URL
https://opencores.org/ocsvn/openrisc/openrisc/trunk
Subversion Repositories openrisc
[/] [openrisc/] [trunk/] [gnu-stable/] [gdb-7.2/] [gdb/] [macroexp.c] - Rev 853
Go to most recent revision | Compare with Previous | Blame | View Log
/* C preprocessor macro expansion for GDB. Copyright (C) 2002, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. Contributed by Red Hat, Inc. This file is part of GDB. 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */ #include "defs.h" #include "gdb_obstack.h" #include "bcache.h" #include "macrotab.h" #include "macroexp.h" #include "gdb_assert.h" #include "c-lang.h" /* A resizeable, substringable string type. */ /* A string type that we can resize, quickly append to, and use to refer to substrings of other strings. */ struct macro_buffer { /* An array of characters. The first LEN bytes are the real text, but there are SIZE bytes allocated to the array. If SIZE is zero, then this doesn't point to a malloc'ed block. If SHARED is non-zero, then this buffer is actually a pointer into some larger string, and we shouldn't append characters to it, etc. Because of sharing, we can't assume in general that the text is null-terminated. */ char *text; /* The number of characters in the string. */ int len; /* The number of characters allocated to the string. If SHARED is non-zero, this is meaningless; in this case, we set it to zero so that any "do we have room to append something?" tests will fail, so we don't always have to check SHARED before using this field. */ int size; /* Zero if TEXT can be safely realloc'ed (i.e., it's its own malloc block). Non-zero if TEXT is actually pointing into the middle of some other block, and we shouldn't reallocate it. */ int shared; /* For detecting token splicing. This is the index in TEXT of the first character of the token that abuts the end of TEXT. If TEXT contains no tokens, then we set this equal to LEN. If TEXT ends in whitespace, then there is no token abutting the end of TEXT (it's just whitespace), and again, we set this equal to LEN. We set this to -1 if we don't know the nature of TEXT. */ int last_token; /* If this buffer is holding the result from get_token, then this is non-zero if it is an identifier token, zero otherwise. */ int is_identifier; }; /* Set the macro buffer *B to the empty string, guessing that its final contents will fit in N bytes. (It'll get resized if it doesn't, so the guess doesn't have to be right.) Allocate the initial storage with xmalloc. */ static void init_buffer (struct macro_buffer *b, int n) { b->size = n; if (n > 0) b->text = (char *) xmalloc (n); else b->text = NULL; b->len = 0; b->shared = 0; b->last_token = -1; } /* Set the macro buffer *BUF to refer to the LEN bytes at ADDR, as a shared substring. */ static void init_shared_buffer (struct macro_buffer *buf, char *addr, int len) { buf->text = addr; buf->len = len; buf->shared = 1; buf->size = 0; buf->last_token = -1; } /* Free the text of the buffer B. Raise an error if B is shared. */ static void free_buffer (struct macro_buffer *b) { gdb_assert (! b->shared); if (b->size) xfree (b->text); } /* A cleanup function for macro buffers. */ static void cleanup_macro_buffer (void *untyped_buf) { free_buffer ((struct macro_buffer *) untyped_buf); } /* Resize the buffer B to be at least N bytes long. Raise an error if B shouldn't be resized. */ static void resize_buffer (struct macro_buffer *b, int n) { /* We shouldn't be trying to resize shared strings. */ gdb_assert (! b->shared); if (b->size == 0) b->size = n; else while (b->size <= n) b->size *= 2; b->text = xrealloc (b->text, b->size); } /* Append the character C to the buffer B. */ static void appendc (struct macro_buffer *b, int c) { int new_len = b->len + 1; if (new_len > b->size) resize_buffer (b, new_len); b->text[b->len] = c; b->len = new_len; } /* Append the LEN bytes at ADDR to the buffer B. */ static void appendmem (struct macro_buffer *b, char *addr, int len) { int new_len = b->len + len; if (new_len > b->size) resize_buffer (b, new_len); memcpy (b->text + b->len, addr, len); b->len = new_len; } /* Recognizing preprocessor tokens. */ int macro_is_whitespace (int c) { return (c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f'); } int macro_is_digit (int c) { return ('0' <= c && c <= '9'); } int macro_is_identifier_nondigit (int c) { return (c == '_' || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z')); } static