This skill is the authoritative reference for IDA's type system as exposed through idasql. For annotation workflows that use types, see annotations. For decompiler-specific type interactions (ctree, lvars, union selection, numform), see decompiler.

Trigger Intents

Use this skill when user asks to:

create/edit structs, unions, enums, typedefs
inspect function prototype argument types
resolve hidden pointer/typedef behavior
apply or refine recovered data models

Route to:

decompiler for expression-level type context
annotations for applying and documenting type decisions
re-source for recursive structure-recovery workflows

Do This First (Warm-Start Sequence)

-- 1) Inventory local types
SELECT ordinal, name, kind, size
FROM types
ORDER BY ordinal
LIMIT 30;

-- 2) Large/high-signal structs
SELECT name, size
FROM types
WHERE is_struct = 1
ORDER BY size DESC
LIMIT 20;

-- 3) Prototype introspection sample
SELECT type_name, arg_index, arg_name, arg_type
FROM types_func_args
WHERE arg_index >= 0
LIMIT 40;

Interpretation guidance:

Start with inventory and prioritize large/high-fanout types.
Use types_func_args resolved fields for typedef-aware reasoning.

Failure and Recovery

Type insert/update failed:
- Validate declaration syntax and target ordinal/name existence.
Conflicting/incomplete type picture:
- Correlate with decompiler (ctree_lvars, call args) before committing changes.
Unexpected disassembly rendering:
- Re-check operand format settings and applied declarations.

Handoff Patterns

types -> decompiler to validate semantic effect in pseudocode.
types -> annotations for naming/comments on newly typed fields.
types -> re-source for multi-function struct refinement.

Type Tables

local_types

Local type declarations as stored in the database. Use this for quick inventory/filtering of local types; use types* tables for deeper editing workflows.

Column	Type	Description
`ordinal`	INT	Type ordinal (local type ID)
`name`	TEXT	Type name
`type`	TEXT	Declared type text
`is_struct`	INT	1=struct
`is_enum`	INT	1=enum
`is_typedef`	INT	1=typedef

-- Quick local type inventory
SELECT ordinal, name, type FROM local_types ORDER BY ordinal LIMIT 50;

For canonical schema and owner mapping, see ../connect/references/schema-catalog.md (local_types).

types

All local type definitions. Supports INSERT (create struct/union/enum), UPDATE, and DELETE.

Column	Type	Description
`ordinal`	INT	Type ordinal (unique identifier)
`name`	TEXT	Type name
`size`	INT	Size in bytes
`kind`	TEXT	struct/union/enum/typedef/func
`is_struct`	INT	1=struct
`is_union`	INT	1=union
`is_enum`	INT	1=enum

-- List all structs
SELECT ordinal, name, size FROM types WHERE is_struct = 1 ORDER BY size DESC;

-- List all enums
SELECT ordinal, name FROM types WHERE is_enum = 1;

-- Find types by name pattern
SELECT * FROM types WHERE name LIKE '%CONTEXT%';

Creating Types

-- Create a struct
INSERT INTO types (name, kind) VALUES ('MY_HEADER', 'struct');

-- Create a union
INSERT INTO types (name, kind) VALUES ('PARAM_UNION', 'union');

-- Create an enum
INSERT INTO types (name, kind) VALUES ('CMD_TYPE', 'enum');

-- Verify creation (get the assigned ordinal)
SELECT ordinal, name, kind FROM types WHERE name = 'MY_HEADER';

Deleting Types

-- Delete a type by name
DELETE FROM types WHERE name = 'MY_HEADER';

-- Delete by ordinal
DELETE FROM types WHERE ordinal = 42;

types_members

Structure and union members. Supports INSERT, UPDATE, and DELETE.

