Re: [PATCH] libgccjit: add some reflection functions in the jit C api

[Andrea Corallo <andrea.corallo@arm.com>]

Antoni Boucher via Jit <jit@gcc.gnu.org> writes:

Hi Antoni,

Just had a quick look, please find some quite minor comments in line.

> From b0edc9eb8e8d3ba9e1c6a8d061a8627c0b0cf102 Mon Sep 17 00:00:00 2001
> From: Antoni Boucher <bouanto@zoho.com>
> Date: Sat, 1 Aug 2020 17:52:17 -0400
> Subject: [PATCH] This patch add some reflection functions in the jit C api
>  [PR96889]
>
> 2020-09-1  Antoni Boucher  <bouanto@zoho.com>
>
>     gcc/jit/
>             PR target/96889
>             * docs/topics/compatibility.rst (LIBGCCJIT_ABI_14): New ABI tag.
>             * docs/topics/functions.rst: Add documentation for the
>             functions gcc_jit_function_get_return_type and
>             gcc_jit_function_get_param_count
>             * libgccjit.c: New functions:
>               * gcc_jit_function_get_return_type;
>               * gcc_jit_function_get_param_count;
>               * gcc_jit_function_type_get_return_type;
>               * gcc_jit_function_type_get_param_count;
>               * gcc_jit_function_type_get_param_type;
>               * gcc_jit_type_unqualified;
>               * gcc_jit_type_is_array;
>               * gcc_jit_type_is_bool;
>               * gcc_jit_type_is_function_ptr_type;
>               * gcc_jit_type_is_int;
>               * gcc_jit_type_is_pointer;
>               * gcc_jit_type_is_vector;
>               * gcc_jit_vector_type_get_element_type;
>               * gcc_jit_vector_type_get_num_units;
>               * gcc_jit_struct_get_field;
>               * gcc_jit_type_is_struct;
>               * gcc_jit_struct_get_field_count;
>             * libgccjit.h
>             * jit-recording.h: New functions (is_struct and is_vector)
>             * libgccjit.map (LIBGCCJIT_ABI_14): New ABI tag.
>
>     gcc/testsuite/
>             PR target/96889
>             * jit.dg/all-non-failing-tests.h: Add test-reflection.c.
>             * jit.dg/test-reflection.c: New test.
> ---
>  gcc/jit/docs/topics/compatibility.rst        |  41 +++
>  gcc/jit/docs/topics/functions.rst            |  10 +
>  gcc/jit/jit-recording.h                      |  16 ++
>  gcc/jit/libgccjit.c                          | 254 +++++++++++++++++++
>  gcc/jit/libgccjit.h                          | 117 +++++++++
>  gcc/jit/libgccjit.map                        |  21 ++
>  gcc/testsuite/jit.dg/all-non-failing-tests.h |  10 +
>  gcc/testsuite/jit.dg/test-reflection.c       |  89 +++++++
>  8 files changed, 558 insertions(+)
>  create mode 100644 gcc/testsuite/jit.dg/test-reflection.c
>
> diff --git a/gcc/jit/docs/topics/compatibility.rst b/gcc/jit/docs/topics/compatibility.rst
> index 6bfa101ed71..16f24d20a75 100644
> --- a/gcc/jit/docs/topics/compatibility.rst
> +++ b/gcc/jit/docs/topics/compatibility.rst
> @@ -226,3 +226,44 @@ entrypoints:
>  --------------------
>  ``LIBGCCJIT_ABI_14`` covers the addition of
>  :func:`gcc_jit_global_set_initializer`
> +
> +.. _LIBGCCJIT_ABI_15:
> +
> +``LIBGCCJIT_ABI_15``
> +--------------------
> +``LIBGCCJIT_ABI_15`` covers the addition of reflection functions via API
> +entrypoints:
> +
> +  * :func:`gcc_jit_function_get_return_type`
> +
> +  * :func:`gcc_jit_function_get_param_count`
> +
> +  * :func:`gcc_jit_type_is_array`
> +
> +  * :func:`gcc_jit_type_is_bool`
> +
> +  * :func:`gcc_jit_type_is_int`
> +
> +  * :func:`gcc_jit_type_is_pointer`
> +
> +  * :func:`gcc_jit_type_is_struct`
> +
> +  * :func:`gcc_jit_type_is_vector`
> +
> +  * :func:`gcc_jit_type_unqualified`
> +
> +  * :func:`gcc_jit_type_is_function_ptr_type`
