/* Generate code from to output assembler insns as recognized from rtl. Copyright (C) 1987, 1988, 1992, 1994, 1995, 1997, 1998, 1999, 2000, 2002, 2003 Free Software Foundation, Inc. This file is part of GCC. GCC 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. GCC 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 GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This program reads the machine description for the compiler target machine and produces a file containing these things: 1. An array of `struct insn_data', which is indexed by insn code number, which contains: a. `name' is the name for that pattern. Nameless patterns are given a name. b. `output' hold either the output template, an array of output templates, or an output function. c. `genfun' is the function to generate a body for that pattern, given operands as arguments. d. `n_operands' is the number of distinct operands in the pattern for that insn, e. `n_dups' is the number of match_dup's that appear in the insn's pattern. This says how many elements of `recog_data.dup_loc' are significant after an insn has been recognized. f. `n_alternatives' is the number of alternatives in the constraints of each pattern. g. `output_format' tells what type of thing `output' is. h. `operand' is the base of an array of operand data for the insn. 2. An array of `struct insn_operand data', used by `operand' above. a. `predicate', an int-valued function, is the match_operand predicate for this operand. b. `constraint' is the constraint for this operand. This exists only if register constraints appear in match_operand rtx's. c. `address_p' indicates that the operand appears within ADDRESS rtx's. This exists only if there are *no* register constraints in the match_operand rtx's. d. `mode' is the machine mode that that operand is supposed to have. e. `strict_low', is nonzero for operands contained in a STRICT_LOW_PART. f. `eliminable', is nonzero for operands that are matched normally by MATCH_OPERAND; it is zero for operands that should not be changed during register elimination such as MATCH_OPERATORs. The code number of an insn is simply its position in the machine description; code numbers are assigned sequentially to entries in the description, starting with code number 0. Thus, the following entry in the machine description (define_insn "clrdf" [(set (match_operand:DF 0 "general_operand" "") (const_int 0))] "" "clrd %0") assuming it is the 25th entry present, would cause insn_data[24].template to be "clrd %0", and insn_data[24].n_operands to be 1. */ #include "bconfig.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "errors.h" #include "gensupport.h" /* No instruction can have more operands than this. Sorry for this arbitrary limit, but what machine will have an instruction with this many operands? */ #define MAX_MAX_OPERANDS 40 static int n_occurrences (int, const char *); static const char *strip_whitespace (const char *); /* insns in the machine description are assigned sequential code numbers that are used by insn-recog.c (produced by genrecog) to communicate to insn-output.c (produced by this program). */ static int next_code_number; /* This counts all definitions in the md file, for the sake of error messages. */ static int next_index_number; /* This counts all operands used in the md file. The first is null. */ static int next_operand_number = 1; /* Record in this chain all information about the operands we will output. */ struct operand_data { struct operand_data *next; int index; const char *predicate; const char *constraint; enum machine_mode mode; unsigned char n_alternatives; char address_p; char strict_low; char eliminable; char seen; }; /* Begin with a null operand at index 0. */ static struct operand_data null_operand = { 0, 0, "", "", VOIDmode, 0, 0, 0, 0, 0 }; static struct operand_data *odata = &null_operand; static struct operand_data **odata_end = &null_operand.next; /* Must match the constants in recog.h. */ #define INSN_OUTPUT_FORMAT_NONE 0 /* abort */ #define INSN_OUTPUT_FORMAT_SINGLE 1 /* const char * */ #define INSN_OUTPUT_FORMAT_MULTI 2 /* const char * const * */ #define