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Changed binary expression parsing to use precedence parsing.

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This commit is contained in:
Erik Verbruggen
2010-01-28 15:22:36 +01:00
parent 3dd011fcb6
commit 0fdf02ab4d
1 changed files with 116 additions and 217 deletions
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333
src/libs/cplusplus/pp-engine.cpp
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@@ -246,10 +246,10 @@ protected:
return text;
}
bool process_expression()
{ return process_constant_expression(); }
inline void process_expression()
{ process_constant_expression(); }
bool process_primary()
void process_primary()
{
if ((*_lex)->is(T_NUMERIC_LITERAL)) {
int base = 10;
@@ -262,13 +262,11 @@ protected:
}
_value.set_long(tokenSpell().toLong(0, base));
++(*_lex);
return true;
} else if (isTokenDefined()) {
++(*_lex);
if ((*_lex)->is(T_IDENTIFIER)) {
_value.set_long(isMacroDefined(tokenSpell(), (*_lex)->offset, env, client));
++(*_lex);
return true;
} else if ((*_lex)->is(T_LPAREN)) {
++(*_lex);
if ((*_lex)->is(T_IDENTIFIER)) {
@@ -276,245 +274,62 @@ protected:
++(*_lex);
if ((*_lex)->is(T_RPAREN)) {
++(*_lex);
return true;
}
}
return false;
}
return true;
} else if ((*_lex)->is(T_IDENTIFIER)) {
_value.set_long(0);
++(*_lex);
return true;
} else if ((*_lex)->is(T_MINUS)) {
++(*_lex);
process_primary();
_value.set_long(- _value.l);
return true;
} else if ((*_lex)->is(T_PLUS)) {
++(*_lex);
process_primary();
return true;
} else if ((*_lex)->is(T_EXCLAIM)) {
++(*_lex);
process_primary();
_value.set_long(_value.is_zero());
return true;
} else if ((*_lex)->is(T_LPAREN)) {
++(*_lex);
process_expression();
if ((*_lex)->is(T_RPAREN))
++(*_lex);
return true;
}
return false;
}
bool process_multiplicative()
Value process_expression_with_operator_precedence(const Value &lhs, int minPrecedence)
{
Value result = lhs;
while (precedence((*_lex)->kind()) >= minPrecedence) {
const int oper = (*_lex)->kind();
const int operPrecedence = precedence(oper);
++(*_lex);
process_primary();
Value rhs = _value;
for (int LA_token_kind = (*_lex)->kind(), LA_precedence = precedence(LA_token_kind);
LA_precedence > operPrecedence && isBinaryOperator(LA_token_kind)
|| LA_precedence == operPrecedence && isRightAssoc(LA_token_kind);
LA_token_kind = (*_lex)->kind(), LA_precedence = precedence(LA_token_kind)) {
rhs = process_expression_with_operator_precedence(rhs, LA_precedence);
}
result = evaluate_expression(oper, result, rhs);
}
return result;
}
void process_constant_expression()
{
process_primary();
_value = process_expression_with_operator_precedence(_value, precedence(T_PIPE_PIPE));
while ((*_lex)->is(T_STAR) || (*_lex)->is(T_SLASH) || (*_lex)->is(T_PERCENT)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_primary();
if (op.is(T_STAR)) {
_value = left * _value;
} else if (op.is(T_SLASH)) {
if (_value.is_zero())
_value.set_long(0);
else
_value = left / _value;
} else if (op.is(T_PERCENT)) {
if (_value.is_zero())
_value.set_long(0);
else
_value = left % _value;
}
}
return true;
}
bool process_additive()
{
process_multiplicative();
while ((*_lex)->is(T_PLUS) || (*_lex)->is(T_MINUS)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_multiplicative();
if (op.is(T_PLUS))
_value = left + _value;
else if (op.is(T_MINUS))
_value = left - _value;
}
return true;
}
bool process_shift()
{
process_additive();
while ((*_lex)->is(T_MINUS_MINUS) || (*_lex)->is(T_GREATER_GREATER)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_additive();
if (op.is(T_MINUS_MINUS))
_value = left << _value;
else if (op.is(T_GREATER_GREATER))
_value = left >> _value;
}
return true;
}
bool process_relational()
{
process_shift();
