/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying

   file LICENSE.rst or https://cmake.org/licensing for details.  */

#include "cmExprParserHelper.h"

#include <iostream>

#include <stdexcept>

#include <utility>

#include "cmExprLexer.h"

#include "cmStringAlgorithms.h"

int cmExpr_yyparse(yyscan_t yyscanner);

//

cmExprParserHelper::cmExprParserHelper()

{

  this->FileLine = -1;

  this->FileName = nullptr;

  this->Result = 0;

}

cmExprParserHelper::~cmExprParserHelper() = default;

int cmExprParserHelper::ParseString(char const* str, int verb)

{

  if (!str) {

    return 0;

  }

  // printf("Do some parsing: %s\n", str);

  this->Verbose = verb;

  this->InputBuffer = str;

  this->InputBufferPos = 0;

  this->CurrentLine = 0;

  this->Result = 0;

  yyscan_t yyscanner;

  cmExpr_yylex_init(&yyscanner);

  cmExpr_yyset_extra(this, yyscanner);

  try {

    int res = cmExpr_yyparse(yyscanner);

    if (res != 0) {

      std::string e =

        cmStrCat("cannot parse the expression: \"", this->InputBuffer,

                 "\": ", this->ErrorString, '.');

      this->SetError(std::move(e));

    }

  } catch (std::runtime_error const& fail) {

    std::string e = cmStrCat("cannot evaluate the expression: \"",

                             this->InputBuffer, "\": ", fail.what(), '.');

    this->SetError(std::move(e));

  } catch (std::out_of_range const&) {

    std::string e =

      cmStrCat("cannot evaluate the expression: \"", this->InputBuffer,

               "\": a numeric value is out of range.");

    this->SetError(std::move(e));

  } catch (...) {

    std::string e =

      cmStrCat("cannot parse the expression: \"", this->InputBuffer, "\".");

    this->SetError(std::move(e));

  }

  cmExpr_yylex_destroy(yyscanner);

  if (!this->ErrorString.empty()) {

    return 0;

  }

  if (this->Verbose) {

    std::cerr << "Expanding [" << str << "] produced: [" << this->Result << "]"

              << std::endl;

  }

  return 1;

}

int cmExprParserHelper::LexInput(char* buf, int maxlen)

{

  // std::cout << "JPLexInput ";

  // std::cout.write(buf, maxlen);

  // std::cout << std::endl;

  if (maxlen < 1) {

    return 0;

  }

  if (this->InputBufferPos < this->InputBuffer.size()) {

    buf[0] = this->InputBuffer[this->InputBufferPos++];

    if (buf[0] == '\n') {

      this->CurrentLine++;

    }

    return (1);

  }

  buf[0] = '\n';

  return (0);

}

void cmExprParserHelper::Error(char const* str)

{

  unsigned long pos = static_cast<unsigned long>(this->InputBufferPos);

  this->ErrorString = cmStrCat(str, " (", pos, ')');

}

void cmExprParserHelper::Warning(std::string str)

{

  this->WarningString = cmStrCat(this->WarningString, std::move(str), '\n');

}

void cmExprParserHelper::UnexpectedChar(char c)

{

  unsigned long pos = static_cast<unsigned long>(this->InputBufferPos);

  this->WarningString = cmStrCat(

    this->WarningString, "Unexpected character in expression at position ",

    pos, ": ", c, '\n');

}

void cmExprParserHelper::SetResult(std::int64_t value)

{

  this->Result = value;

}

void cmExprParserHelper::SetError(std::string errorString)

{

  this->ErrorString = std::move(errorString);

}

std::int64_t cmExprParserHelper::ShL(std::int64_t l, std::int64_t r)

{

  if (l < 0) {

    this->Warning(

      cmStrCat("left shift of negative value in:\n  ", l, " << ", r));

  }

  if (r < 0) {

    this->Warning(

      cmStrCat("shift exponent is negative in:\n  ", l, " << ", r));

    r &= 0x3F;

  }

  if (r >= 64) {

    this->Warning(

      cmStrCat("shift exponent is too large in:\n  ", l, " << ", r));

    r &= 0x3F;

  }

  return static_cast<std::int64_t>(static_cast<std::uint64_t>(l) << r);

