/* CPP Library. (Directive handling.) Copyright (C) 1986, 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. Contributed by Per Bothner, 1994-95. Based on CCCP program by Paul Rubin, June 1986 Adapted to ANSI C, Richard Stallman, Jan 1987 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "config.h" #include "system.h" #include "cpplib.h" #include "cpphash.h" #include "obstack.h" /* Chained list of answers to an assertion. */ struct answer { struct answer *next; unsigned int count; cpp_token first[1]; }; /* Stack of conditionals currently in progress (including both successful and failing conditionals). */ struct if_stack { struct if_stack *next; unsigned int line; /* Line where condition started. */ const cpp_hashnode *mi_cmacro;/* macro name for #ifndef around entire file */ bool skip_elses; /* Can future #else / #elif be skipped? */ bool was_skipping; /* If were skipping on entry. */ int type; /* Most recent conditional, for diagnostics. */ }; /* Contains a registered pragma or pragma namespace. */ typedef void (*pragma_cb) PARAMS ((cpp_reader *)); struct pragma_entry { struct pragma_entry *next; const cpp_hashnode *pragma; /* Name and length. */ int is_nspace; union { pragma_cb handler; struct pragma_entry *space; } u; }; /* Values for the origin field of struct directive. KANDR directives come from traditional (K&R) C. STDC89 directives come from the 1989 C standard. EXTENSION directives are extensions. */ #define KANDR 0 #define STDC89 1 #define EXTENSION 2 /* Values for the flags field of struct directive. COND indicates a conditional; IF_COND an opening conditional. INCL means to treat "..." and <...> as q-char and h-char sequences respectively. IN_I means this directive should be handled even if -fpreprocessed is in effect (these are the directives with callback hooks). */ #define COND (1 << 0) #define IF_COND (1 << 1) #define INCL (1 << 2) #define IN_I (1 << 3) /* Defines one #-directive, including how to handle it. */ typedef void (*directive_handler) PARAMS ((cpp_reader *)); typedef struct directive directive; struct directive { directive_handler handler; /* Function to handle directive. */ const U_CHAR *name; /* Name of directive. */ unsigned short length; /* Length of name. */ unsigned char origin; /* Origin of directive. */ unsigned char flags; /* Flags describing this directive. */ }; /* Forward declarations. */ static void skip_rest_of_line PARAMS ((cpp_reader *)); static void check_eol PARAMS ((cpp_reader *)); static void start_directive PARAMS ((cpp_reader *)); static void end_directive PARAMS ((cpp_reader *, int)); static void directive_diagnostics PARAMS ((cpp_reader *, const directive *, int)); static void run_directive PARAMS ((cpp_reader *, int, const char *, size_t)); static const cpp_token *glue_header_name PARAMS ((cpp_reader *)); static const cpp_token *parse_include PARAMS ((cpp_reader *)); static void push_conditional PARAMS ((cpp_reader *, int, int, const cpp_hashnode *)); static unsigned int read_flag PARAMS ((cpp_reader *, unsigned int)); static int strtoul_for_line PARAMS ((const U_CHAR *, unsigned int, unsigned long *)); static void do_diagnostic PARAMS ((cpp_reader *, enum error_type, int)); static cpp_hashnode *lex_macro_node PARAMS ((cpp_reader *)); static void do_include_common PARAMS ((cpp_reader *, enum include_type)); static struct pragma_entry *lookup_pragma_entry PARAMS ((struct pragma_entry *, const cpp_hashnode *pragma)); static struct pragma_entry *insert_pragma_entry PARAMS ((cpp_reader *, struct pragma_entry **, const cpp_hashnode *, pragma_cb)); static void do_pragma_once PARAMS ((cpp_reader *)); static void do_pragma_poison PARAMS ((cpp_reader *)); static void do_pragma_system_header PARAMS ((cpp_reader *)); static void do_pragma_dependency PARAMS ((cpp_reader *)); static const cpp_token *get_token_no_padding PARAMS ((cpp_reader *)); static const cpp_token *get__Pragma_string PARAMS ((cpp_reader *)); static void destringize_and_run PARAMS ((cpp_reader *, const cpp_string *)); static int parse_answer PARAMS ((cpp_reader *, struct answer **, int)); static cpp_hashnode *parse_assertion PARAMS ((cpp_reader *, struct answer **, int)); static struct answer ** find_answer PARAMS ((cpp_hashnode *, const struct answer *)); static void handle_assertion PARAMS ((cpp_reader *, const char *, int)); /* This is the table of directive handlers. It is ordered by frequency of occurrence; the numbers at the end are directive counts from all the source code I have lying around (egcs and libc CVS as of 1999-05-18, plus grub-0.5.91, linux-2.2.9, and pcmcia-cs-3.0.9). This is no longer important as directive lookup is now O(1). All extensions other than #warning and #include_next are deprecated. The name is where the extension appears to have come from. */ #define DIRECTIVE_TABLE \ D(define, T_DEFINE = 0, KANDR, IN_I) /* 270554 */ \ D(include, T_INCLUDE, KANDR, INCL) /* 52262 */ \ D(endif, T_ENDIF, KANDR, COND) /* 45855 */ \ D(ifdef, T_IFDEF, KANDR, COND | IF_COND) /* 22000 */ \ D(if, T_IF, KANDR, COND | IF_COND) /* 18162 */ \ D(else, T_ELSE, KANDR, COND) /* 9863 */ \ D(ifndef, T_IFNDEF, KANDR, COND | IF_COND) /* 9675 */ \ D(undef, T_UNDEF, KANDR, IN_I) /* 4837 */ \ D(line, T_LINE, KANDR, IN_I) /* 2465 */ \ D(elif, T_ELIF, STDC89, COND) /* 610 */ \ D(error, T_ERROR, STDC89, 0) /* 475 */ \ D(pragma, T_PRAGMA, STDC89, IN_I) /* 195 */ \ D(warning, T_WARNING, EXTENSION, 0) /* 22 */ \ D(include_next, T_INCLUDE_NEXT, EXTENSION, INCL) /* 19 */ \ D(ident, T_IDENT, EXTENSION, IN_I) /* 11 */ \ D(import, T_IMPORT, EXTENSION, INCL) /* 0 ObjC */ \ D(assert, T_ASSERT, EXTENSION, 0) /* 0 SVR4 */ \ D(unassert, T_UNASSERT, EXTENSION, 0) /* 0 SVR4 */ \ SCCS_ENTRY /* 0 SVR4? */ /* #sccs is not always recognized. */ #ifdef SCCS_DIRECTIVE # define SCCS_ENTRY D(sccs, T_SCCS, EXTENSION, 0) #else # define SCCS_ENTRY /* nothing */ #endif /* Use the table to generate a series of prototypes, an enum for the directive names, and an array of directive handlers. */ /* The directive-processing functions are declared to return int instead of void, because some old compilers have trouble with pointers to functions returning void. */ /* Don't invoke CONCAT2 with any whitespace or K&R cc will fail. */ #define D(name, t, o, f) static void CONCAT2(do_,name) PARAMS ((cpp_reader *)); DIRECTIVE_TABLE #undef D #define D(n, tag, o, f) tag, enum { DIRECTIVE_TABLE N_DIRECTIVES }; #undef D /* Don't invoke CONCAT2 with any whitespace or K&R cc will fail. */ #define D(name, t, origin, flags) \ { CONCAT2(do_,name), (const U_CHAR *) STRINGX(name), \ sizeof STRINGX(name) - 1, origin, flags }, static const directive dtable[] = { DIRECTIVE_TABLE }; #undef D #undef DIRECTIVE_TABLE #define SEEN_EOL() (pfile->cur_token[-1].type == CPP_EOF) /* Skip any remaining tokens in a directive. */ static void skip_rest_of_line (pfile) cpp_reader *pfile; { /* Discard all stacked contexts. */ while (pfile->context != &pfile->base_context) _cpp_pop_context (pfile); /* Sweep up all tokens remaining on the line. */ if (! SEEN_EOL ()) while (_cpp_lex_token (pfile)->type != CPP_EOF) ; } /* Ensure there are no stray tokens at the end of a directive. */ static void check_eol (pfile) cpp_reader *pfile; { if (! SEEN_EOL () && _cpp_lex_token (pfile)->type != CPP_EOF) cpp_pedwarn (pfile, "extra tokens at end of #%s directive", pfile->directive->name); } /* Called when entering a directive, _Pragma or command-line directive. */ static void start_directive (pfile) cpp_reader *pfile; { /* Setup in-directive state. */ pfile->state.in_directive = 1; pfile->state.save_comments = 0; /* Some handlers need the position of the # for diagnostics. */ pfile->directive_line = pfile->line; } /* Called when leaving a directive, _Pragma or command-line directive. */ static void end_directive (pfile, skip_line) cpp_reader *pfile; int skip_line; { /* We don't skip for an assembler #. */ if (skip_line) { skip_rest_of_line (pfile); if (!pfile->keep_tokens) { pfile->cur_run = &pfile->base_run; pfile->cur_token = pfile->base_run.base; } } /* Restore state. */ pfile->state.save_comments = ! CPP_OPTION (pfile, discard_comments); pfile->state.in_directive = 0; pfile->state.angled_headers = 0; pfile->state.line_extension = 0; pfile->directive = 0; } /* Output diagnostics for a directive DIR. INDENTED is non-zero if the '#' was indented. */ static void directive_diagnostics (pfile, dir, indented) cpp_reader *pfile; const directive *dir; int indented; { if (pfile->state.line_extension) { if (CPP_PEDANTIC (pfile) && ! pfile->state.skipping) cpp_pedwarn (pfile, "style of line directive is a GCC extension"); } else { /* Issue -pedantic warnings for extensions. */ if (CPP_PEDANTIC (pfile) && ! pfile->state.skipping && dir->origin == EXTENSION) cpp_pedwarn (pfile, "#%s is a GCC extension", dir->name); /* Traditionally, a directive is ignored unless its # is in column 1. Therefore in code intended to work with K+R compilers, directives added by C89 must have their # indented, and directives present in traditional C must not. This is true even of directives in skipped conditional blocks. */ if (CPP_WTRADITIONAL (pfile)) { if (dir == &dtable[T_ELIF]) cpp_warning (pfile, "suggest not using #elif in traditional C"); else if (indented && dir->origin == KANDR) cpp_warning (pfile, "traditional C ignores #%s with the # indented", dir->name); else if (!indented && dir->origin != KANDR) cpp_warning (pfile, "suggest hiding #%s from traditional C with an indented #", dir->name); } } } /* Check if we have a known directive. INDENTED is non-zero if the '#' of the directive was indented. This function is in this file to save unnecessarily exporting dtable etc. to cpplex.c. Returns non-zero if the line of tokens has been handled, zero if we should continue processing the line. */ int _cpp_handle_directive (pfile, indented) cpp_reader *pfile; int indented; { const directive *dir = 0; const cpp_token *dname; int skip = 1; start_directive (pfile); dname = _cpp_lex_token (pfile); if (dname->type == CPP_NAME) { if (dname->val.node->directive_index) dir = &dtable[dname->val.node->directive_index - 1]; } /* We do not recognise the # followed by a number extension in assembler code. */ else if (dname->type == CPP_NUMBER && CPP_OPTION (pfile, lang) != CLK_ASM) { dir = &dtable[T_LINE]; pfile->state.line_extension = 1; } if (dir) { /* If we have a directive that is not an opening conditional, invalidate any control macro. */ if (! (dir->flags & IF_COND)) pfile->mi_valid = false; /* Kluge alert. In order to be sure that code like this #define HASH # HASH define foo bar does not cause '#define foo bar' to get executed when compiled with -save-temps, we recognize directives in -fpreprocessed mode only if the # is in column 1. cppmacro.c puts a space in front of any '#' at the start of a macro. */ if (CPP_OPTION (pfile, preprocessed) && (indented || !(dir->flags & IN_I))) { skip = 0; dir = 0; } else { /* In failed conditional groups, all non-conditional directives are ignored. Before doing that, whether skipping or not, we should lex angle-bracketed headers correctly, and maybe output some diagnostics. */ pfile->state.angled_headers = dir->flags & INCL; if (! CPP_OPTION (pfile, preprocessed)) directive_diagnostics (pfile, dir, indented); if (pfile->state.skipping && !