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mirror of https://github.com/sqlite/sqlite.git synced 2025-07-29 08:01:23 +03:00

Modify lemon to use much less memory for its parser tables. This reduces

the size of the library by 50K, which is important for an embedded library. (CVS 389)

FossilOrigin-Name: 67a135a051e7c96ddbfe85976539b4b8372c7026
This commit is contained in:
drh
2002-02-23 19:39:46 +00:00
parent b59499c73b
commit b29b0a5227
4 changed files with 51 additions and 45 deletions

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@ -1,5 +1,5 @@
C Bug\sfix\sin\slemon:\s3-way\sconflicts\s(SHIFT/REDUCE/REDUCE)\swere\snot\sdetected\sor\nresolved.\s\sThis\sis\snow\sfixed.\s\sAlso,\stable\scompression\sworks\sa\slittle\sbetter.\s(CVS\s388)
D 2002-02-23T18:45:13
C Modify\slemon\sto\suse\smuch\sless\smemory\sfor\sits\sparser\stables.\s\sThis\sreduces\nthe\ssize\sof\sthe\slibrary\sby\s50K,\swhich\sis\simportant\sfor\san\sembedded\slibrary.\s(CVS\s389)
D 2002-02-23T19:39:47
F Makefile.in 9fa4277413bf1d9cf91365f07d4108d7d87ed2af
F Makefile.template 3372d45f8853afdb70bd30cc6fb50a3cd9069834
F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@ -99,8 +99,8 @@ F test/unique.test 07776624b82221a80c8b4138ce0dd8b0853bb3ea
F test/update.test 3cf1ca0565f678063c2dfa9a7948d2d66ae1a778
F test/vacuum.test 8acf8669f3b627e54149b25165b034aa06c2432e
F test/where.test 032d581c3de4893eba33b569e581c46b941bb02a
F tool/lemon.c 7502222a5d704d9d5d1ac437f73667855d687862
F tool/lempar.c 9b604e6a8b3d55c0b9cbcb130a7302fb8bafe2b9
F tool/lemon.c d4b4e127e70633be1bbea49c2ccba5cdb4b77a5f
F tool/lempar.c 2ff255186fffb38a43a9f7b010e87eee6308edcc
F tool/memleak.awk 296dfbce7a9ca499b95ce04e30334e64a50052e0
F tool/opNames.awk 5ba1f48aa854ee3b7c3d2b54233665bc3e649ea2
F tool/opcodeDoc.awk b3a2a3d5d3075b8bd90b7afe24283efdd586659c
@ -125,7 +125,7 @@ F www/speed.tcl 83457b2bf6bb430900bd48ca3dd98264d9a916a5
F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
F www/tclsqlite.tcl 829b393d1ab187fd7a5e978631b3429318885c49
F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
P 39fed2df11382b9855d518502a6c2ca200fa66b8
R bbf759a9eca350d9e39199c34c6ab1fb
P 8da0ac9a8bb859377613dd18f4f423eb49c7338b
R a10568441a27cde980e4058838f315f0
U drh
Z 95f9230334dd6740861a9a25c1c709f1
Z 77767b7d4f55ba40f2761ab26d448e78

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@ -1 +1 @@
8da0ac9a8bb859377613dd18f4f423eb49c7338b
67a135a051e7c96ddbfe85976539b4b8372c7026

