Support "link(name, lset)" syntax in DBD files

Both Perl and dbStaticLib support included.
Also added a new std/link directory for link types.
Nothing looks up the registered link support tables yet.

src/ioc/dbStatic/dbBase.h

@@ -44,6 +44,13 @@ typedef struct devSup {
 	struct dsxt	*pdsxt;       /* Extended device support */
 }devSup;
 
+typedef struct linkSup {
+	ELLNODE		node;
+	char 		*name;
+	char		*lset_name;
+	struct lset	*lset;
+} linkSup;
+
 typedef struct dbDeviceMenu {
 	int		nChoice;
 	char		**papChoice;
@@ -162,6 +169,7 @@ typedef struct dbBase {
 	ELLLIST		menuList;
 	ELLLIST		recordTypeList;
 	ELLLIST		drvList;
+	ELLLIST		linkList;
 	ELLLIST		registrarList;
 	ELLLIST		functionList;
 	ELLLIST		variableList;

src/ioc/dbStatic/dbLex.l

@@ -38,6 +38,7 @@ static int yyreset(void)
 "field"		return(tokenFIELD);
 "device"	return(tokenDEVICE);
 "driver"	return(tokenDRIVER);
+"link"		return(tokenLINK);
 "breaktable"	return(tokenBREAKTABLE);
 "record"	return(tokenRECORD);
 "grecord"	return(tokenGRECORD);

src/ioc/dbStatic/dbLexRoutines.c

@@ -75,6 +75,7 @@ static void dbRecordtypeFieldItem(char *name,char *value);
 static void dbDevice(char *recordtype,char *linktype,
 	char *dsetname,char *choicestring);
 static void dbDriver(char *name);
+static void dbLinkType(char *name, char *lset_name);
 static void dbRegistrar(char *name);
 static void dbFunction(char *name);
 static void dbVariable(char *name, char *type);
@@ -785,6 +786,26 @@ static void dbDriver(char *name)
     ellAdd(&pdbbase->drvList,&pdrvSup->node);
 }
 
+static void dbLinkType(char *name, char *lset_name)
+{
+    linkSup *pLinkSup;
+    GPHENTRY *pgphentry;
+
+    pgphentry = gphFind(pdbbase->pgpHash, name, &pdbbase->linkList);
+    if (pgphentry) {
+	return;
+    }
+    pLinkSup = dbCalloc(1,sizeof(linkSup));
+    pLinkSup->name = epicsStrDup(name);
+    pLinkSup->lset_name = epicsStrDup(lset_name);
+    pgphentry = gphAdd(pdbbase->pgpHash, pLinkSup->name, &pdbbase->linkList);
+    if (!pgphentry) {
+	yyerrorAbort("gphAdd failed");
+    } 
+    pgphentry->userPvt = pLinkSup;
+    ellAdd(&pdbbase->linkList, &pLinkSup->node);
+}
+
 static void dbRegistrar(char *name)
 {
     dbText	*ptext;

src/ioc/dbStatic/dbStaticIocRegister.c

@@ -86,6 +86,14 @@ static void dbDumpDriverCallFunc(const iocshArgBuf *args)
     dbDumpDriver(*iocshPpdbbase);
 }
 
+/* dbDumpLink */
+static const iocshArg * const dbDumpLinkArgs[] = { &argPdbbase};
+static const iocshFuncDef dbDumpLinkFuncDef = {"dbDumpLink",1,dbDumpLinkArgs};
+static void dbDumpLinkCallFunc(const iocshArgBuf *args)
+{
+    dbDumpLink(*iocshPpdbbase);
+}
+
 /* dbDumpRegistrar */
 static const iocshArg * const dbDumpRegistrarArgs[] = { &argPdbbase};
 static const iocshFuncDef dbDumpRegistrarFuncDef = {"dbDumpRegistrar",1,dbDumpRegistrarArgs};
@@ -160,6 +168,7 @@ void dbStaticIocRegister(void)
     iocshRegister(&dbDumpFieldFuncDef, dbDumpFieldCallFunc);
     iocshRegister(&dbDumpDeviceFuncDef, dbDumpDeviceCallFunc);
     iocshRegister(&dbDumpDriverFuncDef, dbDumpDriverCallFunc);
+    iocshRegister(&dbDumpLinkFuncDef, dbDumpLinkCallFunc);
     iocshRegister(&dbDumpRegistrarFuncDef,dbDumpRegistrarCallFunc);
     iocshRegister(&dbDumpFunctionFuncDef, dbDumpFunctionCallFunc);
     iocshRegister(&dbDumpVariableFuncDef, dbDumpVariableCallFunc);

src/ioc/dbStatic/dbStaticLib.c

@@ -458,6 +458,7 @@ void dbFreeBase(dbBase *pdbbase)
     dbVariableDef       *pvarNext;
     drvSup		*pdrvSup;
     drvSup		*pdrvSupNext;
+    linkSup		*plinkSup;
     brkTable		*pbrkTable;
     brkTable		*pbrkTableNext;
     chFilterPlugin      *pfilt;
@@ -558,6 +559,11 @@ void dbFreeBase(dbBase *pdbbase)
 	free((void *)pdrvSup);
 	pdrvSup = pdrvSupNext;
     }
+    while ((plinkSup = (linkSup *) ellGet(&pdbbase->linkList))) {
+        free(plinkSup->lset_name);
+        free(plinkSup->name);
+        free(plinkSup);
+    }
     ptext = (dbText *)ellFirst(&pdbbase->registrarList);
     while(ptext) {
 	ptextNext = (dbText *)ellNext(&ptext->node);
@@ -1070,6 +1076,21 @@ long dbWriteDriverFP(DBBASE *pdbbase,FILE *fp)
     return(0);
 }
 
+long dbWriteLinkFP(DBBASE *pdbbase, FILE *fp)
+{
+    linkSup *plinkSup;
+
+    if (!pdbbase) {
+	fprintf(stderr, "pdbbase not specified\n");
+	return -1;
+    }
+    for (plinkSup = (linkSup *) ellFirst(&pdbbase->linkList);
+        plinkSup; plinkSup = (linkSup *) ellNext(&plinkSup->node)) {
+	fprintf(fp, "link(%s,%s)\n", plinkSup->name, plinkSup->lset_name);
+    }
+    return 0;
+}
+
 long dbWriteRegistrarFP(DBBASE *pdbbase,FILE *fp)
 {
     dbText	*ptext;
@@ -3107,6 +3128,12 @@ char * dbGetRelatedField(DBENTRY *psave)
     return(rtnval);
 }
 
+linkSup* dbFindLinkSup(dbBase *pdbbase, const char *name) {
+    GPHENTRY *pgph = gphFind(pdbbase->pgpHash,name,&pdbbase->linkList);
+    if (!pgph) return NULL;
+    return (linkSup *) pgph->userPvt;
+}
+
 int  dbGetNLinks(DBENTRY *pdbentry)
 {
     dbRecordType	*precordType = pdbentry->precordType;
@@ -3460,6 +3487,15 @@ void  dbDumpDriver(DBBASE *pdbbase)
     dbWriteDriverFP(pdbbase,stdout);
 }
 
+void  dbDumpLink(DBBASE *pdbbase)
+{
+    if(!pdbbase) {
+	fprintf(stderr,"pdbbase not specified\n");
+	return;
+    }
+    dbWriteLinkFP(pdbbase,stdout);
+}
+
 void  dbDumpRegistrar(DBBASE *pdbbase)
 {
     if(!pdbbase) {

src/ioc/dbStatic/dbStaticLib.h

@@ -99,6 +99,7 @@ epicsShareFunc long dbWriteDeviceFP(DBBASE *pdbbase, FILE *fp);
 epicsShareFunc long dbWriteDriver(DBBASE *pdbbase,
     const char *filename);
 epicsShareFunc long dbWriteDriverFP(DBBASE *pdbbase, FILE *fp);
+epicsShareFunc long dbWriteLinkFP(DBBASE *pdbbase, FILE *fp);
 epicsShareFunc long dbWriteRegistrarFP(DBBASE *pdbbase, FILE *fp);
 epicsShareFunc long dbWriteFunctionFP(DBBASE *pdbbase, FILE *fp);
 epicsShareFunc long dbWriteVariableFP(DBBASE *pdbbase, FILE *fp);
@@ -208,6 +209,9 @@ epicsShareFunc drvSup * dbFindDriver(dbBase *pdbbase,
     const char *name);
 epicsShareFunc char * dbGetRelatedField(DBENTRY *pdbentry);
 
+epicsShareFunc linkSup * dbFindLinkSup(dbBase *pdbbase,
+    const char *name);
+
 epicsShareFunc int  dbGetNLinks(DBENTRY *pdbentry);
 epicsShareFunc long dbGetLinkField(DBENTRY *pdbentry, int index);
 epicsShareFunc int  dbGetLinkType(DBENTRY *pdbentry);
@@ -227,6 +231,7 @@ epicsShareFunc void dbDumpField(DBBASE *pdbbase,
 epicsShareFunc void dbDumpDevice(DBBASE *pdbbase,
     const char *recordTypeName);
 epicsShareFunc void dbDumpDriver(DBBASE *pdbbase);
+epicsShareFunc void dbDumpLink(DBBASE *pdbbase);
 epicsShareFunc void dbDumpRegistrar(DBBASE *pdbbase);
 epicsShareFunc void dbDumpFunction(DBBASE *pdbbase);
 epicsShareFunc void dbDumpVariable(DBBASE *pdbbase);

src/ioc/dbStatic/dbYacc.y

@@ -20,7 +20,7 @@ static int yyAbort = 0;
 %token tokenINCLUDE tokenPATH tokenADDPATH
 %token tokenALIAS tokenMENU tokenCHOICE tokenRECORDTYPE
 %token tokenFIELD tokenINFO tokenREGISTRAR
-%token tokenDEVICE tokenDRIVER tokenBREAKTABLE
+%token tokenDEVICE tokenDRIVER tokenLINK tokenBREAKTABLE
 %token tokenRECORD tokenGRECORD tokenVARIABLE tokenFUNCTION
 %token <Str> tokenSTRING tokenCDEFS
 
@@ -46,6 +46,7 @@ database_item:	include
 	|	tokenRECORDTYPE recordtype_head recordtype_body
 	|	device
 	|	driver
+	|	link
 	|	registrar
 	|	function
 	|	variable
@@ -162,6 +163,13 @@ driver: tokenDRIVER '(' tokenSTRING ')'
 	dbDriver($3); dbmfFree($3);
 };
 
+link: tokenLINK '(' tokenSTRING ',' tokenSTRING ')'
+{
+	if(dbStaticDebug>2) printf("link %s %s\n",$3,$5);
+	dbLinkType($3,$5);
+	dbmfFree($3); dbmfFree($5);
+};
+
 registrar: tokenREGISTRAR '(' tokenSTRING ')'
 {
 	if(dbStaticDebug>2) printf("registrar %s\n",$3);

src/std/Makefile

@@ -20,6 +20,7 @@ dbRecStd_RCS += dbRecStd.rc
 include $(STDDIR)/rec/Makefile
 include $(STDDIR)/dev/Makefile
 include $(STDDIR)/filters/Makefile
+include $(STDDIR)/link/Makefile
 include $(STDDIR)/softIoc/Makefile
 
 include $(TOP)/configure/RULES

src/std/link/Makefile

@@ -0,0 +1,17 @@
+#*************************************************************************
+# Copyright (c) 2016 UChicago Argonne LLC, as Operator of Argonne
+#     National Laboratory.
+# EPICS BASE is distributed subject to a Software License Agreement found
+# in file LICENSE that is included with this distribution. 
+#*************************************************************************
+
+# This is a Makefile fragment, see src/std/Makefile.
+
+SRC_DIRS += $(STDDIR)/link
+
+DBD += links.dbd
+
+# dbRecStd_SRCS += ...
+
+HTMLS += links.html
+

src/std/link/links.dbd.pod

@@ -0,0 +1,92 @@
+=head1 Link Types
+
+Links are an extensible mechanism for adding new kinds of database link,
+using JSON for link addresses.
+The following link types are available in this release:
+
+=over
+
+=item * L<Constant|/"Constant Link const">
+
+=item * L<Database|/"Database Link db">
+
+=item * L<Channel Access|/"Channel Access Link ca">
+
+=back
+
+=head2 Using Links
+
+...
+must appear inside a pair of braces C< {} > expressed as a JSON
+(L<JavaScript Object Notation|http://www.json.org/>) object, which allows link
+parameters to be defined as needed.
+
+Note that due to the required presence of the double-quote characters in the
+JSON strings in a link field value string in a database file, it will usually
+be necessary to escape all double-quote characters in the JSON object by
+preceding them with a backslash C< \ > character.
+Database configuration tools that support this link mechanism must be careful
+to handle these escapes correctly on reading and writing string values from/to
+a .db file.
+
+=head2 Filter Reference
+
+=cut
+
+link(const,lsetConst)
+
+=head3 Constant Link C<"const">
+
+...
+
+=head4 Parameters
+
+...
+
+=head4 Example
+
+ ...
+
+=cut
+
+link(db,lsetDatabase)
+
+=head3 Database Link C<"db">
+
+...
+
+=head4 Parameters
+
+...
+
+=head4 Example
+
+ ...
+
+=cut
+
+link(ca,lsetChannelAccess)
+
+=head3 Channel Access Link C<"ca">
+
+...
+
+=head4 Parameters
+
+...
+
+=over
+
+=item ...
+
+...
+
+=back
+
+...
+
+=head4 Example
+
+ ...
+
+=cut

src/std/softIoc/RULES

@@ -9,8 +9,10 @@
 
 softIoc.dbd$(DEP): $(COMMON_DIR)/stdRecords.dbd
 softIoc.dbd$(DEP): $(COMMON_DIR)/filters.dbd
+softIoc.dbd$(DEP): $(COMMON_DIR)/links.dbd
 $(COMMON_DIR)/softIoc.dbd: $(COMMON_DIR)/stdRecords.dbd
 $(COMMON_DIR)/softIoc.dbd: $(COMMON_DIR)/filters.dbd
+$(COMMON_DIR)/softIoc.dbd: $(COMMON_DIR)/links.dbd
 $(COMMON_DIR)/softIoc.dbd: $(STDDIR)/softIoc/Makefile
 
 softMain$(DEP): epicsInstallDir.h

src/std/softIoc/base.dbd

@@ -16,6 +16,9 @@ include "stdRecords.dbd"
 # Channel filters & plugins
 include "filters.dbd"
 