Column	Type	Description
`type_ordinal`	INT	Parent type ordinal
`type_name`	TEXT	Parent type name
`member_name`	TEXT	Member name
`offset`	INT	Byte offset
`size`	INT	Member size
`member_type`	TEXT	Type string (e.g., `int`, `void *`, `char[256]`)
`mt_is_ptr`	INT	1=pointer
`mt_is_array`	INT	1=array
`mt_is_struct`	INT	1=embedded struct

-- View members of a struct
SELECT member_name, member_type, offset, size
FROM types_members WHERE type_name = 'MY_HEADER'
ORDER BY offset;

-- Add members (member_type supports: int, void *, char[64], etc.)
INSERT INTO types_members (type_ordinal, member_name, member_type)
VALUES (42, 'magic', 'unsigned int');
INSERT INTO types_members (type_ordinal, member_name, member_type)
VALUES (42, 'data_ptr', 'void *');

-- Rename/retype a member
UPDATE types_members SET member_name = 'signature'
WHERE type_ordinal = 42 AND member_name = 'magic';
UPDATE types_members SET member_type = 'DWORD'
WHERE type_ordinal = 42 AND member_name = 'signature';

-- Delete a member
DELETE FROM types_members
WHERE type_ordinal = 42 AND member_name = 'reserved';

types_enum_values

Enum constant values. Supports INSERT, UPDATE, and DELETE.

Column	Type	Description
`type_ordinal`	INT	Enum type ordinal
`type_name`	TEXT	Enum name
`value_name`	TEXT	Constant name
`value`	INT	Constant value

-- View enum values
SELECT value_name, value FROM types_enum_values
WHERE type_name = 'CMD_TYPE'
ORDER BY value;

-- Add enum values (optional comment column supported)
INSERT INTO types_enum_values (type_ordinal, value_name, value)
VALUES (50, 'CMD_INIT', 0);
INSERT INTO types_enum_values (type_ordinal, value_name, value)
VALUES (50, 'CMD_READ', 1);

-- Rename / delete enum values
UPDATE types_enum_values SET value_name = 'CMD_OPEN'
WHERE type_ordinal = 50 AND value_name = 'CMD_INIT';
DELETE FROM types_enum_values
WHERE type_ordinal = 50 AND value_name = 'CMD_READ';

types_func_args

Function prototype arguments with deep type classification.

Column	Type	Description
`type_ordinal`	INT	Function type ordinal
`type_name`	TEXT	Function type name
`arg_index`	INT	Argument index (-1 = return type, 0+ = args)
`arg_name`	TEXT	Argument name
`arg_type`	TEXT	Argument type string
`calling_conv`	TEXT	Calling convention (on return row only)

Surface-Level Type Classification

Literal type as written — what you see in the declaration:

Column	Description
`is_ptr`	1 if pointer type
`is_int`	1 if exactly `int`
`is_integral`	1 if int-like (int, long, short, char, bool)
`is_float`	1 if float/double
`is_void`	1 if void
`is_struct`	1 if struct/union
`is_array`	1 if array
`ptr_depth`	Pointer depth (int** = 2)
`base_type`	Type with pointers stripped

Resolved Type Classification

After typedef resolution — what the type actually is:

Column	Description
`is_ptr_resolved`	1 if resolved type is pointer
`is_int_resolved`	1 if resolved type is exactly int
`is_integral_resolved`	1 if resolved type is int-like
`is_float_resolved`	1 if resolved type is float/double
`is_void_resolved`	1 if resolved type is void
`ptr_depth_resolved`	Pointer depth after resolution
`base_type_resolved`	Resolved type with pointers stripped

This dual classification is critical for typedef-aware queries. For example, HANDLE appears as non-pointer at surface level but resolves to void *.

-- Typedefs that hide pointers (HANDLE, HMODULE, etc.)
SELECT DISTINCT type_name, arg_type, base_type_resolved
FROM types_func_args
WHERE is_ptr = 0 AND is_ptr_resolved = 1;

-- Functions with struct parameters
SELECT type_name, arg_name, arg_type FROM types_func_args
WHERE arg_index >= 0 AND is_struct = 1;

For more types_func_args query patterns (string parameters, pointer counts, return type filters), see references/type-patterns.md.

