chromium/third_party/dawn/src/tint/lang/wgsl/ast/transform/canonicalize_entry_point_io.h

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#ifndef SRC_TINT_LANG_WGSL_AST_TRANSFORM_CANONICALIZE_ENTRY_POINT_IO_H_
#define SRC_TINT_LANG_WGSL_AST_TRANSFORM_CANONICALIZE_ENTRY_POINT_IO_H_

#include <string>

#include "src/tint/lang/wgsl/ast/internal_attribute.h"
#include "src/tint/lang/wgsl/ast/transform/transform.h"
#include "src/tint/utils/reflection/reflection.h"

namespace tint::ast::transform {

/// CanonicalizeEntryPointIO is a transform used to rewrite shader entry point
/// interfaces into a form that the generators can handle. Each entry point
/// function is stripped of all shader IO attributes and wrapped in a function
/// that provides the shader interface.
/// The transform config determines whether to use global variables, structures,
/// or parameters for the shader inputs and outputs, and optionally adds
/// additional builtins to the shader interface.
///
/// Before:
/// ```
/// struct Locations{
///   @location(1) loc1 : f32;
///   @location(2) loc2 : vec4<u32>;
/// };
///
/// @fragment
/// fn frag_main(@builtin(position) coord : vec4<f32>,
///              locations : Locations) -> @location(0) f32 {
///   if (coord.w > 1.0) {
///     return 0.0;
///   }
///   var col : f32 = (coord.x * locations.loc1);
///   return col;
/// }
/// ```
///
/// After (using structures for all parameters):
/// ```
/// struct Locations{
///   loc1 : f32;
///   loc2 : vec4<u32>;
/// };
///
/// struct frag_main_in {
///   @builtin(position) coord : vec4<f32>;
///   @location(1) loc1 : f32;
///   @location(2) loc2 : vec4<u32>
/// };
///
/// struct frag_main_out {
///   @location(0) loc0 : f32;
/// };
///
/// fn frag_main_inner(coord : vec4<f32>,
///                    locations : Locations) -> f32 {
///   if (coord.w > 1.0) {
///     return 0.0;
///   }
///   var col : f32 = (coord.x * locations.loc1);
///   return col;
/// }
///
/// @fragment
/// fn frag_main(in : frag_main_in) -> frag_main_out {
///   let inner_retval = frag_main_inner(in.coord, Locations(in.loc1, in.loc2));
///   var wrapper_result : frag_main_out;
///   wrapper_result.loc0 = inner_retval;
///   return wrapper_result;
/// }
/// ```
///
/// @note Depends on the following transforms to have been run first:
/// * Unshadow
class CanonicalizeEntryPointIO final : public Castable<CanonicalizeEntryPointIO, Transform> { … };

}  // namespace tint::ast::transform

tint  // namespace tint

#endif  // SRC_TINT_LANG_WGSL_AST_TRANSFORM_CANONICALIZE_ENTRY_POINT_IO_H_