diff --git a/doc/src/sgml/pltcl.sgml b/doc/src/sgml/pltcl.sgml new file mode 100644 index d2175d5..1ac7804 *** a/doc/src/sgml/pltcl.sgml --- b/doc/src/sgml/pltcl.sgml *************** CREATE EVENT TRIGGER tcl_a_snitch ON ddl *** 775,780 **** --- 775,903 ---- + + Error Handling in PL/Tcl + + + error handling + in PL/Tcl + + + + All Tcl errors that are allowed to propagate back to the top level of the + interpreter, that is, errors not caught within the stored procedure + using the Tcl catch command will raise a database + error. + + + Tcl code within or called from the stored procedure can choose to + raise a database error by invoking the elog + command provided by PL/Tcl or by generating an error using the Tcl + error command and not catching it with Tcl's + catch command. + + + Database errors that occur from the PL/Tcl stored procedure's + use of spi_exec, spi_prepare, + and spi_execp are also catchable by Tcl's + catch command. + + + Tcl provides an errorCode variable that can + represent additional information about the error in a form that + is easy for programs to interpret. The contents are in Tcl list + format and the first word identifies the subsystem or + library responsible for the error and beyond that the contents are left + to the individual code or library. For example if Tcl's + open command is asked to open a file that doesn't + exist, errorCode + might contain POSIX ENOENT {no such file or directory} + where the third element may vary by locale but the first and second + will not. + + + When spi_exec, spi_prepare + or spi_execp cause a database error to be raised, + that database eror propagates back to Tcl as a Tcl error. + In this case errorCode is set to a list + where the first element is POSTGRES followed by a + copious decoding of the Postgres error structure. Since fields in the + structure may or may not be present depending on the nature of the + error, how the function was invoked, etc, PL/Tcl has adopted the + convention that subsequent elements of the errorCode + list are key-value pairs where the first value is the name of the + field and the second is its value. + + + Fields that may be present include SQLSTATE, + message, detail, + detail_log, hint, + domain, context_domain, + context, schema, + table, column, + datatype, constraint, + cursor_position, internalquery, + internal_position, filename, + lineno and funcname. + + + You might find it useful to load the results into an array. Code + for doing that might look like + + if {[lindex $errorCode 0] == "POSTGRES"} { + array set errorRow [lrange $errorCode 1 end] + } + + + + In the example below we cause an error by attempting to + SELECT from a table that doesn't exist. + + select tcl_eval('spi_exec "select * from foo;"'); + + + + ERROR: relation "foo" does not exist + + + + + Now we examine the error code. (The double-colons explicitly + reference errorCode as a global variable.) + + select tcl_eval('join $::errorCode "\n"'); + + + + tcl_eval + ------------------------------- + POSTGRES + + SQLSTATE + + 42P01 + + message + + relation "foo" does not exist+ + domain + + postgres-9.6 + + context_domain + + postgres-9.6 + + cursorpos + + 0 + + internalquery + + select * from foo; + + internalpos + + 15 + + filename + + parse_relation.c + + lineno + + 1159 + + funcname + + parserOpenTable + (1 row) + + + + + Modules and the <function>unknown</> Command diff --git a/src/pl/tcl/expected/pltcl_setup.out b/src/pl/tcl/expected/pltcl_setup.out new file mode 100644 index e11718c..0592c48 *** a/src/pl/tcl/expected/pltcl_setup.out --- b/src/pl/tcl/expected/pltcl_setup.out *************** NOTICE: tclsnitch: ddl_command_start DR *** 555,557 **** --- 555,605 ---- NOTICE: tclsnitch: ddl_command_end DROP TABLE drop event trigger tcl_a_snitch; drop event trigger tcl_b_snitch; + -- test error handling + /* + * The ugly hack of messsing with the verbosity is because the error context is + * set to the TCL variable errorInfo, which contains some unstable data (namely + * the full name of the TCL function created by the handler, which includes the + * Postgres backend PID). + */ + \set VERBOSITY terse + CREATE OR REPLACE FUNCTION pg_temp.tcl_eval (varchar) RETURNS varchar AS $$ + eval $1 + $$ LANGUAGE pltcl; + select pg_temp.tcl_eval('spi_exec "select * from foo;"'); + ERROR: relation "foo" does not exist + select pg_temp.tcl_eval($$ + set list [lindex $::errorCode 0]; + foreach "key value" [lrange $::errorCode 1 end] { + if {$key == "domain" || $key == "context_domain" || $key == "lineno"} { + regsub -all {[0-9]} $value "" value + } + lappend list $key $value + }; + return [join $list "\n"] + $$); + tcl_eval + ------------------------------- + POSTGRES + + SQLSTATE + + 42P01 + + message + + relation "foo" does not exist+ + domain + + postgres-. + + context_domain + + postgres-. + + cursor_position + + 0 + + internalquery + + select * from foo; + + internal_position + + 15 + + filename + + parse_relation.c + + lineno + + + + funcname + + parserOpenTable + (1 row) + diff --git a/src/pl/tcl/pltcl.c b/src/pl/tcl/pltcl.c new file mode 100644 index 5b27c73..d8a8a89 *** a/src/pl/tcl/pltcl.c --- b/src/pl/tcl/pltcl.c *************** compile_pltcl_function(Oid fn_oid, Oid t *** 1576,1581 **** --- 1576,1673 ---- return prodesc; } + /********************************************************************** + * pltcl_construct_errorCode() - construct