(dir->flags & COND)) dir = 0; } } else if (dname->type == CPP_EOF) ; /* CPP_EOF is the "null directive". */ else { /* An unknown directive. Don't complain about it in assembly source: we don't know where the comments are, and # may introduce assembler pseudo-ops. Don't complain about invalid directives in skipped conditional groups (6.10 p4). */ if (CPP_OPTION (pfile, lang) == CLK_ASM) skip = 0; else if (!pfile->state.skipping) cpp_error (pfile, "invalid preprocessing directive #%s", cpp_token_as_text (pfile, dname)); } if (dir) { pfile->directive = dir; (*pfile->directive->handler) (pfile); } else if (skip == 0) _cpp_backup_tokens (pfile, 1); end_directive (pfile, skip); return skip; } /* Directive handler wrapper used by the command line option processor. */ static void run_directive (pfile, dir_no, buf, count) cpp_reader *pfile; int dir_no; const char *buf; size_t count; { cpp_push_buffer (pfile, (const U_CHAR *) buf, count, /* from_stage3 */ true, 1); start_directive (pfile); /* We don't want a leading # to be interpreted as a directive. */ pfile->buffer->saved_flags = 0; pfile->directive = &dtable[dir_no]; (void) (*pfile->directive->handler) (pfile); end_directive (pfile, 1); _cpp_pop_buffer (pfile); } /* Checks for validity the macro name in #define, #undef, #ifdef and #ifndef directives. */ static cpp_hashnode * lex_macro_node (pfile) cpp_reader *pfile; { cpp_hashnode *node; const cpp_token *token = _cpp_lex_token (pfile); /* The token immediately after #define must be an identifier. That identifier may not be "defined", per C99 6.10.8p4. In C++, it may not be any of the "named operators" either, per C++98 [lex.digraph], [lex.key]. Finally, the identifier may not have been poisoned. (In that case the lexer has issued the error message for us.) */ if (token->type != CPP_NAME) { if (token->type == CPP_EOF) cpp_error (pfile, "no macro name given in #%s directive", pfile->directive->name); else if (token->flags & NAMED_OP) cpp_error (pfile, "\"%s\" cannot be used as a macro name as it is an operator in C++", NODE_NAME (token->val.node)); else cpp_error (pfile, "macro names must be identifiers"); return 0; } node = token->val.node; if (node->flags & NODE_POISONED) return 0; if (node == pfile->spec_nodes.n_defined) { cpp_error (pfile, "\"%s\" cannot be used as a macro name", NODE_NAME (node)); return 0; } return node; } /* Process a #define directive. Most work is done in cppmacro.c. */ static void do_define (pfile) cpp_reader *pfile; { cpp_hashnode *node = lex_macro_node (pfile); if (node) { if (_cpp_create_definition (pfile, node)) if (pfile->cb.define) (*pfile->cb.define) (pfile, pfile->directive_line, node); } } /* Handle #undef. Marks the identifier NT_VOID in the hash table. */ static void do_undef (pfile) cpp_reader *pfile; { cpp_hashnode *node = lex_macro_node (pfile); /* 6.10.3.5 paragraph 2: [#undef] is ignored if the specified identifier is not currently defined as a macro name. */ if (node && node->type == NT_MACRO) { if (pfile->cb.undef) (*pfile->cb.undef) (pfile, pfile->directive_line, node); if (node->flags & NODE_WARN) cpp_warning (pfile, "undefining \"%s\"", NODE_NAME (node)); _cpp_free_definition (node); } check_eol (pfile); } /* Helper routine used by parse_include. Reinterpret the current line as an h-char-sequence (< ... >); we are looking at the first token after the <. Returns the header as a token, or NULL on failure. */ static const cpp_token * glue_header_name (pfile) cpp_reader *pfile; { cpp_token *header = NULL; const cpp_token *token; unsigned char *dest; size_t len; /* To avoid lexed tokens overwriting our glued name, we can only allocate from the string pool once we've lexed everything. */ dest = BUFF_FRONT (pfile->u_buff); for (;;) { token = cpp_get_token (pfile); if (token->type == CPP_GREATER || token->type == CPP_EOF) break; /* + 1 for terminating NUL. */ len = cpp_token_len (token) + 1; if ((size_t) (BUFF_LIMIT (pfile->u_buff) - dest) < len) { size_t len_so_far = dest - BUFF_FRONT (pfile->u_buff); _cpp_extend_buff (pfile, &pfile->u_buff, len); dest = BUFF_FRONT (pfile->u_buff) + len_so_far; } if (token->flags & PREV_WHITE) *dest++ = ' '; dest = cpp_spell_token (pfile, token, dest); } if (token->type == CPP_EOF) cpp_error (pfile, "missing terminating > character"); else { header = _cpp_temp_token (pfile); header->type = CPP_HEADER_NAME; header->flags = 0; header->val.str.len = dest - BUFF_FRONT (pfile->u_buff); header->val.str.text = BUFF_FRONT (pfile->u_buff); *dest++ = '\0'; BUFF_FRONT (pfile->u_buff) = dest; } return header; } /* Returns the header string of #include, #include_next, #import and #pragma dependency. Returns NULL on error. */ static const cpp_token * parse_include (pfile) cpp_reader *pfile; { const unsigned char *dir; const cpp_token *header; if (pfile->directive == &dtable[T_PRAGMA]) dir = U"pragma dependency"; else dir = pfile->directive->name; /* Allow macro expansion. */ header = cpp_get_token (pfile); if (header->type != CPP_STRING && header->type != CPP_HEADER_NAME) { if (header->type != CPP_LESS) { cpp_error (pfile, "#%s expects \"FILENAME\" or ", dir); return NULL; } header = glue_header_name (pfile); if (header == NULL) return header; } if (header->val.str.len == 0) { cpp_error (pfile, "empty file name in #%s", dir); return NULL; } return header; } /* Handle #include, #include_next and #import. */ static void do_include_common (pfile, type) cpp_reader *pfile; enum