C Node Types

C language node type mappings for AST semantic extraction

Language Characteristics

• Low-level systems language: Direct memory access, pointer arithmetic
• Static typing: Compile-time type checking
• Manual memory management: malloc/free, no garbage collection
• Preprocessor: Text substitution before compilation (#include, #define)
• Structs/unions/enums: Aggregate data types (no classes)
• Pointers: First-class support for memory addresses
• Function definitions vs declarations: Prototypes vs implementations
• Storage classes: static, extern, register, auto
• Type qualifiers: const, volatile, restrict
• No function overloading: Each function has unique name

Semantic Type Encoding

Semantic types use 8-bit encoding: - Bits 7-2: Base category (e.g., DEFINITION_FUNCTION = 0x04) - Bits 1-0: Refinement within category

Example: DEFINITION_FUNCTION | SemanticRefinements::Function::REGULAR - Base: 0x04 (function definition) - Refinement: 0x00 (regular function) - Combined: 0x04

Node Categories

• Translation Unit
• Preprocessor Directives
• Declarations
• Type Specifiers
• Statements
• Expressions
• Identifiers and Literals
• Comments
• Storage and Type Qualifiers
• Attributes and Extensions
• Structural Elements
• Punctuation
• Assignment Operators
• Comparison Operators
• Arithmetic Operators
• Logical Operators
• Member Access Operators
• Keywords
• Preprocessor Directive Tokens
• GNU Extensions
• Parser Errors

Translation Unit

Top-level compilation unit

Node Type	Semantic Type	Name Extraction	Description
translation_unit	DEFINITION_MODULE	NONE	Translation unit: the root of a C source file

Preprocessor Directives

C preprocessor constructs (#include, #define, etc.)

The C preprocessor performs text substitution before compilation. These nodes represent preprocessor directives and macro expansions.

Node Type	Semantic Type	Name Extraction	Description
preproc_include	EXTERNAL_IMPORT	Import::MODULE	NODE_TEXT
preproc_def	DEFINITION_VARIABLE	Variable::IMMUTABLE	FIND_IDENTIFIER
preproc_function_def	DEFINITION_FUNCTION	Function::REGULAR	FIND_IDENTIFIER
preproc_call	COMPUTATION_CALL	Call::MACRO	FIND_CALL_TARGET
preproc_if	FLOW_CONDITIONAL	Conditional::BINARY	NONE
preproc_ifdef	FLOW_CONDITIONAL	Conditional::BINARY	FIND_IDENTIFIER
preproc_else	FLOW_CONDITIONAL	Conditional::BINARY	NONE
preproc_elif	FLOW_CONDITIONAL	Conditional::BINARY	NONE
preproc_params	ORGANIZATION_LIST	Organization::COLLECTION	NONE
preproc_arg	METADATA_DIRECTIVE	NODE_TEXT	Preprocessor argument text
defined	METADATA_DIRECTIVE	NODE_TEXT	defined() operator in preprocessor conditionals
preproc_defined	METADATA_DIRECTIVE	NONE	Preprocessor defined check
preproc_directive	METADATA_DIRECTIVE	NODE_TEXT	Generic preprocessor directive

Declarations

Function definitions, variable declarations, type definitions

C distinguishes between declarations (prototypes) and definitions (implementations). Function definitions have bodies (IS_EMBODIED).

Node Type	Semantic Type	Name Extraction	Description
function_definition	DEFINITION_FUNCTION	Function::REGULAR	FIND_IN_DECLARATOR
declaration	DEFINITION_VARIABLE	Variable::MUTABLE	FIND_IDENTIFIER
struct_specifier	DEFINITION_CLASS	Class::REGULAR	FIND_IDENTIFIER
union_specifier	DEFINITION_CLASS	Class::REGULAR	FIND_IDENTIFIER
enum_specifier	DEFINITION_CLASS	Class::ENUM	FIND_IDENTIFIER
typedef_declaration	DEFINITION_CLASS	Class::REGULAR	FIND_IDENTIFIER
type_definition	DEFINITION_CLASS	FIND_IDENTIFIER	Type definition (alternate form)
field_declaration	DEFINITION_VARIABLE	Variable::FIELD	FIND_IDENTIFIER
enumerator	DEFINITION_VARIABLE	Variable::FIELD	FIND_IDENTIFIER
parameter_declaration	DEFINITION_VARIABLE	Variable::PARAMETER	FIND_IDENTIFIER
init_declarator	DEFINITION_VARIABLE	Variable::MUTABLE	FIND_IDENTIFIER

Type Specifiers

Type system nodes

C has primitive types, user-defined types, and compound types built with pointers, arrays, and function types.