Type Views

Convenience views for filtering types:

View	Description
`types_v_structs`	`SELECT * FROM types WHERE is_struct = 1`
`types_v_unions`	`SELECT * FROM types WHERE is_union = 1`
`types_v_enums`	`SELECT * FROM types WHERE is_enum = 1`
`types_v_typedefs`	`SELECT * FROM types WHERE is_typedef = 1`
`types_v_funcs`	`SELECT * FROM types WHERE is_func = 1`
`types_v_inheritance`	Struct/class inheritance relationships (baseclasses from `types_members`)

`types_v_inheritance` view

Shows struct/class inheritance relationships extracted from baseclass members.

Column	Type	Description
`derived_ordinal`	INT	Ordinal of the derived type
`derived_name`	TEXT	Name of the derived type
`base_type_name`	TEXT	Name of the base type
`base_ordinal`	INT	Ordinal of the base type
`base_offset`	INT	Byte offset of the base within the derived type

-- Find base classes of a type
SELECT * FROM types_v_inheritance WHERE derived_name = 'MyClass';

-- Recursive ancestors
WITH RECURSIVE ancestors(name, depth) AS (
    SELECT base_type_name, 1 FROM types_v_inheritance WHERE derived_name = 'MyClass'
    UNION ALL
    SELECT i.base_type_name, a.depth + 1
    FROM types_v_inheritance i JOIN ancestors a ON i.derived_name = a.name
    WHERE a.depth < 10
)
SELECT * FROM ancestors;

Importing C Declarations (parse_decls)

parse_decls(text) imports C declarations into the local type library. This is the most powerful way to seed types.

-- Import a simple struct
SELECT parse_decls('
struct MY_HEADER {
    unsigned int magic;
    unsigned int version;
    unsigned int size;
    void *data;
};
');

-- Import with pragmas for packing (enums, typedefs, nested unions)
SELECT parse_decls('
#pragma pack(push, 1)
typedef enum operations_e { op_empty=0, op_open=11, op_read=22 } operations_e;
typedef struct command_t { operations_e cmd_id; unsigned __int64 ret; } command_t;
#pragma pack(pop)
');

-- Verify imported types
SELECT name, kind, size FROM types WHERE name IN ('command_t', 'operations_e');

For a full multi-struct parse_decls example with nested unions, see references/type-patterns.md.

Applying Types to Functions and Variables

Function Prototypes

-- Apply type to function via prototype column
UPDATE funcs SET prototype = 'void __fastcall exec_command(command_t *cmd);'
WHERE address = 0x140001BD0;

-- Apply via set_type function
SELECT set_type(0x140001BD0, 'void __fastcall exec_command(command_t *cmd);');

-- Read current type at address
SELECT type_at(0x140001BD0);

-- Clear type (reset to auto-detected)
SELECT set_type(0x140001BD0, '');

-- Re-decompile to see effect
SELECT decompile(0x140001BD0, 1);

Local Variables

-- Change local variable type
UPDATE ctree_lvars SET type = 'MY_HEADER *'
WHERE func_addr = 0x401000 AND idx = 0;

-- Change and verify
SELECT decompile(0x401000, 1);
SELECT idx, name, type FROM ctree_lvars
WHERE func_addr = 0x401000 AND idx = 0;

Call Sites

Use call-site typing for indirect calls when function prototypes and local-variable types still leave a specific call under-typed.

-- Discover indirect call sites first
SELECT call_ea, target_op, target_var_name, arg_count
FROM ctree_v_indirect_calls
WHERE func_addr = 0x140001BD0
ORDER BY call_ea;

-- Apply a prototype to one call site
SELECT apply_callee_type(
  0x140001C3E,
  'int __fastcall emit_message(const char *name, const char *target, int flag, const char *tag);'
);

-- Verify the persisted call-site typing
SELECT callee_type_at(0x140001C3E);
SELECT call_arg_addrs(0x140001C3E);
SELECT decompile(0x140001BD0, 1);