}

std::int64_t cmExprParserHelper::ShR(std::int64_t l, std::int64_t r)

{

  if (r < 0) {

    this->Warning(

      cmStrCat("shift exponent is negative in:\n  ", l, " >> ", r));

    r &= 0x3F;

  }

  if (r >= 64) {

    this->Warning(

      cmStrCat("shift exponent is too large in:\n  ", l, " >> ", r));

    r &= 0x3F;

  }

  return l >> r;

}

std::int64_t cmExprParserHelper::Add(std::int64_t l, std::int64_t r)

{

  std::int64_t sum;

  if (this->AddOverflow(l, r, &sum)) {

    this->Warning(cmStrCat("signed integer overflow in:\n  ", l, " + ", r));

  }

  return sum;

}

std::int64_t cmExprParserHelper::Sub(std::int64_t l, std::int64_t r)

{

  std::int64_t diff;

  if (this->SubOverflow(l, r, &diff)) {

    this->Warning(cmStrCat("signed integer overflow in:\n  ", l, " - ", r));

  }

  return diff;

}

std::int64_t cmExprParserHelper::Mul(std::int64_t l, std::int64_t r)

{

  std::int64_t prod;

  if (this->MulOverflow(l, r, &prod)) {

    this->Warning(cmStrCat("signed integer overflow in:\n  ", l, " * ", r));

  }

  return prod;

}

std::int64_t cmExprParserHelper::Div(std::int64_t l, std::int64_t r)

{

  if (r == 0) {

    throw std::overflow_error("divide by zero");

  }

  if (l == INT64_MIN && r == -1) {

    throw std::overflow_error("signed integer overflow in division");

  }

  return l / r;

}

std::int64_t cmExprParserHelper::Mod(std::int64_t l, std::int64_t r)

{

  if (r == 0) {

    throw std::overflow_error("modulo by zero");

  }

  if (l == INT64_MIN && r == -1) {

    throw std::overflow_error("signed integer overflow in modulo");

  }

  return l % r;

}

std::int64_t cmExprParserHelper::Neg(std::int64_t x)

{

  if (static_cast<std::uint64_t>(x) == 0x8000000000000000) {

    this->Warning(cmStrCat("signed integer cannot negate:\n  ", x));

    return x;

  }

  return -x;

}

// The __has_builtin preprocessor check was added in Clang 2.6 and GCC 10.

// The __builtin_X_overflow intrinsics were added in Clang 3.4 and GCC 5.

#ifndef __has_builtin

#  if defined(__GNUC__) && __GNUC__ >= 5

#    define __has_builtin(x) 1

#  else

#    define __has_builtin(x) 0

#  endif

#endif

bool cmExprParserHelper::AddOverflow(long l, long r, long* p)

{

#if __has_builtin(__builtin_saddl_overflow)

  return __builtin_saddl_overflow(l, r, p);

#else

  *p = l + r;

  return false;

#endif

}

bool cmExprParserHelper::AddOverflow(long long l, long long r, long long* p)

{

#if __has_builtin(__builtin_saddll_overflow)

  return __builtin_saddll_overflow(l, r, p);

#else

  *p = l + r;

  return false;

#endif

}

bool cmExprParserHelper::SubOverflow(long l, long r, long* p)

{

#if __has_builtin(__builtin_ssubl_overflow)

  return __builtin_ssubl_overflow(l, r, p);

#else

  *p = l - r;

  return false;

#endif

}

bool cmExprParserHelper::SubOverflow(long long l, long long r, long long* p)

{

#if __has_builtin(__builtin_ssubll_overflow)

  return __builtin_ssubll_overflow(l, r, p);

#else

  *p = l - r;

  return false;

#endif

}

bool cmExprParserHelper::MulOverflow(long l, long r, long* p)

{

#if __has_builtin(__builtin_smull_overflow)

  return __builtin_smull_overflow(l, r, p);

#else

  *p = l * r;

  return false;

#endif

}

bool cmExprParserHelper::MulOverflow(long long l, long long r, long long* p)

{

#if __has_builtin(__builtin_smulll_overflow)

  return __builtin_smulll_overflow(l, r, p);

#else

  *p = l * r;

  return false;

#endif

}