verilator/src/V3ParseImp.h

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Common header between parser and lex
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2009-2020 by Wilson Snyder. This program is free software; you
// can redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//*************************************************************************

#ifndef _V3PARSEIMP_H_
#define _V3PARSEIMP_H_ 1

#include "config_build.h"
#include "verilatedos.h"

#include "V3Error.h"
#include "V3FileLine.h"
#include "V3Global.h"
#include "V3Parse.h"
#include "V3ParseSym.h"

#include <algorithm>
#include <deque>

class V3Lexer;

// IMPORTANT: Don't include this file other than in the bison and flex,
// as it's definitions will confuse other parsers

//======================================================================
// Types (between parser & lexer)

typedef enum { uniq_NONE, uniq_UNIQUE, uniq_UNIQUE0, uniq_PRIORITY } V3UniqState;

typedef enum { iprop_NONE, iprop_CONTEXT, iprop_PURE } V3ImportProperty;

//============================================================================
// Parser YYSType, e.g. for parser's yylval
// We can't use bison's %union as we want to pass the fileline with all tokens

struct V3ParseBisonYYSType {
    FileLine* fl;
    AstNode* scp;  // Symbol table scope for future lookups
    int token;  // Read token, aka tok
    union {
        V3Number* nump;
        string* strp;
        int cint;
        double cdouble;
        bool cbool;
        V3UniqState uniqstate;
        V3ImportProperty iprop;
        VSigning::en signstate;
        V3ErrorCode::en errcodeen;
        AstAttrType::en attrtypeen;
        VLifetime::en lifetime;

        AstNode* nodep;

        AstBasicDType* bdtypep;
        AstBegin* beginp;
        AstCase* casep;
        AstCaseItem* caseitemp;
        AstCell* cellp;
        AstClass* classp;
        AstConst* constp;
        AstFork* forkp;
        AstMemberDType* memberp;
        AstNodeModule* modulep;
        AstNodeUOrStructDType* uorstructp;
        AstNodeDType* dtypep;
        AstNodeFTask* ftaskp;
        AstNodeFTaskRef* ftaskrefp;
        AstNodeRange* rangep;
        AstNodeSenItem* senitemp;
        AstNodeVarRef* varnodep;
        AstPackage* packagep;
        AstPackageRef* packagerefp;
        AstParseRef* parserefp;
        AstPatMember* patmemberp;
        AstPattern* patternp;
        AstPin* pinp;
        AstRefDType* refdtypep;
        AstSenTree* sentreep;
        AstVar* varp;
        AstVarRef* varrefp;
    };
};
std::ostream& operator<<(std::ostream& os, const V3ParseBisonYYSType& rhs);

#define YYSTYPE V3ParseBisonYYSType

//######################################################################

class V3ParseImp {
    // MEMBERS
    AstNetlist* m_rootp;  // Root of the design
    VInFilter* m_filterp;  // Reading filter
    V3ParseSym* m_symp;  // Symbol table

    V3Lexer* m_lexerp;  // Current FlexLexer
    static V3ParseImp* s_parsep;  // Current THIS, bison() isn't class based
    FileLine* m_lexFileline;  // Filename/linenumber currently active for lexing

    FileLine* m_bisonLastFileline;  // Filename/linenumber of last token

    bool m_inLibrary;  // Currently reading a library vs. regular file
    int m_lexKwdDepth;  // Inside a `begin_keywords
    int m_lexKwdLast;  // Last LEX state in `begin_keywords
    VOptionBool m_unconnectedDrive;  // Last unconnected drive

    int m_lexPrevToken;  // previous parsed token (for lexer)
    std::deque<V3ParseBisonYYSType> m_tokensAhead;  // Tokens we parsed ahead of parser

    std::deque<string*> m_stringps;  // Created strings for later cleanup
    std::deque<V3Number*> m_numberps;  // Created numbers for later cleanup
    std::deque<FileLine> m_lexLintState;  // Current lint state for save/restore
    std::deque<string> m_ppBuffers;  // Preprocessor->lex buffer of characters to process

    AstNode* m_tagNodep;  // Points to the node to set to m_tag or NULL to not set.
    VTimescale m_timeLastUnit;  // Last `timescale's unit

public:
    // Note these are an exception to using the filename as the debug type
    static int debugBison() {
        static int level = -1;
        if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel("bison");
        return level;
    }
    static int debugFlex() {
        static int level = -1;
        if (VL_UNLIKELY(level < 0)) level = v3Global.opt.debugSrcLevel("flex");
        return level;
    }
    static int debug() {
        static int level = -1;
        if (VL_UNLIKELY(level < 0))
            level = std::max(std::max(debugBison(), debugFlex()),
                             v3Global.opt.debugSrcLevel("V3ParseImp"));
        return level;
    }