INSN_OUTPUT_FORMAT_FUNCTION 3 /* const char * (*)(...) */ /* Record in this chain all information that we will output, associated with the code number of the insn. */ struct data { struct data *next; const char *name; const char *template; int code_number; int index_number; int lineno; int n_operands; /* Number of operands this insn recognizes */ int n_dups; /* Number times match_dup appears in pattern */ int n_alternatives; /* Number of alternatives in each constraint */ int operand_number; /* Operand index in the big array. */ int output_format; /* INSN_OUTPUT_FORMAT_*. */ struct operand_data operand[MAX_MAX_OPERANDS]; }; /* This variable points to the first link in the insn chain. */ static struct data *idata, **idata_end = &idata; static void output_prologue (void); static void output_predicate_decls (void); static void output_operand_data (void); static void output_insn_data (void); static void output_get_insn_name (void); static void scan_operands (struct data *, rtx, int, int); static int compare_operands (struct operand_data *, struct operand_data *); static void place_operands (struct data *); static void process_template (struct data *, const char *); static void validate_insn_alternatives (struct data *); static void validate_insn_operands (struct data *); static void gen_insn (rtx, int); static void gen_peephole (rtx, int); static void gen_expand (rtx, int); static void gen_split (rtx, int); static void check_constraint_len (void); static int constraint_len (const char *, int); const char * get_insn_name (int index) { static char buf[100]; struct data *i, *last_named = NULL; for (i = idata; i ; i = i->next) { if (i->index_number == index) return i->name; if (i->name) last_named = i; } if (last_named) sprintf(buf, "%s+%d", last_named->name, index - last_named->index_number); else sprintf(buf, "insn %d", index); return buf; } static void output_prologue (void) { printf ("/* Generated automatically by the program `genoutput'\n\ from the machine description file `md'. */\n\n"); printf ("#include \"config.h\"\n"); printf ("#include \"system.h\"\n"); printf ("#include \"coretypes.h\"\n"); printf ("#include \"tm.h\"\n"); printf ("#include \"flags.h\"\n"); printf ("#include \"ggc.h\"\n"); printf ("#include \"rtl.h\"\n"); printf ("#include \"expr.h\"\n"); printf ("#include \"insn-codes.h\"\n"); printf ("#include \"tm_p.h\"\n"); printf ("#include \"function.h\"\n"); printf ("#include \"regs.h\"\n"); printf ("#include \"hard-reg-set.h\"\n"); printf ("#include \"real.h\"\n"); printf ("#include \"insn-config.h\"\n\n"); printf ("#include \"conditions.h\"\n"); printf ("#include \"insn-attr.h\"\n\n"); printf ("#include \"recog.h\"\n\n"); printf ("#include \"toplev.h\"\n"); printf ("#include \"output.h\"\n"); printf ("#include \"target.h\"\n"); } /* We need to define all predicates used. Keep a list of those we have defined so far. There normally aren't very many predicates used, so a linked list should be fast enough. */ struct predicate { const char *name; struct predicate *next; }; static void output_predicate_decls (void) { struct predicate *predicates = 0; struct operand_data *d; struct predicate *p, *next; for (d = odata; d; d = d->next) if (d->predicate && d->predicate[0]) { for (p = predicates; p; p = p->next) if (strcmp (p->name, d->predicate) == 0) break; if (p == 0) { printf ("extern int %s (rtx, enum machine_mode);\n", d->predicate); p = (struct predicate *) xmalloc (sizeof (struct predicate)); p->name = d->predicate; p->next = predicates; predicates = p; } } printf ("\n\n"); for (p = predicates; p; p = next) { next = p->next; free (p); } } static void output_operand_data (void) { struct operand_data *d; printf ("\nstatic const struct insn_operand_data operand_data[] = \n{\n"); for (d = odata; d; d = d->next) { printf (" {\n"); printf (" %s,\n", d->predicate && d->predicate[0] ? d->predicate : "0"); printf (" \"%s\",\n", d->constraint ? d->constraint : ""); printf (" %smode,\n", GET_MODE_NAME (d->mode)); printf (" %d,\n", d->strict_low); printf (" %d\n", d->eliminable); printf(" },\n"); } printf("};\n\n\n"); } static void output_insn_data (void) { struct data *d; int name_offset = 0; int next_name_offset; const char * last_name = 0; const char * next_name = 0; struct data *n; for (n = idata, next_name_offset = 1; n; n = n->next, next_name_offset++) if (n->name) { next_name = n->name; break; } printf ("\nconst struct insn_data insn_data[] = \n{\n"); for (d = idata; d; d = d->next) { printf (" {\n"); if (d->name) { printf (" \"%s\",\n", d->name); name_offset = 0; last_name = d->name; next_name = 0; for (n = d->next, next_name_offset = 1; n; n = n->next, next_name_offset++) { if (n->name) { next_name = n->name; break; } } } else { name_offset++; if (next_name && (last_name == 0 || name_offset > next_name_offset / 2)) printf (" \"%s-%d\",\n", next_name, next_name_offset - name_offset); else printf (" \"%s+%d\",\n", last_name, name_offset); } switch (d->output_format) { case INSN_OUTPUT_FORMAT_NONE: printf (" 0,\n"); break; case INSN_OUTPUT_FORMAT_SINGLE: { const char *p = d->template; char prev = 0; printf (" \""); while (*p) { if (IS_VSPACE (*p) && prev != '\\') { /* Preserve two consecutive \n's or \r's, but treat \r\n as a single newline. */ if (*p == '\n' && prev != '\r') printf ("\\n\\\n"); } else putchar (*p); prev = *p; ++p; } printf ("\",\n"); } break; case INSN_OUTPUT_FORMAT_MULTI: case INSN_OUTPUT_FORMAT_FUNCTION: printf (" (const PTR) output_%d,\n", d->code_number); break; default: abort (); } if (d->name && d->name[0] != '*') printf (" (insn_gen_fn) gen_%s,\n", d->name); else printf (" 0,\n"); printf (" &operand_data[%d],\n", d->operand_number); printf (" %d,\n", d->n_operands); printf (" %d,\n", d->n_dups); printf (" %d,\n", d->n_alternatives); printf (" %d\n", d->output_format); printf(" },\n"); } printf ("};\n\n\n"); } static void output_get_insn_name (void) { printf ("const char *\n"); printf ("get_insn_name (code)\n"); printf (" int code;\n"); printf ("{\n"); printf (" if (code == NOOP_MOVE_INSN_CODE)\n"); printf (" return \"NOOP_MOVE\";\n"); printf (" else\n"); printf (" return insn_data[code].name;\n"); printf ("}\n"); } /* Stores in max_opno the largest operand number present in `part', if that is larger than the previous value of max_opno, and the rest of the operand data into `d->operand[i]'. THIS_ADDRESS_P is nonzero if the containing rtx was an ADDRESS. THIS_STRICT_LOW is nonzero if the containing rtx was a STRICT_LOW_PART. */ static int max_opno; static int num_dups; static void scan_operands (struct data *d, rtx part, int this_address_p, int this_strict_low) { int i, j; const char *format_ptr; int opno; if (part == 0) return; switch (GET_CODE (part)) { case MATCH_OPERAND: opno = XINT (part, 0); if (opno > max_opno) max_opno = opno; if (max_opno >= MAX_MAX_OPERANDS) { message_with_line (d->lineno, "maximum number of operands exceeded"); have_error = 1; return; } if (d->operand[opno].seen) { message_with_line (d->lineno, "repeated operand number %d\n", opno); have_error = 1; } d->operand[opno].seen = 1; d->operand[opno].mode = GET_MODE (part); d->operand[opno].strict_low = this_strict_low; d->operand[opno].predicate = XSTR (part, 1); d->operand[opno].constraint = strip_whitespace (XSTR (part, 2)); d->operand[opno].n_alternatives = n_occurrences (',', d->operand[opno].constraint) + 1; d->operand[opno].address_p = this_address_p; d->operand[opno].eliminable = 1; return; case MATCH_SCRATCH: opno = XINT (part, 0); if (opno > max_opno) max_opno = opno; if (max_opno >= MAX_MAX_OPERANDS) { message_with_line (d->lineno, "maximum number of operands exceeded"); have_error = 1; return; } if (d->operand[opno].seen) { message_with_line (d->lineno, "repeated operand number %d\n", opno); have_error = 1; } d->operand[opno].seen = 1; d->operand[opno].mode = GET_MODE (part); d->operand[opno].strict_low = 0; d->operand[opno].predicate = "scratch_operand"; d->operand[opno].constraint = strip_whitespace (XSTR (part, 1)); d->operand[opno].n_alternatives = n_occurrences (',', d->operand[opno].constraint) + 1; d->operand[opno].address_p = 0; d->operand[opno].eliminable = 0; return; case MATCH_OPERATOR: case MATCH_PARALLEL: opno = XINT (part, 0); if (opno > max_opno) max_opno = opno; if (max_opno >= MAX_MAX_OPERANDS) { message_with_line (d->lineno, "maximum