void set_token (struct macro_buffer *tok, char *start, char *end) { init_shared_buffer (tok, start, end - start); tok->last_token = 0; /* Presumed; get_identifier may overwrite this. */ tok->is_identifier = 0; } static int get_comment (struct macro_buffer *tok, char *p, char *end) { if (p + 2 > end) return 0; else if (p[0] == '/' && p[1] == '*') { char *tok_start = p; p += 2; for (; p < end; p++) if (p + 2 <= end && p[0] == '*' && p[1] == '/') { p += 2; set_token (tok, tok_start, p); return 1; } error (_("Unterminated comment in macro expansion.")); } else if (p[0] == '/' && p[1] == '/') { char *tok_start = p; p += 2; for (; p < end; p++) if (*p == '\n') break; set_token (tok, tok_start, p); return 1; } else return 0; } static int get_identifier (struct macro_buffer *tok, char *p, char *end) { if (p < end && macro_is_identifier_nondigit (*p)) { char *tok_start = p; while (p < end && (macro_is_identifier_nondigit (*p) || macro_is_digit (*p))) p++; set_token (tok, tok_start, p); tok->is_identifier = 1; return 1; } else return 0; } static int get_pp_number (struct macro_buffer *tok, char *p, char *end) { if (p < end && (macro_is_digit (*p) || (*p == '.' && p + 2 <= end && macro_is_digit (p[1])))) { char *tok_start = p; while (p < end) { if (p + 2 <= end && strchr ("eEpP", *p) && (p[1] == '+' || p[1] == '-')) p += 2; else if (macro_is_digit (*p) || macro_is_identifier_nondigit (*p) || *p == '.') p++; else break; } set_token (tok, tok_start, p); return 1; } else return 0; } /* If the text starting at P going up to (but not including) END starts with a character constant, set *TOK to point to that character constant, and return 1. Otherwise, return zero. Signal an error if it contains a malformed or incomplete character constant. */ static int get_character_constant (struct macro_buffer *tok, char *p, char *end) { /* ISO/IEC 9899:1999 (E) Section 6.4.4.4 paragraph 1 But of course, what really matters is that we handle it the same way GDB's C/C++ lexer does. So we call parse_escape in utils.c to handle escape sequences. */ if ((p + 1 <= end && *p == '\'') || (p + 2 <= end && (p[0] == 'L' || p[0] == 'u' || p[0] == 'U') && p[1] == '\'')) { char *tok_start = p; char *body_start; int char_count = 0; if (*p == '\'') p++; else if (*p == 'L' || *p == 'u' || *p == 'U') p += 2; else gdb_assert (0); body_start = p; for (;;) { if (p >= end) error (_("Unmatched single quote.")); else if (*p == '\'') { if (!char_count) error (_("A character constant must contain at least one " "character.")); p++; break; } else if (*p == '\\') { p++; char_count += c_parse_escape (&p, NULL); } else { p++; char_count++; } } set_token (tok, tok_start, p); return 1; } else return 0; } /* If the text starting at P going up to (but not including) END starts with a string literal, set *TOK to point to that string literal, and return 1. Otherwise, return zero. Signal an error if it contains a malformed or incomplete string literal. */ static int get_string_literal (struct macro_buffer *tok, char *p, char *end) { if ((p + 1 <= end && *p == '"') || (p + 2 <= end && (p[0] == 'L' || p[0] == 'u' || p[0] == 'U') && p[1] == '"')) { char *tok_start = p; if (*p == '"') p++; else if (*p == 'L' || *p == 'u' || *p == 'U') p += 2; else gdb_assert (0); for (;;) { if (p >= end) error (_("Unterminated string in expression.")); else if (*p == '"') { p++; break; } else if (*p == '\n') error (_("Newline characters may not appear in string " "constants.")); else if (*p == '\\') { p++; c_parse_escape (&p, NULL); } else p++; } set_token (tok, tok_start, p); return 1; } else return 0; } static int get_punctuator (struct macro_buffer *tok, char *p, char *end) { /* Here, speed is much less important than correctness and clarity. */ /* ISO/IEC 9899:1999 (E) Section 6.4.6 Paragraph 1. Note that this table is ordered in a special way. A punctuator which is a prefix of another punctuator must appear after its "extension". Otherwise, the wrong token will be returned. */ static const char * const punctuators[] = { "[", "]", "(", ")", "{", "}", "?", ";", ",", "~", "...", ".", "->", "--", "-=", "-", "++", "+=", "+", "*=", "*", "!