Node Type	Semantic Type	Name Extraction	Description
primitive_type	TYPE_PRIMITIVE	NODE_TEXT	Primitive type: int, char, float, double, void, etc.
type_identifier	TYPE_REFERENCE	NODE_TEXT	User-defined type reference: struct/union/enum/typedef name
sized_type_specifier	TYPE_PRIMITIVE	NODE_TEXT	Sized type specifier: long int, short int, etc.
pointer_declarator	TYPE_COMPOSITE	FIND_IDENTIFIER	Pointer declarator: *name
array_declarator	TYPE_COMPOSITE	FIND_IDENTIFIER	Array declarator: name[size]
function_declarator	TYPE_COMPOSITE	FIND_IDENTIFIER	Function declarator: name(params)
abstract_declarator	TYPE_COMPOSITE	NONE	Abstract declarator (type without name)
parenthesized_declarator	TYPE_COMPOSITE	FIND_IDENTIFIER	Parenthesized declarator: (*name)
abstract_pointer_declarator	TYPE_REFERENCE	NONE	Abstract pointer declarator
abstract_parenthesized_declarator	TYPE_REFERENCE	NONE	Abstract parenthesized declarator
abstract_array_declarator	TYPE_COMPOSITE	NONE	Abstract array declarator
abstract_function_declarator	TYPE_COMPOSITE	NONE	Abstract function declarator
type_descriptor	TYPE_REFERENCE	NONE	Type descriptor in expressions
macro_type_specifier	TYPE_REFERENCE	NODE_TEXT	Macro used as type specifier
bitfield_clause	TYPE_COMPOSITE	NONE	Bitfield specification: : width

Statements

Control flow and executable statements

Node Type	Semantic Type	Name Extraction	Description
compound_statement	ORGANIZATION_BLOCK	Organization::SEQUENTIAL	NONE
labeled_statement	EXECUTION_STATEMENT	FIND_IDENTIFIER	Labeled statement: label: statement
expression_statement	EXECUTION_STATEMENT	NONE	Expression statement: expression;
if_statement	FLOW_CONDITIONAL	Conditional::BINARY	NONE
else_clause	FLOW_CONDITIONAL	NONE	Else clause in if statement
switch_statement	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
case_statement	FLOW_CONDITIONAL	Conditional::MULTIWAY	NONE
while_statement	FLOW_LOOP	Loop::CONDITIONAL	NONE
for_statement	FLOW_LOOP	Loop::COUNTER	NONE
do_statement	FLOW_LOOP	Loop::CONDITIONAL	NONE
goto_statement	FLOW_JUMP	Jump::GOTO	FIND_IDENTIFIER
continue_statement	FLOW_JUMP	Jump::CONTINUE	NONE
break_statement	FLOW_JUMP	Jump::BREAK	NONE
return_statement	FLOW_JUMP	Jump::RETURN	NONE

Expressions

Computation, access, and operator expressions

Node Type	Semantic Type	Name Extraction	Description
call_expression	COMPUTATION_CALL	Call::FUNCTION	FIND_CALL_TARGET
field_expression	COMPUTATION_ACCESS	FIND_IDENTIFIER	Field access: struct.field or struct->field
subscript_expression	COMPUTATION_ACCESS	NONE	Array subscript: array[index]
assignment_expression	OPERATOR_ASSIGNMENT	Assignment::SIMPLE	NONE
binary_expression	OPERATOR_ARITHMETIC	Arithmetic::BINARY	NONE
unary_expression	OPERATOR_ARITHMETIC	Arithmetic::UNARY	NONE
update_expression	OPERATOR_ARITHMETIC	Arithmetic::UNARY	NONE
cast_expression	COMPUTATION_EXPRESSION	NONE	Cast expression: (type)expr
sizeof_expression	OPERATOR_ARITHMETIC	Arithmetic::UNARY	NONE
conditional_expression	FLOW_CONDITIONAL	Conditional::TERNARY	NONE
comma_expression	ORGANIZATION_LIST	Organization::COLLECTION	NONE
parenthesized_expression	COMPUTATION_EXPRESSION	NONE	Parenthesized expression: (expr)
pointer_expression	COMPUTATION_ACCESS	NONE	Pointer dereference or address-of
compound_literal_expression	LITERAL_STRUCTURED	NONE	Compound literal: (type){ initializers }
offsetof_expression	COMPUTATION_CALL	NONE	offsetof expression: offsetof(type, member)

