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#include "src/tint/lang/wgsl/ast/transform/remove_unreachable_statements.h"

#include <memory>
#include <unordered_map>
#include <utility>
#include <vector>

#include "src/tint/lang/wgsl/ast/traverse_expressions.h"
#include "src/tint/lang/wgsl/program/clone_context.h"
#include "src/tint/lang/wgsl/program/program_builder.h"
#include "src/tint/lang/wgsl/resolver/resolve.h"
#include "src/tint/lang/wgsl/sem/block_statement.h"
#include "src/tint/lang/wgsl/sem/function.h"
#include "src/tint/lang/wgsl/sem/statement.h"
#include "src/tint/lang/wgsl/sem/variable.h"
#include "src/tint/utils/containers/map.h"
#include "src/tint/utils/macros/scoped_assignment.h"

TINT_INSTANTIATE_TYPEINFO(tint::ast::transform::RemoveUnreachableStatements);

namespace tint::ast::transform {

RemoveUnreachableStatements::RemoveUnreachableStatements() = default;

RemoveUnreachableStatements::~RemoveUnreachableStatements() = default;

Transform::ApplyResult RemoveUnreachableStatements::Apply(const Program& src,
                                                          const DataMap&,
                                                          DataMap&) const {
    ProgramBuilder b;
    program::CloneContext ctx{&b, &src, /* auto_clone_symbols */ true};

    bool made_changes = false;
    for (auto* node : src.ASTNodes().Objects()) {
        if (auto* stmt = src.Sem().Get<sem::Statement>(node)) {
            if (!stmt->IsReachable()) {
                RemoveStatement(ctx, stmt->Declaration());
                made_changes = true;
            }
        }
    }

    if (!made_changes) {
        return SkipTransform;
    }

    ctx.Clone();
    return resolver::Resolve(b);
}

}  // namespace tint::ast::transform