include_type type; { const cpp_token *header; /* For #include_next, if this is the primary source file, warn and use the normal search logic. */ if (type == IT_INCLUDE_NEXT && ! pfile->buffer->prev) { cpp_warning (pfile, "#include_next in primary source file"); type = IT_INCLUDE; } else if (type == IT_IMPORT && CPP_OPTION (pfile, warn_import)) { CPP_OPTION (pfile, warn_import) = 0; cpp_warning (pfile, "#import is obsolete, use an #ifndef wrapper in the header file"); } header = parse_include (pfile); if (header) { /* Prevent #include recursion. */ if (pfile->line_maps.depth >= CPP_STACK_MAX) cpp_fatal (pfile, "#include nested too deeply"); else { check_eol (pfile); /* Get out of macro context, if we are. */ skip_rest_of_line (pfile); if (pfile->cb.include) (*pfile->cb.include) (pfile, pfile->directive_line, pfile->directive->name, header); _cpp_execute_include (pfile, header, type); } } } static void do_include (pfile) cpp_reader *pfile; { do_include_common (pfile, IT_INCLUDE); } static void do_import (pfile) cpp_reader *pfile; { do_include_common (pfile, IT_IMPORT); } static void do_include_next (pfile) cpp_reader *pfile; { do_include_common (pfile, IT_INCLUDE_NEXT); } /* Subroutine of do_line. Read possible flags after file name. LAST is the last flag seen; 0 if this is the first flag. Return the flag if it is valid, 0 at the end of the directive. Otherwise complain. */ static unsigned int read_flag (pfile, last) cpp_reader *pfile; unsigned int last; { const cpp_token *token = _cpp_lex_token (pfile); if (token->type == CPP_NUMBER && token->val.str.len == 1) { unsigned int flag = token->val.str.text[0] - '0'; if (flag > last && flag <= 4 && (flag != 4 || last == 3) && (flag != 2 || last == 0)) return flag; } if (token->type != CPP_EOF) cpp_error (pfile, "invalid flag \"%s\" in line directive", cpp_token_as_text (pfile, token)); return 0; } /* Another subroutine of do_line. Convert a number in STR, of length LEN, to binary; store it in NUMP, and return 0 if the number was well-formed, 1 if not. Temporary, hopefully. */ static int strtoul_for_line (str, len, nump) const U_CHAR *str; unsigned int len; unsigned long *nump; { unsigned long reg = 0; U_CHAR c; while (len--) { c = *str++; if (!ISDIGIT (c)) return 1; reg *= 10; reg += c - '0'; } *nump = reg; return 0; } /* Interpret #line command. Note that the filename string (if any) is treated as if it were an include filename. That means no escape handling. */ static void do_line (pfile) cpp_reader *pfile; { const cpp_token *token; const char *new_file = pfile->map->to_file; unsigned long new_lineno; unsigned int cap, new_sysp = pfile->map->sysp; enum lc_reason reason = LC_RENAME; /* C99 raised the minimum limit on #line numbers. */ cap = CPP_OPTION (pfile, c99) ? 2147483647 : 32767; /* Putting this in _cpp_handle_directive risks two calls to _cpp_backup_tokens in some circumstances, which can segfault. */ if (pfile->state.line_extension) _cpp_backup_tokens (pfile, 1); /* #line commands expand macros. */ token = cpp_get_token (pfile); if (token->type != CPP_NUMBER || strtoul_for_line (token->val.str.text, token->val.str.len, &new_lineno)) { cpp_error (pfile, "\"%s\" after #line is not a positive integer", cpp_token_as_text (pfile, token)); return; } if (CPP_PEDANTIC (pfile) && ! pfile->state.line_extension && (new_lineno == 0 || new_lineno > cap)) cpp_pedwarn (pfile, "line number out of range"); token = cpp_get_token (pfile); if (token->type == CPP_STRING) { new_file = (const char *) token->val.str.text; /* Only accept flags for the # 55 form. */ if (pfile->state.line_extension) { int flag; new_sysp = 0; flag = read_flag (pfile, 0); if (flag == 1) { reason = LC_ENTER; /* Fake an include for cpp_included (). */ _cpp_fake_include (pfile, new_file); flag = read_flag (pfile, flag); } else if (flag == 2) { reason = LC_LEAVE; flag = read_flag (pfile, flag); } if (flag == 3) { new_sysp = 1; flag = read_flag (pfile, flag); if (flag == 4) new_sysp = 2; } } check_eol (pfile); } else if (token->type != CPP_EOF) { cpp_error (pfile, "\"%s\" is not a valid filename", cpp_token_as_text (pfile, token)); return; } skip_rest_of_line (pfile); _cpp_do_file_change (pfile, reason, new_file, new_lineno, new_sysp); } /* Arrange the file_change callback. pfile->line has changed to FILE_LINE of TO_FILE, for reason REASON. SYSP is 1 for a system header, 2 for a system header that needs to be extern "C" protected, and zero otherwise. */ void _cpp_do_file_change (pfile, reason, to_file, file_line, sysp) cpp_reader *pfile; enum lc_reason reason; const char *to_file; unsigned int file_line; unsigned int sysp; { pfile->map = add_line_map (&pfile->line_maps, reason, sysp, pfile->line, to_file, file_line); if (pfile->cb.file_change) (*pfile->cb.file_change) (pfile, pfile->map); } /* * Report a warning or error detected by the program we are * processing. Use the directive's tokens in the error message. */ static void do_diagnostic (pfile, code, print_dir) cpp_reader *pfile; enum error_type code; int print_dir; { if (_cpp_begin_message (pfile, code, 0, 0)) { if (print_dir) fprintf (stderr, "#%s ", pfile->directive->name); pfile->state.prevent_expansion++; cpp_output_line (pfile, stderr); pfile->state.prevent_expansion--; } } static void do_error (pfile) cpp_reader *pfile; { do_diagnostic (pfile, ERROR, 1); } static void do_warning (pfile) cpp_reader *pfile; { /* We want #warning diagnostics to be emitted in system headers too. */ do_diagnostic (pfile, WARNING_SYSHDR, 1); } /* Report program identification. */ static void do_ident (pfile) cpp_reader *pfile; { const cpp_token *str = cpp_get_token (pfile); if (str->type != CPP_STRING) cpp_error (pfile, "invalid #ident directive"); else if (pfile->cb.ident) (*pfile->cb.ident) (pfile, pfile->directive_line, &str->val.str); check_eol (pfile); } /* Lookup a PRAGMA name in a singly-linked CHAIN. Returns the matching entry, or NULL if none is found. The returned entry could be the start of a namespace chain, or a pragma. */ static struct pragma_entry * lookup_pragma_entry (chain, pragma) struct pragma_entry *chain; const cpp_hashnode *pragma; { while (chain && chain->pragma != pragma) chain = chain->next; return chain; } /* Create and insert a pragma entry for NAME at the beginning of a singly-linked CHAIN. If handler is NULL, it is a namespace, otherwise it is a pragma and its handler. */ static struct pragma_entry * insert_pragma_entry (pfile, chain, pragma, handler) cpp_reader *pfile; struct pragma_entry **chain; const cpp_hashnode *pragma; pragma_cb handler; { struct pragma_entry *new; new = (struct pragma_entry *) _cpp_aligned_alloc (pfile, sizeof (struct pragma_entry)); new->pragma = pragma; if (handler) { new->is_nspace = 0; new->u.handler = handler; } else { new->is_nspace = 1; new->u.space = NULL; } new->next = *chain; *chain = new; return new; } /* Register a pragma NAME in namespace SPACE. If SPACE is null, it goes in the global namespace. HANDLER is the handler it will call, which must be non-NULL. */ void cpp_register_pragma (pfile, space, name, handler) cpp_reader *pfile; const char *space; const char *name; pragma_cb handler; { struct pragma_entry **chain = &pfile->pragmas; struct pragma_entry *entry; const cpp_hashnode *node; if (!handler) abort (); if (space) { node = cpp_lookup (pfile, U space, strlen (space)); entry = lookup_pragma_entry (*chain, node); if (!entry) entry = insert_pragma_entry (pfile, chain, node, NULL); else if (!entry->is_nspace) goto clash; chain = &entry->u.space; } /* Check for duplicates. */ node = cpp_lookup (pfile, U name, strlen (name)); entry = lookup_pragma_entry (*chain, node); if (entry) { if (entry->is_nspace) clash: cpp_ice (pfile, "registering \"%s\" as both a pragma and a pragma namespace", NODE_NAME (node)); else if (space) cpp_ice (pfile, "#pragma %s %s is already registered", space, name); else cpp_ice (pfile, "#pragma %s is already registered", name); } else insert_pragma_entry (pfile, chain, node, handler); } /* Register the pragmas the preprocessor itself handles. */ void _cpp_init_internal_pragmas (pfile) cpp_reader *pfile; { /* Pragmas in the global namespace. */ cpp_register_pragma (pfile, 0, "poison", do_pragma_poison); cpp_register_pragma (pfile, 0, "once", do_pragma_once); /* New GCC-specific pragmas should be put in the GCC namespace. */ cpp_register_pragma (pfile, "GCC", "poison", do_pragma_poison); cpp_register_pragma (pfile, "GCC", "system_header", do_pragma_system_header); cpp_register_pragma (pfile, "GCC", "dependency", do_pragma_dependency); } /* Pragmata handling. We handle some, and pass the rest on to the front end. C99 defines three pragmas and says that no macro expansion is to be performed on them; whether or not macro expansion happens for other pragmas is implementation defined. This implementation never macro-expands the text after #pragma. */ static void do_pragma (pfile) cpp_reader *pfile; { const struct pragma_entry *p = NULL; const cpp_token *token; unsigned int count = 1; pfile->state.prevent_expansion++; token = cpp_get_token (pfile); if (token->type == CPP_NAME) { p = lookup_pragma_entry (pfile->pragmas, token->val.node); if (p && p->is_nspace) { count = 2; token = cpp_get_token (pfile); if (token->type == CPP_NAME) p = lookup_pragma_entry (p->u.space, token->val.node); else p = NULL; } } /* FIXME. This is an awful kludge to get the front ends to update their notion of line number for diagnostic purposes. The line number should be passed to the handler and they should do it themselves. Stand-alone CPP must ignore us, otherwise it will prefix the directive with spaces, hence the 1. Ugh. */ if (pfile->cb.line_change) (*pfile->cb.line_change)(pfile, token, 1); if (p) (*p->u.handler) (pfile); else if (pfile->cb.def_pragma) { _cpp_backup_tokens (pfile, count); (*pfile->cb.def_pragma) (pfile, pfile->directive_line); } pfile->state.prevent_expansion--; } static void do_pragma_once (pfile) cpp_reader *pfile; { cpp_warning (pfile, "#pragma once is obsolete"); if (pfile->buffer->prev == NULL) cpp_warning (pfile, "#pragma once in main file"); else _cpp_never_reread (pfile->buffer->inc); check_eol (pfile); } static void do_pragma_poison (pfile) cpp_reader *pfile; { /* Poison these symbols so that all subsequent usage produces an error message. */ const cpp_token *tok; cpp_hashnode *hp; pfile->state.poisoned_ok = 1; for (;;) { tok = _cpp_lex_token (pfile); if (tok->type == CPP_EOF) break; if (tok->type != CPP_NAME) { cpp_error (pfile, "invalid #pragma GCC poison directive"); break; } hp = tok->val.node; if (hp->flags & NODE_POISONED) continue; if (hp->type == NT_MACRO) cpp_warning (pfile, "poisoning existing macro \"%s\"", NODE_NAME (hp)); _cpp_free_definition (hp); hp->flags |= NODE_POISONED | NODE_DIAGNOSTIC; } pfile->state.poisoned_ok = 0; } /* Mark the current header as a system header. This will suppress some categories of warnings (notably those from -pedantic). It is intended for use in system libraries that cannot be implemented in conforming C, but cannot be certain that their headers appear in a system include directory. To prevent abuse, it is rejected in the primary source file. */ static void do_pragma_system_header (pfile) cpp_reader *pfile; { cpp_buffer *buffer = pfile->buffer; if (buffer->prev == 0) cpp_warning (pfile, "#pragma system_header ignored outside include file"); else { check_eol (pfile); skip_rest_of_line (pfile); cpp_make_system_header (pfile, 1, 0); } } /* Check the modified date of the current include file against a specified file. Issue a diagnostic, if the specified file is newer. We use this to determine if a fixed header should be refixed. */ static void do_pragma_dependency (pfile) cpp_reader *pfile; { const cpp_token *header; int ordering; header = parse_include (pfile); if (!header) return; ordering = _cpp_compare_file_date (pfile, header); if (ordering < 0) cpp_warning (pfile, "cannot find source %s", cpp_token_as_text (pfile, header)); else if (ordering > 0) { cpp_warning (pfile, "current file is older than %s", cpp_token_as_text (pfile, header)); if (cpp_get_token (pfile)->type != CPP_EOF) { _cpp_backup_tokens (pfile, 1); do_diagnostic (pfile, WARNING, 0); } } } /* Get a token but skip padding. */ static const cpp_token * get_token_no_padding (pfile) cpp_reader *pfile; { for (;;) { const cpp_token *result = cpp_get_token (pfile); if (result->type != CPP_PADDING) return result; } } /* Check syntax is "(string-literal)". Returns the string on success, or NULL on failure. */ static const cpp_token * get__Pragma_string (pfile) cpp_reader *pfile; { const cpp_token *string; if (get_token_no_padding (pfile)->type != CPP_OPEN_PAREN) return NULL; string = get_token_no_padding (pfile); if (string->type != CPP_STRING && string->type != CPP_WSTRING) return NULL; if (get_token_no_padding (pfile)->type != CPP_CLOSE_PAREN) return NULL; return string; } /* Destringize IN into a temporary buffer, by removing the first \ of \" and \\ sequences, and process the result as a #pragma directive. */ static void destringize_and_run (pfile, in) cpp_reader *pfile; const cpp_string *in; { const unsigned char *src, *limit; char *dest, *result; dest = result = alloca (in->len + 1); for (src = in->text, limit = src + in->len; src < limit;) { /* We know there is a character following the backslash. */ if (*src == '\\' && (src[1] == '\\' || src[1] == '"')) src++; *dest++ = *src++; } *dest = '\0'; run_directive (pfile, T_PRAGMA, result, dest - result); } /* Handle the _Pragma operator. */ void _cpp_do__Pragma (pfile) cpp_reader *pfile; { const cpp_token *string = get__Pragma_string (pfile); if (!string) cpp_error (pfile, "_Pragma takes a parenthesized string literal"); else { /* Ideally, we'd like token1 _Pragma ("foo") token2 to be output as token1 # 7 "file.c" #pragma foo # 7 "file.c" token2 Getting these correct line markers is a little tricky. */ unsigned int orig_line = pfile->line; destringize_and_run (pfile, &string->val.str); pfile->line = orig_line; pfile->buffer->saved_flags = BOL; } } /* Just ignore #sccs, on systems where we define it at all. */ #ifdef SCCS_DIRECTIVE static void do_sccs (pfile) cpp_reader *pfile ATTRIBUTE_UNUSED; { } #endif static void do_ifdef (pfile) cpp_reader *pfile; { int skip = 1; if (! pfile->state.skipping) { const cpp_hashnode *node = lex_macro_node (pfile); if (node) skip = node->type != NT_MACRO; if (node) check_eol (pfile); } push_conditional (pfile, skip, T_IFDEF, 0); } static void do_ifndef (pfile) cpp_reader *pfile; { int skip = 1; const cpp_hashnode *node = 0; if (! pfile->state.skipping) { node = lex_macro_node (pfile); if (node) skip = node->type == NT_MACRO; if (node) check_eol (pfile); } push_conditional (pfile, skip, T_IFNDEF, node); } /* _cpp_parse_expr puts a macro in a "#if !defined ()" expression in pfile->mi_ind_cmacro so we can handle multiple-include optimisations. If macro expansion occurs in the expression, we cannot treat it as a controlling conditional, since the expansion could change in the future. That is handled by cpp_get_token. */ static void do_if (pfile) cpp_reader *pfile; { int skip = 1; if (! pfile->state.skipping) skip = _cpp_parse_expr (pfile) == 0; push_conditional (pfile, skip, T_IF, pfile->mi_ind_cmacro); } /* Flip skipping state if appropriate and continue without changing if_stack; this is so that the error message for missing #endif's etc. will point to the original #if. */ static void do_else (pfile) cpp_reader *pfile; { cpp_buffer *buffer = pfile->buffer; struct if_stack *ifs = buffer->if_stack; if (ifs == NULL) cpp_error (pfile, "#else without #if"); else { if (ifs->type == T_ELSE) { cpp_error (pfile, "#else after #else"); cpp_error_with_line (pfile, ifs->line, 0, "the conditional began here"); } ifs->type = T_ELSE; /* Skip any future (erroneous) #elses or #elifs. */ pfile->state.skipping = ifs->skip_elses; ifs->skip_elses = true; /* Invalidate any controlling macro. */ ifs->mi_cmacro = 0; /* Only check EOL if was not originally skipping. */ if (!ifs->was_skipping) check_eol (pfile); } } /* handle a #elif directive by not changing if_stack either. see the comment above do_else. */ static void do_elif (pfile) cpp_reader *pfile; { cpp_buffer *buffer = pfile->buffer; struct if_stack *ifs = buffer->if_stack; if (ifs == NULL) cpp_error (pfile, "#elif without #if"); else { if (ifs->type == T_ELSE) { cpp_error (pfile, "#elif after #else"); cpp_error_with_line (pfile, ifs->line, 0, "the conditional began here"); } ifs->type = T_ELIF; /* Only evaluate this if we aren't skipping elses. During evaluation, set skipping to false to get lexer warnings. */ if (ifs->skip_elses) pfile->state.skipping = 1; else { pfile->state.skipping = 0; pfile->state.skipping = ! _cpp_parse_expr (pfile); ifs->skip_elses = ! pfile->state.skipping; } /* Invalidate any controlling macro. */ ifs->mi_cmacro = 0; } } /* #endif pops the if stack and resets pfile->state.skipping. */ static void do_endif (pfile) cpp_reader *pfile; { cpp_buffer *buffer = pfile->buffer; struct if_stack *ifs = buffer->if_stack; if (ifs == NULL) cpp_error (pfile, "#endif without #if"); else { /* Only check EOL if was not originally skipping. */ if (!ifs->was_skipping) check_eol (pfile); /* If potential control macro, we go back outside again. */ if (ifs->next == 0 && ifs->mi_cmacro) { pfile->mi_valid = true; pfile->mi_cmacro = ifs->mi_cmacro; } buffer->if_stack = ifs->next; pfile->state.skipping = ifs->was_skipping; obstack_free (&pfile->buffer_ob, ifs); } } /* Push an if_stack entry and set pfile->state.skipping accordingly. If this is a #if or #ifndef, CMACRO is a potentially controlling macro - we need to check here that we are at the top of the file. */ static void push_conditional (pfile, skip, type, cmacro) cpp_reader *pfile; int skip; int type; const cpp_hashnode *cmacro; { struct if_stack *ifs; cpp_buffer *buffer = pfile->buffer; ifs = xobnew (&pfile->buffer_ob, struct if_stack); ifs->line = pfile->directive_line; ifs->next = buffer->if_stack; ifs->skip_elses = pfile->state.skipping || !skip; ifs->was_skipping = pfile->state.skipping; ifs->type = type; /* This condition is effectively a test for top-of-file. */ if (pfile->mi_valid && pfile->mi_cmacro == 0) ifs->mi_cmacro = cmacro; else ifs->mi_cmacro = 0; pfile->state.skipping = skip; buffer->if_stack = ifs; } /* Read the tokens of the answer into the macro pool. Only commit the memory if we intend it as permanent storage, i.e. the #assert case. Returns 0 on success. */ static int parse_answer (pfile, answerp, type) cpp_reader *pfile; struct answer **answerp; int type; { const cpp_token *paren; struct answer *answer; unsigned int acount; /* In a conditional, it is legal to not have an open paren. We should save the following token in this case. */ paren = cpp_get_token (pfile); /* If not a paren, see if we're OK. */ if (paren->type != CPP_OPEN_PAREN) { /* In a conditional no answer is a test for any answer. It could be followed by any token. */ if (type == T_IF) { _cpp_backup_tokens (pfile, 1); return 0; } /* #unassert with no answer is valid - it removes all answers. */ if (type == T_UNASSERT && paren->type == CPP_EOF) return 0; cpp_error (pfile, "missing '(' after predicate"); return 1; } for (acount = 0;; acount++) { size_t room_needed; const cpp_token *token = cpp_get_token (pfile); cpp_token *dest; if (token->type == CPP_CLOSE_PAREN) break; if (token->type == CPP_EOF) { cpp_error (pfile, "missing ')' to complete answer"); return 1; } /* struct answer includes the space for one token. */ room_needed = (sizeof (struct answer) + acount * sizeof (cpp_token)); if (BUFF_ROOM (pfile->a_buff) < room_needed) _cpp_extend_buff (pfile, &pfile->a_buff, sizeof (struct answer)); dest = &((struct answer *) BUFF_FRONT (pfile->a_buff))->first[acount]; *dest = *token; /* Drop whitespace at start, for answer equivalence purposes. */ if (acount == 0) dest->flags &= ~PREV_WHITE; } if (acount == 0) { cpp_error (pfile, "predicate's answer is empty"); return 1; } answer = (struct answer *) BUFF_FRONT (pfile->a_buff); answer->count = acount; answer->next = NULL; *answerp = answer; return 0; } /* Parses an assertion, returning a pointer to the hash node of the predicate, or 0 on error. If an answer was supplied, it is placed in ANSWERP, otherwise it is set to 0. */ static cpp_hashnode * parse_assertion (pfile, answerp, type) cpp_reader *pfile; struct answer **answerp; int type; { cpp_hashnode *result = 0; const cpp_token *predicate; /* We don't expand predicates or answers. */ pfile->state.prevent_expansion++; *answerp = 0; predicate = cpp_get_token (pfile); if (predicate->type == CPP_EOF) cpp_error (pfile, "assertion without predicate"); else if (predicate->type != CPP_NAME) cpp_error (pfile, "predicate must be an identifier"); else if (parse_answer (pfile, answerp, type) == 0) { unsigned int len = NODE_LEN (predicate->val.node); unsigned char *sym = alloca (len + 1); /* Prefix '#' to get it out of macro namespace. */ sym[0] = '#'; memcpy (sym + 1, NODE_NAME (predicate->val.node), len); result = cpp_lookup (pfile, sym, len + 1); } pfile->state.prevent_expansion--; return result; } /* Returns a pointer to the pointer to the answer in the answer chain, or a pointer to NULL if the answer is not in the chain. */ static struct answer ** find_answer (node, candidate) cpp_hashnode *node; const struct answer *candidate; { unsigned int i; struct answer **result; for (result = &node->value.answers; *result; result = &(*result)->next) { struct answer *answer = *result; if (answer->count == candidate->count) { for (i = 0; i < answer->count; i++) if (! _cpp_equiv_tokens (&answer->first[i], &candidate->first[i])) break; if (i == answer->count) break; } } return result; } /* Test an assertion within a preprocessor conditional. Returns non-zero on failure, zero on success. On success, the result of the test is written into VALUE. */ int _cpp_test_assertion (pfile, value) cpp_reader *pfile; int *value; { struct answer *answer; cpp_hashnode *node; node = parse_assertion (pfile, &answer, T_IF); if (node) *value = (node->type == NT_ASSERTION && (answer == 0 || *find_answer (node, answer) != 0)); /* We don't commit the memory for the answer - it's temporary only. */ return node == 0; } static void do_assert (pfile) cpp_reader *pfile; { struct answer *new_answer; cpp_hashnode *node; node = parse_assertion (pfile, &new_answer, T_ASSERT); if (node) { /* Place the new answer in the answer list. First check there is not a duplicate. */ new_answer->next = 0; if (node->type == NT_ASSERTION) { if (*find_answer (node, new_answer)) { cpp_warning (pfile, "\"%s\" re-asserted", NODE_NAME (node) + 1); return; } new_answer->next = node->value.answers; } node->type = NT_ASSERTION; node->value.answers = new_answer; BUFF_FRONT (pfile->a_buff) += (sizeof (struct answer) + (new_answer->count - 1) * sizeof (cpp_token)); check_eol (pfile); } } static void do_unassert (pfile) cpp_reader *pfile; { cpp_hashnode *node; struct answer *answer; node = parse_assertion (pfile, &answer, T_UNASSERT); /* It isn't an error to #unassert something that isn't asserted. */ if (node && node->type == NT_ASSERTION) { if (answer) { struct answer **p = find_answer (node, answer), *temp; /* Remove the answer from the list. */ temp = *p; if (temp) *p = temp->next; /* Did we free the last answer? */ if (node->value.answers == 0) node->type = NT_VOID; check_eol (pfile); } else _cpp_free_definition (node); } /* We don't commit the memory for the answer - it's temporary only. */ } /* These are for -D, -U, -A. */ /* Process the string STR as if it appeared as the body of a #define. If STR is just an identifier, define it with value 1. If STR has anything after the identifier, then it should be identifier=definition. */ void cpp_define (pfile, str) cpp_reader *pfile; const char *str; { char *buf, *p; size_t count; /* Copy the entire option so we can modify it. Change the first "=" in the string to a space. If there is none, tack " 1" on the end. */ count = strlen (str); buf = (char *) alloca (count + 3); memcpy (buf, str, count); p = strchr (str, '='); if (p) buf[p - str] = ' '; else { buf[count++] = ' '; buf[count++] = '1'; } buf[count] = '\0'; run_directive (pfile, T_DEFINE, buf, count); } /* Slight variant of the above for use by initialize_builtins. */ void _cpp_define_builtin (pfile, str) cpp_reader *pfile; const char *str; { run_directive (pfile, T_DEFINE, str, strlen (str)); } /* Process MACRO as if it appeared as the body of an #undef. */ void cpp_undef (pfile, macro) cpp_reader *pfile; const char *macro; { run_directive (pfile, T_UNDEF, macro, strlen (macro)); } /* Process the string STR as if it appeared as the body of a #assert. */ void cpp_assert (pfile, str) cpp_reader *pfile; const char *str; { handle_assertion (pfile, str, T_ASSERT); } /* Process STR as if it appeared as the body of an #unassert. */ void cpp_unassert (pfile, str) cpp_reader *pfile; const char *str; { handle_assertion (pfile, str, T_UNASSERT); } /* Common code for cpp_assert (-A) and cpp_unassert (-A-). */ static void handle_assertion (pfile, str, type) cpp_reader *pfile; const char *str; int type; { size_t count = strlen (str); const char *p = strchr (str, '='); if (p) { /* Copy the entire option so we can modify it. Change the first "=" in the string to a '(', and tack a ')' on the end. */ char *buf = (char *) alloca (count + 2); memcpy (buf, str, count); buf[p - str] = '('; buf[count++] = ')'; buf[count] = '\0'; str = buf; } run_directive (pfile, type, str, count); } /* The number of errors for a given reader. */ unsigned int cpp_errors (pfile) cpp_reader *pfile; { return pfile->errors; } /* The options structure. */ cpp_options * cpp_get_options (pfile) cpp_reader *pfile; { return &pfile->opts; } /* The callbacks structure. */ cpp_callbacks * cpp_get_callbacks (pfile) cpp_reader *pfile; { return &pfile->cb; } /* The line map set. */ const struct line_maps * cpp_get_line_maps (pfile) cpp_reader *pfile; { return &pfile->line_maps; } /* Copy the given callbacks structure to our own. */ void cpp_set_callbacks (pfile, cb) cpp_reader *pfile; cpp_callbacks *cb; { pfile->cb = *cb; } /* Push a new buffer on the buffer stack. Returns the new buffer; it doesn't fail. It does not generate a file change call back; that is the responsibility of the caller. */ cpp_buffer * cpp_push_buffer (pfile, buffer, len, from_stage3, return_at_eof) cpp_reader *pfile; const U_CHAR *buffer; size_t len; int from_stage3; int return_at_eof; { cpp_buffer *new = xobnew (&pfile->buffer_ob, cpp_buffer); /* Clears, amongst other things, if_stack and mi_cmacro. */ memset (new, 0, sizeof (cpp_buffer)); new->line_base = new->buf = new->cur = buffer; new->rlimit = buffer + len; new->from_stage3 = from_stage3; new->prev = pfile->buffer; new->return_at_eof = return_at_eof; new->saved_flags = BOL; pfile->buffer = new; return new; } /* If called from do_line, pops a single buffer. Otherwise pops all buffers until a real file is reached. Generates appropriate call-backs. */ void _cpp_pop_buffer (pfile) cpp_reader *pfile; { cpp_buffer *buffer = pfile->buffer; struct if_stack *ifs; /* Walk back up the conditional stack till we reach its level at entry to this file, issuing error messages. */ for (ifs = buffer->if_stack; ifs; ifs = ifs->next) cpp_error_with_line (pfile, ifs->line, 0, "unterminated #%s", dtable[ifs->type].name); /* In case of a missing #endif. */ pfile->state.skipping = 0; /* Update the reader's buffer before _cpp_do_file_change. */ pfile->buffer = buffer->prev; if (buffer->inc) _cpp_pop_file_buffer (pfile, buffer->inc); obstack_free (&pfile->buffer_ob, buffer); } void _cpp_init_directives (pfile) cpp_reader *pfile; { unsigned int i; cpp_hashnode *node; /* Register the directives. */ for (i = 0; i < (unsigned int) N_DIRECTIVES; i++) { node = cpp_lookup (pfile, dtable[i].name, dtable[i].length); node->directive_index = i + 1; } }