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Now escaping character and string constants correctly

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git-svn-id: http://picoc.googlecode.com/svn/trunk@85 21eae674-98b7-11dd-bd71-f92a316d2d60
This commit is contained in:
zik.saleeba 2009-02-19 04:34:36 +00:00
parent 2caa072dec
commit f45882e7e2
1 changed files with 55 additions and 7 deletions
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62
lex.c
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@ -151,16 +151,56 @@ enum LexToken LexGetWord(struct LexState *Lexer, struct Value *Value)
return TokenIdentifier;
}
/* unescape a character from a string or character constant */
unsigned char LexUnEscapeCharacter(const char **From, const char *End)
{
unsigned char ThisChar;
while ( *From != End && **From == '\\' &&
&(*From)[1] != End && (*From)[1] == '\n')
(*From) += 2; /* skip escaped end of lines */
if (*From == End)
return '\\';
if (**From == '\\')
{ /* it's escaped */
(*From)++;
if (*From == End)
return '\\';
ThisChar = *(*From)++;
switch (ThisChar)
{
case '\\': return '\\';
case '\'': return '\'';
case '"': return '"';
case 'a': return '\a';
case 'b': return '\b';
case 'f': return '\f';
case 'n': return '\n';
case 'r': return '\r';
case 't': return '\t';
case 'v': return '\v';
default: return ThisChar;
}
}
else
return *(*From)++;
}
/* get a string constant - used while scanning */
enum LexToken LexGetStringConstant(struct LexState *Lexer, struct Value *Value)
{
int Escape = FALSE;
const char *StartPos = Lexer->Pos;
const char *EndPos;
char *EscBuf;
char *EscBufPos;
// XXX - do escaping here
Value->Typ = &StringType;
while (Lexer->Pos != Lexer->End && (*Lexer->Pos != '"' || Escape))
{
{ /* find the end */
if (Escape)
Escape = FALSE;
else if (*Lexer->Pos == '\\')
@ -168,7 +208,14 @@ enum LexToken LexGetStringConstant(struct LexState *Lexer, struct Value *Value)
Lexer->Pos++;
}
Value->Val->String = (char *)StrRegister2(StartPos, Lexer->Pos - StartPos);
EndPos = Lexer->Pos;
EscBuf = HeapAllocStack(EndPos - StartPos);
for (EscBufPos = EscBuf, Lexer->Pos = StartPos; Lexer->Pos != EndPos;)
*EscBufPos++ = LexUnEscapeCharacter(&Lexer->Pos, EndPos);
Value->Val->String = (char *)StrRegister2(EscBuf, EscBufPos - EscBuf);
HeapPopStack(EscBuf, EndPos - StartPos);
if (*Lexer->Pos == '"')
Lexer->Pos++;
@ -179,11 +226,12 @@ enum LexToken LexGetStringConstant(struct LexState *Lexer, struct Value *Value)
enum LexToken LexGetCharacterConstant(struct LexState *Lexer, struct Value *Value)
{
Value->Typ = &IntType;
Value->Val->Integer = Lexer->Pos[1];
if (Lexer->Pos[2] != '\'')
LexFail(Lexer, "illegal character '%c'", Lexer->Pos[2]);
Lexer->Pos++;
Value->Val->Integer = LexUnEscapeCharacter(&Lexer->Pos, Lexer->End);
if (Lexer->Pos != Lexer->End || *Lexer->Pos != '\'')
LexFail(Lexer, "expected \"'\"");
Lexer->Pos += 3;
Lexer->Pos++;
return TokenCharacterConstant;
}