=", "!", "&&", "&=", "&", "/=", "/", "%>", "%:%:", "%:", "%=", "%", "^=", "^", "##", "#", ":>", ":", "||", "|=", "|", "<<=", "<<", "<=", "<:", "<%", "<", ">>=", ">>", ">=", ">", "==", "=", 0 }; int i; if (p + 1 <= end) { for (i = 0; punctuators[i]; i++) { const char *punctuator = punctuators[i]; if (p[0] == punctuator[0]) { int len = strlen (punctuator); if (p + len <= end && ! memcmp (p, punctuator, len)) { set_token (tok, p, p + len); return 1; } } } } return 0; } /* Peel the next preprocessor token off of SRC, and put it in TOK. Mutate TOK to refer to the first token in SRC, and mutate SRC to refer to the text after that token. SRC must be a shared buffer; the resulting TOK will be shared, pointing into the same string SRC does. Initialize TOK's last_token field. Return non-zero if we succeed, or 0 if we didn't find any more tokens in SRC. */ static int get_token (struct macro_buffer *tok, struct macro_buffer *src) { char *p = src->text; char *end = p + src->len; gdb_assert (src->shared); /* From the ISO C standard, ISO/IEC 9899:1999 (E), section 6.4: preprocessing-token: header-name identifier pp-number character-constant string-literal punctuator each non-white-space character that cannot be one of the above We don't have to deal with header-name tokens, since those can only occur after a #include, which we will never see. */ while (p < end) if (macro_is_whitespace (*p)) p++; else if (get_comment (tok, p, end)) p += tok->len; else if (get_pp_number (tok, p, end) || get_character_constant (tok, p, end) || get_string_literal (tok, p, end) /* Note: the grammar in the standard seems to be ambiguous: L'x' can be either a wide character constant, or an identifier followed by a normal character constant. By trying `get_identifier' after we try get_character_constant and get_string_literal, we give the wide character syntax precedence. Now, since GDB doesn't handle wide character constants anyway, is this the right thing to do? */ || get_identifier (tok, p, end) || get_punctuator (tok, p, end)) { /* How many characters did we consume, including whitespace? */ int consumed = p - src->text + tok->len; src->text += consumed; src->len -= consumed; return 1; } else { /* We have found a "non-whitespace character that cannot be one of the above." Make a token out of it. */ int consumed; set_token (tok, p, p + 1); consumed = p - src->text + tok->len; src->text += consumed; src->len -= consumed; return 1; } return 0; } /* Appending token strings, with and without splicing */ /* Append the macro buffer SRC to the end of DEST, and ensure that doing so doesn't splice the token at the end of SRC with the token at the beginning of DEST. SRC and DEST must have their last_token fields set. Upon return, DEST's last_token field is set correctly. For example: If DEST is "(" and SRC is "y", then we can return with DEST set to "(y" --- we've simply appended the two buffers. However, if DEST is "x" and SRC is "y", then we must not return with DEST set to "xy" --- that would splice the two tokens "x" and "y" together to make a single token "xy". However, it would be fine to return with DEST set to "x y". Similarly, "<" and "<" must yield "< <", not "<<", etc. */ static void append_tokens_without_splicing (struct macro_buffer *dest, struct macro_buffer *src) { int original_dest_len = dest->len; struct macro_buffer dest_tail, new_token; gdb_assert (src->last_token != -1); gdb_assert (dest->last_token != -1); /* First, just try appending the two, and call get_token to see if we got a splice. */ appendmem (dest, src->text, src->len); /* If DEST originally had no token abutting its end, then we can't have spliced anything, so we're done. */ if (dest->last_token == original_dest_len) { dest->last_token = original_dest_len + src->last_token; return; } /* Set DEST_TAIL to point to the last token in DEST, followed by all the stuff we just appended. */ init_shared_buffer (&dest_tail, dest->text + dest->last_token, dest->len - dest->last_token); /* Re-parse DEST's last token. We know that DEST used to contain at least one token, so if it doesn't contain any after the append, then we must have spliced "/" and "*" or "/" and "/" to make a comment start. (Just for the record, I got this right the first time. This is not a bug fix.) */ if (get_token (&new_token, &dest_tail) && (new_token.text + new_token.len == dest->text + original_dest_len)) { /* No splice, so we're done. */ dest->last_token = original_dest_len + src->last_token; return; } /* Okay, a simple append caused a splice. Let's chop dest back to its original length and try again, but separate the texts with a space. */ dest->len = original_dest_len; appendc (dest, ' '); appendmem (dest, src->text, src->len); init_shared_buffer (&dest_tail, dest->text + dest->last_token, dest->len - dest->last_token); /* Try to re-parse DEST's last token, as above. */ if (get_token (&new_token, &dest_tail) && (new_token.text + new_token.len == dest->text + original_dest_len)) { /* No splice, so we're done. */ dest->last_token = original_dest_len + 1 + src->last_token; return; } /* As far as I know, there's no case where inserting a space isn't enough to prevent a splice. */ internal_error (__FILE__, __LINE__, _("unable to avoid splicing tokens during macro expansion")); } /* Stringify an argument, and insert it into DEST. ARG is the text to stringify; it is LEN bytes long. */ static void stringify (struct macro_buffer *dest, char *arg, int len) { /* Trim initial whitespace from ARG. */ while (len > 0 && macro_is_whitespace (*arg)) { ++arg; --len; } /* Trim trailing whitespace from ARG. */ while (len > 0 && macro_is_whitespace (arg[len - 1])) --len; /* Insert the string. */ appendc (dest, '"'); while (len > 0) { /* We could try to handle strange cases here, like control characters, but there doesn't seem to be much point. */ if (macro_is_whitespace (*arg)) { /* Replace a sequence of whitespace with a single space. */ appendc (dest, ' '); while (len > 1 && macro_is_whitespace (arg[1])) { ++arg; --len; } } else if (*arg == '\\' || *arg == '"') { appendc (dest, '\\'); appendc (dest, *arg); } else appendc (dest, *arg); ++arg; --len; } appendc (dest, '"'); dest->last_token = dest->len; } /* Expanding macros! */ /* A singly-linked list of the names of the macros we are currently expanding --- for detecting expansion loops. */ struct macro_name_list { const char *name; struct macro_name_list *next; }; /* Return non-zero if we are currently expanding the macro named NAME, according to LIST; otherwise, return zero. You know, it would be possible to get rid of all the NO_LOOP arguments to these functions by simply generating a new lookup function and baton which refuses to find the definition for a particular macro, and otherwise delegates the decision to another function/baton pair. But that makes the linked list of excluded macros chained through untyped baton pointers, which will make it harder to debug. :( */ static int currently_rescanning (struct macro_name_list *list, const char *name) { for (; list; list = list->next) if (strcmp (name, list->name) == 0) return 1; return 0; } /* Gather the arguments to a macro expansion. NAME is the name of the macro being invoked. (It's only used for printing error messages.) Assume that SRC is the text of the macro invocation immediately following the macro name. For example, if we're processing the text foo(bar, baz), then NAME would be foo and SRC will be (bar, baz). If SRC doesn't start with an open paren ( token at all, return zero, leave SRC unchanged, and don't set *ARGC_P to anything. If SRC doesn't contain a properly terminated argument list, then raise an error. For a variadic macro, NARGS holds the number of formal arguments to the macro. For a GNU-style variadic macro, this should be the number of named arguments. For a non-variadic macro, NARGS should be -1. Otherwise, return a pointer to the first element of an array of macro buffers referring to the argument texts, and set *ARGC_P to the number of arguments we found --- the number of elements in the array. The macro buffers share their text with SRC, and their last_token fields are initialized. The array is allocated with xmalloc, and the caller is responsible for freeing it. NOTE WELL: if SRC starts with a open paren ( token followed immediately by a close paren ) token (e.g., the invocation looks like "foo()"), we treat that as one argument, which happens to be the empty list of tokens. The caller should keep in mind that such a sequence of tokens is a valid way to invoke one-parameter function-like macros, but also a valid way to invoke zero-parameter function-like macros. Eeew. Consume the tokens from SRC; after this call, SRC contains the text following the invocation. */ static struct macro_buffer * gather_arguments (const char *name, struct macro_buffer *src, int nargs, int *argc_p) { struct macro_buffer tok; int args_len, args_size; struct macro_buffer *args = NULL; struct cleanup *back_to = make_cleanup (free_current_contents, &args); /* Does SRC start with an opening paren token? Read from a copy of SRC, so SRC itself is unaffected if we don't find an