HLSL does not support pointers or references. This change generates
errors in sema for generating pointer, and reference types as well as
common operators (address-of, dereference, arrow), which are used with
pointers and are unsupported in HLSL.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123167
HLSL has a language feature called Semantics which get attached to
declarations like attributes and are used in a variety of ways.
One example of semantic use is here with the `SV_GroupIndex` semantic
which, when applied to an input for a compute shader is pre-populated
by the driver with a flattened thread index.
Differential Revision: https://reviews.llvm.org/D122699
# Conflicts:
# clang/include/clang/Basic/Attr.td
# clang/include/clang/Basic/AttrDocs.td
This adds diagnostics for conflicting attributes on the same
declarataion, conflicting attributes on a forward and final
declaration, and defines a more narrowly scoped HLSLEntry attribute
target.
Big shout out to @aaron.ballman for the great feedback and review on
this!
Updating the diagnostics as per the feedback on
https://reviews.llvm.org/D122627.
This change correctly handles missing argument lists, and changes the
subject for the `numthreads` attribute to be global functions.
I did not handle applying the attribute to template functions because
that currently fails parsing in a way that is consisetent with the
current DXC codebase (Microsoft attributes are not supported on
templates).
A future improvement to the diagnostic maybe warranted.
HLSL uses Microsoft-style attributes `[attr]`, which clang mostly
ignores. For HLSL we need to handle known Microsoft attributes, and to
maintain C/C++ as-is we ignore unknown attributes.
To utilize this new code path, this change adds the HLSL `numthreads`
attribute.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D122627
Chris Bieneman