/* $NetBSD: lex.c,v 1.134 2022/10/01 10:04:06 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: lex.c,v 1.134 2022/10/01 10:04:06 rillig Exp $"); #endif #include #include #include #include #include #include #include #include "lint1.h" #include "cgram.h" #define CHAR_MASK ((1U << CHAR_SIZE) - 1) /* Current position (it's also updated when an included file is parsed) */ pos_t curr_pos = { "", 1, 0 }; /* * Current position in C source (not updated when an included file is * parsed). */ pos_t csrc_pos = { "", 1, 0 }; bool in_gcc_attribute; bool in_system_header; /* * Valid values for 'since' are 78, 90, 99, 11. * * As of 2022-04-30, lint treats 11 like 99, in order to provide good error * messages instead of a simple parse error. If the keyword '_Generic' were * not defined, it would be interpreted as an implicit function call, leading * to a parse error. */ #define kwdef(name, token, scl, tspec, tqual, since, gcc, deco) \ { \ name, token, scl, tspec, tqual, \ (since) == 90, \ /* CONSTCOND */ (since) == 99 || (since) == 11, \ (gcc) > 0, \ ((deco) & 1) != 0, ((deco) & 2) != 0, ((deco) & 4) != 0, \ } #define kwdef_token(name, token, since, gcc, deco) \ kwdef(name, token, 0, 0, 0, since, gcc, deco) #define kwdef_sclass(name, sclass, since, gcc, deco) \ kwdef(name, T_SCLASS, sclass, 0, 0, since, gcc, deco) #define kwdef_type(name, tspec, since) \ kwdef(name, T_TYPE, 0, tspec, 0, since, 0, 1) #define kwdef_tqual(name, tqual, since, gcc, deco) \ kwdef(name, T_QUAL, 0, 0, tqual, since, gcc, deco) #define kwdef_keyword(name, token) \ kwdef(name, token, 0, 0, 0, 78, 0, 1) /* During initialization, these keywords are written to the symbol table. */ static const struct keyword { const char *kw_name; /* keyword */ int kw_token; /* token returned by yylex() */ scl_t kw_scl; /* storage class if kw_token T_SCLASS */ tspec_t kw_tspec; /* type spec. if kw_token * T_TYPE or T_STRUCT_OR_UNION */ tqual_t kw_tqual; /* type qual. if kw_token T_QUAL */ bool kw_c90:1; /* C90 keyword */ bool kw_c99_or_c11:1; /* C99 or C11 keyword */ bool kw_gcc:1; /* GCC keyword */ bool kw_plain:1; /* 'name' */ bool kw_leading:1; /* '__name' */ bool kw_both:1; /* '__name__' */ } keywords[] = { kwdef_keyword( "_Alignas", T_ALIGNAS), kwdef_keyword( "_Alignof", T_ALIGNOF), kwdef_token( "alignof", T_ALIGNOF, 78,0,6), kwdef_token( "asm", T_ASM, 78,1,7), kwdef_token( "attribute", T_ATTRIBUTE, 78,1,6), kwdef_sclass( "auto", AUTO, 78,0,1), kwdef_type( "_Bool", BOOL, 99), kwdef_keyword( "break", T_BREAK), kwdef_token( "__builtin_offsetof", T_BUILTIN_OFFSETOF, 78,1,1), kwdef_keyword( "case", T_CASE), kwdef_type( "char", CHAR, 78), kwdef_type( "_Complex", COMPLEX, 99), kwdef_tqual( "const", CONST, 90,0,7), kwdef_keyword( "continue", T_CONTINUE), kwdef_keyword( "default", T_DEFAULT), kwdef_keyword( "do", T_DO), kwdef_type( "double", DOUBLE, 78), kwdef_keyword( "else", T_ELSE), kwdef_keyword( "enum", T_ENUM), kwdef_token( "__extension__",T_EXTENSION, 78,1,1), kwdef_sclass( "extern", EXTERN, 78,0,1), kwdef_type( "float", FLOAT, 78), kwdef_keyword( "for", T_FOR), kwdef_token( "_Generic", T_GENERIC, 11,0,1), kwdef_keyword( "goto", T_GOTO), kwdef_keyword( "if", T_IF), kwdef_token( "__imag__", T_IMAG, 78,1,1), kwdef_sclass( "inline", INLINE, 99,0,7), kwdef_type( "int", INT, 78), #ifdef INT128_SIZE kwdef_type( "__int128_t", INT128, 99), #endif kwdef_type( "long", LONG, 78), kwdef_token( "_Noreturn", T_NORETURN, 11,0,1), kwdef_token( "__packed", T_PACKED, 78,0,1), kwdef_token( "__real__", T_REAL, 78,1,1), kwdef_sclass( "register", REG, 78,0,1), kwdef_tqual( "restrict", RESTRICT, 99,0,7), kwdef_keyword( "return", T_RETURN), kwdef_type( "short", SHORT, 78), kwdef( "signed", T_TYPE, 0, SIGNED, 0, 90,0,3), kwdef_keyword( "sizeof", T_SIZEOF), kwdef_sclass( "static", STATIC, 78,0,1), kwdef_keyword( "_Static_assert", T_STATIC_ASSERT), kwdef("struct", T_STRUCT_OR_UNION, 0, STRUCT, 0, 