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@ -2927,6 +2927,20 @@ int mhflag; /* True if generating makeheaders output */
*plineno = lineno;
}
/*
** Return the name of a C datatype able to represent values between
** 0 and N, inclusive.
*/
static const char *minimum_size_type(int N){
if( N<=255 ){
return "unsigned char";
}else if( N<65535 ){
return "unsigned short int";
}else{
return "unsigned int";
}
}
/* Generate C source code for the parser */
void ReportTable(lemp, mhflag)
struct lemon *lemp;
@ -2978,10 +2992,10 @@ int mhflag; /* Output in makeheaders format if true */
/* Generate the defines */
fprintf(out,"/* \001 */\n");
fprintf(out,"#define YYCODETYPE %s\n",
lemp->nsymbol>250?"int":"unsigned char"); lineno++;
minimum_size_type(lemp->nsymbol+5)); lineno++;
fprintf(out,"#define YYNOCODE %d\n",lemp->nsymbol+1); lineno++;
fprintf(out,"#define YYACTIONTYPE %s\n",
lemp->nstate+lemp->nrule>250?"int":"unsigned char"); lineno++;
minimum_size_type(lemp->nstate+lemp->nrule+5)); lineno++;
print_stack_union(out,lemp,&lineno,mhflag);
if( lemp->stacksize ){
if( atoi(lemp->stacksize)<=0 ){
@ -3027,13 +3041,16 @@ int mhflag; /* Output in makeheaders format if true */
** structure:
** struct yyActionEntry {
** YYCODETYPE lookahead;
** YYCODETYPE next;
** YYACTIONTYPE action;
** struct yyActionEntry *next;
** }
**
** The entries are grouped into hash tables, one hash table for each
** parser state. The hash table has a size which is the smallest
** power of two needed to hold all entries.
** parser state. The hash table has a size which is the number of
** entries in that table. In case of a collision, the "next" value
** contains one more than the index into the hash table of the next
** entry in the collision chain. A "next" value of 0 means the end
** of the chain has been reached.
*/
tablecnt = 0;
@ -3053,8 +3070,7 @@ int mhflag; /* Output in makeheaders format if true */
stp->naction++;
}
}
tablesize = 1;
while( tablesize<stp->naction ) tablesize += tablesize;
tablesize = stp->naction;
assert( tablesize<= sizeof(table)/sizeof(table[0]) );
for(j=0; j<tablesize; j++){
table[j] = 0;
@ -3069,7 +3085,7 @@ int mhflag; /* Output in makeheaders format if true */
if( ap->sp->index==lemp->nsymbol ){
stp->tabdfltact = action;
}else if( action>=0 ){
h = ap->sp->index & (tablesize-1);
h = ap->sp->index % tablesize;
ap->collide = table[h];
table[h] = ap;
}
@ -3089,22 +3105,13 @@ int mhflag; /* Output in makeheaders format if true */
/* Print the hash table */
fprintf(out,"/* State %d */\n",stp->index); lineno++;
for(j=0; j<tablesize; j++){
if( table[j]==0 ){
fprintf(out,
" {YYNOCODE,0,0}, /* Unused */\n");
}else{
fprintf(out," {%4d,%4d, ",
assert( table[j]!=0 );
fprintf(out," {%4d,%4d,%4d}, /* ",
table[j]->sp->index,
collide[j]+1,
compute_action(lemp,table[j]));
if( collide[j]>=0 ){
fprintf(out,"&yyActionTable[%4d] }, /* ",
collide[j] + tablecnt);
}else{
fprintf(out,"0 }, /* ");
}
PrintAction(table[j],out,22);
fprintf(out," */\n");
}
PrintAction(table[j],out,22);
fprintf(out," */\n");
lineno++;
}
@ -3119,18 +3126,15 @@ int mhflag; /* Output in makeheaders format if true */
** Each entry is an element of the following structure:
** struct yyStateEntry {
** struct yyActionEntry *hashtbl;
** int mask;
** YYCODETYPE nEntry;
** YYACTIONTYPE actionDefault;
** }
*/
for(i=0; i<lemp->nstate; i++){
int tablesize;
stp = lemp->sorted[i];
tablesize = 1;
while( tablesize<stp->naction ) tablesize += tablesize;
fprintf(out," { &yyActionTable[%d], %d, %d},\n",
fprintf(out," { &yyActionTable[%d],%4d,%4d },\n",
stp->tabstart,
tablesize - 1,
stp->naction,
stp->tabdfltact); lineno++;
}
tplt_xfer(lemp->name,in,out,&lineno);

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@ -76,8 +76,8 @@
*/
struct yyActionEntry {
YYCODETYPE lookahead; /* The value of the look-ahead token */
YYCODETYPE next; /* Next entry + 1. Zero at end of collision chain */
YYACTIONTYPE action; /* Action to take for this look-ahead */
struct yyActionEntry *next; /* Next look-ahead with the same hash, or NULL */
};
static struct yyActionEntry yyActionTable[] = {
%%
@ -89,15 +89,14 @@ static struct yyActionEntry yyActionTable[] = {
**
** + A pointer to the start of the action hash table in yyActionTable.
**
** + A mask used to hash the look-ahead token. The mask is an integer
** which is one less than the size of the hash table.
** + The number of entries in the action hash table.
**
** + The default action. This is the action to take if no entry for
** the given look-ahead is found in the action hash table.
*/
struct yyStateEntry {
struct yyActionEntry *hashtbl; /* Start of the hash table in yyActionTable */
int mask; /* Mask used for hashing the look-ahead */
YYCODETYPE nEntry; /* Number of entries in action hash table */
YYACTIONTYPE actionDefault; /* Default action if look-ahead not found */
};
static struct yyStateEntry yyStateTable[] = {
@ -297,13 +296,16 @@ static int yy_find_parser_action(
/* if( pParser->idx<0 ) return YY_NO_ACTION; */
pState = &yyStateTable[pParser->top->stateno];
if( iLookAhead!=YYNOCODE ){
pAction = &pState->hashtbl[iLookAhead & pState->mask];
while( pAction ){
if( pState->nEntry==0 ){
return pState->actionDefault;
}else if( iLookAhead!=YYNOCODE ){
pAction = &pState->hashtbl[iLookAhead % pState->nEntry];
while( 1 ){
if( pAction->lookahead==iLookAhead ) return pAction->action;
pAction = pAction->next;
if( pAction->next==0 ) return pState->actionDefault;
pAction = &pState->hashtbl[pAction->next-1];
}
}else if( pState->mask!=0 || pState->hashtbl->lookahead!=YYNOCODE ){
}else if( pState->hashtbl->lookahead!=YYNOCODE ){
return YY_NO_ACTION;
}
return pState->actionDefault;