llvm-project

f3599e55 - [mlir][acc] Add OpenACCSupport for extensible dialect handling (#164510)

[mlir][acc] Add OpenACCSupport for extensible dialect handling (#164510) The OpenACC dialect must coexist with source language dialects (FIR, CIR, etc.) to enable offloading. While type interfaces (`PointerLikeType` and `MappableType`) provide the primary contract for variable mapping, some scenarios require pipeline-specific customization or need to express information that cannot be adequately captured through operation and type interfaces alone. This commit introduces the `OpenACCSupport` analysis, which provides extensible support APIs that can be customized per-pipeline. The analysis follows the Concept-Model pattern used in MLIR's `AliasAnalysis` and is never invalidated, persisting throughout the pass pipeline. The initial API, `getVariableName(Value) -> string`, retrieves variable names from MLIR values by: - Checking for `acc.var_name` attributes - Extracting names from ACC data clause operations (e.g., `acc.copyin`) - Walking through `ViewLikeOpInterface` operations to find the source This will be used in the implicit data mapping pass to automatically generate device mappings with correct user-visible variable names. Usage: Passes call `getAnalysis<OpenACCSupport>()` to get a cached instance with either the default or a previously- registered custom implementation. Custom implementations can be registered in a setup pass by calling `setImplementation()` before the consumer pass runs.