78,0,1), kwdef_keyword( "switch", T_SWITCH), kwdef_token( "__symbolrename", T_SYMBOLRENAME, 78,0,1), kwdef_tqual( "__thread", THREAD, 78,1,1), kwdef_tqual( "_Thread_local", THREAD, 11,0,1), kwdef_sclass( "typedef", TYPEDEF, 78,0,1), kwdef_token( "typeof", T_TYPEOF, 78,1,7), #ifdef INT128_SIZE kwdef_type( "__uint128_t", UINT128, 99), #endif kwdef("union", T_STRUCT_OR_UNION, 0, UNION, 0, 78,0,1), kwdef_type( "unsigned", UNSIGN, 78), kwdef_type( "void", VOID, 78), kwdef_tqual( "volatile", VOLATILE, 90,0,7), kwdef_keyword( "while", T_WHILE), #undef kwdef #undef kwdef_token #undef kwdef_sclass #undef kwdef_type #undef kwdef_tqual #undef kwdef_keyword }; /* Symbol table */ static sym_t *symtab[HSHSIZ1]; /* type of next expected symbol */ symt_t symtyp; static int get_escaped_char(int); static unsigned int hash(const char *s) { unsigned int v; const char *p; v = 0; for (p = s; *p != '\0'; p++) { v = (v << 4) + (unsigned char)*p; v ^= v >> 28; } return v % HSHSIZ1; } static void symtab_add(sym_t *sym) { unsigned int h; h = hash(sym->s_name); if ((sym->s_symtab_next = symtab[h]) != NULL) symtab[h]->s_symtab_ref = &sym->s_symtab_next; sym->s_symtab_ref = &symtab[h]; symtab[h] = sym; } static sym_t * symtab_search(sbuf_t *sb) { unsigned int h = hash(sb->sb_name); for (sym_t *sym = symtab[h]; sym != NULL; sym = sym->s_symtab_next) { if (strcmp(sym->s_name, sb->sb_name) != 0) continue; const struct keyword *kw = sym->s_keyword; if (kw != NULL || in_gcc_attribute) return sym; if (kw == NULL && !in_gcc_attribute && sym->s_kind == symtyp) return sym; } return NULL; } static void symtab_remove(sym_t *sym) { if ((*sym->s_symtab_ref = sym->s_symtab_next) != NULL) sym->s_symtab_next->s_symtab_ref = sym->s_symtab_ref; sym->s_symtab_next = NULL; } static void symtab_remove_locals(void) { for (size_t i = 0; i < HSHSIZ1; i++) { for (sym_t *sym = symtab[i]; sym != NULL; ) { sym_t *next = sym->s_symtab_next; if (sym->s_block_level >= 1) symtab_remove(sym); sym = next; } } } #ifdef DEBUG static int sym_by_name(const void *va, const void *vb) { const sym_t *a = *(const sym_t *const *)va; const sym_t *b = *(const sym_t *const *)vb; return strcmp(a->s_name, b->s_name); } struct syms { const sym_t **items; size_t len; size_t cap; }; static void syms_add(struct syms *syms, const sym_t *sym) { while (syms->len >= syms->cap) { syms->cap *= 2; syms->items = xrealloc(syms->items, syms->cap * sizeof(syms->items[0])); } syms->items[syms->len++] = sym; } void debug_symtab(void) { struct syms syms = { xcalloc(64, sizeof(syms.items[0])), 0, 64 }; for (int level = -1;; level++) { bool more = false; size_t n = sizeof(symtab) / sizeof(symtab[0]); syms.len = 0; for (size_t i = 0; i < n; i++) { for (sym_t *sym = symtab[i]; sym != NULL;) { if (sym->s_block_level == level && sym->s_keyword == NULL) syms_add(&syms, sym); if (sym->s_block_level > level) more = true; sym = sym->s_symtab_next; } } if (syms.len > 0) { debug_printf("symbol table level %d\n", level); debug_indent_inc(); qsort(syms.items, syms.len, sizeof(syms.items[0]), sym_by_name); for (size_t i = 0; i < syms.len; i++) debug_sym("", syms.items[i], "\n"); debug_indent_dec(); lint_assert(level != -1); } if (!more) break; } free(syms.items); } #endif static void add_keyword(const struct keyword *kw, bool leading, bool trailing) { sym_t *sym; char buf[256]; const char *name; if (!leading && !trailing) { name = kw->kw_name; } else { (void)snprintf(buf, sizeof(buf), "%s%s%s", leading ? "__" : "", kw->kw_name, trailing ? "__" : ""); name = xstrdup(buf); } sym = block_zero_alloc(sizeof(*sym)); sym->s_name = name; sym->s_keyword = kw; sym->u.s_keyword.sk_token = kw->kw_token; if (kw->kw_token == T_TYPE || kw->kw_token == T_STRUCT_OR_UNION) { sym->u.s_keyword.sk_tspec = kw->kw_tspec; } else if (kw->kw_token == T_SCLASS) { sym->s_scl = kw->kw_scl; } else if (kw->kw_token == T_QUAL) { sym->u.s_keyword.sk_qualifier = kw->kw_tqual; } symtab_add(sym); } static bool is_keyword_known(const