Re: [sr-dev] [PATCH] Adding define/ifdef/ifndef to cfg preprocessing

Since include_file was just added, why not go one extra step and allow things like (adapted from etc/kamailio.cfg): #!define PRESENCE #!ifdef PRESENCE loadmodule "presence.so" loadmodule "presence_xml.so" #!else #!ifndef KAMAILIO ... #!endif #!endif M4 is already used and a better alternative IMO, but cfg is clearly not a typical language, so I imagine someone may find this useful. Patch against commit 7362f824. For a minimal test input, this can be used: ===== listen=::1 #!define xyz #!ifdef xyz listen=::2 #!ifndef abc listen=::3 #!else listen=::4 #!endif listen=::5 #!endif ===== While wr're at it, the ID token seemed wrong -- it misses _ids_that_start_with_underscores (?). Bogdan diff --git a/cfg.lex b/cfg.lex index 8490364..df4a2ee 100644 --- a/cfg.lex +++ b/cfg.lex @@ -105,6 +105,12 @@ #define PVAR_P_S 7 /* pvar: $(...) or $foo(...)*/ #define PVARID_S 8 /* $foo.bar...*/ #define STR_BETWEEN_S 9 + #define LINECOMMENT_S 10 + #define DEFINE_S 11 + #define DEFINE_EOL_S 12 + #define IFDEF_S 13 + #define IFDEF_EOL_S 14 + #define IFDEF_SKIP_S 15 #define STR_BUF_ALLOC_UNIT 128 struct str_buf{ @@ -152,11 +158,18 @@ struct sr_yy_fname *next; } *sr_yy_fname_list = 0; + static int pp_define(int len, const char * text); + static int pp_ifdef_type(int pos); + static void pp_ifdef_var(int len, const char * text); + static void pp_ifdef(); + static void pp_else(); + static void pp_endif(); %} /* start conditions */ %x STRING1 STRING2 STR_BETWEEN COMMENT COMMENT_LN ATTR SELECT AVP_PVAR PVAR_P %x PVARID INCLF +%x LINECOMMENT DEFINE_ID DEFINE_EOL IFDEF_ID IFDEF_EOL IFDEF_SKIP /* config script types : #!SER or #!KAMAILIO or #!MAX_COMPAT */ SER_CFG SER @@ -474,8 +487,9 @@ TLSv1 "tlsv1"|"TLSv1"|"TLSV1" LETTER [a-zA-Z] DIGIT [0-9] -ALPHANUM {LETTER}|{DIGIT}|[_] -ID {LETTER}{ALPHANUM}* +LETTER_ {LETTER}|[_] +ALPHANUM {LETTER_}|{DIGIT} +ID {LETTER_}{ALPHANUM}* NUM_ID {ALPHANUM}+ HEX [0-9a-fA-F] HEXNUMBER 0x{HEX}+ @@ -506,6 +520,12 @@ COM_LINE # COM_START "/\*" COM_END "\*/" +DEFINE define +IFDEF ifdef +IFNDEF ifndef +ENDIF endif +/* else is already defined */ + EAT_ABLE [\ \t\b\r] %% @@ -1121,7 +1141,36 @@ EAT_ABLE [\ \t\b\r] sr_cfg_compat=SR_COMPAT_KAMAILIO;} <INITIAL>{COM_LINE}!{MAXCOMPAT_CFG}{CR} { count(); sr_cfg_compat=SR_COMPAT_MAX;} -<INITIAL>{COM_LINE}.*{CR} { count(); } + +<INITIAL>{COM_LINE}!{DEFINE}{EAT_ABLE}+ { count(); + state = DEFINE_S; BEGIN(DEFINE_ID); } +<DEFINE_ID>{ID} { count(); + if (pp_define(yyleng, yytext)) return 1; + state = DEFINE_EOL_S; BEGIN(DEFINE_EOL); } +<DEFINE_EOL>{EAT_ABLE}*{CR} { count(); + state = INITIAL; BEGIN(INITIAL); } + +<INITIAL,IFDEF_SKIP>{COM_LINE}!{IFDEF}{EAT_ABLE}+ { count(); + if (pp_ifdef_type(1)) return 1; + state = IFDEF_S; BEGIN(IFDEF_ID); } +<INITIAL,IFDEF_SKIP>{COM_LINE}!