> +
> +  * :func:`gcc_jit_function_type_get_return_type`
> +
> +  * :func:`gcc_jit_function_type_get_param_count`
> +
> +  * :func:`gcc_jit_function_type_get_param_type`
> +
> +  * :func:`gcc_jit_vector_type_get_num_units`
> +
> +  * :func:`gcc_jit_vector_type_get_element_type`
> +
> +  * :func:`gcc_jit_struct_get_field`
> +
> +  * :func:`gcc_jit_struct_get_field_count`
> diff --git a/gcc/jit/docs/topics/functions.rst b/gcc/jit/docs/topics/functions.rst
> index eb40d64010e..9819c28cda2 100644
> --- a/gcc/jit/docs/topics/functions.rst
> +++ b/gcc/jit/docs/topics/functions.rst
> @@ -171,6 +171,16 @@ Functions
>     underlying string, so it is valid to pass in a pointer to an on-stack
>     buffer.
>  
> +.. function::  size_t \
> +               gcc_jit_function_get_param_count (gcc_jit_function *func)
> +
> +   Get the number of parameters of the function.
> +
> +.. function::  gcc_jit_type \*
> +               gcc_jit_function_get_return_type (gcc_jit_function *func)
> +
> +   Get the return type of the function.
> +
>  Blocks
>  ------
>  .. type:: gcc_jit_block
> diff --git a/gcc/jit/jit-recording.h b/gcc/jit/jit-recording.h
> index 30e37aff387..525b8bc921d 100644
> --- a/gcc/jit/jit-recording.h
> +++ b/gcc/jit/jit-recording.h
> @@ -538,7 +538,9 @@ public:
>    virtual bool is_bool () const = 0;
>    virtual type *is_pointer () = 0;
>    virtual type *is_array () = 0;
> +  virtual struct_ *is_struct () { return NULL; }
>    virtual bool is_void () const { return false; }
> +  virtual vector_type *is_vector () { return NULL; }
>    virtual bool has_known_size () const { return true; }
>  
>    bool is_numeric () const
> @@ -595,6 +597,8 @@ public:
>    bool is_bool () const FINAL OVERRIDE;
>    type *is_pointer () FINAL OVERRIDE { return dereference (); }
>    type *is_array () FINAL OVERRIDE { return NULL; }
> +  vector_type *is_vector () FINAL OVERRIDE { return NULL; }
> +  struct_ *is_struct () FINAL OVERRIDE { return NULL; }
>    bool is_void () const FINAL OVERRIDE { return m_kind == GCC_JIT_TYPE_VOID; }
>  
>  public:
> @@ -629,6 +633,8 @@ public:
>    bool is_bool () const FINAL OVERRIDE { return false; }
>    type *is_pointer () FINAL OVERRIDE { return m_other_type; }
>    type *is_array () FINAL OVERRIDE { return NULL; }
> +  vector_type *is_vector () FINAL OVERRIDE { return NULL; }
> +  struct_ *is_struct () FINAL OVERRIDE { return NULL; }
>  
>  private:
>    string * make_debug_string () FINAL OVERRIDE;
> @@ -655,6 +661,7 @@ public:
>    bool is_bool () const FINAL OVERRIDE { return m_other_type->is_bool (); }
>    type *is_pointer () FINAL OVERRIDE { return m_other_type->is_pointer (); }
>    type *is_array () FINAL OVERRIDE { return m_other_type->is_array (); }
> +  struct_ *is_struct () FINAL OVERRIDE { return m_other_type->is_struct (); }
>  
>  protected:
>    type *m_other_type;
> @@ -737,6 +744,8 @@ public:
>  
>    void replay_into (replayer *) FINAL OVERRIDE;
>  
> +  vector_type *is_vector () FINAL OVERRIDE { return this; }
> +
>  private:
>    string * make_debug_string () FINAL OVERRIDE;
>    void write_reproducer (reproducer &r) FINAL OVERRIDE;
> @@ -765,6 +774,8 @@ class array_type : public type
>    bool is_bool () const FINAL OVERRIDE { return false; }
>    type *is_pointer () FINAL OVERRIDE { return NULL; }
>    type *is_array () FINAL OVERRIDE { return m_element_type; }
> +  vector_type *is_vector () FINAL OVERRIDE { return NULL; }
> +  struct_ *is_struct () FINAL OVERRIDE { return NULL; }
>    int num_elements () { return m_num_elements; }
>  
>    void replay_into (replayer *) FINAL OVERRIDE;
