/* Hash tables.   Copyright (C) 2000-2026 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify itunder the terms of the GNU General Public License as published by theFree Software Foundation; either version 3, or (at your option) anylater version. This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details. You should have received a copy of the GNU General Public Licensealong with this program; see the file COPYING3.  If not see<http://www.gnu.org/licenses/>.  */ #ifndef LIBCPP_SYMTAB_H#define LIBCPP_SYMTAB_H #include "obstack.h" #ifndef GTY#define GTY(x) /* nothing */#endif /* This is what each hash table entry points to.  It may be embedded   deeply within another object.  */typedef struct ht_identifier ht_identifier;typedef struct ht_identifier *ht_identifier_ptr;struct GTY(()) ht_identifier {  /* We know the 'len'gth of the 'str'ing; use it in the GTY markup.  */  const unsigned char * GTY((string_length ("1 + %h.len"))) str;  unsigned int len;  unsigned int hash_value;}; #define HT_LEN(NODE) ((NODE)->len)#define HT_STR(NODE) ((NODE)->str) typedef struct ht cpp_hash_table;typedef struct ht_identifier *hashnode; enum ht_lookup_option {HT_NO_INSERT = 0, HT_ALLOC}; /* An identifier hash table for cpplib and the front ends.  */struct ht{  /* Identifiers are allocated from here.  */  struct obstack stack;   hashnode *entries;  /* Call back, allocate a node.  */  hashnode (*alloc_node) (cpp_hash_table *);  /* Call back, allocate something that hangs off a node like a cpp_macro.     NULL means use the usual allocator.  */  void * (*alloc_subobject) (size_t);   unsigned int nslots;		/* Total slots in the entries array.  */  unsigned int nelements;	/* Number of live elements.  */   /* Link to reader, if any.  For the benefit of cpplib.  */  struct cpp_reader *pfile;   /* Table usage statistics.  */  unsigned int searches;  unsigned int collisions;   /* Should 'entries' be freed when it is no longer needed?  */  bool entries_owned;}; /* Initialize the hashtable with 2 ^ order entries.  */extern cpp_hash_table *ht_create (unsigned int order); /* Frees all memory associated with a hash table.  */extern void ht_destroy (cpp_hash_table *); extern hashnode ht_lookup (cpp_hash_table *, const unsigned char *,			   size_t, enum ht_lookup_option);extern hashnode ht_lookup_with_hash (cpp_hash_table *, const unsigned char *,                                     size_t, unsigned int,                                     enum ht_lookup_option);inline hashnode ht_lookup (cpp_hash_table *ht, const ht_identifier &id,			   ht_lookup_option opt){  return ht_lookup_with_hash (ht, id.str, id.len, id.hash_value, opt);} #define HT_HASHSTEP(r, c) ((r) * 67 + ((c) - 113));#define HT_HASHFINISH(r, len) ((r) + (len)) /* For all nodes in TABLE, make a callback.  The callback takes   TABLE->PFILE, the node, and a PTR, and the callback sequence stops   if the callback returns zero.  */typedef int (*ht_cb) (struct cpp_reader *, hashnode, const void *);extern void ht_forall (cpp_hash_table *, ht_cb, const void *); /* For all nodes in TABLE, call the callback.  If the callback returns   a nonzero value, the node is removed from the table.  */extern void ht_purge (cpp_hash_table *, ht_cb, const void *); /* Restore the hash table.  */extern void ht_load (cpp_hash_table *ht, hashnode *entries,		     unsigned int nslots, unsigned int nelements, bool own); /* Dump allocation statistics to stderr.  */extern void ht_dump_statistics (cpp_hash_table *); #endif /* LIBCPP_SYMTAB_H */