qualifiers.tq_volatile); tpp = &(*tpp)->t_subt; qual_ptr *next = p->p_next; free(p); p = next; } debug_step("%s: '%s'", __func__, type_name(decl->s_type)); return decl; } static type_t * block_derive_array(type_t *stp, bool has_dim, int dim) { type_t *tp = block_derive_type(stp, ARRAY); tp->u.dimension = dim; #if 0 /* * When the type of the declaration 'void *b[4]' is constructed (see * add_function, add_array, add_pointer), the intermediate type * 'void[4]' is invalid and only later gets the '*' inserted in the * middle of the type. Due to the invalid intermediate type, this * check cannot be enabled yet. */ if (stp->t_tspec == VOID) { /* array of incomplete type */ error(301); tp->t_subt = gettyp(CHAR); } #endif if (dim < 0) /* negative array dimension (%d) */ error(20, dim); else if (dim == 0 && has_dim) /* zero sized array requires C99 or later */ c99ism(322); else if (dim == 0 && !has_dim) tp->t_incomplete_array = true; debug_step("%s: '%s'", __func__, type_name(tp)); return tp; } sym_t * add_array(sym_t *decl, bool has_dim, int dim) { debug_dcs(); type_t **tpp = &decl->s_type; lint_assert(*tpp != NULL); while (*tpp != dcs->d_type) { tpp = &(*tpp)->t_subt; lint_assert(*tpp != NULL); } *tpp = block_derive_array(dcs->d_type, has_dim, dim); debug_step("%s: '%s'", __func__, type_name(decl->s_type)); return decl; } static type_t * block_derive_function(type_t *ret, bool proto, sym_t *params, bool vararg, bool noreturn) { type_t *tp = block_derive_type(ret, FUNC); tp->t_proto = proto; if (proto) tp->u.params = params; tp->t_noreturn = noreturn; tp->t_vararg = vararg; debug_step("%s: '%s'", __func__, type_name(tp)); return tp; } static const char * tag_name(scl_t sc) { return sc == STRUCT_TAG ? "struct" : sc == UNION_TAG ? "union" : "enum"; } static void check_prototype_parameters(sym_t *args) { for (sym_t *sym = dcs->d_first_dlsym; sym != NULL; sym = sym->s_level_next) { scl_t sc = sym->s_scl; if (sc == STRUCT_TAG || sc == UNION_TAG || sc == ENUM_TAG) /* dubious tag declaration '%s %s' */ warning(85, tag_name(sc), sym->s_name); } for (sym_t *arg = args; arg != NULL; arg = arg->s_next) { if (arg->s_type->t_tspec == VOID && !(arg == args && arg->s_next == NULL)) { /* void must be sole parameter */ error(60); arg->s_type = gettyp(INT); } } } static void old_style_function(sym_t *decl, sym_t *params) { /* * Remember the list of parameters only if this really seems to be a * function definition. */ if (dcs->d_enclosing->d_kind == DLK_EXTERN && decl->s_type == dcs->d_enclosing->d_type) { /* * Assume that this becomes a function definition. If not, it * will be corrected in check_function_definition. */ if (params != NULL) { decl->s_osdef = true; decl->u.s_old_style_params = params; } } else { if (params != NULL) /* function prototype parameters must have types */ warning(62); } } sym_t * add_function(sym_t *decl, parameter_list params) { debug_enter(); debug_dcs_all(); debug_sym("decl: ", decl, "\n"); #ifdef DEBUG for (const sym_t *p = params.first; p != NULL; p = p->s_next) debug_sym("param: ", p, "\n"); #endif if (params.prototype) { if (!allow_c90) /* function prototypes are illegal in traditional C */ warning(270); check_prototype_parameters(params.first); if (params.first != NULL && params.first->s_type->t_tspec == VOID) params.first = NULL; } else old_style_function(decl, params.first); if (params.used) decl->s_used = true; /* * The symbols are removed from the symbol table by * end_declaration_level after add_function. To be able to restore them * if this is a function definition, a pointer to the list of all * symbols is stored in dcs->d_enclosing->d_func_proto_syms. Also, a * list of the parameters (concatenated by s_next) is stored in * dcs->d_enclosing->d_func_params. (dcs->d_enclosing must be used * because *dcs is the declaration stack element created for the list * of params and is removed after add_function.) */ if (dcs->d_enclosing->d_kind == DLK_EXTERN && decl->s_type == dcs->d_enclosing->d_type) { dcs->d_enclosing->d_func_proto_syms = dcs->d_first_dlsym; dcs->d_enclosing->d_func_params = params.first; debug_dcs_all(); } type_t **tpp = &decl->s_type; lint_assert(*tpp != NULL); while (*tpp != dcs->d_enclosing->d_type) { tpp = &(*tpp)->t_subt; lint_assert(*tpp != NULL); } *tpp = block_derive_function(dcs->d_enclosing->d_type, params.prototype, params.first, params.vararg, params.noreturn || dcs->d_enclosing->d_noreturn); debug_step("add_function: '%s'", type_name(decl->s_type)); debug_dcs_all(); debug_leave(); return decl; } /* * In a function declaration, a list of identifiers (as opposed to a list of * types) is allowed only if it's also a function definition. */ void check_function_definition(sym_t *sym, bool msg) { if (sym->s_osdef) { if (msg) /* incomplete or misplaced function definition */ error(22); sym->s_osdef = false; sym->u.s_old_style_params = NULL; } } /* The symbol gets a storage class and a definedness. */ sym_t * declarator_name(sym_t *sym) { scl_t sc = NO_SCL; if (sym->s_scl == NO_SCL) dcs->d_redeclared_symbol = NULL; else if (sym->s_defparam) { sym->s_defparam = false; dcs->d_redeclared_symbol = NULL; } else { dcs->d_redeclared_symbol = sym; if (is_query_enabled[16] && sym->s_scl == STATIC && dcs->d_scl != STATIC) { /* '%s' was declared 'static', now non-'static' */ query_message(16, sym->s_name); print_previous_declaration(sym); } sym = pushdown(sym); } switch (dcs->d_kind) { case DLK_STRUCT: case DLK_UNION: sym->u.s_member.sm_containing_type = dcs->d_tag_type->u.sou; sym->s_def = DEF; sc = dcs->d_kind == DLK_STRUCT ? STRUCT_MEMBER : UNION_MEMBER; break; case DLK_EXTERN: /* * Symbols that are 'static' or without any storage class are * tentatively defined. Symbols that are tentatively defined or * declared may later become defined if an initializer is seen * or this is a function definition. */ sc = dcs->d_scl; if (sc == NO_SCL || sc == THREAD_LOCAL) { sc = EXTERN; sym->s_def = TDEF; } else if (sc == STATIC) sym->s_def = TDEF; else if (sc == TYPEDEF) sym->s_def = DEF; else { lint_assert(sc == EXTERN); sym->s_def = DECL; } break; case DLK_PROTO_PARAMS: sym->s_param = true; /* FALLTHROUGH */ case DLK_OLD_STYLE_PARAMS: lint_assert(dcs->d_scl == NO_SCL || dcs->d_scl == REG); sym->s_register = dcs->d_scl == REG; sc = AUTO; sym->s_def = DEF; break; case DLK_AUTO: if ((sc = dcs->d_scl) == NO_SCL) { /* * XXX somewhat ugly because we don't know whether this * is AUTO or EXTERN (functions). If we are wrong, it * must be corrected in declare_local, when the * necessary type information is available. */ sc = AUTO; sym->s_def = DEF; } else if (sc == AUTO || sc == STATIC || sc == TYPEDEF || sc == THREAD_LOCAL) sym->s_def = DEF; else if (sc == REG) { sym->s_register = true; sc = AUTO; sym->s_def = DEF; } else { lint_assert(sc == EXTERN); sym->s_def = DECL; } break; default: lint_assert(dcs->d_kind == DLK_ABSTRACT); /* try to continue after syntax errors */ sc = NO_SCL; } sym->s_scl = sc; sym->s_type = dcs->d_type; if (dcs->d_used) sym->s_used = true; dcs->d_func_proto_syms = NULL; debug_sym("declarator_name: ", sym, "\n"); debug_func_dcs(__func__); return sym; } sym_t * old_style_function_parameter_name(sym_t *sym) { if (sym->s_scl != NO_SCL) { if (block_level == sym->s_block_level) { /* redeclaration of formal parameter '%s' */ error(21, sym->s_name); lint_assert(sym->s_defparam); } sym = pushdown(sym); } sym->s_type = gettyp(INT); sym->s_scl = AUTO; sym->s_def = DEF; sym->s_defparam = true; sym->s_param = true; debug_sym("old_style_function_parameter_name: ", sym, "\n"); return sym; } /*- * Checks all possible cases of tag redeclarations. * * decl whether T_LBRACE follows * semi whether T_SEMI follows */ static sym_t * new_tag(sym_t *tag, scl_t scl, bool decl, bool semi) { if (tag->s_block_level < block_level) { if (semi) { /* "struct a;" */ if (allow_c90) { /* XXX: Why is this warning suppressed in C90 mode? */ if (allow_trad || allow_c99) /* declaration of '%s %s' intro... */ warning(44, tag_name(scl), tag->s_name); tag = pushdown(tag); } else if (tag->s_scl != scl) /* base type is really '%s %s' */ warning(45, tag_name(tag->s_scl), tag->s_name); dcs->d_enclosing->d_nonempty_decl = true; } else if (decl) { /* "struct a { ... } " */ if (hflag) /* redefinition of '%s' hides earlier one */ warning(43, tag->s_name); tag = pushdown(tag); dcs->d_enclosing->d_nonempty_decl = true; } else if (tag->s_scl != scl) { /* base type is really '%s %s' */ warning(45, tag_name(tag->s_scl), tag->s_name); /* XXX: Why is this warning suppressed in C90 mode? */ if (allow_trad || allow_c99) /* declaration of '%s %s' introduces ... */ warning(44, tag_name(scl), tag->s_name); tag = pushdown(tag); dcs->d_enclosing->d_nonempty_decl = true; } } else { if (tag->s_scl != scl || (decl && !is_incomplete(tag->s_type))) { /* %s tag '%s' redeclared as %s */ error(46, tag_name(tag->s_scl), tag->s_name, tag_name(scl)); print_previous_declaration(tag); tag = pushdown(tag); dcs->d_enclosing->d_nonempty_decl = true; } else if (semi || decl) dcs->d_enclosing->d_nonempty_decl = true; } debug_sym("new_tag: ", tag, "\n"); debug_dcs_all(); return tag; } /*- * tag the symbol table entry of the tag * kind the kind of the tag (STRUCT/UNION/ENUM) * decl whether the tag type will be completed in this declaration * (when the following token is T_LBRACE) * semi whether the following token is T_SEMI */ type_t * make_tag_type(sym_t *tag, tspec_t kind, bool decl, bool semi) { scl_t scl; type_t *tp; if (kind == STRUCT) scl = STRUCT_TAG; else if (kind == UNION) scl = UNION_TAG; else { lint_assert(kind == ENUM); scl = ENUM_TAG; } if (tag != NULL) { if (tag->s_scl != NO_SCL) tag = new_tag(tag, scl, decl, semi); else { /* a new tag, no empty declaration */ dcs->d_enclosing->d_nonempty_decl = true; if (scl == ENUM_TAG && !decl) { /* TODO: Make this an error in C99 mode as well. */ if (allow_c90 && ((!allow_trad && !allow_c99) || pflag)) /* forward reference to enum type */ warning(42); } } if (tag->s_scl == NO_SCL) { tag->s_scl = scl; tag->s_type = tp = block_zero_alloc(sizeof(*tp), "type"); tp->t_packed = dcs->d_packed; } else tp = tag->s_type; } else { tag = block_zero_alloc(sizeof(*tag), "sym"); tag->s_name = unnamed; tag->s_def_pos = unique_curr_pos(); tag->s_kind = SK_TAG; tag->s_scl = scl; tag->s_block_level = -1; tag->s_type = tp = block_zero_alloc(sizeof(*tp), "type"); tp->t_packed = dcs->d_packed; dcs->d_enclosing->d_nonempty_decl = true; } if (tp->t_tspec == NO_TSPEC) { tp->t_tspec = kind; if (kind != ENUM) { tp->u.sou = block_zero_alloc(sizeof(*tp->u.sou), "struct_or_union"); tp->u.sou->sou_align = 1; tp->u.sou->sou_tag = tag; tp->u.sou->sou_incomplete = true; } else { tp->t_is_enum = true; tp->u.enumer = block_zero_alloc( sizeof(*tp->u.enumer), "enumeration"); tp->u.enumer->en_tag = tag; tp->u.enumer->en_incomplete = true; } } debug_printf("%s: '%s'", __func__, type_name(tp)); debug_sym(" ", tag, "\n"); debug_dcs_all(); return tp; } static bool has_named_member(const struct_or_union *sou) { for (const sym_t *mem = sou->sou_first_member; mem != NULL; mem = mem->s_next) { if (mem->s_name != unnamed) return true; if (is_struct_or_union(mem->s_type->t_tspec) && has_named_member(mem->s_type->u.sou)) return true; } return false; } type_t * complete_struct_or_union(sym_t *first_member) { type_t *tp = dcs->d_tag_type; if (tp == NULL) /* in case of syntax errors */ return gettyp(INT); dcs_align(dcs->d_sou_align, 0); struct_or_union *sou = tp->u.sou; sou->sou_align = dcs->d_sou_align; sou->sou_incomplete = false; sou->sou_first_member = first_member; if (tp->t_packed) pack_struct_or_union(tp); else sou->sou_size_in_bits = dcs->d_sou_size_in_bits; if (sou->sou_size_in_bits == 0) /* zero sized %s is a C99 feature */ c99ism(47, tspec_name(tp->t_tspec)); else if (!has_named_member(sou)) /* '%s' has no named members */ warning(65, type_name(tp)); debug_step("%s: '%s'", __func__, type_name(tp)); debug_dcs_all(); return tp; } type_t * complete_enum(sym_t *first_enumerator) { type_t *tp = dcs->d_tag_type; tp->u.enumer->en_incomplete = false; tp->u.enumer->en_first_enumerator = first_enumerator; debug_step("%s: '%s'", __func__, type_name(tp)); debug_func_dcs(__func__); return tp; } sym_t * enumeration_constant(sym_t *sym, int val, bool implicit) { if (sym->s_scl != NO_SCL) { if (sym->s_block_level == block_level) { /* no hflag, because this is illegal */ if (sym->s_param) /* enumeration constant '%s' hides parameter */ warning(57, sym->s_name); else { /* redeclaration of '%s' */ error(27, sym->s_name); /* * Inside blocks, it should not be too * complicated to find the position of the * previous declaration */ if (block_level == 0) print_previous_declaration(sym); } } else { if (hflag) /* redefinition of '%s' hides earlier one */ warning(43, sym->s_name); } sym = pushdown(sym); } sym->s_scl = ENUM_CONST; sym->s_type = dcs->d_tag_type; sym->u.s_enum_constant = val; if (implicit && val == TARG_INT_MIN) /* enumeration value '%s' overflows */ warning(48, sym->s_name); enumval = val == TARG_INT_MAX ? TARG_INT_MIN : val + 1; debug_sym("enumeration_constant: ", sym, "\n"); return sym; } static bool str_ends_with(const char *s, const char *suffix) { size_t s_len = strlen(s); size_t suffix_len = strlen(suffix); return s_len >= suffix_len && memcmp(s + s_len - suffix_len, suffix, suffix_len) == 0; } void check_extern_declaration(const sym_t *sym) { if (sym->s_scl == EXTERN && dcs->d_redeclared_symbol == NULL && str_ends_with(curr_pos.p_file, ".c") && allow_c90 && !ch_isdigit(sym->s_name[0]) && /* see mktempsym */ strcmp(sym->s_name, "main") != 0) { /* missing%s header declaration for '%s' */ warning(351, sym->s_type->t_tspec == FUNC ? "" : " 'extern'", sym->s_name); } if (sym->s_type->t_tspec == FUNC && sym->s_scl == EXTERN && sym->s_def == DECL && !in_system_header) /* redundant 'extern' in function declaration of '%s' */ query_message(13, sym->s_name); } /* * Check whether the symbol cannot be initialized due to type/storage class. * Return whether an error has been detected. */ static bool check_init(const sym_t *sym) { if (sym->s_type->t_tspec == FUNC) { /* cannot initialize function '%s' */ error(24, sym->s_name); return true; } if (sym->s_scl == TYPEDEF) { /* cannot initialize typedef '%s' */ error(25, sym->s_name); return true; } if (sym->s_scl == EXTERN && sym->s_def == DECL) { if (dcs->d_kind == DLK_EXTERN) /* cannot initialize extern declaration '%s' */ warning(26, sym->s_name); else { /* cannot initialize extern declaration '%s' */ error(26, sym->s_name); return true; } } return false; } /* * Compares a prototype declaration with the remembered parameters of a * previous old-style function definition. */ static bool check_old_style_definition(const sym_t *rdsym, const sym_t *dsym) { const sym_t *old_params = rdsym->u.s_old_style_params; const sym_t *proto_params = dsym->s_type->u.params; bool msg = false; int old_n = 0; for (const sym_t *p = old_params; p != NULL; p = p->s_next) old_n++; int proto_n = 0; for (const sym_t *p = proto_params; p != NULL; p = p->s_next) proto_n++; if (old_n != proto_n) { /* prototype does not match old-style definition */ error(63); msg = true; goto end; } const sym_t *arg = old_params; const sym_t *parg = proto_params; int n = 1; while (old_n-- > 0) { bool dowarn = false; if (!types_compatible(arg->s_type, parg->s_type, true, true, &dowarn) || dowarn) { /* prototype does not match old-style ... */ error(299, n); msg = true; } arg = arg->s_next; parg = parg->s_next; n++; } end: if (msg && rflag) /* old-style definition */ message_at(300, &rdsym->s_def_pos); return msg; } /* Process a single external or 'static' declarator. */ static void declare_extern(sym_t *dsym, bool has_initializer, const sbuf_t *renaming) { if (renaming != NULL) { lint_assert(dsym->s_rename == NULL); char *s = level_zero_alloc(1, renaming->sb_len + 1, "string"); (void)memcpy(s, renaming->sb_name, renaming->sb_len + 1); dsym->s_rename = s; } check_extern_declaration(dsym); check_function_definition(dsym, true); check_type(dsym); if (has_initializer && !check_init(dsym)) dsym->s_def = DEF; /* * Declarations of functions are marked as "tentative" in * declarator_name(). This is wrong because there are no tentative * function definitions. */ if (dsym->s_type->t_tspec == FUNC && dsym->s_def == TDEF) dsym->s_def = DECL; if (dcs->d_inline) { if (dsym->s_type->t_tspec == FUNC) { dsym->s_inline = true; } else { /* variable '%s' declared inline */ warning(268, dsym->s_name); } } /* Write the declaration into the output file */ if (plibflg && llibflg && dsym->s_type->t_tspec == FUNC && dsym->s_type->t_proto) { /* * With both LINTLIBRARY and PROTOLIB the prototype is written * as a function definition to the output file. */ bool rval = dsym->s_type->t_subt->t_tspec != VOID; outfdef(dsym, &dsym->s_def_pos, rval, false, NULL); } else if (!is_compiler_builtin(dsym->s_name) && !