MDEV-38329: Named Parameters in Invocation of Stored Routines

[rajatmohan22]

MDEV-38329: Named Parameters in Invocation of Stored Routines

Description

This a draft PR begins implimentation of support for named parameters in stored routine invocation, for ex:

CALL proc(param3 => 10, param5 => 'foo');
SELECT func(param2 => 3.1415);

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Current State

right now CALL arguments are parsed strictly as positional expressions -

• CALL → opt_sp_cparam_list → sp_cparams
• Each argument is parsed as expr
• Arguments are pushed into Lex->value_list
• Binding in sp_head::execute_procedure() is strictly positional

There is no syntax of argument names and no name-based resolution. This PR starts adding support for ident => expr syntax.

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Current Commit (WIP)

Commit 1: Introduce CALL parameter structure

Adds a Call_param structure in LEX:
LEX_CSTRING name
Item *value
Adds List<Call_param> call_param_list

Clears call_param_list in call_statement_start()

No functional changes yet.
Parser and binding logic remain unchanged.

This commit prepares the LEX layer to store named arguments in addition to positional ones.

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Planned Implementation Steps

The remaining work to follow in additional commits in this PR:

1. Extend grammar in sql/sql_yacc.yy to allow both expr and ident => expr inside routine argument lists.

2. Represent CALL arguments as structured entries instead of raw Item* only, e.g. { name, Item* } where name is empty for positional arguments.

3. Add a resolution step before calling sp_head::execute_procedure(thd, &args). This step will:

• Resolve named arguments using sp_pcontext / sp_variable
• Preserve positional arguments (positional first, then named)
• Apply default values for omitted parameters
• Error on unknown parameter names, duplicate parameters, and missing required parameters

4. Add MTR tests covering procedures, stored functions, mixed positional + named usage, and error cases.

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Design Direction

Resolution will occur before invoking execute_procedure() so that the existing positional binding logic — adjust_formal_params_to_actual_params() and bind_input_param() — can remain largely unchanged.

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This PR is opened as a draft for early feedback on approach before implementing grammar and resolution logic.

[CLAassistant]

All committers have signed the CLA.

[rajatmohan22]

@abarkov @gkodinov hello,

I’ve pushed the initial groundwork for MDEV-38329 (introducing the Call_param structure in LEX and wiring it into call_statement_start(), no functional changes yet).

I’m currently continuing to research the execution and binding flow carefully before moving to the next step. I’d really appreciate your feedback when you have a moment and your help in keeping tabs on this PR so I stay aligned with the intended direction.

Thank you very much.