Conf: Symbol hashes for all scopes

This is a backport cherry-pick of commits
  165156beeb2926472bbceca3c103aacc3f81a8cc
  cce974e8ea992d0e6d2f649eca7880b436d91d71

from the v3.0 branch as we need symbol hashes directly inside their
scopes for more general usage than before.

6 files changed, 61 insertions, 62 deletions

diff --git a/conf/cf-lex.l b/conf/cf-lex.l
index e789e864..8637de40 100644
--- a/conf/cf-lex.l
+++ b/conf/cf-lex.l
@@ -73,22 +73,22 @@ static uint cf_hash(const byte *c);
 #define KW_FN(k)		cf_hash(k)
 #define KW_ORDER		8 /* Fixed */
 
-#define SYM_KEY(n)		n->name, n->scope
+#define SYM_KEY(n)		n->name
 #define SYM_NEXT(n)		n->next
-#define SYM_EQ(a,s1,b,s2)	!strcmp(a,b) && s1 == s2
-#define SYM_FN(k,s)		cf_hash(k) ^ ptr_hash(s)
-#define SYM_ORDER		6 /* Initial */
+#define SYM_EQ(a,b)		!strcmp(a,b)
+#define SYM_FN(k)		cf_hash(k)
+#define SYM_ORDER		4 /* Initial */
 
 #define SYM_REHASH		sym_rehash
-#define SYM_PARAMS		/8, *1, 2, 2, 6, 20
+#define SYM_PARAMS		/8, *1, 2, 2, 4, 20
 
 
 HASH_DEFINE_REHASH_FN(SYM, struct symbol)
 
 HASH(struct keyword) kw_hash;
 
-
 struct sym_scope *conf_this_scope;
+struct sym_scope *global_root_scope;
 
 linpool *cfg_mem;
 
@@ -580,12 +580,13 @@ cf_new_symbol(const byte *c)
   *s = (struct symbol) { .scope = conf_this_scope, .class = SYM_VOID, };
   strcpy(s->name, c);
 
-  if (!new_config->sym_hash.data)
-    HASH_INIT(new_config->sym_hash, new_config->pool, SYM_ORDER);
+  if (!conf_this_scope->hash.data)
+    HASH_INIT(conf_this_scope->hash, new_config->pool, SYM_ORDER);
 
-  HASH_INSERT2(new_config->sym_hash, SYM, new_config->pool, s);
+  HASH_INSERT2(conf_this_scope->hash, SYM, new_config->pool, s);
 
-  add_tail(&(new_config->symbols), &(s->n));
+  if (conf_this_scope == new_config->root_scope)
+    add_tail(&(new_config->symbols), &(s->n));
 
   return s;
 }
@@ -595,32 +596,27 @@ cf_symbol_from_keyword(const struct keyword *kw)
 { return cf_new_symbol(kw->name); }
 
 /**
- * cf_find_local_symbol - find a symbol by name
- * @cfg: specificed config
- * @scope: specified symbol scope
+ * cf_find_symbol_scope - find a symbol by name
+ * @scope: config scope
  * @c: symbol name
  *
- * This functions searches the symbol table in the config @cfg for a symbol of
- * given name. First it examines the scope @scope, then the parent scope
+ * This functions searches the symbol table in the scope @scope for a symbol of
+ * given name. First it examines the current scope, then the underlying one
  * and so on until it either finds the symbol and returns a pointer to its
  * &symbol structure or reaches the end of the scope chain and returns %NULL to
  * signify no match.
  */
 struct symbol *
-cf_find_local_symbol(const struct config *cfg, const struct sym_scope *scope, const byte *c)
+cf_find_symbol_scope(const struct sym_scope *scope, const byte *c)
 {
   struct symbol *s;
 
-  if (cfg->sym_hash.data)
-    for (; scope; scope = scope->next)
-      if (s = HASH_FIND(cfg->sym_hash, SYM, c, scope))
-	return s;
-
-  /* In CLI command parsing, fallback points to the current config, otherwise it is NULL. */
-  if (cfg->fallback &&
-      cfg->fallback->sym_hash.data &&
-      (s = HASH_FIND(cfg->fallback->sym_hash, SYM, c, cfg->fallback->root_scope)))
-    return s;
+  /* Find the symbol here or anywhere below */
+  while (scope)
+    if (scope->hash.data && (s = HASH_FIND(scope->hash, SYM, c)))
+      return s;
+    else
+      scope = scope->next;
 
   return NULL;
 }
@@ -637,7 +633,7 @@ cf_find_local_symbol(const struct config *cfg, const struct sym_scope *scope, co
 struct symbol *
 cf_get_symbol(const byte *c)
 {
-  return cf_find_local_symbol(new_config, conf_this_scope, c) ?: cf_new_symbol(c);
+  return cf_find_symbol_scope(conf_this_scope, c) ?: cf_new_symbol(c);
 }
 
