Debug.h

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#ifndef HALIDE_DEBUG_H
#define HALIDE_DEBUG_H
 
/** \file
 * Defines functions for debug logging during code generation.
 */
 
#include <cstdlib>
#include <iostream>
#include <string>
 
namespace Halide {
 
struct Expr;
struct Type;
// Forward declare some things from IRPrinter, which we can't include yet.
std::ostream &operator<<(std::ostream &stream, const Expr &);
std::ostream &operator<<(std::ostream &stream, const Type &);
 
class Module;
std::ostream &operator<<(std::ostream &stream, const Module &);
 
struct Target;
/** Emit a halide Target in a human readable form */
std::ostream &operator<<(std::ostream &stream, const Target &);
 
namespace Internal {
 
struct Stmt;
std::ostream &operator<<(std::ostream &stream, const Stmt &);
 
struct LoweredFunc;
std::ostream &operator<<(std::ostream &, const LoweredFunc &);
 
/** For optional debugging during codegen, use the debug class as
 * follows:
 *
 \code
 debug(verbosity) << "The expression is " << expr << "\n";
 \endcode
 *
 * verbosity of 0 always prints, 1 should print after every major
 * stage, 2 should be used for more detail, and 3 should be used for
 * tracing everything that occurs. The verbosity with which to print
 * is determined by the value of the environment variable
 * HL_DEBUG_CODEGEN
 */
 
class debug {
    const bool logging;
 
public:
    debug(int verbosity)
        : logging(verbosity <= debug_level()) {
    }
 
    template<typename T>
    debug &operator<<(T &&x) {
        if (logging) {
            std::cerr << std::forward<T>(x);
        }
        return *this;
    }
 
    static int debug_level();
};
 
}  // namespace Internal
}  // namespace Halide
 
#endif