Changes:
1. Enabling IN/OUT/INOUT mode for sql_mode=DEFAULT,
adding tests for sql_mode=DEFAULT based by mostly
translating compat/oracle.sp-inout.test to SQL/PSM
with minor changes (e.g. testing trigger OLD.column and
NEW.column as IN/OUT parameters).
2. Removing duplicate grammar:
sp_pdparam and sp_fdparam implemented exactly the same syntax after
- the first patch for MDEV-10654 (for sql_mode=ORACLE)
- the change #1 from this patch (for sql_mode=DEFAULT)
Removing separate rules and adding a single "sp_param" rule instead,
which now covers both PRDEDURE and FUNCTION parameters
(and CURSOR parameters as well!).
3. Adding a helper rule sp_param_name_and_mode, which is a combination
of the parameter name and the IN/OUT/INOUT mode. It allows to simplify
the grammer a bit.
4. The first patch unintentionally allowed IN/OUT/INOUT mode
to be specified in CURSOR parameters.
This is good for the IN keyword - it is allowed in PL/SQL CURSORs.
This is not good the the OUT/INOUT keywords - they should not be allowed.
Adding a additional symantic post-check.
Changing the way how a cursor is opened to fetch its structure only,
e.g. for a cursor FOR loop record variable.
The old methods with setting thd->lex->limit_rows_examined to an Item_uint(0)
was not reliable and could push these messages into diagnostics area:
The query examined at least 1 rows, which exceeds LIMIT ROWS EXAMINED (0)
The new method should be more reliable, as it completely prevents the call
of do_select() in JOIN::exec_inner() during the cursor structure discovery,
so the execution of the cursor SELECT query returns immediately after the
preparation step (when the result row structure becomes known),
without even entering the code that fetches the result rows.
Parse context frames (sp_pcontext) can have holes in variable run-time offsets,
the missing offsets reside on the children contexts in such cases.
Example:
CREATE PROCEDURE p1() AS
x0 INT:=100; -- context 0, position 0, run-time 0
CURSOR cur(
p0 INT, -- context 1, position 0, run-time 1
p1 INT -- context 1, position 1, run-time 2
) IS SELECT p0, p1;
x1 INT:=101; -- context 0, position 1, run-time 3
BEGIN
...
END;
Fixing a few methods to take this into account:
- sp_pcontext::find_variable()
- sp_pcontext::retrieve_field_definitions()
- LEX::sp_variable_declarations_init()
- LEX::sp_variable_declarations_finalize()
- LEX::sp_variable_declarations_rowtype_finalize()
- LEX::sp_variable_declarations_with_ref_finalize()
Adding a convenience method:
sp_pcontext::get_last_context_variable(uint offset_from_the_end);
to access variables from the end, rather than from the beginning.
This helps to loop through the context variable array (m_vars)
on the fragment that does not have any holes.
Additionally, renaming sp_pcontext::find_context_variable() to
sp_pcontext::get_context_variable(). This method simply returns
the variable by its index. So let's rename to avoid assumptions
that some heavy lookup is going on inside.
The bug was introduced in the patch for "MDEV-10597 Cursors with parameters".
The LEX created in assignment_source_expr was not put into
thd->lex->sphead->m_lex (the stack of LEX'es), so syntax error in "expr"
caused a wrong memory cleanup in sp_head::~sp_head().
The fix changes the code to use sp_head::push_lex() followed by
sp_head::restore_lex(), like it happens in all other similar cases.