(has_initializer && dsym->s_type->t_incomplete_array)) { outsym(dsym, dsym->s_scl, dsym->s_def); } sym_t *rdsym = dcs->d_redeclared_symbol; if (rdsym != NULL) { /* * If the old symbol stems from an old-style function * definition, we have remembered the params in * rdsym->s_old_style_params and compare them with the params * of the prototype. */ bool redec = rdsym->s_osdef && dsym->s_type->t_proto && check_old_style_definition(rdsym, dsym); bool dowarn = false; if (!redec && !check_redeclaration(dsym, &dowarn)) { if (dowarn) { /* TODO: Make this an error in C99 mode as well. */ if (!allow_trad && !allow_c99) /* redeclaration of '%s' */ error(27, dsym->s_name); else /* redeclaration of '%s' */ warning(27, dsym->s_name); print_previous_declaration(rdsym); } /* * Take over the remembered params if the new symbol is * not a prototype. */ if (rdsym->s_osdef && !dsym->s_type->t_proto) { dsym->s_osdef = rdsym->s_osdef; dsym->u.s_old_style_params = rdsym->u.s_old_style_params; dsym->s_def_pos = rdsym->s_def_pos; } if (rdsym->s_type->t_proto && !dsym->s_type->t_proto) dsym->s_def_pos = rdsym->s_def_pos; else if (rdsym->s_def == DEF && dsym->s_def != DEF) dsym->s_def_pos = rdsym->s_def_pos; copy_usage_info(dsym, rdsym); /* Once a name is defined, it remains defined. */ if (rdsym->s_def == DEF) dsym->s_def = DEF; /* once a function is inline, it remains inline */ if (rdsym->s_inline) dsym->s_inline = true; complete_type(dsym, rdsym); } symtab_remove_forever(rdsym); } if (dsym->s_scl == TYPEDEF) { dsym->s_type = block_dup_type(dsym->s_type); dsym->s_type->t_typedef = true; set_first_typedef(dsym->s_type, dsym); if (dsym->s_type->t_tspec == STRUCT) /* typedef '%s' of struct type '%s' */ query_message(21, dsym->s_name, type_name(dsym->s_type)); else if (dsym->s_type->t_tspec == UNION) /* typedef '%s' of union type '%s' */ query_message(22, dsym->s_name, type_name(dsym->s_type)); else if (dsym->s_type->t_tspec == PTR && dsym->s_type->t_subt->t_tspec == STRUCT) /* typedef '%s' of pointer to struct type '%s' */ query_message(23, dsym->s_name, type_name(dsym->s_type)); else if (dsym->s_type->t_tspec == PTR && dsym->s_type->t_subt->t_tspec == UNION) /* typedef '%s' of pointer to union type '%s' */ query_message(24, dsym->s_name, type_name(dsym->s_type)); } debug_printf("%s: ", __func__); debug_sym("", dsym, "\n"); } void declare(sym_t *decl, bool has_initializer, sbuf_t *renaming) { if (dcs->d_kind == DLK_EXTERN) declare_extern(decl, has_initializer, renaming); else if (dcs->d_kind == DLK_OLD_STYLE_PARAMS || dcs->d_kind == DLK_PROTO_PARAMS) { if (renaming != NULL) /* symbol renaming can't be used on function ... */ error(310); else (void)declare_parameter(decl, has_initializer); } else { lint_assert(dcs->d_kind == DLK_AUTO); if (renaming != NULL) /* symbol renaming can't be used on automatic ... */ error(311); else declare_local(decl, has_initializer); } debug_printf("%s: ", __func__); debug_sym("", decl, "\n"); } /* * Copies information about usage into a new symbol table entry of * the same symbol. */ void copy_usage_info(sym_t *sym, const sym_t *rdsym) { sym->s_set_pos = rdsym->s_set_pos; sym->s_use_pos = rdsym->s_use_pos; sym->s_set = rdsym->s_set; sym->s_used = rdsym->s_used; } /* * Prints an error and returns true if a symbol is redeclared/redefined. * Otherwise, returns false and, in some cases of minor problems, prints * a warning. */ bool check_redeclaration(sym_t *dsym, bool *dowarn) { sym_t *rdsym = dcs->d_redeclared_symbol; if (rdsym->s_scl == ENUM_CONST) { /* redeclaration of '%s' */ error(27, dsym->s_name); print_previous_declaration(rdsym); return true; } if (rdsym->s_scl == TYPEDEF) { /* typedef '%s' redeclared */ error(89, dsym->s_name); print_previous_declaration(rdsym); return true; } if (dsym->s_scl == TYPEDEF) { /* redeclaration of '%s' */ error(27, dsym->s_name); print_previous_declaration(rdsym); return true; } if (rdsym->s_def == DEF && dsym->s_def == DEF) { /* redefinition of '%s' */ error(28, dsym->s_name); print_previous_declaration(rdsym); return true; } if (!types_compatible(rdsym->s_type, dsym->s_type, false, false, dowarn)) { /* redeclaration of '%s' with type '%s', expected '%s' */ error(347, dsym->s_name, type_name(dsym->s_type), type_name(rdsym->s_type)); print_previous_declaration(rdsym); return true; } if (rdsym->s_scl == EXTERN && dsym->s_scl == EXTERN) return false; if (rdsym->s_scl == STATIC && dsym->s_scl == STATIC) return false; if (rdsym->s_scl == STATIC && dsym->s_def == DECL) return false; if (rdsym->s_scl == EXTERN && rdsym->s_def == DEF) { /* * All cases except "int a = 1; static int a;" are caught above * with or without a warning */ /* redeclaration of '%s' */ error(27, dsym->s_name); print_previous_declaration(rdsym); return true; } if (rdsym->s_scl == EXTERN) { /* '%s' was previously declared extern, becomes static */ warning(29, dsym->s_name); print_previous_declaration(rdsym); return false; } /*- * Now it's one of: * "static a; int a;" * "static a; int a = 1;" * "static a = 1; int a;" */ /* TODO: Make this an error in C99 mode as well. */ if (!allow_trad && !allow_c99) { /* redeclaration of '%s'; C90 or later require static */ warning(30, dsym->s_name); print_previous_declaration(rdsym); } dsym->s_scl = STATIC; return false; } static bool qualifiers_correspond(const type_t *tp1, const type_t *tp2, bool ignqual) { if (tp1->t_const != tp2->t_const && !ignqual && allow_c90) return false; if (tp1->t_volatile != tp2->t_volatile && !ignqual && allow_c90) return false; return true; } bool pointer_types_are_compatible(const type_t *tp1, const type_t *tp2, bool ignqual) { return tp1->t_tspec == VOID || tp2->t_tspec == VOID || qualifiers_correspond(tp1, tp2, ignqual); } static bool prototypes_compatible(const type_t *tp1, const type_t *tp2, bool *dowarn) { if (tp1->t_vararg != tp2->t_vararg) return false; const sym_t *p1 = tp1->u.params; const sym_t *p2 = tp2->u.params; for (; p1 != NULL && p2 != NULL; p1 = p1->s_next, p2 = p2->s_next) { if (!types_compatible(p1->s_type, p2->s_type, true, false, dowarn)) return false; } return p1 == p2; } /* * Returns whether all parameters of a prototype are compatible with an * old-style function declaration. */ static bool is_old_style_compat(const type_t *tp) { if (tp->t_vararg) return false; for (const sym_t *p = tp->u.params; p != NULL; p = p->s_next) { tspec_t t = p->s_type->t_tspec; if (t == FLOAT || t == CHAR || t == SCHAR || t == UCHAR || t == SHORT || t == USHORT) return false; } return true; } /*- * ignqual ignore type qualifiers; used for function parameters * promot promote the left type; used for comparison of parameters of * old-style function definitions with parameters of prototypes. * *dowarn is set to true if an old-style function declaration is not * compatible with a prototype */ bool types_compatible(const type_t *tp1, const type_t *tp2, bool ignqual, bool promot, bool *dowarn) { while (tp1 != NULL && tp2 != NULL) { tspec_t t = tp1->t_tspec; if (promot) { if (t == FLOAT) t = DOUBLE; else if (t == CHAR || t == SCHAR) t = INT; else if (t == UCHAR) t = allow_c90 ? INT : UINT; else if (t == SHORT) t = INT; else if (t == USHORT) { /* CONSTCOND */ t = TARG_INT_MAX < TARG_USHRT_MAX || !allow_c90 ? UINT : INT; } } if (t != tp2->t_tspec) return false; if (!qualifiers_correspond(tp1, tp2, ignqual)) return false; if (is_struct_or_union(t)) return tp1->u.sou == tp2->u.sou; if (t == ENUM && eflag) return tp1->u.enumer == tp2->u.enumer; if (t == ARRAY && tp1->u.dimension != tp2->u.dimension) { if (tp1->u.dimension != 0 && tp2->u.dimension != 0) return false; } if (t == FUNC && allow_c90) { if (tp1->t_proto && tp2->t_proto) { if (!prototypes_compatible(tp1, tp2, dowarn)) return false; } else if ((tp1->t_proto || tp2->t_proto) && dowarn != NULL && !is_old_style_compat(tp1->t_proto ? tp1 : tp2)) *dowarn = true; } tp1 = tp1->t_subt; tp2 = tp2->t_subt; ignqual = promot = false; } return tp1 == tp2; } /* * Completes a type by copying the dimension and prototype information from a * second compatible type. * * Following lines are legal: * "typedef a[]; a b; a b[10]; a c; a c[20];" * "typedef ft(); ft f; f(int); ft g; g(long);" * This means that, if a type is completed, the type structure must be * duplicated. */ void complete_type(sym_t *dsym, const sym_t *ssym) { type_t **dstp = &dsym->s_type; type_t *src = ssym->s_type; while (*dstp != NULL) { type_t *dst = *dstp; lint_assert(src != NULL); lint_assert(dst->t_tspec == src->t_tspec); if (dst->t_tspec == ARRAY) { if (dst->u.dimension == 0 && src->u.dimension != 0) { *dstp = dst = block_dup_type(dst); dst->u.dimension = src->u.dimension; dst->t_incomplete_array = false; } } else if (dst->t_tspec == FUNC) { if (!dst->t_proto && src->t_proto) { *dstp = dst = block_dup_type(dst); dst->t_proto = true; dst->u.params = src->u.params; } } dstp = &dst->t_subt; src = src->t_subt; } debug_printf("%s: ", __func__); debug_sym("dsym: ", dsym, ""); debug_sym("ssym: ", ssym, "\n"); } sym_t * declare_parameter(sym_t *sym, bool has_initializer) { check_function_definition(sym, true); check_type(sym); if (dcs->d_redeclared_symbol != NULL && dcs->d_redeclared_symbol->s_block_level == block_level) { /* redeclaration of formal parameter '%s' */ error(237, sym->s_name); symtab_remove_forever(dcs->d_redeclared_symbol); sym->s_param = true; } if (!sym->s_param) { /* declared parameter '%s' is missing */ error(53, sym->s_name); sym->s_param = true; } if (has_initializer) /* cannot initialize parameter '%s' */ error(52, sym->s_name); if (sym->s_type == NULL) /* for c(void()) */ sym->s_type = gettyp(VOID); tspec_t t = sym->s_type->t_tspec; if (t == ARRAY) sym->s_type = block_derive_type(sym->s_type->t_subt, PTR); if (t == FUNC) { if (!allow_c90) /* parameter '%s' has function type, should be ... */ warning(50, sym->s_name); sym->s_type = block_derive_type(sym->s_type, PTR); } if (t == FLOAT && !allow_c90) sym->s_type = gettyp(DOUBLE); if (dcs->d_inline) /* parameter '%s' declared inline */ warning(269, sym->s_name); if (sym->s_type->t_const && (sym->s_scl == AUTO || sym->s_scl == REG)) { /* const automatic variable '%s' */ query_message(18, sym->s_name); } /* * Arguments must have complete types. length_in_bits prints the needed * error messages (null dimension is impossible because arrays are * converted to pointers). */ if (sym->s_type->t_tspec != VOID) (void)length_in_bits(sym->s_type, sym->s_name); sym->s_used = dcs->d_used; mark_as_set(sym); debug_printf("%s: ", __func__); debug_sym("", sym, "\n"); return sym; } static bool is_character_pointer(const type_t *tp) { tspec_t st; return tp->t_tspec == PTR && (st = tp->t_subt->t_tspec, st == CHAR || st == SCHAR || st == UCHAR); } void check_func_lint_directives(void) { /* check for illegal combinations of lint directives */ if (printflike_argnum != -1 && scanflike_argnum != -1) { /* ** PRINTFLIKE ** and ** SCANFLIKE ** cannot be combined */ warning(289); printflike_argnum = scanflike_argnum = -1; } if (nvararg != -1 && (printflike_argnum != -1 || scanflike_argnum != -1)) { /* dubious use of ** VARARGS ** with ** %s ** */ warning(288, printflike_argnum != -1 ? "PRINTFLIKE" : "SCANFLIKE"); nvararg = -1; } /* * check if the numeric argument of a lint directive is compatible with * the number of parameters of the function. */ int narg = 0; for (const sym_t *p = dcs->d_func_params; p != NULL; p = p->s_next) narg++; if (nargusg > narg) { /* parameter number mismatch in comment ** %s ** */ warning(283, "ARGSUSED"); nargusg = 0; } if (nvararg > narg) { /* parameter number mismatch in comment ** %s ** */ warning(283, "VARARGS"); nvararg = 0; } if (printflike_argnum > narg) { /* parameter number mismatch in comment ** %s ** */ warning(283, "PRINTFLIKE"); printflike_argnum = -1; } else if (printflike_argnum == 0) { printflike_argnum = -1; } if (scanflike_argnum > narg) { /* parameter number mismatch in comment ** %s ** */ warning(283, "SCANFLIKE"); scanflike_argnum = -1; } else if (scanflike_argnum == 0) { scanflike_argnum = -1; } if (printflike_argnum != -1 || scanflike_argnum != -1) { narg = printflike_argnum != -1 ? printflike_argnum : scanflike_argnum; const sym_t *param = dcs->d_func_params; for (int n = 1; n < narg; n++) param = param->s_next; if (!is_character_pointer(param->s_type)) { /* parameter %d must be 'char *' for PRINTFLIKE/... */ warning(293, narg); printflike_argnum = scanflike_argnum = -1; } } } /* * Checks compatibility of an old-style function definition with a previous * prototype declaration. * Returns true if the position of the previous declaration should be reported. */ static bool check_prototype_declaration(const sym_t *old_param, const sym_t *proto_param) { type_t *old_tp = old_param->s_type; type_t *proto_tp = proto_param->s_type; bool dowarn = false; if (!types_compatible(old_tp, proto_tp, true, true, &dowarn)) { if (types_compatible(old_tp, proto_tp, true, false, &dowarn)) { /* type of '%s' does not match prototype */ return gnuism(58, old_param->s_name); } else { /* type of '%s' does not match prototype */ error(58, old_param->s_name); return true; } } if (dowarn) { /* TODO: Make this an error in C99 mode as well. */ if (!allow_trad && !allow_c99) /* type of '%s' does not match prototype */ error(58, old_param->s_name); else /* type of '%s' does not match prototype */ warning(58, old_param->s_name); return true; } return false; } /* * Warn about parameters in old-style function definitions that default to int. * Check that an old-style function definition is compatible to a previous * prototype. */ void check_func_old_style_parameters(void) { sym_t *old_params = funcsym->u.s_old_style_params; sym_t *proto_params = funcsym->s_type->u.params; for (sym_t *arg = old_params; arg != NULL; arg = arg->s_next) { if (arg->s_defparam) { /* type of parameter '%s' defaults to 'int' */ warning(32, arg->s_name); arg->s_defparam = false; mark_as_set(arg); } } /* * If this is an old-style function definition and a prototype exists, * compare the types of parameters. */ if (funcsym->s_osdef && funcsym->s_type->t_proto) { /* * If the number of parameters does not match, we need not * continue. */ int old_n = 0, proto_n = 0; bool msg = false; for (const sym_t *p = proto_params; p != NULL; p = p->s_next) proto_n++; for (const sym_t *p = old_params; p != NULL; p = p->s_next) old_n++; if (old_n != proto_n) { /* parameter mismatch: %d declared, %d defined */ error(51, proto_n, old_n); msg = true; } else { const sym_t *proto_param = proto_params; const sym_t *old_param = old_params; while (old_n-- > 0) { msg |= check_prototype_declaration(old_param, proto_param); proto_param = proto_param->s_next; old_param = old_param->s_next; } } if (msg && rflag) /* prototype declaration */ message_at(285, &dcs->d_redeclared_symbol->s_def_pos); /* from now on the prototype is valid */ funcsym->s_osdef = false; funcsym->u.s_old_style_params = NULL; } } static void check_local_hiding(const sym_t *dsym, const sym_t *rdsym) { switch (dsym->s_scl) { case AUTO: /* automatic '%s' hides external declaration with type '%s' */ warning(86, dsym->s_name, type_name(rdsym->s_type)); break; case STATIC: /* static '%s' hides external declaration with type '%s' */ warning(87, dsym->s_name, type_name(rdsym->s_type)); break; case TYPEDEF: /* typedef '%s' hides external declaration with type '%s' */ warning(88, dsym->s_name, type_name(rdsym->s_type)); break; case EXTERN: /* Already checked in declare_external_in_block. */ break; default: lint_assert(/*CONSTCOND*/false); } } static void check_local_redeclaration(const sym_t *dsym, sym_t *rdsym) { if (rdsym->s_block_level == 0) { if (hflag) check_local_hiding(dsym, rdsym); } else if (rdsym->s_block_level == block_level) { /* no hflag, because it's illegal! */ if (rdsym->s_param) { /* * if allow_c90, a "redeclaration of '%s'" error is * produced below */ if (!allow_c90) { if (hflag) /* declaration of '%s' hides ... */ warning(91, dsym->s_name); symtab_remove_forever(rdsym); } } } else if (rdsym->s_block_level < block_level && hflag) /* declaration of '%s' hides earlier one */ warning(95, dsym->s_name); if (rdsym->s_block_level == block_level) { /* redeclaration of '%s' */ error(27, dsym->s_name); symtab_remove_forever(rdsym); } } /* Processes (re)declarations of external symbols inside blocks. */ static void declare_external_in_block(sym_t *dsym) { /* look for a symbol with the same name */ sym_t *esym = dcs->d_redeclared_symbol; while (esym != NULL && esym->s_block_level != 0) { while ((esym = esym->s_symtab_next) != NULL) { if (esym->s_kind != SK_VCFT) continue; if (strcmp(dsym->s_name, esym->s_name) == 0) break; } } if (esym == NULL) return; if (esym->s_scl != EXTERN && esym->s_scl != STATIC) { /* gcc accepts this without a warning, pcc prints an error. */ /* redeclaration of '%s' */ warning(27, dsym->s_name); print_previous_declaration(esym); return; } bool dowarn = false; bool compatible = types_compatible(esym->s_type, dsym->s_type, false, false, &dowarn); if (!compatible || dowarn) { if (esym->s_scl == EXTERN) { /* inconsistent redeclaration of extern '%s' */ warning(90, dsym->s_name); print_previous_declaration(esym); } else { /* inconsistent redeclaration of static '%s' */ warning(92, dsym->s_name); print_previous_declaration(esym); } } if (compatible) { /* * Remember the external symbol, so we can update usage * information at the end of the block. */ dsym->s_ext_sym = esym; } } /* * Completes a single local declaration/definition. */ void declare_local(sym_t *dsym, bool has_initializer) { /* Correct a mistake done in declarator_name(). */ if (dsym->s_type->t_tspec == FUNC) { dsym->s_def = DECL; if (dcs->d_scl == NO_SCL) dsym->s_scl = EXTERN; } if (dsym->s_scl == EXTERN) /* nested 'extern' declaration of '%s' */ warning(352, dsym->s_name); if (dsym->s_type->t_tspec == FUNC) { if (dsym->s_scl == STATIC) { /* dubious static function '%s' at block level */ warning(93, dsym->s_name); dsym->s_scl = EXTERN; } else if (dsym->s_scl != EXTERN && dsym->s_scl != TYPEDEF) { /* function '%s' has illegal storage class */ error(94, dsym->s_name); dsym->s_scl = EXTERN; } } /* * functions