RuleAnalysisLegacyToolchain (Buck)

```
public interface RuleAnalysisLegacyToolchain
```
Allows legacy Toolchains to be exposed in a generic way to the rule analysis graph via providers.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`ProviderInfoCollection`	`getProviders(DependencyOnlyRuleAnalysisContext context, TargetConfiguration targetConfiguration)`
`void`	`visitToolDependencies(TargetConfiguration targetConfiguration, java.util.function.Consumer<BuildTarget> builder)`	Add the dependencies for this toolchain to the graph.

- Method Detail
  - getProviders
```
ProviderInfoCollection getProviders(DependencyOnlyRuleAnalysisContext context,
                                    TargetConfiguration targetConfiguration)
```
    Returns:
    
    the providers that describe this specific toolchain. e.g. A C++ toolchain might return a C++ToolchainInfo object that has a compiler, and default compiler flags
  - visitToolDependencies
```
void visitToolDependencies(TargetConfiguration targetConfiguration,
                           java.util.function.Consumer<BuildTarget> builder)
```
    Add the dependencies for this toolchain to the graph. This includes things like build targets for a compiler or linker, etc.
    
    Parameters:
    
    targetConfiguration - the configuration this toolchain will be used in
    
    builder - the builder to add dependencies to