 /**
@@ -685,23 +681,15 @@ static enum yytokentype
 cf_lex_symbol(const char *data)
 {
   /* Have we defined such a symbol? */
-  struct symbol *sym = cf_find_local_symbol(new_config, conf_this_scope, data);
-
-  if (sym && (sym->class != SYM_VOID))
-  {
-    cf_lval.s = sym;
-    return CF_SYM_KNOWN;
-  }
+  struct symbol *sym = cf_get_symbol(data);
+  cf_lval.s = sym;
 
-  /* Is it a keyword? */
+  /* Is it a keyword? Prefer the keyword. */
   struct keyword *k = HASH_FIND(kw_hash, KW, data);
   if (k)
   {
     if (k->value > 0)
-    {
-      cf_lval.kw = k;
       return k->value;
-    }
     else
     {
       cf_lval.i = -k->value;
@@ -709,19 +697,23 @@ cf_lex_symbol(const char *data)
     }
   }
 
-  /* OK, undefined symbol */
-  cf_lval.s = cf_new_symbol(data);
-  return CF_SYM_UNDEFINED;
+  /* OK, only a symbol. */
+  if (sym->class == SYM_VOID)
+    return CF_SYM_UNDEFINED;
+  else
+    return CF_SYM_KNOWN;
 }
 
 static void
 cf_lex_init_kh(void)
 {
-  HASH_INIT(kw_hash, config_pool, KW_ORDER);
+  HASH_INIT(kw_hash, &root_pool, KW_ORDER);
 
   struct keyword *k;
   for (k=keyword_list; k->name; k++)
     HASH_INSERT(kw_hash, KW, k);
+
+  global_root_scope = mb_allocz(&root_pool, sizeof(*global_root_scope));
 }
 
 /**
@@ -757,6 +749,11 @@ cf_lex_init(int is_cli, struct config *c)
   c->root_scope = cfg_allocz(sizeof(struct sym_scope));
   conf_this_scope = c->root_scope;
   conf_this_scope->active = 1;
+
+  if (is_cli)
+    conf_this_scope->next = config->root_scope;
+  else
+    conf_this_scope->next = global_root_scope;
 }
 
 /**
diff --git a/conf/conf.c b/conf/conf.c
index 7ef729b3..b9239d9b 100644
--- a/conf/conf.c
+++ b/conf/conf.c
@@ -170,7 +170,6 @@ int
 cli_parse(struct config *c)
 {
   int done = 0;
-  c->fallback = config;
   new_config = c;
   cfg_mem = c->mem;
   if (setjmp(conf_jmpbuf))
@@ -181,7 +180,6 @@ cli_parse(struct config *c)
   done = 1;
 
 cleanup:
-  c->fallback = NULL;
   new_config = NULL;
   cfg_mem = NULL;
   return done;
@@ -551,7 +549,6 @@ order_shutdown(int gr)
   init_list(&c->tables);
   init_list(&c->symbols);
   memset(c->def_tables, 0, sizeof(c->def_tables));
-  HASH_INIT(c->sym_hash, c->pool, 4);
   c->shutdown = 1;
   c->gr_down = gr;
 
diff --git a/conf/conf.h b/conf/conf.h
index d40f955e..fe8ee5bf 100644
--- a/conf/conf.h
+++ b/conf/conf.h
@@ -16,7 +16,6 @@
 #include "lib/timer.h"
 
 /* Configuration structure */
-
 struct config {
   pool *pool;				/* Pool the configuration is stored in */
   linpool *mem;				/* Linear pool containing configuration data */
@@ -53,8 +52,7 @@ struct config {
   char *err_file_name;			/* File name containing error */
   char *file_name;			/* Name of main configuration file */
   int file_fd;				/* File descriptor of main configuration file */
-  HASH(struct symbol) sym_hash;		/* Lexer: symbol hash table */
-  struct config *fallback;		/* Link to regular config for CLI parsing */
+
   struct sym_scope *root_scope;		/* Scope for root symbols */
   int obstacle_count;			/* Number of items blocking freeing of this config */
   int shutdown;				/* This is a pseudo-config for daemon shutdown */
@@ -133,12 +131,17 @@ struct symbol {
 struct sym_scope {
   struct sym_scope *next;		/* Next on scope stack */
   struct symbol *name;			/* Name of this scope */
+
+  HASH(struct symbol) hash;		/* Local symbol hash */
+
   uint slots;				/* Variable slots */
   byte active;				/* Currently entered */
   byte block;				/* No independent stack frame */
   byte soft_scopes;			/* Number of soft scopes above */
 };
 
+extern struct sym_scope *global_root_scope;
+
 struct bytestring {
   size_t length;
   byte data[];
@@ -187,12 +190,14 @@ int cf_lex(void);
 void cf_lex_init(int is_cli, struct config *c);
 void cf_lex_unwind(void);
 