> @@ -799,6 +810,8 @@ public:
>    bool is_bool () const FINAL OVERRIDE { return false; }
>    type *is_pointer () FINAL OVERRIDE { return NULL; }
>    type *is_array () FINAL OVERRIDE { return NULL; }
> +  vector_type *is_vector () FINAL OVERRIDE { return NULL; }
> +  struct_ *is_struct () FINAL OVERRIDE { return NULL; }
>  
>    void replay_into (replayer *) FINAL OVERRIDE;
>  
> @@ -912,6 +925,7 @@ public:
>    bool is_bool () const FINAL OVERRIDE { return false; }
>    type *is_pointer () FINAL OVERRIDE { return NULL; }
>    type *is_array () FINAL OVERRIDE { return NULL; }
> +  vector_type *is_vector () FINAL OVERRIDE { return NULL; }
>  
>    bool has_known_size () const FINAL OVERRIDE { return m_fields != NULL; }
>  
> @@ -943,6 +957,8 @@ public:
>  
>    const char *access_as_type (reproducer &r) FINAL OVERRIDE;
>  
> +  struct_ *is_struct () FINAL OVERRIDE { return this; }
> +
>  private:
>    string * make_debug_string () FINAL OVERRIDE;
>    void write_reproducer (reproducer &r) FINAL OVERRIDE;
> diff --git a/gcc/jit/libgccjit.c b/gcc/jit/libgccjit.c
> index a00aefc7108..94a0f1955ec 100644
> --- a/gcc/jit/libgccjit.c
> +++ b/gcc/jit/libgccjit.c
> @@ -21,6 +21,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "config.h"
>  #include "system.h"
>  #include "coretypes.h"
> +#include "tm.h"
>  #include "timevar.h"
>  #include "typed-splay-tree.h"
>  #include "cppbuiltin.h"
> @@ -60,6 +61,14 @@ struct gcc_jit_struct : public gcc::jit::recording::struct_
>  {
>  };
>  
> +struct gcc_jit_function_type : public gcc::jit::recording::function_type
> +{
> +};
> +
> +struct gcc_jit_vector_type : public gcc::jit::recording::vector_type
> +{
> +};
> +
>  struct gcc_jit_field : public gcc::jit::recording::field
>  {
>  };
> @@ -510,6 +519,195 @@ gcc_jit_type_get_volatile (gcc_jit_type *type)
>    return (gcc_jit_type *)type->get_volatile ();
>  }
>  
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_array method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_type_is_array (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +
> +  return (gcc_jit_type *)type->is_array ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_bool method, in
> +   jit-recording.c.  */
> +
> +int
> +gcc_jit_type_is_bool (gcc_jit_type *type)
> +{
> +  RETURN_VAL_IF_FAIL (type, FALSE, NULL, NULL, "NULL type");
> +
> +  return type->is_bool ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_pointer method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_type_is_pointer (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +
> +  return (gcc_jit_type *)type->is_pointer ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_int method, in
> +   jit-recording.c.  */
> +
> +int
> +gcc_jit_type_is_int (gcc_jit_type *type)
> +{
> +  RETURN_VAL_IF_FAIL (type, FALSE, NULL, NULL, "NULL type");
> +
> +  return type->is_int ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_vector method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_vector_type *
> +gcc_jit_type_is_vector (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +  gcc::jit::recording::vector_type *vector_type = type->is_vector();
                                                                   ^^^
                                                                 space here
> +  return (gcc_jit_vector_type *)vector_type;
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::is_struct method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_struct *
> +gcc_jit_type_is_struct (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +  gcc::jit::recording::struct_ *struct_type = type->is_struct();