a Tcl errorCode + * list with detailed information from the PostgreSQL server + **********************************************************************/ + static void + pltcl_construct_errorCode(Tcl_Interp *interp, ErrorData *edata) + { + Tcl_Obj *obj = Tcl_NewObj(); + + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("POSTGRES", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("SQLSTATE", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(unpack_sql_state(edata->sqlerrcode), -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("message", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->message, -1)); + + if (edata->detail) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("detail", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->detail, -1)); + } + if (edata->detail_log) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("detail_log", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->detail_log, -1)); + } + if (edata->hint) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("hint", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->hint, -1)); + } + if (edata->domain) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("domain", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->domain, -1)); + } + if (edata->context_domain) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("context_domain", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->context_domain, -1)); + } + if (edata->context) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("context", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->context, -1)); + } + if (edata->schema_name) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("schema", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->schema_name, -1)); + } + if (edata->table_name) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("table", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->table_name, -1)); + } + if (edata->column_name) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("column", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->column_name, -1)); + } + if (edata->datatype_name) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("datatype", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->datatype_name, -1)); + } + if (edata->constraint_name) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("constraint", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->constraint_name, -1)); + } + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("cursor_position", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewIntObj(edata->cursorpos)); + if (edata->internalquery) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("internalquery", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->internalquery, -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("internal_position", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewIntObj(edata->internalpos)); + } + if (edata->filename) + { + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("filename", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->filename, -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("lineno", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewIntObj(edata->lineno)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj("funcname", -1)); + Tcl_ListObjAppendElement(interp, obj, Tcl_NewStringObj(edata->funcname, -1)); + } + + Tcl_SetObjErrorCode(interp, obj); + } + /********************************************************************** * pltcl_elog() - elog() support for PLTcl *************** pltcl_elog(ClientData cdata, Tcl_Interp *** 1610,1615 **** --- 1702,1709 ---- level = loglevels[priIndex]; + level = loglevels[priIndex]; + if (level == ERROR) { /* *************** pltcl_elog(ClientData cdata, Tcl_Interp *** 1652,1657 **** --- 1746,1752 ---- UTF_BEGIN; Tcl_SetObjResult(interp, Tcl_NewStringObj(UTF_E2U(edata->message), -1)); UTF_END; + pltcl_construct_errorCode(interp, edata); FreeErrorData(edata); return TCL_ERROR; *************** pltcl_subtrans_abort(Tcl_Interp *interp, *** 1884,1889 **** --- 1979,1985 ---- UTF_BEGIN; Tcl_SetResult(interp, UTF_E2U(edata->message), TCL_VOLATILE); UTF_END; + pltcl_construct_errorCode(interp, edata); FreeErrorData(edata); } diff --git a/src/pl/tcl/sql/pltcl_setup.sql b/src/pl/tcl/sql/pltcl_setup.sql new file mode 100644 index 53358ea..3ee8583 *** a/src/pl/tcl/sql/pltcl_setup.sql --- b/src/pl/tcl/sql/pltcl_setup.sql *************** drop table foo; *** 595,597 **** --- 595,623 ---- drop event trigger tcl_a_snitch; drop event trigger tcl_b_snitch; + + + -- test error handling + + /* + * The ugly hack of messsing with the verbosity is because the error context is + * set to the TCL variable errorInfo, which contains some unstable data (namely + * the full name of the TCL function created by the handler, which includes the + * Postgres backend PID). + */ + \set VERBOSITY terse + CREATE OR REPLACE FUNCTION pg_temp.tcl_eval (varchar) RETURNS varchar AS $$ + eval $1 + $$ LANGUAGE pltcl; + + select pg_temp.tcl_eval('spi_exec "select * from foo;"'); + select pg_temp.tcl_eval($$ + set list [lindex $::errorCode 0]; + foreach "key value" [lrange $::errorCode 1 end] { + if {$key == "domain" || $key == "context_domain" || $key == "lineno"} { + regsub -all {[0-9]} $value "" value + } + lappend list $key $value + }; + return [join $list "\n"] + $$);