while ((*_lex)->is(T_LESS) || (*_lex)->is(T_LESS_EQUAL) ||
(*_lex)->is(T_GREATER) || (*_lex)->is(T_GREATER_EQUAL)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_shift();
if (op.is(T_LESS))
_value = left < _value;
else if (op.is(T_LESS_EQUAL))
_value = left <= _value;
else if (op.is(T_GREATER))
_value = left > _value;
else if (op.is(T_GREATER_EQUAL))
_value = left >= _value;
}
return true;
}
bool process_equality()
{
process_relational();
while ((*_lex)->is(T_EXCLAIM_EQUAL) || (*_lex)->is(T_EQUAL_EQUAL)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_relational();
if (op.is(T_EXCLAIM_EQUAL))
_value = left != _value;
else if (op.is(T_EQUAL_EQUAL))
_value = left == _value;
}
return true;
}
bool process_and()
{
process_equality();
while ((*_lex)->is(T_AMPER)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_equality();
_value = left & _value;
}
return true;
}
bool process_xor()
{
process_and();
while ((*_lex)->is(T_CARET)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_and();
_value = left ^ _value;
}
return true;
}
bool process_or()
{
process_xor();
while ((*_lex)->is(T_PIPE)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_xor();
_value = left | _value;
}
return true;
}
bool process_logical_and()
{
process_or();
while ((*_lex)->is(T_AMPER_AMPER)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_or();
_value = left && _value;
}
return true;
}
bool process_logical_or()
{
process_logical_and();
while ((*_lex)->is(T_PIPE_PIPE)) {
const Token op = *(*_lex);
++(*_lex);
const Value left = _value;
process_logical_and();
_value = left || _value;
}
return true;
}
bool process_constant_expression()
{
process_logical_or();
const Value cond = _value;
if ((*_lex)->is(T_QUESTION)) {
const Value cond = _value;
++(*_lex);
process_constant_expression();
Value left = _value, right;
@@ -525,10 +340,94 @@ protected:
}
_value = ! cond.is_zero() ? left : right;
}
return true;
}
private:
inline int precedence(int tokenKind) const
{
switch (tokenKind) {
case T_PIPE_PIPE: return 0;
case T_AMPER_AMPER: return 1;
case T_PIPE: return 2;
case T_CARET: return 3;
case T_AMPER: return 4;
case T_EQUAL_EQUAL:
case T_EXCLAIM_EQUAL: return 5;
case T_GREATER:
case T_LESS:
case T_LESS_EQUAL:
case T_GREATER_EQUAL: return 6;
case T_LESS_LESS:
case T_GREATER_GREATER: return 7;
case T_PLUS:
case T_MINUS: return 8;
case T_STAR:
case T_SLASH:
case T_PERCENT: return 9;
default:
return -1;
}
}
static inline bool isBinaryOperator(int tokenKind)
{
switch (tokenKind) {
case T_PIPE_PIPE:
case T_AMPER_AMPER:
case T_PIPE:
case T_CARET:
case T_AMPER:
case T_EQUAL_EQUAL:
case T_EXCLAIM_EQUAL:
case T_GREATER:
case T_LESS:
case T_LESS_EQUAL:
case T_GREATER_EQUAL:
case T_LESS_LESS:
case T_GREATER_GREATER:
case T_PLUS:
case T_MINUS:
case T_STAR:
case T_SLASH:
case T_PERCENT:
return true;
default:
return false;
}
}
static inline Value evaluate_expression(int tokenKind, const Value &lhs, const Value &rhs)
{
switch (tokenKind) {
case T_PIPE_PIPE: return lhs || rhs;
case T_AMPER_AMPER: return lhs && rhs;
case T_PIPE: return lhs | rhs;
case T_CARET: return lhs ^ rhs;
case T_AMPER: return lhs & rhs;
case T_EQUAL_EQUAL: return lhs == rhs;
case T_EXCLAIM_EQUAL: return lhs != rhs;
case T_GREATER: return lhs > rhs;
case T_LESS: return lhs < rhs;
case T_LESS_EQUAL: return lhs <= rhs;
case T_GREATER_EQUAL: return lhs >= rhs;
case T_LESS_LESS: return lhs << rhs;
case T_GREATER_GREATER: return lhs >> rhs;
case T_PLUS: return lhs + rhs;
case T_MINUS: return lhs - rhs;
case T_STAR: return lhs * rhs;
case T_SLASH: return rhs.is_zero() ? Value() : lhs / rhs;
case T_PERCENT: return rhs.is_zero() ? Value() : lhs % rhs;
default:
return Value();
}
}
static inline bool isRightAssoc(int /*tokenKind*/)
{ return false; }
private:
Client *client;
Environment *env;