src/declare.c

   1 /*
   2  *  Render C declarations.
   3  *  Copyright © 2011, 2021, 2023 Nick Bowler
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <config.h>
  20 #include <stdio.h>
  21 #include <stdbool.h>
  22 #include <assert.h>
  23
  24 #include "cdecl.h"
  25 #include "cdecl-internal.h"
  26
  27 static size_t
  28 declare_declarator(char *buf, size_t n, struct cdecl_declarator *d);
  29
  30 static size_t declare_decl(char *buf, size_t n, struct cdecl *decl)
  31 {
  32         size_t ret = 0, rc;
  33
  34         rc = cdecl__explain_specs(buf, n, decl->specifiers, -1);
  35         if (decl->declarators->type != CDECL_DECL_NULL)
  36                 ret += cdecl__advance(&buf, &n, rc);
  37         else
  38                 ret += cdecl__advance_(&buf, &n, rc);
  39
  40         return ret + declare_declarator(buf, n, decl->declarators);
  41 }
  42
  43 static size_t
  44 declare_postfix_child(char *buf, size_t n, struct cdecl_declarator *d)
  45 {
  46         size_t ret = 0, rc;
  47
  48         if (d->type == CDECL_DECL_POINTER) {
  49                 rc = snprintf(buf, n, "(");
  50                 ret += cdecl__advance_(&buf, &n, rc);
  51         }
  52
  53         rc = declare_declarator(buf, n, d);
  54         ret += cdecl__advance_(&buf, &n, rc);
  55
  56         if (d->type == CDECL_DECL_POINTER) {
  57                 rc = snprintf(buf, n, ")");
  58                 ret += cdecl__advance_(&buf, &n, rc);
  59         }
  60
  61         return ret;
  62 }
  63
  64 static size_t declare_pointer(char *buf, size_t n, struct cdecl_pointer *p)
  65 {
  66         size_t ret = 0, rc;
  67
  68         rc = snprintf(buf, n, "*");
  69         if (p->qualifiers)
  70                 ret += cdecl__advance(&buf, &n, rc);
  71         else
  72                 ret += cdecl__advance_(&buf, &n, rc);
  73
  74         rc = cdecl__explain_specs(buf, n, p->qualifiers, CDECL_SPEC_QUAL);
  75         return ret + rc;
  76 }
  77
  78 static bool pointer_needs_space(struct cdecl_declarator *d)
  79 {
  80         assert(d->type == CDECL_DECL_POINTER);
  81
  82         if (d->u.pointer.qualifiers)
  83                 return d->child->type != CDECL_DECL_NULL;
  84
  85         return false;
  86 }
  87
  88 static size_t declare_array(char *buf, size_t n, struct cdecl_array *a)
  89 {
  90         size_t ret = 0, rc;
  91
  92         rc = snprintf(buf, n, "[");
  93         ret += cdecl__advance_(&buf, &n, rc);
  94
  95         if (a->vla)
  96                 rc = snprintf(buf, n, "%s", a->vla[0] ? a->vla : "*");
  97         else
  98                 rc = snprintf(buf, n, "%.0ju", a->length);
  99         ret += cdecl__advance_(&buf, &n, rc);
 100
 101         return ret + snprintf(buf, n, "]");
 102 }
 103
 104 static size_t declare_function(char *buf, size_t n, struct cdecl_function *f)
 105 {
 106         size_t ret = 0, rc;
 107
 108         rc = snprintf(buf, n, "(");
 109         ret += cdecl__advance_(&buf, &n, rc);
 110
 111         for (struct cdecl *p = f->parameters; p; p = p->next) {
 112                 rc = declare_decl(buf, n, p);
 113                 ret += cdecl__advance_(&buf, &n, rc);
 114
 115                 rc = 0;
 116                 if (p->next)
 117                         rc = snprintf(buf, n, ", ");
 118                 else if (f->variadic)
 119                         rc = snprintf(buf, n, ", ...");
 120                 ret += cdecl__advance_(&buf, &n, rc);
 121         }
 122
 123         return ret + snprintf(buf, n, ")");
 124 }
 125
 126 static size_t
 127 declare_declarator(char *buf, size_t n, struct cdecl_declarator *d)
 128 {
 129         size_t ret = 0, rc;
 130
 131         for (; d; d = d->child) {
 132                 switch (d->type) {
 133                 case CDECL_DECL_NULL:
 134                         break;
 135                 case CDECL_DECL_IDENT:
 136                         rc = snprintf(buf, n, "%s", d->u.ident);
 137                         ret += cdecl__advance_(&buf, &n, rc);
 138                         break;
 139                 case CDECL_DECL_POINTER:
 140                         rc = declare_pointer(buf, n, &d->u.pointer);
 141                         if (pointer_needs_space(d))
 142                                 ret += cdecl__advance(&buf, &n, rc);
 143                         else
 144                                 ret += cdecl__advance_(&buf, &n, rc);
 145                         break;
 146                 /*
 147                  * Arrays and functions are special: since they are postfix,
 148                  * we need to render the children before rendering their
 149                  * "bodies".
 150                  */
 151                 case CDECL_DECL_ARRAY:
 152                         rc = declare_postfix_child(buf, n, d->child);
 153                         ret += cdecl__advance_(&buf, &n, rc);
 154                         return ret + declare_array(buf, n, &d->u.array);
 155                 case CDECL_DECL_FUNCTION:
 156                         rc = declare_postfix_child(buf, n, d->child);
 157                         ret += cdecl__advance_(&buf, &n, rc);
 158                         return ret + declare_function(buf, n, &d->u.function);
 159                 default:
 160                         assert(0);
 161                 }
 162         }
 163
 164         return ret;
 165 }
 166
 167 size_t cdecl_declare(char *buf, size_t n, struct cdecl *decl)
 168 {
 169         return declare_decl(buf, n, decl);
 170 }