Likewise

> +  return (gcc_jit_struct *)struct_type;
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::vector_type::get_num_units method, in
> +   jit-recording.c.  */
> +
> +ssize_t
> +gcc_jit_vector_type_get_num_units (gcc_jit_vector_type *vector_type)
> +{
> +  RETURN_VAL_IF_FAIL (vector_type, -1, NULL, NULL, "NULL vector_type");
> +  return vector_type->get_num_units ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::vector_type::get_element_type method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_vector_type_get_element_type (gcc_jit_vector_type *vector_type)
> +{
> +  RETURN_NULL_IF_FAIL (vector_type, NULL, NULL, "NULL vector_type");
> +  return (gcc_jit_type *)vector_type->get_element_type ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::unqualified method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_type_unqualified (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +
> +  return (gcc_jit_type *)type->unqualified ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::type::dyn_cast_function_type method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_function_type *
> +gcc_jit_type_is_function_ptr_type (gcc_jit_type *type)
> +{
> +  RETURN_NULL_IF_FAIL (type, NULL, NULL, "NULL type");
> +  gcc::jit::recording::type *func_ptr_type = type->dereference ();
> +  RETURN_NULL_IF_FAIL (func_ptr_type, NULL, NULL, "NULL type");
> +  gcc::jit::recording::function_type *func_type = func_ptr_type->dyn_cast_function_type();

Likewise (also exceeded 80 characters).

> +  RETURN_NULL_IF_FAIL (func_type, NULL, NULL, "NULL type");
> +
> +  return (gcc_jit_function_type *)func_type;
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::function_type::get_return_type method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_function_type_get_return_type (gcc_jit_function_type *function_type)
> +{
> +  RETURN_NULL_IF_FAIL (function_type, NULL, NULL, "NULL struct_type");
> +  return (gcc_jit_type *)function_type->get_return_type ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::function_type::get_param_types method, in
> +   jit-recording.c.  */
> +
> +ssize_t
> +gcc_jit_function_type_get_param_count (gcc_jit_function_type *function_type)
> +{
> +  RETURN_VAL_IF_FAIL (function_type, -1, NULL, NULL, "NULL struct_type");
> +  return function_type->get_param_types ().length();

Likewise

> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::function_type::get_param_types method, in
> +   jit-recording.c.  */
> +
> +gcc_jit_type *
> +gcc_jit_function_type_get_param_type (gcc_jit_function_type *function_type, int index)

Excedes 80 characters

> +{
> +  RETURN_NULL_IF_FAIL (function_type, NULL, NULL, "NULL struct_type");
> +  int num_params = function_type->get_param_types ().length ();
> +  gcc::jit::recording::context *ctxt = function_type->m_ctxt;
> +  RETURN_NULL_IF_FAIL_PRINTF3 (index < num_params,
> +			       ctxt, NULL,
> +			       "index of %d is too large (%s has %d params)",
> +			       index,
> +			       function_type->get_debug_string (),
> +			       num_params);
> +  return (gcc_jit_type *)function_type->get_param_types ()[index];
> +}
> +
>  /* Public entrypoint.  See description in libgccjit.h.
>  
>     After error-checking, the real work is done by the
> @@ -731,6 +929,33 @@ gcc_jit_struct_set_fields (gcc_jit_struct *struct_type,
>  			   (gcc::jit::recording::field **)fields);
>  }
>  
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::fields::get_field method in
> +   jit-recording.c.  */
> +extern gcc_jit_field *
> +gcc_jit_struct_get_field (gcc_jit_struct *struct_type,
> +			   int index)
> +{
> +  RETURN_NULL_IF_FAIL (struct_type, NULL, NULL, "NULL struct type");
> +  return (gcc_jit_field *)struct_type->get_fields()->get_field(index);

Space before (

> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, this calls the trivial
> +   gcc::jit::recording::struct_::get_fields method in
> +   jit-recording.h.  */
> +
> +ssize_t
> +gcc_jit_struct_get_field_count (gcc_jit_struct *struct_type)
> +{
> +  RETURN_VAL_IF_FAIL (struct_type, -1, NULL, NULL, "NULL struct type");
> +  return struct_type->get_fields()->length();