{IFNDEF}{EAT_ABLE}+ { count(); + if (pp_ifdef_type(0)) return 1; + state = IFDEF_S; BEGIN(IFDEF_ID); } +<IFDEF_ID>{ID} { count(); + pp_ifdef_var(yyleng, yytext); + state = IFDEF_EOL_S; BEGIN(IFDEF_EOL); } +<IFDEF_EOL>{EAT_ABLE}*{CR} { count(); pp_ifdef(); } + +<INITIAL,IFDEF_SKIP>{COM_LINE}!{ELSE}{EAT_ABLE}*{CR} { count(); pp_else(); } + +<INITIAL,IFDEF_SKIP>{COM_LINE}!{ENDIF}{EAT_ABLE}*{CR} { count(); pp_endif(); } + + /* we're in an ifdef that evaluated to false -- throw it away */ +<IFDEF_SKIP>.|{CR} { count(); } + + /* this is split so the shebangs match more, giving them priority */ +<INITIAL>{COM_LINE} { count(); state = LINECOMMENT_S; BEGIN(LINECOMMENT); } +<LINECOMMENT>.*{CR} { count(); state = INITIAL_S; BEGIN(INITIAL); } <INITIAL>{ID} { count(); addstr(&s_buf, yytext, yyleng); yylval.strval=s_buf.s; @@ -1472,3 +1521,102 @@ static int sr_pop_yy_state() return 0; } +/* define/ifdef support */ + +#define MAX_DEFINES 1024 +static str pp_defines[MAX_DEFINES]; +static int pp_num_defines = 0; + +/* pp_ifdef_stack[i] is 1 if the ifdef test at depth i is either + * ifdef(defined), ifndef(undefined), or the opposite of these + * two, but in an else branch + */ +#define MAX_IFDEFS 16 +static int pp_ifdef_stack[MAX_IFDEFS]; +static int pp_sptr = 0; /* stack pointer */ + +static int pp_lookup(int len, const char * text) +{ + str var = {(char *)text, len}; + int i; + + for (i=0; i<pp_num_defines; i++) + if (STR_EQ(pp_defines[i], var)) + return i; + + return -1; +} + +static int pp_define(int len, const char * text) +{ + if (pp_num_defines == MAX_DEFINES) { + LOG(L_CRIT, "ERROR: too many defines -- adjust MAX_DEFINES\n"); + return -1; + } + + if (pp_lookup(len, text) >= 0) { + LOG(L_CRIT, "ERROR: already defined: %.*s\n", len, text); + return -1; + } + + pp_defines[pp_num_defines].len = len; + pp_defines[pp_num_defines].s = (char*)pkg_malloc(len+1); + memcpy(pp_defines[pp_num_defines].s, text, len); + pp_num_defines++; + + return 0; +} + +static int pp_ifdef_type(int type) +{ + if (pp_sptr == MAX_IFDEFS) { + LOG(L_CRIT, "ERROR: too many nested ifdefs -- adjust MAX_IFDEFS\n"); + return -1; + } + + pp_ifdef_stack[pp_sptr] = type; + return 0; +} + +/* this sets the result of the if[n]def expr: + * ifdef defined -> 1 + * ifdef undefined -> 0 + * ifndef defined -> 0 + * ifndef undefined -> 1 + */ +static void pp_ifdef_var(int len, const char * text) +{ + pp_ifdef_stack[pp_sptr] ^= (pp_lookup(len, text) < 0); +} + +static void pp_update_state() +{ + int i; + + for (i=0; i<pp_sptr; i++) + if (! pp_ifdef_stack[i]) { + state = IFDEF_SKIP_S; BEGIN(IFDEF_SKIP); + return; + } + + state = INITIAL; BEGIN(INITIAL); +} + +static void pp_ifdef() +{ + pp_sptr++; + pp_update_state(); +} + +static void pp_else() +{ + pp_ifdef_stack[pp_sptr-1] ^= 1; + pp_update_state(); +} + +static void pp_endif() +{ + pp_sptr--; + pp_update_state(); +} + ------------------------------------------------------------------------ _______________________________________________ sr-dev mailing list sr-dev(a)lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev