Ioss_SmartAssert.h

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// Copyright(C) 1999-2020, 2022, 2023 National Technology & Engineering Solutions
// of Sandia, LLC (NTESS).  Under the terms of Contract DE-NA0003525 with
// NTESS, the U.S. Government retains certain rights in this software.
//
// See packages/seacas/LICENSE for details
#pragma once
 
#include "ioss_export.h"
 
#if _MSC_VER > 1000
 
// note:
// moving this after pragma push will render it useless (VC6)
//
// identifier truncated to 255 chars in debug information
#pragma warning(disable : 4786)
 
#pragma warning(push)
// *this used in base-member initialization; it's ok
#pragma warning(disable : 4355)
#endif
 
#include <iostream>
#include <map>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
 
namespace Ioss {
  enum {
 
    // default behavior - just loges this assert
    // (a message is shown to the user to the console)
    lvl_warn = 100,
 
    // default behavior - asks the user what to do:
    // Ignore/ Retry/ etc.
    lvl_debug = 200,
 
    // default behavior - throws a smart_assert_error
    lvl_error = 300,
 
    // default behavior - dumps all assert context to console,
    // and aborts
    lvl_fatal = 1000
  };
 
  /*
      contains details about a failed assertion
  */
  class IOSS_EXPORT assert_context
  {
    using string = std::string;
 
  public:
    assert_context() = default;
 
    // where the assertion failed: file & line
    void set_file_line(const char *file, int line)
    {
      file_ = file;
      line_ = line;
    }
    const string &get_context_file() const { return file_; }
    int           get_context_line() const { return line_; }
 
    // get/ set expression
    void          set_expr(const string &str) { expr_ = str; }
    const string &get_expr() const { return expr_; }
 
    using val_and_str = std::pair<string, string>;
    using vals_array  = std::vector<val_and_str>;
    // return values array as a vector of pairs:
    // [Value, corresponding string]
    const vals_array &get_vals_array() const { return vals_; }
    // adds one value and its corresponding string
    void add_val(const string &val, const string &str) { vals_.emplace_back(val, str); }
 
    // get/set level of assertion
    void set_level(int nLevel) { level_ = nLevel; }
    int  get_level() const { return level_; }
 
    // get/set (user-friendly) message
    void set_level_msg(const char *strMsg)
    {
      if (strMsg != nullptr) {
        msg_ = strMsg;
      }
      else {
        msg_.erase();
      }
    }
    const string &get_level_msg() const { return msg_; }
 
  private:
    // where the assertion occurred
    string file_{};
    int    line_{0};
 
    // expression and values
    string     expr_{};
    vals_array vals_{};
 
    // level and message
    int    level_{lvl_debug};
    string msg_{};
  };
 
  namespace SmartAssert {
 
    using assert_func = void (*)(const assert_context &);
 
    // helpers
    IOSS_EXPORT std::string get_typeof_level(int nLevel);
    IOSS_EXPORT void        dump_context_summary(const assert_context &context, std::ostream &out);
    IOSS_EXPORT void        dump_context_detail(const assert_context &context, std::ostream &out);
 
    // defaults
    IOSS_EXPORT void default_warn_handler(const assert_context &context);
    IOSS_EXPORT void default_debug_handler(const assert_context &context);
    IOSS_EXPORT void default_error_handler(const assert_context &context);
    IOSS_EXPORT void default_fatal_handler(const assert_context &context);
    IOSS_EXPORT void default_logger(const assert_context &context);
 
  } // namespace SmartAssert
 
  namespace Private {
    IOSS_EXPORT void init_assert();
    IOSS_EXPORT void set_default_log_stream(std::ostream &out);
    IOSS_EXPORT void set_default_log_name(const char *str);
 
    // allows finding if a value is of type 'const char *'
    // and is null; if so, we cannot print it to an ostream
    // directly!!!
    template <class T> struct is_null_finder
    {
      bool is(const T & /*unused*/) const { return false; }
    };
 
    template <> struct is_null_finder<char *>
    {
      bool is(char *const &val) { return val == nullptr; }
    };
 
    template <> struct is_null_finder<const char *>
    {
      bool is(const char *const &val) { return val == nullptr; }
    };
 
  } // namespace Private
 
  struct IOSS_EXPORT Assert
  {
    using assert_func = SmartAssert::assert_func;
 
    // helpers, in order to be able to compile the code
    Assert &SMART_ASSERT_A;
    Assert &SMART_ASSERT_B;
 
    explicit Assert(const char *expr) : SMART_ASSERT_A(*this), SMART_ASSERT_B(*this)
    {
      context_.set_expr(expr);
 
      if ((logger() == nullptr) || handlers().size() < 4) {
        // used before main!
        Ioss::Private::init_assert();
      }
    }
 
    Assert(const Assert &other)
        : SMART_ASSERT_A(*this), SMART_ASSERT_B(*this), context_(other.context_)
    {
      other.needs_handling_ = false;
    }
 
    ~Assert()
    {
      if (needs_handling_) {
        handle_assert();
      }
    }
 
    template <class type> Assert &print_current_val(const type &val, const char *my_msg)
    {
      std::ostringstream out;
 