Identifiers and Literals

Names and constant values

Node Type	Semantic Type	Name Extraction	Description
identifier	NAME_IDENTIFIER	NODE_TEXT	Identifier: variable, function, or type name
field_identifier	NAME_IDENTIFIER	NODE_TEXT	Field identifier in struct access
statement_identifier	NAME_IDENTIFIER	NODE_TEXT	Statement identifier (goto label)
number_literal	LITERAL_NUMBER	NODE_TEXT	Number literal: 42, 3.14, 0xFF, etc.
char_literal	LITERAL_STRING	String::LITERAL	NODE_TEXT
string_literal	LITERAL_STRING	String::LITERAL	NODE_TEXT
concatenated_string	LITERAL_STRING	String::LITERAL	NODE_TEXT
string_content	LITERAL_STRING	NODE_TEXT	String content (inside quotes)
escape_sequence	LITERAL_STRING	NODE_TEXT	Escape sequence in string: \n, \t, etc.
character	LITERAL_STRING	NODE_TEXT	Character content
true	LITERAL_ATOMIC	NODE_TEXT	Boolean true (C99 stdbool.h)
false	LITERAL_ATOMIC	NODE_TEXT	Boolean false (C99 stdbool.h)
null	LITERAL_ATOMIC	NODE_TEXT	Null pointer: null (lowercase)
NULL	LITERAL_ATOMIC	NODE_TEXT	Null pointer: NULL (uppercase macro)
nullptr	LITERAL_ATOMIC	NODE_TEXT	Null pointer: nullptr (C23)

Comments

Code comments

Node Type	Semantic Type	Name Extraction	Description
comment	METADATA_COMMENT	NODE_TEXT	Comment: line or block style

Storage and Type Qualifiers

Storage class specifiers and type qualifiers

Storage classes control linkage and lifetime. Type qualifiers modify how values can be accessed.

Node Type	Semantic Type	Name Extraction	Description
storage_class_specifier	METADATA_ANNOTATION	NODE_TEXT	Storage class specifier: static, extern, register, auto
type_qualifier	METADATA_ANNOTATION	NODE_TEXT	Type qualifier: const, volatile, restrict

Attributes and Extensions

Compiler-specific attributes and extensions

Node Type	Semantic Type	Name Extraction	Description
variadic_parameter	PATTERN_COLLECT	NODE_TEXT	Variadic parameter: ... in function declaration
attribute_specifier	METADATA_ANNOTATION	NODE_TEXT	GNU/C11 attribute specifier
ms_declspec_modifier	METADATA_ANNOTATION	NODE_TEXT	Microsoft __declspec modifier
ms_restrict_modifier	METADATA_ANNOTATION	NODE_TEXT	Microsoft restrict modifier
ms_pointer_modifier	METADATA_ANNOTATION	NODE_TEXT	Microsoft pointer modifier
ms_call_modifier	METADATA_ANNOTATION	NODE_TEXT	Microsoft call modifier (__cdecl, __stdcall, etc.)
linkage_specification	METADATA_ANNOTATION	NODE_TEXT	Linkage specification: extern "C"
attribute_declaration	METADATA_ANNOTATION	NONE	C11 attribute declaration: [[attribute]]
attribute	METADATA_ANNOTATION	NODE_TEXT	Attribute in attribute list
alignas_qualifier	METADATA_ANNOTATION	NODE_TEXT	C11 alignas qualifier

Structural Elements

Lists and organizational nodes

Node Type	Semantic Type	Name Extraction	Description
initializer_pair	PATTERN_DESTRUCTURE	FIND_PROPERTY	Designated initializer: .field = value or [index] = value
argument_list	ORGANIZATION_LIST	Organization::COLLECTION	NONE
subscript_designator	COMPUTATION_ACCESS	NONE	Array subscript in designator
initializer_list	LITERAL_STRUCTURED	Structured::SEQUENCE	NONE
field_designator	PATTERN_DESTRUCTURE	FIND_PROPERTY	Field designator: .field
parameter_list	ORGANIZATION_LIST	Organization::COLLECTION	NONE
field_declaration_list	ORGANIZATION_LIST	NONE	Field declaration list in struct/union
enumerator_list	ORGANIZATION_LIST	NONE	Enumerator list in enum
declaration_list	ORGANIZATION_LIST	NONE	Declaration list (multiple declarations)
system_lib_string	EXTERNAL_IMPORT	NODE_TEXT	System library string: <header.h>

