error_reporter.h

/*
Copyright 2013-present Barefoot Networks, Inc.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
 
#ifndef LIB_ERROR_REPORTER_H_
#define LIB_ERROR_REPORTER_H_
 
#include <iostream>
#include <ostream>
#include <set>
#include <type_traits>
#include <unordered_map>
 
#include <boost/format.hpp>
 
#include "absl/strings/str_format.h"
#include "bug_helper.h"
#include "error_catalog.h"
#include "error_helper.h"
#include "exceptions.h"
 
namespace P4 {

enum class DiagnosticAction {
    Ignore,  
    Info,    
    Warn,    
    Error    
};
 
// Keeps track of compilation errors.
// Errors are specified using the error() and warning() methods,
// that use boost::format format strings, i.e.,
// %1%, %2%, etc (starting at 1, not at 0).
// Some compatibility for printf-style arguments is also supported.
class ErrorReporter {
 protected:
    unsigned int infoCount;
    unsigned int warningCount;
    unsigned int errorCount;
    unsigned int maxErrorCount;  
 
    std::ostream *outputstream;

    std::set<std::pair<int, const Util::SourceInfo>> errorTracker;

    virtual void emit_message(const ErrorMessage &msg) {
        *outputstream << msg.toString();
        outputstream->flush();
    }
 
    virtual void emit_message(const ParserErrorMessage &msg) {
        *outputstream << msg.toString();
        outputstream->flush();
    }

    bool error_reported(int err, Util::SourceInfo source) {
        if (!source.isValid()) return false;
        auto p = errorTracker.emplace(err, source);
        return !p.second;  // if insertion took place, then we have not seen the error.
    }

    cstring get_error_name(int errorCode) { return ErrorCatalog::getCatalog().getName(errorCode); }
 
 public:
    ErrorReporter()
        : infoCount(0),
          warningCount(0),
          errorCount(0),
          maxErrorCount(20),
          defaultInfoDiagnosticAction(DiagnosticAction::Info),
          defaultWarningDiagnosticAction(DiagnosticAction::Warn) {
        outputstream = &std::cerr;
    }
 
    // error message for a bug
    template <typename... Args>
    std::string bug_message(const char *format, Args &&...args) {
        boost::format fmt(format);
        // FIXME: This will implicitly take location of the first argument having
        // SourceInfo. Not sure if this always desireable or not.
        return ::P4::bug_helper(fmt, "", "", std::forward<Args>(args)...);
    }
 
    template <typename... Args>
    std::string format_message(const char *format, Args &&...args) {
        boost::format fmt(format);
        return ::P4::error_helper(fmt, std::forward<Args>(args)...).toString();
    }
 
    template <class T, typename = decltype(std::declval<T>()->getSourceInfo()), typename... Args>
    void diagnose(DiagnosticAction action, const int errorCode, const char *format,
                  const char *suffix, T node, Args &&...args) {
        if (!node || error_reported(errorCode, node->getSourceInfo())) return;
 
        if (cstring name = get_error_name(errorCode))
            diagnose(getDiagnosticAction(name, action), name, format, suffix, node,
                     std::forward<Args>(args)...);
        else
            diagnose(action, nullptr, format, suffix, node, std::forward<Args>(args)...);
    }
 
    template <typename... Args>
    void diagnose(DiagnosticAction action, const int errorCode, const char *format,
                  const char *suffix, Args &&...args) {
        if (cstring name = get_error_name(errorCode))
            diagnose(getDiagnosticAction(name, action), name, format, suffix,
                     std::forward<Args>(args)...);
        else
            diagnose(action, nullptr, format, suffix, std::forward<Args>(args)...);
    }

    template <typename... Args>
    void diagnose(DiagnosticAction action, const char *diagnosticName, const char *format,
                  const char *suffix, Args &&...args) {
        if (action == DiagnosticAction::Ignore) return;
 
