Types

gcc_jit_type

gcc_jit_type represents a type within the library.

gcc_jit_object *gcc_jit_type_as_object(gcc_jit_type *type)

Upcast a type to an object.

Types can be created in several ways:

  • fundamental types can be accessed using gcc_jit_context_get_type():

    gcc_jit_type *int_type = gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);

    See gcc_jit_context_get_type() for the available types.

  • derived types can be accessed by using functions such as gcc_jit_type_get_pointer() and gcc_jit_type_get_const():

    gcc_jit_type *const_int_star = gcc_jit_type_get_pointer (gcc_jit_type_get_const (int_type));
gcc_jit_type *int_const_star = gcc_jit_type_get_const (gcc_jit_type_get_pointer (int_type));

  • by creating structures (see below).

Standard types

gcc_jit_type *gcc_jit_context_get_type(gcc_jit_context *ctxt, enum gcc_jit_types type_)

Access a specific type. The available types are:

enum gcc_jit_types value Meaning
GCC_JIT_TYPE_VOID C’s void type.
GCC_JIT_TYPE_VOID_PTR C’s void *.
GCC_JIT_TYPE_BOOL C++’s bool type; also C99’s _Bool type, aka bool if using stdbool.h.
GCC_JIT_TYPE_CHAR C’s char (of some signedness)
GCC_JIT_TYPE_SIGNED_CHAR C’s signed char
GCC_JIT_TYPE_UNSIGNED_CHAR C’s unsigned char
GCC_JIT_TYPE_SHORT C’s short (signed)
GCC_JIT_TYPE_UNSIGNED_SHORT C’s unsigned short
GCC_JIT_TYPE_INT C’s int (signed)
GCC_JIT_TYPE_UNSIGNED_INT C’s unsigned int
GCC_JIT_TYPE_LONG C’s long (signed)
GCC_JIT_TYPE_UNSIGNED_LONG C’s unsigned long
GCC_JIT_TYPE_LONG_LONG C99’s long long (signed)
GCC_JIT_TYPE_UNSIGNED_LONG_LONG C99’s unsigned long long
GCC_JIT_TYPE_FLOAT  
GCC_JIT_TYPE_DOUBLE  
GCC_JIT_TYPE_LONG_DOUBLE  
GCC_JIT_TYPE_CONST_CHAR_PTR C type: (const char *)
GCC_JIT_TYPE_SIZE_T C’s size_t type
GCC_JIT_TYPE_FILE_PTR C type: (FILE *)
GCC_JIT_TYPE_COMPLEX_FLOAT C99’s _Complex float
GCC_JIT_TYPE_COMPLEX_DOUBLE C99’s _Complex double
GCC_JIT_TYPE_COMPLEX_LONG_DOUBLE C99’s _Complex long double
gcc_jit_type * gcc_jit_context_get_int_type(gcc_jit_context *ctxt, int num_bytes, int is_signed)

Access the integer type of the given size.

Pointers, const, and volatile

gcc_jit_type *gcc_jit_type_get_pointer(gcc_jit_type *type)

Given type “T”, get type “T*”.

gcc_jit_type *gcc_jit_type_get_const(gcc_jit_type *type)

Given type “T”, get type “const T”.

gcc_jit_type *gcc_jit_type_get_volatile(gcc_jit_type *type)

Given type “T”, get type “volatile T”.

gcc_jit_type * gcc_jit_context_new_array_type(gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_type *element_type, int num_elements)

Given non-void type “T”, get type “T[N]” (for a constant N).

gcc_jit_type * gcc_jit_type_get_aligned(gcc_jit_type *type, size_t alignment_in_bytes)

Given non-void type “T”, get type:

T __attribute__ ((aligned (ALIGNMENT_IN_BYTES)))

The alignment must be a power of two.

This entrypoint was added in LIBGCCJIT_ABI_7; you can test for its presence using

#ifdef LIBGCCJIT_HAVE_gcc_jit_type_get_aligned

Vector types

gcc_jit_type * gcc_jit_type_get_vector(gcc_jit_type *type, size_t num_units)

Given type “T”, get type:

T  __attribute__ ((vector_size (sizeof(T) * num_units))

T must be integral or floating point; num_units must be a power of two.