    // Functions called by lex rules:
    int yylexThis();
    static bool optFuture(const string& flag) { return v3Global.opt.isFuture(flag); }

    void tagNodep(AstNode* nodep) { m_tagNodep = nodep; }
    AstNode* tagNodep() const { return m_tagNodep; }
    void lexTimescaleParse(FileLine* fl, const char* textp);
    void timescaleMod(FileLine* fl, AstNodeModule* modp, bool unitSet, double unitVal,
                      bool precSet, double precVal);
    VTimescale timeLastUnit() const { return m_timeLastUnit; }

    FileLine* lexFileline() const { return m_lexFileline; }
    FileLine* lexCopyOrSameFileLine() { return lexFileline()->copyOrSameFileLine(); }
    static void lexErrorPreprocDirective(FileLine* fl, const char* textp);
    static string lexParseTag(const char* textp);
    static double lexParseTimenum(const char* text);
    void lexPpline(const char* textp);
    void lexVerilatorCmtLint(FileLine* fl, const char* textp, bool warnOff);
    void lexVerilatorCmtLintSave(const FileLine* fl);
    void lexVerilatorCmtLintRestore(FileLine* fl);
    static void lexVerilatorCmtBad(FileLine* fl, const char* textp);

    void lexPushKeywords(int state) {
        ++m_lexKwdDepth;
        m_lexKwdLast = state;
    }
    bool lexPopKeywords() {
        if (m_lexKwdDepth) {
            --m_lexKwdDepth;
            return true;
        } else {
            return false;
        }
    }
    int lexKwdLastState() const { return m_lexKwdLast; }
    static const char* tokenName(int tok);

    void ppPushText(const string& text) {
        m_ppBuffers.push_back(text);
        if (lexFileline()->contentp()) lexFileline()->contentp()->pushText(text);
    }
    size_t ppInputToLex(char* buf, size_t max_size);

    static V3ParseImp* parsep() { return s_parsep; }

    // TODO: Many of these functions are the old interface; they'd be better as non-static
    // and called as READP->newString(...) etc.
    // These can be called by either parser or lexer, as not lex/parser-position aware
    string* newString(const string& text) {
        // Allocate a string, remembering it so we can reclaim storage at lex end
        string* strp = new string(text);
        m_stringps.push_back(strp);
        return strp;
    }
    string* newString(const char* text) {
        // Allocate a string, remembering it so we can reclaim storage at lex end
        string* strp = new string(text);
        m_stringps.push_back(strp);
        return strp;
    }
    string* newString(const char* text, size_t length) {
        string* strp = new string(text, length);
        m_stringps.push_back(strp);
        return strp;
    }
    V3Number* newNumber(FileLine* fl, const char* text) {
        V3Number* nump = new V3Number(V3Number::FileLined(), fl, text);
        m_numberps.push_back(nump);
        return nump;
    }

    // Bison sometimes needs error context without a token, so remember last token's line
    // Only use this if do not have and cannot get a token-relevent fileline
    FileLine* bisonLastFileline() const { return m_bisonLastFileline; }

    // Return next token, for bison, since bison isn't class based, use a global THIS
    AstNetlist* rootp() const { return m_rootp; }
    FileLine* copyOrSameFileLine() { return bisonLastFileline()->copyOrSameFileLine(); }
    bool inLibrary() const { return m_inLibrary; }
    VOptionBool unconnectedDrive() const { return m_unconnectedDrive; }
    void unconnectedDrive(const VOptionBool flag) { m_unconnectedDrive = flag; }

    // Interactions with parser
    int bisonParse();

    // Interactions with lexer
    void lexNew();
    void lexDestroy();
    static int stateVerilogRecent();  // Parser -> lexer communication
    int lexPrevToken() const { return m_lexPrevToken; }  // Parser -> lexer communication
    size_t flexPpInputToLex(char* buf, size_t max_size) { return ppInputToLex(buf, max_size); }

    //==== Symbol tables
    V3ParseSym* symp() { return m_symp; }

public:
    // CONSTRUCTORS
    V3ParseImp(AstNetlist* rootp, VInFilter* filterp, V3ParseSym* parserSymp)
        : m_rootp(rootp)
        , m_filterp(filterp)
        , m_symp(parserSymp) {
        m_lexFileline = NULL;
        m_lexerp = NULL;
        m_inLibrary = false;
        m_lexKwdDepth = 0;
        m_lexKwdLast = stateVerilogRecent();
        m_lexPrevToken = 0;
        m_tagNodep = NULL;
        m_timeLastUnit = v3Global.opt.timeDefaultUnit();
    }
    ~V3ParseImp();
    void parserClear();
    void lexUnputString(const char* textp, size_t length);

    // METHODS
    // Preprocess and read the Verilog file specified into the netlist database
    int tokenToBison();  // Pass token to bison

    void parseFile(FileLine* fileline, const string& modfilename, bool inLibrary,
                   const string& errmsg);

private:
    void lexFile(const string& modname);
    void yylexReadTok();
    void tokenPull();
    void tokenPipeline();  // Internal; called from tokenToBison
    void tokenPipelineSym();
    bool tokenPipeScanParam();
    const V3ParseBisonYYSType* tokenPeekp(size_t depth);
    void preprocDumps(std::ostream& os);
};

#endif  // Guard