        ErrorMessage::MessageType msgType = ErrorMessage::MessageType::None;
        if (action == DiagnosticAction::Info) {
            // Avoid burying errors in a pile of info messages:
            // don't emit any more info messages if we've emitted errors.
            if (errorCount > 0) return;
 
            infoCount++;
            msgType = ErrorMessage::MessageType::Info;
        } else if (action == DiagnosticAction::Warn) {
            // Avoid burying errors in a pile of warnings: don't emit any more warnings if we've
            // emitted errors.
            if (errorCount > 0) return;
 
            warningCount++;
            msgType = ErrorMessage::MessageType::Warning;
        } else if (action == DiagnosticAction::Error) {
            errorCount++;
            msgType = ErrorMessage::MessageType::Error;
        }
 
        boost::format fmt(format);
        ErrorMessage msg(msgType, diagnosticName ? diagnosticName : "", suffix);
        msg = ::P4::error_helper(fmt, msg, std::forward<Args>(args)...);
        emit_message(msg);
 
        if (errorCount > maxErrorCount)
            FATAL_ERROR("Number of errors exceeded set maximum of %1%", maxErrorCount);
    }
 
    unsigned getErrorCount() const { return errorCount; }
 
    unsigned getMaxErrorCount() const { return maxErrorCount; }
    unsigned setMaxErrorCount(unsigned newMaxCount) {
        auto r = maxErrorCount;
        maxErrorCount = newMaxCount;
        return r;
    }
 
    unsigned getWarningCount() const { return warningCount; }
 
    unsigned getInfoCount() const { return infoCount; }

    unsigned getDiagnosticCount() const { return errorCount + warningCount + infoCount; }
 
    void setOutputStream(std::ostream *stream) { outputstream = stream; }
 
    std::ostream *getOutputStream() const { return outputstream; }

    template <typename T>
    void parser_error(const Util::SourceInfo &location, const T &message) {
        errorCount++;
        std::stringstream ss;
        ss << message;
 
        emit_message(ParserErrorMessage(location, ss.str()));
    }

    template <typename... Args>
    void parser_error(const Util::InputSources *sources, const char *fmt, Args &&...args) {
        errorCount++;
 
        Util::SourcePosition position = sources->getCurrentPosition();
        position--;
 
        // Unfortunately, we cannot go with statically checked format string
        // here as it would require some changes to yyerror
        std::string message;
        if (!absl::FormatUntyped(&message, absl::UntypedFormatSpec(fmt),
                                 {absl::FormatArg(args)...})) {
            BUG("Failed to format string");
        }
 
        emit_message(ParserErrorMessage(Util::SourceInfo(sources, position), std::move(message)));
    }

    DiagnosticAction getDiagnosticAction(cstring diagnostic, DiagnosticAction defaultAction) {
        // Actions for errors can never be overridden.
        if (defaultAction == DiagnosticAction::Error) return defaultAction;
        auto it = diagnosticActions.find(diagnostic);
        if (it != diagnosticActions.end()) return it->second;
        // if we're dealing with warnings and they have been globally modified
        // (ignored or turned into errors), then return the global default
        if (defaultAction == DiagnosticAction::Warn &&
            defaultWarningDiagnosticAction != DiagnosticAction::Warn)
            return defaultWarningDiagnosticAction;
        return defaultAction;
    }

    void setDiagnosticAction(std::string_view diagnostic, DiagnosticAction action) {
        diagnosticActions[cstring(diagnostic)] = action;
    }

    DiagnosticAction getDefaultWarningDiagnosticAction() { return defaultWarningDiagnosticAction; }

    void setDefaultWarningDiagnosticAction(DiagnosticAction action) {
        defaultWarningDiagnosticAction = action;
    }

    DiagnosticAction getDefaultInfoDiagnosticAction() { return defaultInfoDiagnosticAction; }

    void setDefaultInfoDiagnosticAction(DiagnosticAction action) {
        defaultInfoDiagnosticAction = action;
    }
 
 private:
    DiagnosticAction defaultInfoDiagnosticAction;

    DiagnosticAction defaultWarningDiagnosticAction;

    std::unordered_map<cstring, DiagnosticAction> diagnosticActions;
};
 
}  // namespace P4
 
#endif /* LIB_ERROR_REPORTER_H_ */