Punctuation

Syntactic punctuation tokens

Node Type	Semantic Type	Name Extraction	Description
,	PARSER_PUNCTUATION	NODE_TEXT	Syntactic punctuation tokens
;	PARSER_PUNCTUATION	NODE_TEXT
.	PARSER_PUNCTUATION	NODE_TEXT
:	PARSER_PUNCTUATION	NODE_TEXT
(	PARSER_DELIMITER	NODE_TEXT
)	PARSER_DELIMITER	NODE_TEXT
[	PARSER_DELIMITER	NODE_TEXT
]	PARSER_DELIMITER	NODE_TEXT
{	PARSER_DELIMITER	NODE_TEXT
}	PARSER_DELIMITER	NODE_TEXT
'	PARSER_DELIMITER	NODE_TEXT
?	FLOW_CONDITIONAL	NONE
...	PATTERN_COLLECT	NODE_TEXT
[[	PARSER_DELIMITER	NONE
]]	PARSER_DELIMITER	NONE
u'	PARSER_DELIMITER	NONE
\n	PARSER_SYNTAX	NONE

Assignment Operators

Simple and compound assignment

Node Type	Semantic Type	Name Extraction	Description
=	OPERATOR_ASSIGNMENT	NODE_TEXT	Simple and compound assignment
+=	OPERATOR_ASSIGNMENT	NODE_TEXT
-=	OPERATOR_ASSIGNMENT	NODE_TEXT
*=	OPERATOR_ASSIGNMENT	NODE_TEXT
/=	OPERATOR_ASSIGNMENT	NODE_TEXT
%=	OPERATOR_ASSIGNMENT	NODE_TEXT
&=	OPERATOR_ASSIGNMENT	NODE_TEXT
|=	OPERATOR_ASSIGNMENT	NODE_TEXT
^=	OPERATOR_ASSIGNMENT	NODE_TEXT
<<=	OPERATOR_ASSIGNMENT	NODE_TEXT
>>=	OPERATOR_ASSIGNMENT	NODE_TEXT

Comparison Operators

Equality and relational operators

Node Type	Semantic Type	Name Extraction	Description
==	OPERATOR_COMPARISON	NODE_TEXT	Equality and relational operators
!=	OPERATOR_COMPARISON	NODE_TEXT
<	OPERATOR_COMPARISON	NODE_TEXT
>	OPERATOR_COMPARISON	NODE_TEXT
<=	OPERATOR_COMPARISON	NODE_TEXT
>=	OPERATOR_COMPARISON	NODE_TEXT

Arithmetic Operators

Mathematical and bitwise operators

Node Type	Semantic Type	Name Extraction	Description
+	OPERATOR_ARITHMETIC	NODE_TEXT	Mathematical and bitwise operators
-	OPERATOR_ARITHMETIC	NODE_TEXT
*	OPERATOR_ARITHMETIC	NODE_TEXT
/	OPERATOR_ARITHMETIC	NODE_TEXT
%	OPERATOR_ARITHMETIC	NODE_TEXT
&	OPERATOR_ARITHMETIC	NODE_TEXT
|	OPERATOR_ARITHMETIC	NODE_TEXT
^	OPERATOR_ARITHMETIC	NODE_TEXT
~	OPERATOR_ARITHMETIC	NODE_TEXT
<<	OPERATOR_ARITHMETIC	NODE_TEXT
>>	OPERATOR_ARITHMETIC	NODE_TEXT
++	OPERATOR_ARITHMETIC	NODE_TEXT
--	OPERATOR_ARITHMETIC	NODE_TEXT

Logical Operators

Boolean operators

Node Type	Semantic Type	Name Extraction	Description
&&	OPERATOR_LOGICAL	NODE_TEXT	Boolean operators
||	OPERATOR_LOGICAL	NODE_TEXT
!	OPERATOR_LOGICAL	NODE_TEXT

Member Access Operators

Pointer and scope operators

Node Type	Semantic Type	Name Extraction	Description
->	COMPUTATION_ACCESS	NODE_TEXT	Pointer and scope operators
::	COMPUTATION_ACCESS	NONE