number of operands exceeded"); have_error = 1; return; } if (d->operand[opno].seen) { message_with_line (d->lineno, "repeated operand number %d\n", opno); have_error = 1; } d->operand[opno].seen = 1; d->operand[opno].mode = GET_MODE (part); d->operand[opno].strict_low = 0; d->operand[opno].predicate = XSTR (part, 1); d->operand[opno].constraint = 0; d->operand[opno].address_p = 0; d->operand[opno].eliminable = 0; for (i = 0; i < XVECLEN (part, 2); i++) scan_operands (d, XVECEXP (part, 2, i), 0, 0); return; case MATCH_DUP: case MATCH_OP_DUP: case MATCH_PAR_DUP: ++num_dups; break; case ADDRESS: scan_operands (d, XEXP (part, 0), 1, 0); return; case STRICT_LOW_PART: scan_operands (d, XEXP (part, 0), 0, 1); return; default: break; } format_ptr = GET_RTX_FORMAT (GET_CODE (part)); for (i = 0; i < GET_RTX_LENGTH (GET_CODE (part)); i++) switch (*format_ptr++) { case 'e': case 'u': scan_operands (d, XEXP (part, i), 0, 0); break; case 'E': if (XVEC (part, i) != NULL) for (j = 0; j < XVECLEN (part, i); j++) scan_operands (d, XVECEXP (part, i, j), 0, 0); break; } } /* Compare two operands for content equality. */ static int compare_operands (struct operand_data *d0, struct operand_data *d1) { const char *p0, *p1; p0 = d0->predicate; if (!p0) p0 = ""; p1 = d1->predicate; if (!p1) p1 = ""; if (strcmp (p0, p1) != 0) return 0; p0 = d0->constraint; if (!p0) p0 = ""; p1 = d1->constraint; if (!p1) p1 = ""; if (strcmp (p0, p1) != 0) return 0; if (d0->mode != d1->mode) return 0; if (d0->strict_low != d1->strict_low) return 0; if (d0->eliminable != d1->eliminable) return 0; return 1; } /* Scan the list of operands we've already committed to output and either find a subsequence that is the same, or allocate a new one at the end. */ static void place_operands (struct data *d) { struct operand_data *od, *od2; int i; if (d->n_operands == 0) { d->operand_number = 0; return; } /* Brute force substring search. */ for (od = odata, i = 0; od; od = od->next, i = 0) if (compare_operands (od, &d->operand[0])) { od2 = od->next; i = 1; while (1) { if (i == d->n_operands) goto full_match; if (od2 == NULL) goto partial_match; if (! compare_operands (od2, &d->operand[i])) break; ++i, od2 = od2->next; } } /* Either partial match at the end of the list, or no match. In either case, we tack on what operands are remaining to the end of the list. */ partial_match: d->operand_number = next_operand_number - i; for (; i < d->n_operands; ++i) { od2 = &d->operand[i]; *odata_end = od2; odata_end = &od2->next; od2->index = next_operand_number++; } *odata_end = NULL; return; full_match: d->operand_number = od->index; return; } /* Process an assembler template from a define_insn or a define_peephole. It is either the assembler code template, a list of assembler code templates, or C code to generate the assembler code template. */ static void process_template (struct data *d, const char *template) { const char *cp; int i; /* Templates starting with * contain straight code to be run. */ if (template[0] == '*') { d->template = 0; d->output_format = INSN_OUTPUT_FORMAT_FUNCTION; printf ("\nstatic const char *output_%d (rtx *, rtx);\n", d->code_number); puts ("\nstatic const char *"); printf ("output_%d (operands, insn)\n", d->code_number); puts (" rtx *operands ATTRIBUTE_UNUSED;"); puts (" rtx insn ATTRIBUTE_UNUSED;"); puts ("{"); puts (template + 1); puts ("}"); } /* If the assembler code template starts with a @ it is a newline-separated list of assembler code templates, one for each alternative. */ else if (template[0] == '@') { d->template = 0; d->output_format = INSN_OUTPUT_FORMAT_MULTI; printf ("\nstatic const char * const output_%d[] = {\n", d->code_number); for (i = 0, cp = &template[1]; *cp; ) { while (ISSPACE (*cp)) cp++; printf (" \""); while (!IS_VSPACE (*cp) && *cp != '\0') { putchar (*cp); cp++; } printf ("\",\n"); i++; } if (i == 1) message_with_line (d->lineno, "'@' is redundant for output template with single alternative"); if (i != d->n_alternatives) { message_with_line (d->lineno, "wrong number of alternatives in the output template"); have_error = 1; } printf ("};\n"); } else { d->template = template; d->output_format = INSN_OUTPUT_FORMAT_SINGLE; } } /* Check insn D for consistency in number of constraint alternatives. */ static void validate_insn_alternatives (struct data *d) { int n = 0, start; /* Make sure all the operands have the same number of alternatives in their constraints. Let N be that number. */ for (start = 0; start < d->n_operands; start++) if (d->operand[start].n_alternatives > 0) { int len, i; const char *p; char c; int which_alternative = 0; int alternative_count_unsure = 0; for (p = d->operand[start].constraint; (c = *p); p += len) { len = CONSTRAINT_LEN (c, p); if (len < 1 || (len > 1 && strchr (",#*+=&%!0123456789", c))) { message_with_line (d->lineno, "invalid length %d for char '%c' in alternative %d of operand %d", len, c, which_alternative, start); len = 1; have_error = 1; } if (c == ',') { which_alternative++; continue; } for (i = 1; i < len; i++) if (p[i] == '\0') { message_with_line (d->lineno, "NUL in alternative %d of operand %d", which_alternative, start); alternative_count_unsure = 1; break; } else if (strchr (",#*", p[i])) { message_with_line (d->lineno, "'%c' in alternative %d of operand %d", p[i], which_alternative, start); alternative_count_unsure = 1; } } if (alternative_count_unsure) have_error = 1; else if (n == 0) n = d->operand[start].n_alternatives; else if (n != d->operand[start].n_alternatives) { message_with_line (d->lineno, "wrong number of alternatives in operand %d", start); have_error = 1; } } /* Record the insn's overall number of alternatives. */ d->n_alternatives = n; } /* Verify that there are no gaps in operand numbers for INSNs. */ static void validate_insn_operands (struct data *d) { int i; for (i = 0; i < d->n_operands; ++i) if (d->operand[i].seen == 0) { message_with_line (d->lineno, "missing operand %d", i); have_error = 1; } } /* Look at a define_insn just read. Assign its code number. Record on idata the template and the number of arguments. If the insn has a hairy output action, output a function for now. */ static void gen_insn (rtx insn, int lineno) { struct data *d = (struct data *) xmalloc (sizeof (struct data)); int i; d->code_number = next_code_number; d->index_number = next_index_number; d->lineno = lineno; if (XSTR (insn, 0)[0]) d->name = XSTR (insn, 0); else d->name = 0; /* Build up the list in the same order as the insns are seen in the machine description. */ d->next = 0; *idata_end = d; idata_end = &d->next; max_opno = -1; num_dups = 0; memset (d->operand, 0, sizeof (d->operand)); for (i = 0; i < XVECLEN (insn, 1); i++) scan_operands (d, XVECEXP (insn, 1, i), 0, 0); d->n_operands = max_opno + 1; d->n_dups = num_dups; check_constraint_len (); validate_insn_operands (d); validate_insn_alternatives (d); place_operands (d); process_template (d, XTMPL (insn, 3)); } /* Look at a define_peephole just read. Assign its code number. Record on idata the template and the number of arguments. If the insn has a hairy output action, output it now. */ static void gen_peephole (rtx peep, int lineno) { struct data *d = (struct data *) xmalloc (sizeof (struct data)); int i; d->code_number = next_code_number; d->index_number = next_index_number; d->lineno = lineno; d->name = 0; /* Build up the list in the same order as the insns are seen in the machine description. */ d->next = 0; *idata_end = d; idata_end = &d->next; max_opno = -1; num_dups = 0; memset (d->operand, 0, sizeof (d->operand)); /* Get the number of operands by scanning all the patterns of the peephole optimizer. But ignore all the rest of the information thus obtained. */ for (i = 0; i < XVECLEN (peep, 0); i++) scan_operands (d, XVECEXP (peep, 0, i), 0, 0); d->n_operands = max_opno + 1; d->n_dups = 0; validate_insn_alternatives (d); place_operands (d); process_template (d, XTMPL (peep, 2)); } /* Process a define_expand just read. Assign its code number, only for the purposes of `insn_gen_function'. */ static void gen_expand (rtx insn, int lineno) { struct data *d = (struct data *) xmalloc (sizeof (struct data)); int i; d->code_number = next_code_number; d->index_number = next_index_number; d->lineno = lineno; if (XSTR (insn, 0)[0]) d->name = XSTR (insn, 