opening paren. */ { struct macro_buffer temp; init_shared_buffer (&temp, src->text, src->len); if (! get_token (&tok, &temp) || tok.len != 1 || tok.text[0] != '(') { discard_cleanups (back_to); return 0; } } /* Consume SRC's opening paren. */ get_token (&tok, src); args_len = 0; args_size = 6; args = (struct macro_buffer *) xmalloc (sizeof (*args) * args_size); for (;;) { struct macro_buffer *arg; int depth; /* Make sure we have room for the next argument. */ if (args_len >= args_size) { args_size *= 2; args = xrealloc (args, sizeof (*args) * args_size); } /* Initialize the next argument. */ arg = &args[args_len++]; set_token (arg, src->text, src->text); /* Gather the argument's tokens. */ depth = 0; for (;;) { if (! get_token (&tok, src)) error (_("Malformed argument list for macro `%s'."), name); /* Is tok an opening paren? */ if (tok.len == 1 && tok.text[0] == '(') depth++; /* Is tok is a closing paren? */ else if (tok.len == 1 && tok.text[0] == ')') { /* If it's a closing paren at the top level, then that's the end of the argument list. */ if (depth == 0) { /* In the varargs case, the last argument may be missing. Add an empty argument in this case. */ if (nargs != -1 && args_len == nargs - 1) { /* Make sure we have room for the argument. */ if (args_len >= args_size) { args_size++; args = xrealloc (args, sizeof (*args) * args_size); } arg = &args[args_len++]; set_token (arg, src->text, src->text); } discard_cleanups (back_to); *argc_p = args_len; return args; } depth--; } /* If tok is a comma at top level, then that's the end of the current argument. However, if we are handling a variadic macro and we are computing the last argument, we want to include the comma and remaining tokens. */ else if (tok.len == 1 && tok.text[0] == ',' && depth == 0 && (nargs == -1 || args_len < nargs)) break; /* Extend the current argument to enclose this token. If this is the current argument's first token, leave out any leading whitespace, just for aesthetics. */ if (arg->len == 0) { arg->text = tok.text; arg->len = tok.len; arg->last_token = 0; } else { arg->len = (tok.text + tok.len) - arg->text; arg->last_token = tok.text - arg->text; } } } } /* The `expand' and `substitute_args' functions both invoke `scan' recursively, so we need a forward declaration somewhere. */ static void scan (struct macro_buffer *dest, struct macro_buffer *src, struct macro_name_list *no_loop, macro_lookup_ftype *lookup_func, void *lookup_baton); /* A helper function for substitute_args. ARGV is a vector of all the arguments; ARGC is the number of arguments. IS_VARARGS is true if the macro being substituted is a varargs macro; in this case VA_ARG_NAME is the name of the "variable" argument. VA_ARG_NAME is ignored if IS_VARARGS is false. If the token TOK is the name of a parameter, return the parameter's index. If TOK is not an argument, return -1. */ static int find_parameter (const struct macro_buffer *tok, int is_varargs, const struct macro_buffer *va_arg_name, int argc, const char * const *argv) { int i; if (! tok->is_identifier) return -1; for (i = 0; i < argc; ++i) if (tok->len == strlen (argv[i]) && ! memcmp (tok->text, argv[i], tok->len)) return i; if (is_varargs && tok->len == va_arg_name->len && ! memcmp (tok->text, va_arg_name->text, tok->len)) return argc - 1; return -1; } /* Given the macro definition DEF, being invoked with the actual arguments given by ARGC and ARGV, substitute the arguments into the replacement list, and store the result in DEST. IS_VARARGS should be true if DEF is a varargs macro. In this case, VA_ARG_NAME should be the name of the "variable" argument -- either __VA_ARGS__ for c99-style varargs, or the final argument name, for GNU-style varargs. If IS_VARARGS is false, this parameter is ignored. If it is necessary to expand macro invocations in one of the arguments, use LOOKUP_FUNC and LOOKUP_BATON to find the macro definitions, and don't expand invocations of the macros listed in NO_LOOP. */ static void substitute_args (struct macro_buffer *dest, struct macro_definition *def, int is_varargs, const struct macro_buffer *va_arg_name, int argc, struct macro_buffer *argv, struct macro_name_list *no_loop, macro_lookup_ftype *lookup_func, void *lookup_baton) { /* A macro buffer for the macro's replacement list. */ struct macro_buffer replacement_list; /* The token we are currently considering. */ struct macro_buffer tok; /* The replacement list's