[sr-dev] [PATCH] Adding define/ifdef/ifndef to cfg preprocessing
Bogdan Harjoc
harjoc at gmail.com
Fri Oct 2 02:51:27 CEST 2009
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();
+}
+
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