Keywords

Reserved words

Node Type	Semantic Type	Name Extraction	Description
if	FLOW_CONDITIONAL	NODE_TEXT	Reserved words
else	FLOW_CONDITIONAL	NODE_TEXT
while	FLOW_LOOP	NODE_TEXT
for	FLOW_LOOP	NODE_TEXT
do	FLOW_LOOP	NODE_TEXT
switch	FLOW_CONDITIONAL	NODE_TEXT
case	FLOW_CONDITIONAL	NODE_TEXT
default	FLOW_CONDITIONAL	NODE_TEXT
break	FLOW_JUMP	NODE_TEXT
continue	FLOW_JUMP	NODE_TEXT
return	FLOW_JUMP	NODE_TEXT
goto	FLOW_JUMP	NODE_TEXT
const	METADATA_ANNOTATION	NODE_TEXT
static	METADATA_ANNOTATION	NODE_TEXT
extern	METADATA_ANNOTATION	NODE_TEXT
register	METADATA_ANNOTATION	NODE_TEXT
volatile	METADATA_ANNOTATION	NODE_TEXT
inline	METADATA_ANNOTATION	NODE_TEXT
typedef	METADATA_ANNOTATION	NODE_TEXT
struct	METADATA_ANNOTATION	NODE_TEXT
union	METADATA_ANNOTATION	NODE_TEXT
enum	METADATA_ANNOTATION	NODE_TEXT
sizeof	OPERATOR_ARITHMETIC	NODE_TEXT
offsetof	COMPUTATION_CALL	NODE_TEXT
unsigned	TYPE_PRIMITIVE	NODE_TEXT
signed	TYPE_PRIMITIVE	NODE_TEXT
long	TYPE_PRIMITIVE	NODE_TEXT
short	TYPE_PRIMITIVE	NODE_TEXT
auto	TYPE_PRIMITIVE	NODE_TEXT
restrict	METADATA_ANNOTATION	NODE_TEXT
thread_local	METADATA_ANNOTATION	NODE_TEXT
alignas	METADATA_ANNOTATION	NODE_TEXT
constexpr	METADATA_ANNOTATION	NODE_TEXT
asm	EXECUTION_STATEMENT	NONE

Preprocessor Directive Tokens

Preprocessor directive keywords

Node Type	Semantic Type	Name Extraction	Description
#include	METADATA_DIRECTIVE	NODE_TEXT	Preprocessor directive keywords
#define	METADATA_DIRECTIVE	NODE_TEXT
#ifdef	METADATA_DIRECTIVE	NODE_TEXT
#ifndef	METADATA_DIRECTIVE	NODE_TEXT
#if	METADATA_DIRECTIVE	NODE_TEXT
#else	METADATA_DIRECTIVE	NODE_TEXT
#elif	METADATA_DIRECTIVE	NODE_TEXT
#endif	METADATA_DIRECTIVE	NODE_TEXT
#undef	METADATA_DIRECTIVE	NODE_TEXT
#pragma	METADATA_DIRECTIVE	NODE_TEXT

GNU Extensions

GCC-specific language extensions

Node Type	Semantic Type	Name Extraction	Description
__asm__	EXECUTION_STATEMENT	NODE_TEXT	GNU inline assembly: __asm__(...)
gnu_asm_expression	COMPUTATION_EXPRESSION	NONE	GNU asm expression
gnu_asm_output_operand	COMPUTATION_EXPRESSION	NONE	GNU asm output operand
gnu_asm_input_operand	COMPUTATION_EXPRESSION	NONE	GNU asm input operand
gnu_asm_input_operand_list	ORGANIZATION_LIST	NONE	GNU asm input operand list
gnu_asm_output_operand_list	ORGANIZATION_LIST	NONE	GNU asm output operand list
gnu_asm_clobber_list	ORGANIZATION_LIST	NONE	GNU asm clobber list
gnu_asm_qualifier	METADATA_ANNOTATION	NODE_TEXT	GNU asm qualifier (volatile, inline, goto)
__attribute__	METADATA_ANNOTATION	NODE_TEXT	GNU attribute specifier
__restrict__	METADATA_ANNOTATION	NODE_TEXT	GNU restrict keyword
__declspec	METADATA_ANNOTATION	NODE_TEXT	Microsoft __declspec
__forceinline	METADATA_ANNOTATION	NODE_TEXT	Microsoft __forceinline
__stdcall	METADATA_ANNOTATION	NODE_TEXT	Microsoft __stdcall

Parser Errors

Error nodes from parsing

Node Type	Semantic Type	Name Extraction	Description
ERROR	PARSER_SYNTAX	NODE_TEXT	Error nodes from parsing

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