Likewise

> +}
> +
>  /* Public entrypoint.  See description in libgccjit.h.
>  
>     After error-checking, the real work is done by the
> @@ -1012,6 +1237,35 @@ gcc_jit_function_get_param (gcc_jit_function *func, int index)
>    return static_cast <gcc_jit_param *> (func->get_param (index));
>  }
>  
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::function::get_params method, in
> +   jit-recording.h.
> +  */
> +
> +ssize_t
> +gcc_jit_function_get_param_count (gcc_jit_function *func)
> +{
> +  RETURN_VAL_IF_FAIL (func, -1, NULL, NULL, "NULL function");
> +  gcc::jit::recording::context *ctxt = func->m_ctxt;
> +  JIT_LOG_FUNC (ctxt->get_logger ());
> +  return func->get_params ().length ();
> +}
> +
> +/* Public entrypoint.  See description in libgccjit.h.
> +
> +   After error-checking, the real work is done by the
> +   gcc::jit::recording::function::get_return_type method, in
> +   jit-recording.h.  */
> +
> +gcc_jit_type *
> +gcc_jit_function_get_return_type (gcc_jit_function *func)
> +{
> +    RETURN_NULL_IF_FAIL (func, NULL, NULL, "NULL function");
> +    return (gcc_jit_type *)func->get_return_type ();
> +}
> +
>  /* Public entrypoint.  See description in libgccjit.h.
>  
>     After error-checking, the real work is done by the
> diff --git a/gcc/jit/libgccjit.h b/gcc/jit/libgccjit.h
> index 7134841bb07..b0a3d941e9c 100644
> --- a/gcc/jit/libgccjit.h
> +++ b/gcc/jit/libgccjit.h
> @@ -96,6 +96,12 @@ typedef struct gcc_jit_field gcc_jit_field;
>     the layout for, or an opaque type.  */
>  typedef struct gcc_jit_struct gcc_jit_struct;
>  
> +/* A gcc_jit_function_type encapsulates a function type.  */
> +typedef struct gcc_jit_function_type gcc_jit_function_type;
> +
> +/* A gcc_jit_vector_type encapsulates a vector type.  */
> +typedef struct gcc_jit_vector_type gcc_jit_vector_type;
> +
>  /* A gcc_jit_function encapsulates a function: either one that you're
>     creating yourself, or a reference to one that you're dynamically
>     linking to within the rest of the process.  */
> @@ -586,6 +592,60 @@ gcc_jit_type_get_const (gcc_jit_type *type);
>  extern gcc_jit_type *
>  gcc_jit_type_get_volatile (gcc_jit_type *type);
>  
> +/* Given type "T", return TRUE if the type is an array.  */
> +extern gcc_jit_type *
> +gcc_jit_type_is_array (gcc_jit_type *type);
> +
> +/* Given type "T", return TRUE if the type is a bool.  */
> +extern int
> +gcc_jit_type_is_bool (gcc_jit_type *type);
> +
> +/* Given type "T", return the function type if it is one.  */
> +extern gcc_jit_function_type *
> +gcc_jit_type_is_function_ptr_type (gcc_jit_type *type);
> +
> +/* Given a function type, return its return type. */

GNU stile wants dot + 2 spaces at the end of a comment.

> +extern gcc_jit_type *
> +gcc_jit_function_type_get_return_type (gcc_jit_function_type *function_type);
> +
> +/* Given a function type, return its number of parameters. */

Likewise

> +extern ssize_t
> +gcc_jit_function_type_get_param_count (gcc_jit_function_type *function_type);
> +
> +/* Given a function type, return the type of the specified parameter. */

Likewise

> +extern gcc_jit_type *
> +gcc_jit_function_type_get_param_type (gcc_jit_function_type *function_type, int index);

Exceeds 80 characters

> +
> +/* Given type "T", return the type pointed by the pointer type
> + * or NULL if it's not a pointer.  */
> +extern gcc_jit_type *
> +gcc_jit_type_is_pointer (gcc_jit_type *type);
> +
> +/* Given type "T", return TRUE if the type is an int.  */
> +extern int
> +gcc_jit_type_is_int (gcc_jit_type *type);
> +
> +/* Given type "T", return the unqualified type, i.e. for a
> + * decorated type, return the type it wraps.  */
> +extern gcc_jit_type *
> +gcc_jit_type_unqualified (gcc_jit_type *type);
> +
> +/* Given type "T", return TRUE if the type is a vector type.  */
> +extern gcc_jit_vector_type *
> +gcc_jit_type_is_vector (gcc_jit_type *type);
> +
> +/* Given type "T", return the struct type or NULL.  */
> +extern gcc_jit_struct *
> +gcc_jit_type_is_struct (gcc_jit_type *type);
> +
> +/* Given a vector type, return the number of units it contains. */