struct keyword *kw) { if ((kw->kw_c90 || kw->kw_c99_or_c11) && !allow_c90) return false; /* * In the 1990s, GCC defined several keywords that were later * incorporated into C99, therefore in GCC mode, all C99 keywords are * made available. The C11 keywords are made available as well, but * there are so few that they don't matter practically. */ if (allow_gcc) return true; if (kw->kw_gcc) return false; if (kw->kw_c99_or_c11 && !allow_c99) return false; return true; } /* * All keywords are written to the symbol table. This saves us looking * in an extra table for each name we found. */ void initscan(void) { const struct keyword *kw, *end; end = keywords + sizeof(keywords) / sizeof(keywords[0]); for (kw = keywords; kw != end; kw++) { if (!is_keyword_known(kw)) continue; if (kw->kw_plain) add_keyword(kw, false, false); if (kw->kw_leading) add_keyword(kw, true, false); if (kw->kw_both) add_keyword(kw, true, true); } } /* * Read a character and ensure that it is positive (except EOF). * Increment line count(s) if necessary. */ static int inpc(void) { int c; if ((c = lex_input()) == EOF) return c; c &= CHAR_MASK; if (c == '\0') return EOF; /* lex returns 0 on EOF. */ if (c == '\n') lex_next_line(); return c; } static int lex_keyword(sym_t *sym) { int t; if ((t = sym->u.s_keyword.sk_token) == T_SCLASS) { yylval.y_scl = sym->s_scl; } else if (t == T_TYPE || t == T_STRUCT_OR_UNION) { yylval.y_tspec = sym->u.s_keyword.sk_tspec; } else if (t == T_QUAL) { yylval.y_tqual = sym->u.s_keyword.sk_qualifier; } return t; } /* * Lex has found a letter followed by zero or more letters or digits. * It looks for a symbol in the symbol table with the same name. This * symbol must either be a keyword or a symbol of the type required by * symtyp (label, member, tag, ...). * * If it is a keyword, the token is returned. In some cases it is described * more deeply by data written to yylval. * * If it is a symbol, T_NAME is returned and the name is stored in yylval. * If there is already a symbol of the same name and type in the symbol * table, yylval.y_name->sb_sym points there. */ extern int lex_name(const char *yytext, size_t yyleng) { char *s; sbuf_t *sb; sym_t *sym; int tok; sb = xmalloc(sizeof(*sb)); sb->sb_name = yytext; sb->sb_len = yyleng; if ((sym = symtab_search(sb)) != NULL && sym->s_keyword != NULL) { free(sb); return lex_keyword(sym); } sb->sb_sym = sym; if (sym != NULL) { lint_assert(block_level >= sym->s_block_level); sb->sb_name = sym->s_name; tok = sym->s_scl == TYPEDEF ? T_TYPENAME : T_NAME; } else { s = block_zero_alloc(yyleng + 1); (void)memcpy(s, yytext, yyleng + 1); sb->sb_name = s; tok = T_NAME; } yylval.y_name = sb; return tok; } /* * Convert a string representing an integer into internal representation. * Return T_CON, storing the numeric value in yylval, for yylex. */ int lex_integer_constant(const char *yytext, size_t yyleng, int base) { int l_suffix, u_suffix; size_t len; const char *cp; char c, *eptr; tspec_t typ; bool ansiu; bool warned = false; uint64_t uq = 0; /* C11 6.4.4.1p5 */ static const tspec_t suffix_type[2][3] = { { INT, LONG, QUAD, }, { UINT, ULONG, UQUAD, } }; cp = yytext; len = yyleng; /* skip 0[xX] or 0[bB] */ if (base == 16 || base == 2) { cp += 2; len -= 2; } /* read suffixes */ l_suffix = u_suffix = 0; for (;;) { if ((c = cp[len - 1]) == 'l' || c == 'L') { l_suffix++; } else if (c == 'u' || c == 'U') { u_suffix++; } else { break; } len--; } if (l_suffix > 2 || u_suffix > 1) { /* malformed integer constant */ warning(251); if (l_suffix > 2) l_suffix = 2; if (u_suffix > 1) u_suffix = 1; } if (!allow_c90 && u_suffix != 0) { /* suffix U is illegal in traditional C */ warning(97); } typ = suffix_type[u_suffix][l_suffix]; errno = 0; uq = (uint64_t)strtoull(cp, &eptr, base); lint_assert(eptr == cp + len); if (errno != 0) { /* integer constant out of range */ warning(252); warned = true; } /* * If the value is too big for the current