-struct symbol *cf_find_local_symbol(const struct config *cfg, const struct sym_scope *scope, const byte *c);
-static inline struct symbol *cf_find_symbol(const struct config *cfg, const byte *c)
-{ return cf_find_local_symbol(cfg, cfg->root_scope, c); }
+struct symbol *cf_find_symbol_scope(const struct sym_scope *scope, const byte *c);
+static inline struct symbol *cf_find_symbol_cfg(const struct config *cfg, const byte *c)
+{ return cf_find_symbol_scope(cfg->root_scope, c); }
 
-struct keyword;
-struct symbol *cf_symbol_from_keyword(const struct keyword *kw);
+#define cf_find_symbol(where, what) _Generic(*(where), \
+    struct config: cf_find_symbol_cfg, \
+    struct sym_scope: cf_find_symbol_scope \
+    )((where), (what))
 
 struct symbol *cf_get_symbol(const byte *c);
 struct symbol *cf_default_name(char *template, int *counter);
diff --git a/conf/confbase.Y b/conf/confbase.Y
index a43a8cca..0c2807dc 100644
--- a/conf/confbase.Y
+++ b/conf/confbase.Y
@@ -118,7 +118,7 @@ CF_DECLS
 
 %type <t> text opttext
 %type <bs> bytestring
-%type <s> symbol
+%type <s> symbol symbol_known
 
 %type <v> bytestring_text text_or_ipa
 %type <x> bytestring_expr
@@ -166,7 +166,7 @@ definition:
 expr:
    NUM
  | '(' term ')' { $$ = cf_eval_int($2); }
- | CF_SYM_KNOWN {
+ | symbol_known {
      if ($1->class != (SYM_CONSTANT | T_INT)) cf_error("Number constant expected");
      $$ = SYM_VAL($1).i; }
  ;
@@ -177,7 +177,8 @@ expr_us:
  | expr US { $$ = $1 US_; }
  ;
 
-symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN | KEYWORD { $$ = cf_symbol_from_keyword($1); } ;
+symbol: CF_SYM_UNDEFINED | CF_SYM_KNOWN | KEYWORD ;
+symbol_known: CF_SYM_KNOWN | KEYWORD ;
 
 /* Switches */
 
diff --git a/conf/gen_keywords.m4 b/conf/gen_keywords.m4
index 3206c186..4ab6d50d 100644
--- a/conf/gen_keywords.m4
+++ b/conf/gen_keywords.m4
@@ -26,8 +26,7 @@ m4_define(CF_DEFINES, `m4_divert(-1)')
 m4_define(CF_handle_kw, `m4_divert(1){ "m4_translit($1,[[A-Z]],[[a-z]])", $1, NULL },
 m4_divert(-1)')
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)CF_handle_kw($1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token[[]]CF_toks
-)DNL')
+m4_define(CF_KEYWORDS, `CF_iterate([[CF_keywd]], [[$@]])DNL')
 m4_define(CF_KEYWORDS_EXCLUSIVE, `CF_KEYWORDS($@)')
 
 # CLI commands generate keywords as well
diff --git a/conf/gen_parser.m4 b/conf/gen_parser.m4
index a26af851..caf22307 100644
--- a/conf/gen_parser.m4
+++ b/conf/gen_parser.m4
@@ -31,13 +31,13 @@ m4_define(CF_iterate, `m4_define([[CF_iter]], m4_defn([[$1]]))CF_itera($2)')
 
 m4_define(CF_append, `m4_define([[$1]], m4_ifdef([[$1]], m4_defn([[$1]])[[$3]])[[$2]])')
 
-# Keywords act as %token<kw>
+# Keywords act as %token<s>
 m4_define(CF_keywd, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)CF_append([[CF_kw_rule]],$1,[[ | ]])m4_define([[CF_toks]],CF_toks $1)]])')
-m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token<kw>[[]]CF_toks
+m4_define(CF_KEYWORDS, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd]], [[$@]])m4_ifelse(CF_toks,,,%token<s>[[]]CF_toks
 )DNL')
 
 m4_define(CF_keywd2, `m4_ifdef([[CF_tok_$1]],,[[m4_define([[CF_tok_$1]],1)m4_define([[CF_toks]],CF_toks $1)]])')
-m4_define(CF_KEYWORDS_EXCLUSIVE, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd2]], [[$@]])m4_ifelse(CF_toks,,,%token<kw>[[]]CF_toks
+m4_define(CF_KEYWORDS_EXCLUSIVE, `m4_define([[CF_toks]],[[]])CF_iterate([[CF_keywd2]], [[$@]])m4_ifelse(CF_toks,,,%token<s>[[]]CF_toks
 )DNL')
 
 # CLI commands
@@ -61,7 +61,7 @@ m4_undivert(1)DNL
 
 m4_undivert(2)DNL
 
-%type <kw> KEYWORD
+%type <s> KEYWORD
 
 %%
 KEYWORD: CF_kw_rule;