Convert RecSup function possible exceptions to dbAccess error codes

modules/database/src/ioc/db/Makefile

@@ -68,6 +68,7 @@ HTMLS += dbCommonOutput.html
 
 dbCore_SRCS += dbLock.c
 dbCore_SRCS += dbAccess.c
+dbCore_SRCS += dbAccessNoThrow.c
 dbCore_SRCS += dbBkpt.c
 dbCore_SRCS += dbChannel.c
 dbCore_SRCS += dbConstLink.c

modules/database/src/ioc/db/dbAccess.c

@@ -38,6 +38,7 @@
 #include "caeventmask.h"
 #include "callback.h"
 #include "dbAccessDefs.h"
+#include "dbAccessNoThrow.h"
 #include "dbAddr.h"
 #include "dbBase.h"
 #include "dbBkpt.h"
@@ -928,7 +929,7 @@ long dbGet(DBADDR *paddr, short dbrType,
         if(!paddr->vfields || !(prset=dbGetRset(paddr))->get_vfield)
             return S_db_badDbrtype;
 
-        return prset->get_vfield(paddr, vfield);
+        return dbRecSupGetVFieldNoThrow(prset, paddr, vfield);
     }
 
     if (nRequest && *nRequest == 0)
@@ -1345,7 +1346,7 @@ long dbPut(DBADDR *paddr, short dbrType,
         if(!paddr->vfields || !prset->put_vfield)
             return S_db_badDbrtype;
 
-        return prset->put_vfield(paddr, vfield);
+        return dbRecSupPutVFieldNoThrow(prset, paddr, vfield);
     }
 
     if (special == SPC_ATTRIBUTE || paddr->ro)

modules/database/src/ioc/db/dbAccessNoThrow.cpp

@@ -0,0 +1,60 @@
+/*************************************************************************\
+* Copyright (c) 2021 Lucas Russo
+* SPDX-License-Identifier: EPICS
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#include <stdexcept>
+
+#include "recSup.h"
+#include "dbAccessDefs.h"
+#include "errlog.h"
+#include "dbAccessNoThrow.h"
+
+/*
+ * Maps possible excpetions to DB error codes. Using the
+ * "exception dispatcher" pattern.
+ */
+inline long dbExceptionToLong()
+{
+    try {
+        throw;
+    }
+    catch (std::exception& e) {
+        errlogPrintf("dbExceptionToLong: Unhandled exception %s: %s\n",
+                typeid(e).name(), e.what());
+        return S_db_errArg;
+    }
+}
+
+/*
+ * Pseudo variadic templates for use without C++11 features
+ */
+
+template <typename F, typename T1, typename T2>
+long dbRecSupNoThrowWrapper(F f, T1 t1, T2 t2) {
+    try {
+        return f(t1, t2);
+    }
+    catch(...){
+        return dbExceptionToLong();
+    }
+}
+
+/*
+ * Wraps all RecordSupport functions from throwable functions to no-throwable ones,
+ * without using C++11 features
+ *
+ * For use with C code
+ */
+
+long dbRecSupGetVFieldNoThrow(rset *prset, struct dbAddr *paddr, struct VField *vfield)
+{
+    return dbRecSupNoThrowWrapper(prset->get_vfield, paddr, vfield);
+}
+
+long dbRecSupPutVFieldNoThrow(rset *prset, struct dbAddr *paddr, const struct VField *vfield)
+{
+    return dbRecSupNoThrowWrapper(prset->put_vfield, paddr, vfield);
+}

modules/database/src/ioc/db/dbAccessNoThrow.h

@@ -0,0 +1,26 @@
+/*************************************************************************\
+* Copyright (c) 2021 Lucas Russo
+* SPDX-License-Identifier: EPICS
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#ifndef INC_dbAccessNoThrow_H
+#define INC_dbAccessNoThrow_H
+
+#include <dbCoreAPI.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+DBCORE_API long dbRecSupGetVFieldNoThrow(rset *prset,
+        struct dbAddr *paddr, struct VField *vfield);
+DBCORE_API long dbRecSupPutVFieldNoThrow(rset *prset,
+        struct dbAddr *paddr, const struct VField *vfield);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* INC_dbAccessNoThrow_H */