Typing Surfaces Matrix

Surface	Scope	Semantic vs render-only	Typical use
`UPDATE funcs SET prototype = ...` / `set_type()`	Function/global address	Semantic	Give a function or global the right declared type
`UPDATE ctree_lvars SET type = ...`	One decompiled local/arg	Semantic	Clean up local pointer/struct inference
`apply_callee_type(call_ea, decl)`	One call site	Semantic	Fix an indirect call when the callee prototype must be explicit
`instructions.operand*_format_spec`	One disassembly operand	Render-only	Show enums/struct offsets in listing output
`set_union_selection*`	One decompiler expression	Render-only	Choose a union arm for nicer pseudocode
`set_numform*`	One decompiler expression operand	Render-only	Change numeric rendering without changing base type

Names

-- Set a name at address
SELECT set_name(0x402000, 'g_config');

Struct Offset Representation in Disassembly

The instructions table operand*_format_spec column applies struct offset display to disassembly operands:

-- Apply struct-offset: makes `[rax+10h]` display as `[rax+MY_STRUCT.field_name]`
UPDATE instructions SET operand0_format_spec = 'stroff:MY_STRUCT,delta=0'
WHERE address = 0x401030;

-- Apply enum: `enum:CMD_TYPE`; clear back to plain: `clear`
UPDATE instructions SET operand1_format_spec = 'enum:CMD_TYPE'
WHERE address = 0x401020;

Enum/Union Rendering in Decompiled Code

For numform helpers (set_numform*) and union selection helpers (set_union_selection*), see decompiler skill.

apply_callee_type belongs on the semantic side of the fence: it affects call analysis, unlike render-only enum/union formatting helpers.

Performance Rules

Table	Architecture	Key Constraint	Notes
`types`	Cached	`ordinal` (optional)	Full cache rebuilt on demand; usually fast (<1000 types)
`types_members`	Cached	`type_ordinal`	O(1) lookup with constraint; without it iterates all types
`types_enum_values`	Cached	`type_ordinal`	O(1) lookup with constraint
`types_func_args`	Cached	`type_ordinal`	O(1) lookup with constraint

Key rules:

type_ordinal constraint pushdown gives O(1) access to a single type's members, enum values, or func args.
Without constraint, these tables iterate all local types. This is usually fast (most binaries have <1000 local types), but prefer filtered queries when you know the target.
Type views (types_v_structs, etc.) are pre-filtered — use them for categorical queries.
parse_decls() is the fastest way to seed multiple types at once (single call vs multiple INSERTs).

Related Skills

annotations — Workflow expert: how to combine type application with renaming and commenting
decompiler — Deep ctree mechanics, union selection, numform, mutation loop
re-source — Structure recovery methodology from offset casts

Additional Resources

For complete type workflow examples and advanced CTE patterns: references/type-patterns.md

types

Trigger Intents

Do This First (Warm-Start Sequence)

Failure and Recovery

Handoff Patterns

Type Tables

local_types

types

Creating Types

Deleting Types

types_members

types_enum_values

types_func_args

Surface-Level Type Classification

Resolved Type Classification

Type Views

`types_v_inheritance` view

Importing C Declarations (parse_decls)

Applying Types to Functions and Variables

Function Prototypes

Local Variables

Call Sites

Typing Surfaces Matrix

Names

Struct Offset Representation in Disassembly

Enum/Union Rendering in Decompiled Code

Performance Rules

Related Skills

Additional Resources

More from allthingsida/idasql-skills

disassembly

storage

ui-context

data

idapython

types

Trigger Intents

Do This First (Warm-Start Sequence)

Failure and Recovery

Handoff Patterns

Type Tables

local_types

types

Creating Types

Deleting Types

types_members

types_enum_values

types_func_args

Surface-Level Type Classification

Resolved Type Classification

Type Views

types_v_inheritance view

Importing C Declarations (parse_decls)

Applying Types to Functions and Variables

Function Prototypes

Local Variables

Call Sites

Typing Surfaces Matrix

Names

Struct Offset Representation in Disassembly

Enum/Union Rendering in Decompiled Code

Performance Rules

Related Skills

Additional Resources

More from allthingsida/idasql-skills

disassembly

storage

ui-context

data

idapython

`types_v_inheritance` view