This can be used to construct a vector type in which operations are applied element-wise. The compiler will automatically use SIMD instructions where possible. See: https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html

For example, assuming 4-byte ints, then:

typedef int v4si __attribute__ ((vector_size (16)));

can be obtained using:

gcc_jit_type *int_type = gcc_jit_context_get_type (ctxt,
                                                   GCC_JIT_TYPE_INT);
gcc_jit_type *v4si_type = gcc_jit_type_get_vector (int_type, 4);

This API entrypoint was added in LIBGCCJIT_ABI_8; you can test for its presence using

#ifdef LIBGCCJIT_HAVE_gcc_jit_type_get_vector

Vector rvalues can be generated using gcc_jit_context_new_rvalue_from_vector().

Structures and unions

gcc_jit_struct

A compound type analagous to a C struct.

gcc_jit_field

A field within a gcc_jit_struct.

You can model C struct types by creating gcc_jit_struct * and gcc_jit_field instances, in either order:

  • by creating the fields, then the structure. For example, to model:

    struct coord {double x; double y; };

    you could call:

    gcc_jit_field *field_x =
  gcc_jit_context_new_field (ctxt, NULL, double_type, "x");
gcc_jit_field *field_y =
  gcc_jit_context_new_field (ctxt, NULL, double_type, "y");
gcc_jit_field *fields[2] = {field_x, field_y};
gcc_jit_struct *coord =
  gcc_jit_context_new_struct_type (ctxt, NULL, "coord", 2, fields);

  • by creating the structure, then populating it with fields, typically to allow modelling self-referential structs such as:

    struct node { int m_hash; struct node *m_next; };

    like this:

    gcc_jit_type *node =
  gcc_jit_context_new_opaque_struct (ctxt, NULL, "node");
gcc_jit_type *node_ptr =
  gcc_jit_type_get_pointer (node);
gcc_jit_field *field_hash =
  gcc_jit_context_new_field (ctxt, NULL, int_type, "m_hash");
gcc_jit_field *field_next =
  gcc_jit_context_new_field (ctxt, NULL, node_ptr, "m_next");
gcc_jit_field *fields[2] = {field_hash, field_next};
gcc_jit_struct_set_fields (node, NULL, 2, fields);
gcc_jit_field * gcc_jit_context_new_field(gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_type *type, const char *name)

Construct a new field, with the given type and name.

The parameter type must be non-void.

The parameter name must be non-NULL. The call takes a copy of the underlying string, so it is valid to pass in a pointer to an on-stack buffer.

gcc_jit_field * gcc_jit_context_new_bitfield(gcc_jit_context *ctxt, gcc_jit_location *loc, gcc_jit_type *type, int width, const char *name)

Construct a new bit field, with the given type width and name.

The parameter name must be non-NULL. The call takes a copy of the underlying string, so it is valid to pass in a pointer to an on-stack buffer.

The parameter type must be an integer type.

The parameter width must be a positive integer that does not exceed the size of type.

This API entrypoint was added in LIBGCCJIT_ABI_12; you can test for its presence using

#ifdef LIBGCCJIT_HAVE_gcc_jit_context_new_bitfield
gcc_jit_object * gcc_jit_field_as_object(gcc_jit_field *field)

Upcast from field to object.

gcc_jit_struct *gcc_jit_context_new_struct_type(gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name, int num_fields, gcc_jit_field **fields)

Construct a new struct type, with the given name and fields.

The parameter name must be non-NULL. The call takes a copy of the underlying string, so it is valid to pass in a pointer to an on-stack buffer.

gcc_jit_struct * gcc_jit_context_new_opaque_struct(gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name)

Construct a new struct type, with the given name, but without specifying the fields. The fields can be omitted (in which case the size of the struct is not known), or later specified using gcc_jit_struct_set_fields().

The parameter name must be non-NULL. The call takes a copy of the underlying string, so it is valid to pass in a pointer to an on-stack buffer.

gcc_jit_type * gcc_jit_struct_as_type(gcc_jit_struct *struct_type)

Upcast from struct to type.

void gcc_jit_struct_set_fields(gcc_jit_struct *struct_type, gcc_jit_location *loc, int num_fields, gcc_jit_field **fields)

Populate the fields of a formerly-opaque struct type.

This can only be called once on a given struct type.

gcc_jit_type * gcc_jit_context_new_union_type(gcc_jit_context *ctxt, gcc_jit_location *loc, const char *name, int num_fields, gcc_jit_field **fields)

Construct a new union type, with the given name and fields.

The parameter name must be non-NULL. It is copied, so the input buffer does not need to outlive the call.

Example of use:

Function pointer types

Function pointer types can be created using gcc_jit_context_new_function_ptr_type().