// Preprocessor.h
#ifndef SLANG_PREPROCESSOR_H_INCLUDED
#define SLANG_PREPROCESSOR_H_INCLUDED

#include "../core/slang-basic.h"

#include "slang-lexer.h"

#include "slang-include-system.h"

namespace Slang {

class DiagnosticSink;
class Linkage;

struct Preprocessor;

    /// A handler for callbacks invoked by the preprocessor.
    ///
    /// A client of the preprocessor can implement its own `PreprocessorHandler` subtype
    /// in order to insert custom logic that implements higher-level policies
    /// that the preprocessor shouldn't need to understand.
    ///
struct PreprocessorHandler
{
    virtual void handleEndOfFile(Preprocessor* preprocessor);
    virtual void handleFileDependency(String const& path);
};

    /// Description of a preprocessor options/dependencies
struct PreprocessorDesc
{
        /// Required: sink to use when emitting preprocessor diagnostic messages
    DiagnosticSink* sink = nullptr;

        /// Required: name pool to use when creating `Name`s from strings
    NamePool* namePool = nullptr;

        /// Required: file system to use when looking up files
    ISlangFileSystemExt* fileSystem = nullptr;

        /// Required: source manager to use when loading source files
    SourceManager* sourceManager = nullptr;

        /// Optional: include system to use when resolving `#include` directives
    IncludeSystem*  includeSystem = nullptr;

        /// Optional: preprocessor `#define`s to assume are set on input
    Dictionary<String, String> const* defines = nullptr;

        /// Optional: handler for callbacks invoked during preprocessing
    PreprocessorHandler* handler = nullptr;
};

    /// Take a source `file` and preprocess it into a list of tokens.
TokenList preprocessSource(
    SourceFile*             file,
    PreprocessorDesc const& desc);

    /// Convenience wrapper for `preprocessSource` when a `Linkage` is available
TokenList preprocessSource(
    SourceFile*                         file,
    DiagnosticSink*                     sink,
    IncludeSystem*                      includeSystem,
    Dictionary<String, String> const&   defines,
    Linkage*                            linkage,
    PreprocessorHandler*                handler = nullptr);

// The following functions are intended to be used inside of implementations
// of the `PreprocessorHandler` interface, in order to query the current
// state of the preprocessor.

    /// Try to look up a macro with the given `macroName` and produce its value as a string
Result findMacroValue(
    Preprocessor*   preprocessor,
    char const*     macroName,
    String&         outValue,
    SourceLoc&      outLoc);

} // namespace Slang

#endif