type, we must choose * another type. */ ansiu = false; switch (typ) { case INT: if (uq <= TARG_INT_MAX) { /* ok */ } else if (uq <= TARG_UINT_MAX && base != 10) { typ = UINT; } else if (uq <= TARG_LONG_MAX) { typ = LONG; } else { typ = ULONG; if (uq > TARG_ULONG_MAX && !warned) { /* integer constant out of range */ warning(252); } } if (typ == UINT || typ == ULONG) { if (!allow_c90) { typ = LONG; } else if (allow_trad || allow_c99) { /* * Remember that the constant is unsigned * only in ANSI C. * * TODO: C99 behaves like C90 here. */ ansiu = true; } } break; case UINT: if (uq > TARG_UINT_MAX) { typ = ULONG; if (uq > TARG_ULONG_MAX && !warned) { /* integer constant out of range */ warning(252); } } break; case LONG: if (uq > TARG_LONG_MAX && allow_c90) { typ = ULONG; /* TODO: C99 behaves like C90 here. */ if (allow_trad || allow_c99) ansiu = true; if (uq > TARG_ULONG_MAX && !warned) { /* integer constant out of range */ warning(252); } } break; case ULONG: if (uq > TARG_ULONG_MAX && !warned) { /* integer constant out of range */ warning(252); } break; case QUAD: if (uq > TARG_QUAD_MAX && allow_c90) { typ = UQUAD; /* TODO: C99 behaves like C90 here. */ if (allow_trad || allow_c99) ansiu = true; } break; case UQUAD: if (uq > TARG_UQUAD_MAX && !warned) { /* integer constant out of range */ warning(252); } break; default: break; } uq = (uint64_t)convert_integer((int64_t)uq, typ, 0); yylval.y_val = xcalloc(1, sizeof(*yylval.y_val)); yylval.y_val->v_tspec = typ; yylval.y_val->v_unsigned_since_c90 = ansiu; yylval.y_val->v_quad = (int64_t)uq; return T_CON; } /* * Extend or truncate q to match t. If t is signed, sign-extend. * * len is the number of significant bits. If len is 0, len is set * to the width of type t. */ int64_t convert_integer(int64_t q, tspec_t t, unsigned int len) { if (len == 0) len = size_in_bits(t); uint64_t vbits = value_bits(len); return t == PTR || is_uinteger(t) || ((q & bit(len - 1)) == 0) ? (int64_t)(q & vbits) : (int64_t)(q | ~vbits); } /* * Convert a string representing a floating point value into its numerical * representation. Type and value are returned in yylval. * * XXX Currently it is not possible to convert constants of type * long double which are greater than DBL_MAX. */ int lex_floating_constant(const char *yytext, size_t yyleng) { const char *cp; size_t len; tspec_t typ; char c, *eptr; double d; float f = 0; cp = yytext; len = yyleng; if (cp[len - 1] == 'i') len--; /* imaginary, do nothing for now */ if ((c = cp[len - 1]) == 'f' || c == 'F') { typ = FLOAT; len--; } else if (c == 'l' || c == 'L') { typ = LDOUBLE; len--; } else { if (c == 'd' || c == 'D') len--; typ = DOUBLE; } if (!allow_c90 && typ != DOUBLE) { /* suffixes F and L are illegal in traditional C */ warning(98); } errno = 0; d = strtod(cp, &eptr); if (eptr != cp + len) { switch (*eptr) { /* * XXX: non-native non-current strtod() may not handle hex * floats, ignore the rest if we find traces of hex float * syntax... */ case 'p': case 'P': case 'x': case 'X': d = 0; errno = 0; break; default: INTERNAL_ERROR("lex_floating_constant(%.*s)", (int)(eptr - cp), cp); } } if (errno != 0) /* floating-point constant out of range */ warning(248); if (typ == FLOAT) { f = (float)d; if (isfinite(f) == 0) { /* floating-point constant out of range */ warning(248); f = f > 0 ? FLT_MAX : -FLT_MAX; } } yylval.y_val = xcalloc(1, sizeof(*yylval.y_val)); yylval.y_val->v_tspec = typ; if (typ == FLOAT) yylval.y_val->v_ldbl = f; else yylval.y_val->v_ldbl = d; return T_CON; } int lex_operator(int t, op_t o) { yylval.y_op = o; return t; } /* Called if lex found a leading "'". */ int lex_character_constant(void) { size_t n; int val, c; n = 0; val = 0; while ((c = get_escaped_char('\'')) >= 0) { val = (val << CHAR_SIZE) + c; n++; } if (c == -2) { /* unterminated character constant */ error(253); } else if (n > sizeof(int) || (n > 1 && (pflag || hflag))) { /* XXX: should rather be sizeof(TARG_INT) */ /* too many characters in character constant */ error(71); } else if (n > 1) { /* multi-character character constant */ warning(294); } else if (n == 0) { /* empty character constant */ error(73); } if (n == 1) val = (int)convert_integer(val, CHAR, CHAR_SIZE); yylval.y_val = xcalloc(1, sizeof(*yylval.y_val)); yylval.y_val->v_tspec = INT; yylval.y_val->v_quad = val; return T_CON; } /* * Called if lex found a leading L\' */ int lex_wide_character_constant(void) { static char buf[MB_LEN_MAX + 1]; size_t n, nmax; int c; wchar_t wc; nmax = MB_CUR_MAX; n = 0; while ((c = get_escaped_char('\'')) >= 0) { if (n < nmax) buf[n] = (char)c; n++; } wc = 0; if (c == -2) { /* unterminated character constant */ error(253); } else if (n == 0) { /* empty character constant */ error(73); } else if (n > nmax) { n = nmax; /* too many characters in character constant */ error(71); } else { buf[n] = '\0'; (void)mbtowc(NULL, NULL, 0); if (mbtowc(&wc, buf, nmax) < 0) /* invalid multibyte character */ error(291); } yylval.y_val = xcalloc(1, sizeof(*yylval.y_val)); yylval.y_val->v_tspec = WCHAR; yylval.y_val->v_quad = wc; return T_CON; } /* * Read a character which is part of a character constant or of a string * and handle escapes. * * The argument is the character which delimits the character constant or * string. * * Returns -1 if the end of the character constant or string is reached, * -2 if the EOF is reached, and the character otherwise. */ static int get_escaped_char(int delim) { static int pbc = -1; int n, c, v; if (pbc == -1) { c = inpc(); } else { c = pbc; pbc = -1; } if (c == delim) return -1; switch (c) { case '\n': if (!allow_c90) { /* newline in string or char constant */ error(254); return -2; } return c; case '\0': /* syntax error '%s' */ error(249, "EOF or null byte in literal"); return -2; case EOF: return -2; case '\\': switch (c = inpc()) { case '"': if (!allow_c90 && delim == '\'') /* \" inside character constants undef... */ warning(262); return '"'; case '\'': return '\''; case '?': if (!allow_c90) /* \? undefined in traditional C */ warning(263); return '?'; case '\\': return '\\'; case 'a': if (!allow_c90) /* \a undefined in traditional C */ warning(81); return '\a'; case 'b': return '\b'; case 'f': return '\f'; case 'n': return '\n'; case 'r': return '\r'; case 't': return '\t'; case 'v': if (!allow_c90) /* \v undefined in traditional C */ warning(264); return '\v'; case '8': case '9': /* bad octal digit %c */ warning(77, c); /* FALLTHROUGH */ case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': n = 3; v = 0; do { v = (v << 3) + (c - '0'); c = inpc(); } while (--n > 0 && '0' <= c && c <= '7'); pbc = c; if (v > TARG_UCHAR_MAX) { /* character escape does not fit in character */ warning(76); v &= CHAR_MASK; } return v; case 'x': if (!allow_c90) /* \x undefined in traditional C */ warning(82); v = 0; n = 0; while (c = inpc(), isxdigit(c)) { c = isdigit(c) ? c - '0' : toupper(c) - 'A' + 10; v = (v << 4) + c; if (n >= 0) { if ((v & ~CHAR_MASK) != 0) { /* overflow in hex escape */ warning(75); n = -1; } else { n++; } } } pbc = c; if (n == 0) { /* no hex digits follow \x */ error(74); } if (n == -1) { v &= CHAR_MASK; } return v; case '\n': return get_escaped_char(delim); case EOF: return -2; default: if (isprint(c)) { /* dubious escape \%c */ warning(79, c); } else { /* dubious escape \%o */ warning(80, c); } } } return c; } /* See https://gcc.gnu.org/onlinedocs/cpp/Preprocessor-Output.html */ static void parse_line_directive_flags(const char *p, bool *is_begin, bool *is_end, bool *is_system) { *is_begin = false; *is_end = false; *is_system = false; while (*p != '\0') { const char *word_start, *word_end; while (ch_isspace(*p)) p++; word_start = p; while (*p != '\0' && !ch_isspace(*p)) p++; word_end = p; if (word_end - word_start == 1 && word_start[0] == '1') *is_begin = true; if (word_end - word_start == 1 && word_start[0] == '2') *is_end = true; if (word_end - word_start == 1 && word_start[0] == '3') *is_system = true; /* Flag '4' is only interesting for C++. */ } } /* * Called for preprocessor directives. Currently implemented are: * # pragma [argument...] * # lineno * # lineno "filename" * # lineno "filename" GCC-flag... */ void lex_directive(const char *yytext) { const char *cp, *fn; char c, *eptr; size_t fnl; long ln; bool is_begin, is_end, is_system; static bool first = true; /* Go to first non-whitespace after # */ for (cp = yytext + 1; (c = *cp) == ' ' || c == '\t'; cp++) continue; if (!ch_isdigit(c)) { if (strncmp(cp, "pragma", 6) == 0 && ch_isspace(cp[6])) return; error: /* undefined or invalid # directive */ warning(255); return; } ln = strtol(--cp, &eptr, 10); if (eptr == cp) goto error; if ((c = *(cp = eptr)) != ' ' && c != '\t' && c != '\0') goto error; while ((c = *cp++) == ' ' || c == '\t') continue; if (c != '\0') { if (c != '"') goto error; fn = cp; while ((c = *cp) != '"' && c != '\0') cp++; if (c != '"') goto error; if ((fnl = cp++ - fn) > PATH_MAX) goto error; /* empty string means stdin */ if (fnl == 0) { fn = "{standard input}"; fnl = 16; /* strlen (fn) */ } curr_pos.p_file = record_filename(fn, fnl); /* * If this is the first directive, the name is the name * of the C source file as specified at the command line. * It is written to the output file. */ if (first) { csrc_pos.p_file = curr_pos.p_file; outsrc(transform_filename(curr_pos.p_file, strlen(curr_pos.p_file))); first = false; } parse_line_directive_flags(cp, &is_begin, &is_end, &is_system); update_location(curr_pos.p_file, (int)ln, is_begin, is_end); in_system_header = is_system; } curr_pos.p_line = (int)ln - 1; curr_pos.p_uniq = 0; if (curr_pos.p_file == csrc_pos.p_file) { csrc_pos.p_line = (int)ln - 1; csrc_pos.p_uniq = 0; } } /* * Handle lint comments such as ARGSUSED. * * If one of these comments is recognized, the argument, if any, is * parsed and a function which handles this comment is called. */ void lex_comment(void) { int c, lc; static const struct { const char *keywd; bool arg; void (*func)(int); } keywtab[] = { { "ARGSUSED", true, argsused }, { "BITFIELDTYPE", false, bitfieldtype }, { "CONSTCOND", false, constcond }, { "CONSTANTCOND", false, constcond }, { "CONSTANTCONDITION", false, constcond }, { "FALLTHRU", false, fallthru }, { "FALLTHROUGH", false, fallthru }, { "FALL THROUGH", false, fallthru }, { "fallthrough", false, fallthru }, { "LINTLIBRARY", false, lintlib }, { "LINTED", true, linted }, { "LONGLONG", false, longlong }, { "NOSTRICT", true, linted }, { "NOTREACHED", false, not_reached }, { "PRINTFLIKE", true, printflike }, { "PROTOLIB", true, protolib }, { "SCANFLIKE", true, scanflike }, { "VARARGS", true, varargs }, }; char keywd[32]; char arg[32]; size_t l, i; int a; bool eoc; eoc = false; /* Skip whitespace after the start of the comment */ while (c = inpc(), isspace(c)) continue; /* Read the potential keyword to keywd */ l = 0; while (c != EOF && l < sizeof(keywd) - 1 && (isalpha(c) || isspace(c))) { if (islower(c) && l > 0 && ch_isupper(keywd[0])) break; keywd[l++] = (char)c; c = inpc(); } while (l > 0 && ch_isspace(keywd[l - 1])) l--; keywd[l] = '\0'; /* look for the keyword */ for (i = 0; i < sizeof(keywtab) / sizeof(keywtab[0]); i++) { if (strcmp(keywtab[i].keywd, keywd) == 0) break; } if (i == sizeof(keywtab) / sizeof(keywtab[0])) goto skip_rest; /* skip whitespace after the keyword */ while (isspace(c)) c = inpc(); /* read the argument, if the keyword accepts one and there is one */ l = 0; if (keywtab[i].arg) { while (isdigit(c) && l < sizeof(arg) - 1) { arg[l++] = (char)c; c = inpc(); } } arg[l] = '\0'; a = l != 0 ? atoi(arg) : -1; /* skip whitespace after the argument */ while (isspace(c)) c = inpc(); if (c != '*' || (c = inpc()) != '/') { if (keywtab[i].func != linted) /* extra characters in lint comment */ warning(257); } else { /* * remember that we have already found the end