0); else d->name = 0; /* Build up the list in the same order as the insns are seen in the machine description. */ d->next = 0; *idata_end = d; idata_end = &d->next; max_opno = -1; num_dups = 0; memset (d->operand, 0, sizeof (d->operand)); /* Scan the operands to get the specified predicates and modes, since expand_binop needs to know them. */ if (XVEC (insn, 1)) for (i = 0; i < XVECLEN (insn, 1); i++) scan_operands (d, XVECEXP (insn, 1, i), 0, 0); d->n_operands = max_opno + 1; d->n_dups = num_dups; d->template = 0; d->output_format = INSN_OUTPUT_FORMAT_NONE; validate_insn_alternatives (d); place_operands (d); } /* Process a define_split just read. Assign its code number, only for reasons of consistency and to simplify genrecog. */ static void gen_split (rtx split, int lineno) { struct data *d = (struct data *) xmalloc (sizeof (struct data)); int i; d->code_number = next_code_number; d->index_number = next_index_number; d->lineno = lineno; d->name = 0; /* Build up the list in the same order as the insns are seen in the machine description. */ d->next = 0; *idata_end = d; idata_end = &d->next; max_opno = -1; num_dups = 0; memset (d->operand, 0, sizeof (d->operand)); /* Get the number of operands by scanning all the patterns of the split patterns. But ignore all the rest of the information thus obtained. */ for (i = 0; i < XVECLEN (split, 0); i++) scan_operands (d, XVECEXP (split, 0, i), 0, 0); d->n_operands = max_opno + 1; d->n_dups = 0; d->n_alternatives = 0; d->template = 0; d->output_format = INSN_OUTPUT_FORMAT_NONE; place_operands (d); } extern int main (int, char **); int main (int argc, char **argv) { rtx desc; progname = "genoutput"; if (argc <= 1) fatal ("no input file name"); if (init_md_reader_args (argc, argv) != SUCCESS_EXIT_CODE) return (FATAL_EXIT_CODE); output_prologue (); next_code_number = 0; next_index_number = 0; /* Read the machine description. */ while (1) { int line_no; desc = read_md_rtx (&line_no, &next_code_number); if (desc == NULL) break; if (GET_CODE (desc) == DEFINE_INSN) gen_insn (desc, line_no); if (GET_CODE (desc) == DEFINE_PEEPHOLE) gen_peephole (desc, line_no); if (GET_CODE (desc) == DEFINE_EXPAND) gen_expand (desc, line_no); if (GET_CODE (desc) == DEFINE_SPLIT || GET_CODE (desc) == DEFINE_PEEPHOLE2) gen_split (desc, line_no); next_index_number++; } printf("\n\n"); output_predicate_decls (); output_operand_data (); output_insn_data (); output_get_insn_name (); fflush (stdout); return (ferror (stdout) != 0 || have_error ? FATAL_EXIT_CODE : SUCCESS_EXIT_CODE); } /* Return the number of occurrences of character C in string S or -1 if S is the null string. */ static int n_occurrences (int c, const char *s) { int n = 0; if (s == 0 || *s == '\0') return -1; while (*s) n += (*s++ == c); return n; } /* Remove whitespace in `s' by moving up characters until the end. Return a new string. */ static const char * strip_whitespace (const char *s) { char *p, *q; char ch; if (s == 0) return 0; p = q = xmalloc (strlen (s) + 1); while ((ch = *s++) != '\0') if (! ISSPACE (ch)) *p++ = ch; *p = '\0'; return q; } /* Verify that DEFAULT_CONSTRAINT_LEN is used properly and not tampered with. This isn't bullet-proof, but it should catch most genuine mistakes. */ static void check_constraint_len (void) { const char *p; int d; for (p = ",#*+=&%!1234567890"; *p; p++) for (d = -9; d < 9; d++) if (constraint_len (p, d) != d) abort (); } static int constraint_len (const char *p, int genoutput_default_constraint_len) { /* Check that we still match defaults.h . First we do a generation-time check that fails if the value is not the expected one... */ if (DEFAULT_CONSTRAINT_LEN (*p, p) != 1) abort (); /* And now a comile-time check that should give a diagnostic if the definition doesn't exactly match. */ #define DEFAULT_CONSTRAINT_LEN(C,STR) 1 /* Now re-define DEFAULT_CONSTRAINT_LEN so that we can verify it is being used. */ #undef DEFAULT_CONSTRAINT_LEN #define DEFAULT_CONSTRAINT_LEN(C,STR) \ ((C) != *p || STR != p ? -1 : genoutput_default_constraint_len) return CONSTRAINT_LEN (*p, p); /* And set it back. */ #undef DEFAULT_CONSTRAINT_LEN #define DEFAULT_CONSTRAINT_LEN(C,STR) 1 }