a ".pgc " extension. The second patch fixes a coredump when there is
more than one input file (in that case, cur and types were not set to
NULL before processing the second f ile)
The patch below modifies the accepted grammar of ecpg to accept
FETCH [direction] [amount] cursor name
i.e. the IN|FROM clause becomes optional (as in Oracle and Informix).
This removes the incompatibility mentioned in section "Porting From
Other RDBMS Packages" p169, PostgreSQL Programmer's Guide. The grammar
is modified in such a way as to avoid shift/reduce conflicts. It does
not accept the statement "EXEC SQL FETCH;" anymore, as the old grammar
did (this seems to be a bug of the old grammar anyway).
This patch cleans up the handling of space characters in the scanner;
some patte rns require \n to be in {space}, some do not. A second fix is
the handling of cpp continuati on lines; the old pattern did not match
these. The parser is patched to fix an off-by-one error in the #line
directives. The pa rser is also enhanced to report the correct location
of errors in declarations in the "E XEC SQL DECLARE SECTION". Finally,
some right recursions in the parser were replaced by left-recursions.
This patch adds preprocessor directives to ecpg; in particular
EXEC SQL IFDEF, EXEC SQL IFNDEF, EXEC SQL ELSE, EXEC SQL ELIF and EXEC SQL ENDIF
"EXEC SQL IFDEF" is used with defines made with "EXEC SQL DEFINE" and
defines, specified on the command line with -D. Defines, specified on
the command line are persistent across multiple input files. Defines can
be nested up to a maximum level of 128 (see patch). There is a fair
amount of error checking to make sure directives are matched properly. I
need preprocessor directives for porting code, that is written for an
Informix database, to a PostgreSQL database, while maintaining
compatibility with the original code. I decided not to extend the
already large ecpg grammar. Everything is done in the scanner by adding
some states, e.g. to skip all input except newlines and directives. The
preprocessor commands are compatible with Informix. Oracle uses a cpp
replacement.
Rene Hogendoorn
functions. One problem that I have encountered with the function
manager is that it does not allow the user to define type conversion
functions that convert between user types. For instance if mytype1,
mytype2, and mytype3 are three Postgresql user types, and if I wish to
define Postgresql conversion functions like
I run into problems, because the Postgresql dynamic loader would look
for a single link symbol, mytype3, for both pieces of object code. If
I just change the name of one of the Postgresql functions (to make the
symbols distinct), the automatic type conversion that Postgresql uses,
for example, when matching operators to arguments no longer finds the
type conversion function.
The solution that I propose, and have implemented in the attatched
patch extends the CREATE FUNCTION syntax as follows. In the first case
above I use the link symbol mytype2_to_mytype3 for the link object
that implements the first conversion function, and define the
Postgresql operator with the following syntax
The patch includes changes to the parser to include the altered
syntax, changes to the ProcedureStmt node in nodes/parsenodes.h,
changes to commands/define.c to handle the extra information in the AS
clause, and changes to utils/fmgr/dfmgr.c that alter the way that the
dynamic loader figures out what link symbol to use. I store the
string for the link symbol in the prosrc text attribute of the pg_proc
table which is currently unused in rows that reference dynamically
loaded
functions.
Bernie Frankpitt