      Ioss::Private::is_null_finder<type> f;
      bool                                bIsNull = f.is(val);
      if (!bIsNull) {
        out << val;
      }
      else {
        // null string
        out << "null";
      }
      context_.add_val(out.str(), my_msg);
      return *this;
    }
 
    Assert &print_context(const char *file, int line)
    {
      context_.set_file_line(file, line);
      return *this;
    }
 
    Assert &msg(const char *strMsg)
    {
      context_.set_level_msg(strMsg);
      return *this;
    }
 
    Assert &level(int nLevel, const char *strMsg = nullptr)
    {
      context_.set_level(nLevel);
      context_.set_level_msg(strMsg);
      return *this;
    }
 
    Assert &warn(const char *strMsg = nullptr) { return level(lvl_warn, strMsg); }
 
    Assert &debug(const char *strMsg = nullptr) { return level(lvl_debug, strMsg); }
 
    Assert &error(const char *strMsg = nullptr) { return level(lvl_error, strMsg); }
 
    Assert &fatal(const char *strMsg = nullptr) { return level(lvl_fatal, strMsg); }
 
    // in this case, we set the default logger, and make it
    // write everything to this file
    static void set_log(const char *strFileName)
    {
      Ioss::Private::set_default_log_name(strFileName);
      logger() = &SmartAssert::default_logger;
    }
 
    // in this case, we set the default logger, and make it
    // write everything to this log
    static void set_log(std::ostream &out)
    {
      Ioss::Private::set_default_log_stream(out);
      logger() = &SmartAssert::default_logger;
    }
 
    static void set_log(assert_func log) { logger() = log; }
 
    static void set_handler(int nLevel, assert_func handler) { handlers()[nLevel] = handler; }
 
  private:
    // handles the current assertion.
    void handle_assert()
    {
      logger()(context_);
      get_handler(context_.get_level())(context_);
    }
 
    /*
        IMPORTANT NOTE:
        The only reason logger & handlers are functions, are
        because you might use SMART_ASSERT before main().
 
        In this case, since they're statics, they might not
        be initialized. However, making them functions
        will make it work.
    */
 
    // the log
    static assert_func &logger()
    {
      static assert_func inst;
      return inst;
    }
 
    // the handler
    using handlers_collection = std::map<int, assert_func>;
    static handlers_collection &handlers()
    {
      static handlers_collection inst;
      return inst;
    }
 
    static assert_func get_handler(int nLevel)
    {
      const auto found = handlers().find(nLevel);
      if (found != handlers().end()) {
        return (*found).second;
      }
 
      // we always assume the debug handler has been set
      return (*handlers().find(lvl_debug)).second;
    }
 
    assert_context context_;
    mutable bool   needs_handling_{true};
  };
 
  namespace SmartAssert {
    inline Assert make_assert(const char *expr) { return Assert(expr); }
  } // namespace SmartAssert
 
  ////////////////////////////////////////////////////////
  // macro trickery
 
  // note: NEVER define SMART_ASSERT_DEBUG directly
  // (it will be overridden);
  //
  // #define SMART_ASSERT_DEBUG_MODE instead
 
#ifdef SMART_ASSERT_DEBUG_MODE
#if SMART_ASSERT_DEBUG_MODE == 1
#define SMART_ASSERT_DEBUG
#else
#undef SMART_ASSERT_DEBUG
#endif
 
#else
 
// defaults
#ifndef NDEBUG
#define SMART_ASSERT_DEBUG
#else
#undef SMART_ASSERT_DEBUG
#endif
#endif
 
#ifdef SMART_ASSERT_DEBUG
// "debug" mode
#define SMART_ASSERT(expr)                                                                         \
  if ((expr))                                                                                      \
    ;                                                                                              \
  else                                                                                             \
    (void)::Ioss::SmartAssert::make_assert(#expr)                                                  \
        .print_context(__FILE__, __LINE__)                                                         \
        .SMART_ASSERT_A /**/
 
#else
  // "release" mode
#define SMART_ASSERT(expr)                                                                         \
  if (true)                                                                                        \
    ;                                                                                              \
  else                                                                                             \
    (void)::Ioss::SmartAssert::make_assert("").SMART_ASSERT_A /**/
 
#endif // ifdef SMART_ASSERT_DEBUG
 
#define SMART_VERIFY(expr)                                                                         \
  if ((expr))                                                                                      \
    ;                                                                                              \
  else                                                                                             \
    (void)::Ioss::SmartAssert::make_assert(#expr)                                                  \
        .error()                                                                                   \
        .print_context(__FILE__, __LINE__)                                                         \
        .SMART_ASSERT_A /**/
 
#define SMART_ASSERT_A(x) SMART_ASSERT_OP(x, B)
#define SMART_ASSERT_B(x) SMART_ASSERT_OP(x, A)
 
#define SMART_ASSERT_OP(x, next) SMART_ASSERT_A.print_current_val((x), #x).SMART_ASSERT_##next /**/
} // namespace Ioss
 
#if _MSC_VER > 1000
#pragma warning(pop)
#endif