pointer from just before TOK was lexed. */ char *original_rl_start; /* We have a single lookahead token to handle token splicing. */ struct macro_buffer lookahead; /* The lookahead token might not be valid. */ int lookahead_valid; /* The replacement list's pointer from just before LOOKAHEAD was lexed. */ char *lookahead_rl_start; init_shared_buffer (&replacement_list, (char *) def->replacement, strlen (def->replacement)); gdb_assert (dest->len == 0); dest->last_token = 0; original_rl_start = replacement_list.text; if (! get_token (&tok, &replacement_list)) return; lookahead_rl_start = replacement_list.text; lookahead_valid = get_token (&lookahead, &replacement_list); for (;;) { /* Just for aesthetics. If we skipped some whitespace, copy that to DEST. */ if (tok.text > original_rl_start) { appendmem (dest, original_rl_start, tok.text - original_rl_start); dest->last_token = dest->len; } /* Is this token the stringification operator? */ if (tok.len == 1 && tok.text[0] == '#') { int arg; if (!lookahead_valid) error (_("Stringification operator requires an argument.")); arg = find_parameter (&lookahead, is_varargs, va_arg_name, def->argc, def->argv); if (arg == -1) error (_("Argument to stringification operator must name " "a macro parameter.")); stringify (dest, argv[arg].text, argv[arg].len); /* Read one token and let the loop iteration code handle the rest. */ lookahead_rl_start = replacement_list.text; lookahead_valid = get_token (&lookahead, &replacement_list); } /* Is this token the splicing operator? */ else if (tok.len == 2 && tok.text[0] == '#' && tok.text[1] == '#') error (_("Stray splicing operator")); /* Is the next token the splicing operator? */ else if (lookahead_valid && lookahead.len == 2 && lookahead.text[0] == '#' && lookahead.text[1] == '#') { int finished = 0; int prev_was_comma = 0; /* Note that GCC warns if the result of splicing is not a token. In the debugger there doesn't seem to be much benefit from doing this. */ /* Insert the first token. */ if (tok.len == 1 && tok.text[0] == ',') prev_was_comma = 1; else { int arg = find_parameter (&tok, is_varargs, va_arg_name, def->argc, def->argv); if (arg != -1) appendmem (dest, argv[arg].text, argv[arg].len); else appendmem (dest, tok.text, tok.len); } /* Apply a possible sequence of ## operators. */ for (;;) { if (! get_token (&tok, &replacement_list)) error (_("Splicing operator at end of macro")); /* Handle a comma before a ##. If we are handling varargs, and the token on the right hand side is the varargs marker, and the final argument is empty or missing, then drop the comma. This is a GNU extension. There is one ambiguous case here, involving pedantic behavior with an empty argument, but we settle that in favor of GNU-style (GCC uses an option). If we aren't dealing with varargs, we simply insert the comma. */ if (prev_was_comma) { if (! (is_varargs && tok.len == va_arg_name->len && !memcmp (tok.text, va_arg_name->text, tok.len) && argv[argc - 1].len == 0)) appendmem (dest, ",", 1); prev_was_comma = 0; } /* Insert the token. If it is a parameter, insert the argument. If it is a comma, treat it specially. */ if (tok.len == 1 && tok.text[0] == ',') prev_was_comma = 1; else { int arg = find_parameter (&tok, is_varargs, va_arg_name, def->argc, def->argv); if (arg != -1) appendmem (dest, argv[arg].text, argv[arg].len); else appendmem (dest, tok.text, tok.len); } /* Now read another token. If it is another splice, we loop. */ original_rl_start = replacement_list.text; if (! get_token (&tok, &replacement_list)) { finished = 1; break; } if (! (tok.len == 2 && tok.text[0] == '#' && tok.text[1] == '#')) break; } if (prev_was_comma) { /* We saw a comma. Insert it now. */ appendmem (dest, ",", 1); } dest->last_token = dest->len; if (finished) lookahead_valid = 0; else { /* Set up for the loop iterator. */ lookahead = tok; lookahead_rl_start = original_rl_start; lookahead_valid = 1; } } else { /* Is this token an identifier? */ int substituted = 0; int arg = find_parameter (&tok, is_varargs, va_arg_name, def->argc, def->argv); if (arg != -1) { struct macro_buffer arg_src; /* Expand any macro invocations in the argument text, and append the result to dest. Remember that scan mutates its source, so we need to scan a new buffer referring to the argument's text, not the argument itself. */ init_shared_buffer (&arg_src, argv[arg].text, argv[arg].len); scan (dest, &arg_src, no_loop, lookup_func, lookup_baton); substituted = 1; } /* If it wasn't a parameter, then just copy it across. */ if (! substituted) append_tokens_without_splicing (dest, &tok); } if (! lookahead_valid) break; tok = lookahead; original_rl_start = lookahead_rl_start; lookahead_rl_start = replacement_list.text; lookahead_valid = get_token (&lookahead, &replacement_list); } } /* Expand a call to a macro named ID, whose definition is DEF. Append its expansion to DEST. SRC is the input text following the ID token. We are currently rescanning the expansions of the macros named in NO_LOOP; don't re-expand them. Use LOOKUP_FUNC and LOOKUP_BATON to find definitions for any nested macro references. Return 1 if we decided to expand it, zero otherwise. (If it's a function-like macro name that isn't followed by an argument list, we don't expand it.) If we return zero, leave SRC unchanged. */ static int expand (const char *id, struct macro_definition *def, struct macro_buffer *dest, struct macro_buffer *src, struct macro_name_list *no_loop, macro_lookup_ftype *lookup_func, void *lookup_baton) { struct macro_name_list new_no_loop; /* Create a new node to be added to the front of the no-expand list. This list is appropriate for re-scanning replacement lists, but it is *not* appropriate for scanning macro arguments; invocations of the macro whose arguments we are gathering *do* get expanded there. */ new_no_loop.name = id; new_no_loop.next = no_loop; /* What kind of macro are we expanding? */ if (def->kind == macro_object_like) { struct macro_buffer replacement_list; init_shared_buffer (&replacement_list, (char *) def->replacement, strlen (def->replacement)); scan (dest, &replacement_list, &new_no_loop, lookup_func, lookup_baton); return 1; } else if (def->kind == macro_function_like) { struct cleanup *back_to = make_cleanup (null_cleanup, 0); int argc = 0; struct macro_buffer *argv = NULL; struct macro_buffer substituted; struct macro_buffer substituted_src; struct macro_buffer va_arg_name; int is_varargs = 0; if (def->argc >= 1) { if (strcmp (def->argv[def->argc - 1], "...") == 0) { /* In C99-style varargs, substitution is done using __VA_ARGS__. */ init_shared_buffer (&va_arg_name, "__VA_ARGS__", strlen ("__VA_ARGS__")); is_varargs = 1; } else { int len = strlen (def->argv[def->argc - 1]); if (len > 3 && strcmp (def->argv[def->argc - 1] + len - 3, "...") == 0) { /* In GNU-style varargs, the name of the substitution parameter is the name of the formal argument without the "...". */ init_shared_buffer (&va_arg_name, (char *) def->argv[def->argc - 1], len - 3); is_varargs = 1; } } } make_cleanup (free_current_contents, &argv); argv = gather_arguments (id, src, is_varargs ? def->argc : -1, &argc); /* If we couldn't find any argument list, then we don't expand this macro. */ if (! argv) { do_cleanups (back_to); return 0; } /* Check that we're passing an acceptable number of arguments for this macro. */ if (argc != def->argc) { if (is_varargs && argc >= def->argc - 1) { /* Ok. */ } /* Remember that a sequence of tokens like "foo()" is a valid invocation of a macro expecting either zero or one arguments. */ else if (! (argc == 1 && argv[0].len == 0 && def->argc == 0)) error (_("Wrong number of arguments to macro `%s' " "(expected %d, got %d)."), id, def->argc, argc); } /* Note that we don't expand macro invocations in the arguments yet --- we let subst_args take care of that. Parameters that appear as operands of the stringifying operator "#" or the splicing operator "##" don't get macro references expanded, so we can't really tell whether it's appropriate to macro- expand an argument until we see how it's being used. */ init_buffer (&substituted, 0); make_cleanup (cleanup_macro_buffer, &substituted); substitute_args (&substituted, def, is_varargs, &va_arg_name, argc, argv, no_loop, lookup_func, lookup_baton); /* Now `substituted' is the macro's replacement list, with all argument values substituted into it properly. Re-scan it for macro references, but don't expand invocations of this macro. We create a new buffer, `substituted_src', which points into `substituted', and scan that. We can't scan `substituted' itself, since the tokenization process moves the buffer's text pointer around, and we still need to be able to find `substituted's original text buffer after scanning it so we can free it. */ init_shared_buffer (&substituted_src, substituted.text, substituted.len); scan (dest, &substituted_src, &new_no_loop, lookup_func, lookup_baton); do_cleanups (back_to); return 1; } else internal_error (__FILE__, __LINE__, _("bad macro definition kind")); } /* If the single token in SRC_FIRST followed by the tokens in SRC_REST constitute a macro invokation not forbidden in NO_LOOP, append its expansion to DEST and return non-zero. Otherwise, return zero, and leave DEST unchanged. SRC_FIRST and SRC_REST must be shared buffers; DEST must not be one. SRC_FIRST must be a string built by get_token. */ static int maybe_expand (struct macro_buffer *dest, struct macro_buffer *src_first, struct macro_buffer *src_rest, struct macro_name_list *no_loop, macro_lookup_ftype *lookup_func, void *lookup_baton) { gdb_assert (src_first->shared); gdb_assert (src_rest->shared); gdb_assert (! dest->shared); /* Is this token an identifier? */ if (src_first->is_identifier) { /* Make a null-terminated copy of it, since that's what our lookup function expects. */ char *id = xmalloc (src_first->len + 1); struct cleanup *back_to = make_cleanup (xfree, id); memcpy (id, src_first->text, src_first->len); id[src_first->len] = 0; /* If we're currently re-scanning the result of expanding this macro, don't expand it again. */ if (! currently_rescanning (no_loop, id)) { /* Does this identifier have a macro definition in scope? */ struct macro_definition *def = lookup_func (id, lookup_baton); if (def && expand (id, def, dest, src_rest, no_loop, lookup_func, lookup_baton)) { do_cleanups (back_to); return 1; } } do_cleanups (back_to); } return 0; } /* Expand macro references in SRC, appending the results to DEST. Assume we are re-scanning the result of expanding the macros named in NO_LOOP, and don't try to re-expand references to them. SRC must be a shared buffer; DEST must not be one. */ static void scan (struct macro_buffer *dest, struct macro_buffer *src, struct macro_name_list *no_loop, macro_lookup_ftype *lookup_func, void *lookup_baton) { gdb_assert (src->shared); gdb_assert (! dest->shared); for (;;) { struct macro_buffer tok; char *original_src_start = src->text; /* Find the next token in SRC. */ if (! get_token (&tok, src)) break; /* Just for aesthetics. If we skipped some whitespace, copy that to DEST. */ if (tok.text > original_src_start) { appendmem (dest, original_src_start, tok.text - original_src_start); dest->last_token = dest->len; } if (! maybe_expand (dest, &tok, src, no_loop, lookup_func, lookup_baton)) /* We didn't end up expanding tok as a macro reference, so simply append it to dest. */ append_tokens_without_splicing (dest, &tok); } /* Just for aesthetics. If there was any trailing whitespace in src, copy it to dest. */ if (src->len) { appendmem (dest, src->text, src->len); dest->last_token = dest->len; } } char * macro_expand (const char *source, macro_lookup_ftype *lookup_func, void *lookup_func_baton) { struct macro_buffer src, dest; struct cleanup *back_to; init_shared_buffer (&src, (char *) source, strlen (source)); init_buffer (&dest, 0); dest.last_token = 0; back_to = make_cleanup (cleanup_macro_buffer, &dest); scan (&dest, &src, 0, lookup_func, lookup_func_baton); appendc (&dest, '\0'); discard_cleanups (back_to); return dest.text; } char * macro_expand_once (const char *source, macro_lookup_ftype *lookup_func, void *lookup_func_baton) { error (_("Expand-once not implemented yet.")); } char * macro_expand_next (char **lexptr, macro_lookup_ftype *lookup_func, void *lookup_baton) { struct macro_buffer src, dest, tok; struct cleanup *back_to; /* Set up SRC to refer to the input text, pointed to by *lexptr. */ init_shared_buffer (&src, *lexptr, strlen (*lexptr)); /* Set up DEST to receive the expansion, if there is one. */ init_buffer (&dest, 0); dest.last_token = 0; back_to = make_cleanup (cleanup_macro_buffer, &dest); /* Get the text's first preprocessing token. */ if (! get_token (&tok, &src)) { do_cleanups (back_to); return 0; } /* If it's a macro invocation, expand it. */ if (maybe_expand (&dest, &tok, &src, 0, lookup_func, lookup_baton)) { /* It was a macro invocation! Package up the expansion as a null-terminated string and return it. Set *lexptr to the start of the next token in the input. */ appendc (&dest, '\0'); discard_cleanups (back_to); *lexptr = src.text; return dest.text; } else { /* It wasn't a macro invocation. */ do_cleanups (back_to); return 0; } }
Go to most recent revision | Compare with Previous | Blame | View Log