This commit adds support for copying nested hierarchical types of split
types. E.g, a struct of a struct containing both user and builtin interstage
IO variables.
When copying split types, if any subtree does NOT contain builtin interstage
IO, we can copy the whole subtree with one assignment, which saves a bunch
of AST verbosity for memberwise copies of that subtree.
This adds structure splitting, which among other things will enable GS support where input structs
are passed, and thus become input arrays of structs in the GS inputs. That is a common GS case.
The salient points of this PR are:
* Structure splitting has been changed from "always between stages" to "only into the VS and out of
the PS". It had previously happened between stages because it's not legal to pass a struct
containing a builtin IO variable.
* Structs passed between stages are now split into a struct containing ONLY user types, and a
collection of loose builtin IO variables, if any. The user-part is passed as a normal struct
between stages, which is valid SPIR-V now that the builtin IO is removed.
* Internal to the shader, a sanitized struct (with IO qualifiers removed) is used, so that e.g,
functions can work unmodified.
* If a builtin IO such as Position occurs in an arrayed struct, for example as an input to a GS,
the array reference is moved to the split-off loose variable, which is given the array dimension
itself.
When passing things around inside the shader, such as over a function call, the the original type
is used in a sanitized form that removes the builtIn qualifications and makes them temporaries.
This means internal function calls do not have to change. However, the type when returned from
the shader will be member-wise copied from the internal sanitized one to the external type.
The sanitized type is used in variable declarations.
When copying split types and unsplit, if a sub-struct contains only user variables, it is copied
as a single entity to avoid more AST verbosity.
Above strategy arrived at with talks with @johnkslang.
This is a big complex change. I'm inclined to leave it as a WIP until it can get some exposure to
real world cases.
Also, eliminate the 'atom' field of TPpToken.
Parsing a real 300 line shader, through to making the AST, is about 10% faster.
Memory is slightly reduced (< 1%).
The whole google-test suite, inclusive of all testing overhead, SPIR-V generation,
etc., runs 3% faster.
Since this is a code *simplification* that leads to perf. improvement, I'm not
going to invest too much more in measuring the perf. than this. The PP code is
simply now in a better state to see how to further rationalize/improve it.
Implement token pasting as per the C++ specification, within the current
style of the PP code.
Non-identifiers (turning 12 ## 10 into the numeral 1210) is not yet covered;
they should be a simple incremental change built on this one.
Addresses issue #255.
This wasn't needed until the recent generalization of "main" to "entry point",
so makes some HLSL-specific code be generic now, for GLSL functional correctness.
Previously, an error was thrown when assigning a float1 to a scalar float,
or similar for other basic types. This allows that.
Also, this allows calling functions accepting scalars with float1 params,
so for example sin(float1) will work. This is a minor change in
HlslParseContext::findFunction().
A need arose to use capabilities from TIntermediate during
node promotion. These methods have been moved from virtual
methods on the TIntermUnary and TIntermBinary nodes to methods
on TIntermediate, so it is easy for them construct new nodes
and so on.
This is done as a separate commit to verify that no test results
are changed as a result.