One space more before */

> +extern ssize_t
> +gcc_jit_vector_type_get_num_units (gcc_jit_vector_type *vector_type);
> +
> +/* Given a vector type, return the type of its elements. */

Likewise

> +extern gcc_jit_type *
> +gcc_jit_vector_type_get_element_type (gcc_jit_vector_type *vector_type);
> +
>  /* Given type "T", get type "T[N]" (for a constant N).  */
>  extern gcc_jit_type *
>  gcc_jit_context_new_array_type (gcc_jit_context *ctxt,
> @@ -647,6 +707,15 @@ gcc_jit_struct_set_fields (gcc_jit_struct *struct_type,
>  			   int num_fields,
>  			   gcc_jit_field **fields);
>  
> +/* Get a field by index. */

Likewise

> +extern gcc_jit_field *
> +gcc_jit_struct_get_field (gcc_jit_struct *struct_type,
> +			   int index);
> +
> +/* Get the number of fields. */

Likewise

> +extern ssize_t
> +gcc_jit_struct_get_field_count (gcc_jit_struct *struct_type);
> +
>  /* Unions work similarly to structs.  */
>  extern gcc_jit_type *
>  gcc_jit_context_new_union_type (gcc_jit_context *ctxt,
> @@ -740,6 +809,14 @@ gcc_jit_function_as_object (gcc_jit_function *func);
>  extern gcc_jit_param *
>  gcc_jit_function_get_param (gcc_jit_function *func, int index);
>  
> +/* Get the number of params of a function.  */
> +extern ssize_t
> +gcc_jit_function_get_param_count (gcc_jit_function *func);
> +
> +/* Get the return type of a function.  */
> +extern gcc_jit_type *
> +gcc_jit_function_get_return_type (gcc_jit_function *func);
> +
>  /* Emit the function in graphviz format.  */
>  extern void
>  gcc_jit_function_dump_to_dot (gcc_jit_function *func,
> @@ -1518,6 +1595,46 @@ gcc_jit_version_minor (void);
>  extern int
>  gcc_jit_version_patchlevel (void);
>  
> +#define LIBGCCJIT_HAVE_gcc_jit_function_reflection
> +
> +/* Reflection functions to get the number of parameters, return type of
> +   a function and whether a type is a bool from the C API.
> +
> +   This API entrypoint was added in LIBGCCJIT_ABI_15; you can test for its
> +   presence using
> +     #ifdef LIBGCCJIT_HAVE_gcc_jit_function_reflection
> +*/
> +extern gcc_jit_type *
> +gcc_jit_function_get_return_type (gcc_jit_function *func);
> +extern ssize_t
> +gcc_jit_function_get_param_count (gcc_jit_function *func);
> +extern gcc_jit_type *
> +gcc_jit_type_is_array (gcc_jit_type *type);
> +extern int
> +gcc_jit_type_is_bool (gcc_jit_type *type);
> +extern gcc_jit_function_type *
> +gcc_jit_type_is_function_ptr_type (gcc_jit_type *type);
> +extern gcc_jit_type *
> +gcc_jit_function_type_get_return_type (gcc_jit_function_type *function_type);
> +extern ssize_t
> +gcc_jit_function_type_get_param_count (gcc_jit_function_type *function_type);
> +extern gcc_jit_type *
> +gcc_jit_function_type_get_param_type (gcc_jit_function_type *function_type, int index);

Exceeds 80 characters

> +extern int
> +gcc_jit_type_is_int (gcc_jit_type *type);
> +extern gcc_jit_type *
> +gcc_jit_type_is_pointer (gcc_jit_type *type);
> +extern gcc_jit_vector_type *
> +gcc_jit_type_is_vector (gcc_jit_type *type);
> +extern gcc_jit_struct *
> +gcc_jit_type_is_struct (gcc_jit_type *type);
> +extern ssize_t
> +gcc_jit_vector_type_get_num_units (gcc_jit_vector_type *vector_type);
> +extern gcc_jit_type *
> +gcc_jit_vector_type_get_element_type (gcc_jit_vector_type *vector_type);
> +extern gcc_jit_type *
> +gcc_jit_type_unqualified (gcc_jit_type *type);

Apologies for the nit picking :)

  Andrea