of the * comment */ eoc = true; } if (keywtab[i].func != NULL) (*keywtab[i].func)(a); skip_rest: while (!eoc) { lc = c; if ((c = inpc()) == EOF) { /* unterminated comment */ error(256); break; } if (lc == '*' && c == '/') eoc = true; } } /* * Handle // style comments */ void lex_slash_slash_comment(void) { int c; if (!allow_c99 && !allow_gcc) /* %s does not support // comments */ gnuism(312, allow_c90 ? "C90" : "traditional C"); while ((c = inpc()) != EOF && c != '\n') continue; } /* * Clear flags for lint comments LINTED, LONGLONG and CONSTCOND. * clear_warn_flags is called after function definitions and global and * local declarations and definitions. It is also called between * the controlling expression and the body of control statements * (if, switch, for, while). */ void clear_warn_flags(void) { lwarn = LWARN_ALL; quadflg = false; constcond_flag = false; } /* * Strings are stored in a dynamically allocated buffer and passed * in yylval.y_string to the parser. The parser or the routines called * by the parser are responsible for freeing this buffer. */ int lex_string(void) { unsigned char *s; int c; size_t len, max; strg_t *strg; s = xmalloc(max = 64); len = 0; while ((c = get_escaped_char('"')) >= 0) { /* +1 to reserve space for a trailing NUL character */ if (len + 1 == max) s = xrealloc(s, max *= 2); s[len++] = (char)c; } s[len] = '\0'; if (c == -2) /* unterminated string constant */ error(258); strg = xcalloc(1, sizeof(*strg)); strg->st_char = true; strg->st_len = len; strg->st_mem = s; yylval.y_string = strg; return T_STRING; } int lex_wide_string(void) { char *s; int c, n; size_t i, wi; size_t len, max, wlen; wchar_t *ws; strg_t *strg; s = xmalloc(max = 64); len = 0; while ((c = get_escaped_char('"')) >= 0) { /* +1 to save space for a trailing NUL character */ if (len + 1 >= max) s = xrealloc(s, max *= 2); s[len++] = (char)c; } s[len] = '\0'; if (c == -2) /* unterminated string constant */ error(258); /* get length of wide-character string */ (void)mblen(NULL, 0); for (i = 0, wlen = 0; i < len; i += n, wlen++) { if ((n = mblen(&s[i], MB_CUR_MAX)) == -1) { /* invalid multibyte character */ error(291); break; } if (n == 0) n = 1; } ws = xmalloc((wlen + 1) * sizeof(*ws)); /* convert from multibyte to wide char */ (void)mbtowc(NULL, NULL, 0); for (i = 0, wi = 0; i < len; i += n, wi++) { if ((n = mbtowc(&ws[wi], &s[i], MB_CUR_MAX)) == -1) break; if (n == 0) n = 1; } ws[wi] = 0; free(s); strg = xcalloc(1, sizeof(*strg)); strg->st_char = false; strg->st_len = wlen; strg->st_mem = ws; yylval.y_string = strg; return T_STRING; } void lex_next_line(void) { curr_pos.p_line++; curr_pos.p_uniq = 0; debug_step("parsing %s:%d", curr_pos.p_file, curr_pos.p_line); if (curr_pos.p_file == csrc_pos.p_file) { csrc_pos.p_line++; csrc_pos.p_uniq = 0; } } void lex_unknown_character(int c) { /* unknown character \%o */ error(250, c); } /* * The scanner does not create new symbol table entries for symbols it cannot * find in the symbol table. This is to avoid putting undeclared symbols into * the symbol table if a syntax error occurs. * * getsym is called as soon as it is probably ok to put the symbol in the * symbol table. It is still possible that symbols are put in the symbol * table that are not completely declared due to syntax errors. To avoid too * many problems in this case, symbols get type 'int' in getsym. * * XXX calls to getsym should be delayed until declare_1_* is called. */ sym_t * getsym(sbuf_t *sb) { dinfo_t *di; char *s; sym_t *sym; sym = sb->sb_sym; /* * During member declaration it is possible that name() looked * for symbols of type FVFT, although it should have looked for * symbols of type FTAG. Same can happen for labels. Both cases * are compensated here. */ if (symtyp == FMEMBER || symtyp == FLABEL) { if (sym == NULL || sym->s_kind == FVFT) sym = symtab_search(sb); } if (sym != NULL) { lint_assert(sym->s_kind == symtyp); symtyp = FVFT; free(sb); return