may be declared inline at local scope, although this has * no effect for a later definition of the same function. * * XXX it should have an effect if !allow_c90 is set. this would also * be the way gcc behaves. */ if (dcs->d_inline) { if (dsym->s_type->t_tspec == FUNC) dsym->s_inline = true; else { /* variable '%s' declared inline */ warning(268, dsym->s_name); } } if (dsym->s_type->t_const && (dsym->s_scl == AUTO || dsym->s_scl == REG)) { /* const automatic variable '%s' */ query_message(18, dsym->s_name); } check_function_definition(dsym, true); check_type(dsym); if (dcs->d_redeclared_symbol != NULL && dsym->s_scl == EXTERN) declare_external_in_block(dsym); if (dsym->s_scl == EXTERN) { /* * XXX if the static variable at level 0 is only defined later, * checking will be possible. */ if (dsym->s_ext_sym == NULL) outsym(dsym, EXTERN, dsym->s_def); else outsym(dsym, dsym->s_ext_sym->s_scl, dsym->s_def); } if (dcs->d_redeclared_symbol != NULL) check_local_redeclaration(dsym, dcs->d_redeclared_symbol); if (has_initializer && !check_init(dsym)) { dsym->s_def = DEF; mark_as_set(dsym); } if (dsym->s_scl == TYPEDEF) { dsym->s_type = block_dup_type(dsym->s_type); dsym->s_type->t_typedef = true; set_first_typedef(dsym->s_type, dsym); } if (dsym->s_scl == STATIC) /* static variable '%s' in function */ query_message(11, dsym->s_name); debug_printf("%s: ", __func__); debug_sym("", dsym, "\n"); } /* Create a symbol for an abstract declaration. */ static sym_t * abstract_name_level(bool enclosing) { lint_assert(dcs->d_kind == DLK_ABSTRACT || dcs->d_kind == DLK_PROTO_PARAMS); sym_t *sym = block_zero_alloc(sizeof(*sym), "sym"); sym->s_name = unnamed; sym->s_def = DEF; sym->s_scl = ABSTRACT; sym->s_block_level = -1; sym->s_param = dcs->d_kind == DLK_PROTO_PARAMS; /* * At this point, dcs->d_type contains only the basic type. That type * will be updated later, adding pointers, arrays and functions as * necessary. */ sym->s_type = enclosing ? dcs->d_enclosing->d_type : dcs->d_type; dcs->d_redeclared_symbol = NULL; debug_printf("%s: ", __func__); debug_sym("", sym, "\n"); debug_func_dcs(__func__); return sym; } sym_t * abstract_name(void) { return abstract_name_level(false); } sym_t * abstract_enclosing_name(void) { return abstract_name_level(true); } /* Removes anything which has nothing to do on global level. */ void global_clean_up(void) { while (dcs->d_enclosing != NULL) end_declaration_level(); clean_up_after_error(); block_level = 0; mem_block_level = 0; debug_step("%s: mem_block_level = %zu", __func__, mem_block_level); global_clean_up_decl(true); } sym_t * declare_abstract_type(sym_t *sym) { check_function_definition(sym, true); check_type(sym); return sym; } /* Checks size after declarations of variables and their initialization. */ void check_size(const sym_t *dsym) { if (dsym->s_def == DEF && dsym->s_scl != TYPEDEF && dsym->s_type->t_tspec != FUNC && length_in_bits(dsym->s_type, dsym->s_name) == 0 && dsym->s_type->t_tspec == ARRAY && dsym->s_type->u.dimension == 0) { if (!allow_c90) /* empty array declaration for '%s' */ warning(190, dsym->s_name); else /* empty array declaration for '%s' */ error(190, dsym->s_name); } } /* Mark an object as set if it is not already. */ void mark_as_set(sym_t *sym) { if (!sym->s_set) { sym->s_set = true; sym->s_set_pos = unique_curr_pos(); } } /* Mark an object as used if it is not already. */ void mark_as_used(sym_t *sym, bool fcall, bool szof) { if (!sym->s_used) { sym->s_used = true; sym->s_use_pos = unique_curr_pos(); } /* * For function calls, another record is written. * * XXX: Should symbols used in sizeof() be treated as used or not? * Probably not, because there is no point in declaring an external * variable only to get its size. */ if (!fcall && !szof && sym->s_kind == SK_VCFT && sym->s_scl == EXTERN) outusg(sym); } /* Warns about variables and labels that are not used or only set. */ void check_usage(const decl_level *dl) { /* for this warning LINTED has no effect */ int saved_lwarn = lwarn; lwarn = LWARN_ALL; debug_step("begin lwarn %d", lwarn); for (sym_t *sym = dl->d_first_dlsym; sym != NULL; sym = sym->s_level_next) check_usage_sym(dl->d_asm, sym); lwarn = saved_lwarn; debug_step("end lwarn %d", lwarn); } static void check_parameter_usage(bool novar, const sym_t *arg) { lint_assert(arg->s_set); if (novar) return; if (!arg->s_used && !vflag) /* parameter '%s' unused in function '%s' */ warning_at(231, &arg->s_def_pos, arg->s_name, funcsym->s_name); } static void check_variable_usage(bool novar, const sym_t *sym) { lint_assert(block_level != 0); /* example at file scope: int c = ({ return 3; }); */ if (sym->s_block_level == 0 && ch_isdigit(sym->s_name[0])) return; /* errors in expressions easily cause lots of these warnings */ if (seen_error) return; /* * XXX Only variables are checked, although types should probably also * be checked */ scl_t sc = sym->s_scl; if (sc != EXTERN && sc != STATIC && sc != AUTO && sc != REG) return; if (novar) return; if (sc == EXTERN) { if (!sym->s_used && !sym->s_set) { /* '%s' unused in function '%s' */ warning_at(192, &sym->s_def_pos, sym->s_name, funcsym->s_name); } } else { if (sym->s_set && !sym->s_used) { /* '%s' set but not used in function '%s' */ warning_at(191, &sym->s_set_pos, sym->s_name, funcsym->s_name); } else if (!sym->s_used) { /* '%s' unused in function '%s' */ warning_at(192, &sym->s_def_pos, sym->s_name, funcsym->s_name); } } if (sc == EXTERN) { /* * information about usage is taken over into the symbol table * entry at level 0 if the symbol was locally declared as an * external symbol. * * XXX This is wrong for symbols declared static at level 0 if * the usage information stems from sizeof(). This is because * symbols at level 0 only used in sizeof() are considered to * not be used. */ sym_t *xsym = sym->s_ext_sym; if (xsym != NULL) { if (sym->s_used && !xsym->s_used) { xsym->s_used = true; xsym->s_use_pos = sym->s_use_pos; } if (sym->s_set && !xsym->s_set) { xsym->s_set = true; xsym->s_set_pos = sym->s_set_pos; } } } } static void check_label_usage(const sym_t *lab) { lint_assert(block_level == 1); lint_assert(lab->s_block_level == 1); if (funcsym == NULL) /* syntax error '%s' */ error(249, "labels are only valid inside a function"); else if (lab->s_set && !lab->s_used) /* label '%s' unused in function '%s' */ warning_at(232, &lab->s_set_pos, lab->s_name, funcsym->s_name); else if (!lab->s_set) /* undefined label '%s' */ warning_at(23, &lab->s_use_pos, lab->s_name); } static void check_tag_usage(const sym_t *sym) { if (!is_incomplete(sym->s_type)) return; /* always complain about incomplete tags declared inside blocks */ if (zflag || dcs->d_kind != DLK_EXTERN) return; switch (sym->s_type->t_tspec) { case STRUCT: /* struct '%s' never defined */ warning_at(233, &sym->s_def_pos, sym->s_name); break; case UNION: /* union '%s' never defined */ warning_at(234, &sym->s_def_pos, sym->s_name); break; default: lint_assert(sym->s_type->t_tspec == ENUM); /* enum '%s' never defined */ warning_at(235, &sym->s_def_pos, sym->s_name); break; } } /* Warns about a variable or a label that is not used or only set. */ void check_usage_sym(bool novar, const sym_t *sym) { if (sym->s_block_level == -1) return; if (sym->s_kind == SK_VCFT && sym->s_param) check_parameter_usage(novar, sym); else if (sym->s_kind == SK_VCFT) check_variable_usage(novar, sym); else if (sym->s_kind == SK_LABEL) check_label_usage(sym); else if (sym->s_kind == SK_TAG) check_tag_usage(sym); } static void check_global_variable_size(const sym_t *sym) { if (sym->s_def != TDEF) return; if (sym->s_type->t_tspec == FUNC) /* Maybe a syntax error after a function declaration. */ return; if (sym->s_def == TDEF && sym->s_type->t_tspec == VOID) /* Prevent an internal error in length_in_bits below. */ return; pos_t cpos = curr_pos; curr_pos = sym->s_def_pos; int len_in_bits = length_in_bits(sym->s_type, sym->s_name); curr_pos = cpos; if (len_in_bits == 0 && sym->s_type->t_tspec == ARRAY && sym->s_type->u.dimension == 0) { /* TODO: C99 6.7.5.2p1 defines this as an error as well. */ if (!allow_c90 || (sym->s_scl == EXTERN && (allow_trad || allow_c99))) { /* empty array declaration for '%s' */ warning_at(190, &sym->s_def_pos, sym->s_name); } else { /* empty array declaration for '%s' */ error_at(190, &sym->s_def_pos, sym->s_name); } } } static void check_unused_static_global_variable(const sym_t *sym) { if (sym->s_type->t_tspec == FUNC) { if (sym->s_def == DEF) { if (!sym->s_inline) /* static function '%s' unused */ warning_at(236, &sym->s_def_pos, sym->s_name); } else /* static function '%s' declared but not defined */ warning_at(290, &sym->s_def_pos, sym->s_name); } else if (!sym->s_set) /* static variable '%s' unused */ warning_at(226, &sym->s_def_pos, sym->s_name); else /* static variable '%s' set but not used */ warning_at(307, &sym->s_def_pos, sym->s_name); } static void check_static_global_variable(const sym_t *sym) { if (sym->s_type->t_tspec == FUNC && sym->s_used && sym->s_def != DEF) /* static function '%s' called but not defined */ error_at(225, &sym->s_use_pos, sym->s_name); if (!sym->s_used) check_unused_static_global_variable(sym); if (allow_c90 && sym->s_def == TDEF && sym->s_type->t_const) /* const object '%s' should have initializer */ warning_at(227, &sym->s_def_pos, sym->s_name); } static void check_global_variable(const sym_t *sym) { scl_t scl = sym->s_scl; if (scl == TYPEDEF || scl == BOOL_CONST || scl == ENUM_CONST) return; if (scl == NO_SCL) return; /* May be caused by a syntax error. */ lint_assert(scl == EXTERN || scl == STATIC); check_global_variable_size(sym); if (scl == STATIC) check_static_global_variable(sym); } void end_translation_unit(void) { if (block_level != 0 || dcs->d_enclosing != NULL) norecover(); for (const sym_t *sym = dcs->d_first_dlsym; sym != NULL; sym = sym->s_level_next) { if (sym->s_block_level == -1) continue; if (sym->s_kind == SK_VCFT) check_global_variable(sym); else if (sym->s_kind == SK_TAG) check_tag_usage(sym); else lint_assert(sym->s_kind == SK_MEMBER); } } /* * Prints information about location of previous definition/declaration. */ void print_previous_declaration(const sym_t *psym) { if (!rflag) return; if (psym->s_def == DEF || psym->s_def == TDEF) /* previous definition of '%s' */ message_at(261, &psym->s_def_pos, psym->s_name); else /* previous declaration of '%s' */ message_at(260, &psym->s_def_pos, psym->s_name); } /* * Gets a node for a constant and returns the value of this constant * as integer. * * If the node is not constant or too large for int or of type float, * a warning will be printed. * * to_int_constant() should be used only inside declarations. If it is used in * expressions, it frees the memory used for the expression. */ int to_int_constant(tnode_t *tn, bool required) { if (tn == NULL) return 1; val_t *v = integer_constant(tn, required); bool is_unsigned = is_uinteger(v->v_tspec); int64_t val = v->u.integer; free(v); /* * Abstract declarations are used inside expression. To free the memory * would be a fatal error. We don't free blocks that are inside casts * because these will be used later to match types. */ if (tn->tn_op != CON && dcs->d_kind != DLK_ABSTRACT) expr_free_all(); bool out_of_bounds = is_unsigned ? (uint64_t)val > (uint64_t)TARG_INT_MAX : val > (int64_t)TARG_INT_MAX || val < (int64_t)TARG_INT_MIN; if (out_of_bounds) { char buf[256]; unsigned long long abs_val = is_unsigned || val >= 0 ? (unsigned long long)val : -(unsigned long long)val; snprintf(buf, sizeof(buf), "%s%#llx", is_unsigned || val >= 0 ? "" : "-", abs_val); /* constant %s too large for 'int' */ warning(56, buf); } return (int)val; }