+# Link types
+include "links.dbd"
+
 # Standard device support
 include "devSoft.dbd"
 

src/tools/DBD.pm

@@ -6,6 +6,7 @@ use warnings;
 use DBD::Base;
 use DBD::Breaktable;
 use DBD::Driver;
+use DBD::Link;
 use DBD::Menu;
 use DBD::Recordtype;
 use DBD::Recfield;
@@ -21,6 +22,7 @@ sub new {
     my $this = {
         'DBD::Breaktable' => {},
         'DBD::Driver'     => {},
+	'DBD::Link'       => {},
         'DBD::Function'   => {},
         'DBD::Menu'       => {},
         'DBD::Recordtype' => {},
@@ -80,6 +82,10 @@ sub drivers {
     return shift->{'DBD::Driver'};
 }
 
+sub links {
+    return shift->{'DBD::Link'};
+}
+
 sub functions {
     return shift->{'DBD::Function'};
 }

src/tools/DBD/Link.pm

@@ -0,0 +1,22 @@
+package DBD::Link;
+use DBD::Base;
+@ISA = qw(DBD::Base);
+
+sub init {
+    my ($this, $name, $lset) = @_;
+    $this->SUPER::init($lset, "link support (lset)");
+    $this->{KEY} = $name;
+    return $this;
+}
+
+sub key {
+    return shift->{KEY};
+}
+
+sub equals {
+    my ($a, $b) = @_;
+    return $a->SUPER::equals($b)
+        && $a->{KEY} eq $b->{KEY};
+}
+
+1;

src/tools/DBD/Output.pm

@@ -13,6 +13,7 @@ use DBD::Base;
 use DBD::Breaktable;
 use DBD::Device;
 use DBD::Driver;
+use DBD::Link;
 use DBD::Menu;
 use DBD::Recordtype;
 use DBD::Recfield;
@@ -26,6 +27,7 @@ sub OutputDBD {
     OutputMenus($out, $dbd->menus);
     OutputRecordtypes($out, $dbd->recordtypes);
     OutputDrivers($out, $dbd->drivers);
+    OutputLinks($out, $dbd->links);
     OutputRegistrars($out, $dbd->registrars);
     OutputFunctions($out, $dbd->functions);
     OutputVariables($out, $dbd->variables);
@@ -78,6 +80,13 @@ sub OutputDrivers {
         foreach keys %{$drivers};
 }
 
+sub OutputLinks {
+    my ($out, $links) = @_;
+    while (my ($name, $link) = each %{$links}) {
+        printf $out "link(%s, %s)\n", $link->key, $name;
+    }
+}
+
 sub OutputRegistrars {
     my ($out, $registrars) = @_;
     printf $out "registrar(%s)\n", $_

src/tools/DBD/Parser.pm

@@ -13,6 +13,7 @@ use DBD::Base;
 use DBD::Breaktable;
 use DBD::Device;
 use DBD::Driver;
+use DBD::Link;
 use DBD::Menu;
 use DBD::Recordtype;
 use DBD::Recfield;
@@ -37,6 +38,11 @@ sub ParseDBD {
             my ($driver_name) = unquote($1);
             $dbd->add(DBD::Driver->new($driver_name));
         }
+        elsif (m/\G link \s* \( \s* $RXstr \s*, \s* $RXstr \s* \)/oxgc) {
+            print "Link $1, $2\n" if $debug;
+            my ($key, $lset) = unquote($1, $2);
+            $dbd->add(DBD::Link->new($key, $lset));
+        }
         elsif (m/\G registrar \s* \( \s* $RXstr \s* \)/oxgc) {
             print "Registrar: $1\n" if $debug;
             my ($registrar_name) = unquote($1);

src/tools/Makefile

@@ -23,6 +23,7 @@ PERL_MODULES += DBD/Base.pm
 PERL_MODULES += DBD/Breaktable.pm
 PERL_MODULES += DBD/Device.pm
 PERL_MODULES += DBD/Driver.pm
+PERL_MODULES += DBD/Link.pm
 PERL_MODULES += DBD/Function.pm
 PERL_MODULES += DBD/Menu.pm
 PERL_MODULES += DBD/Output.pm