sym; } /* create a new symbol table entry */ /* labels must always be allocated at level 1 (outermost block) */ if (symtyp == FLABEL) { sym = level_zero_alloc(1, sizeof(*sym)); s = level_zero_alloc(1, sb->sb_len + 1); (void)memcpy(s, sb->sb_name, sb->sb_len + 1); sym->s_name = s; sym->s_block_level = 1; di = dcs; while (di->d_enclosing != NULL && di->d_enclosing->d_enclosing != NULL) di = di->d_enclosing; lint_assert(di->d_kind == DK_AUTO); } else { sym = block_zero_alloc(sizeof(*sym)); sym->s_name = sb->sb_name; sym->s_block_level = block_level; di = dcs; } UNIQUE_CURR_POS(sym->s_def_pos); if ((sym->s_kind = symtyp) != FLABEL) sym->s_type = gettyp(INT); symtyp = FVFT; if (!in_gcc_attribute) { symtab_add(sym); *di->d_ldlsym = sym; di->d_ldlsym = &sym->s_level_next; } free(sb); return sym; } /* * Construct a temporary symbol. The symbol name starts with a digit, making * the name illegal. */ sym_t * mktempsym(type_t *tp) { static unsigned n = 0; char *s = level_zero_alloc((size_t)block_level, 64); sym_t *sym = block_zero_alloc(sizeof(*sym)); scl_t scl; (void)snprintf(s, 64, "%.8u_tmp", n++); scl = dcs->d_scl; if (scl == NOSCL) scl = block_level > 0 ? AUTO : EXTERN; sym->s_name = s; sym->s_type = tp; sym->s_block_level = block_level; sym->s_scl = scl; sym->s_kind = FVFT; sym->s_used = true; sym->s_set = true; symtab_add(sym); *dcs->d_ldlsym = sym; dcs->d_ldlsym = &sym->s_level_next; return sym; } /* Remove a symbol forever from the symbol table. */ void rmsym(sym_t *sym) { debug_step("rmsym '%s' %s '%s'", sym->s_name, symt_name(sym->s_kind), type_name(sym->s_type)); symtab_remove(sym); /* avoid that the symbol will later be put back to the symbol table */ sym->s_block_level = -1; } /* * Remove all symbols from the symbol table that have the same level as the * given symbol. */ void rmsyms(sym_t *syms) { sym_t *sym; /* Note the use of s_level_next instead of s_symtab_next. */ for (sym = syms; sym != NULL; sym = sym->s_level_next) { if (sym->s_block_level != -1) { debug_step("rmsyms '%s' %s '%s'", sym->s_name, symt_name(sym->s_kind), type_name(sym->s_type)); symtab_remove(sym); sym->s_symtab_ref = NULL; } } } /* * Put a symbol into the symbol table. */ void inssym(int level, sym_t *sym) { debug_step("inssym '%s' %s '%s'", sym->s_name, symt_name(sym->s_kind), type_name(sym->s_type)); symtab_add(sym); sym->s_block_level = level; /* * Placing the inner symbols to the beginning of the list ensures * that these symbols are preferred over symbols from the outer * blocks that happen to have the same name. */ lint_assert(sym->s_symtab_next != NULL ? sym->s_block_level >= sym->s_symtab_next->s_block_level : true); } /* * Called at level 0 after syntax errors. * * Removes all symbols which are not declared at level 0 from the * symbol table. Also frees all memory which is not associated with * level 0. */ void clean_up_after_error(void) { symtab_remove_locals(); for (size_t i = mem_block_level; i > 0; i--) level_free_all(i); } /* Create a new symbol with the same name as an existing symbol. */ sym_t * pushdown(const sym_t *sym) { sym_t *nsym; debug_step("pushdown '%s' %s '%s'", sym->s_name, symt_name(sym->s_kind), type_name(sym->s_type)); nsym = block_zero_alloc(sizeof(*nsym)); lint_assert(sym->s_block_level <= block_level); nsym->s_name = sym->s_name; UNIQUE_CURR_POS(nsym->s_def_pos); nsym->s_kind = sym->s_kind; nsym->s_block_level = block_level; symtab_add(nsym); *dcs->d_ldlsym = nsym; dcs->d_ldlsym = &nsym->s_level_next; return nsym; } /* * Free any dynamically allocated memory referenced by * the value stack or yylval. * The type of information in yylval is described by tok. */ void freeyyv(void *sp, int tok) { if (tok == T_NAME || tok == T_TYPENAME) { sbuf_t *sb = *(sbuf_t **)sp; free(sb); } else if (tok == T_CON) { val_t *val = *(val_t **)sp; free(val); } else if (tok == T_STRING) { strg_t *strg = *(strg_t **)sp; free(strg->st_mem); free(strg); } }