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cpplib: More lexer work
- From: Neil Booth <neil at daikokuya dot co dot uk>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sat, 19 Apr 2003 17:36:08 +0100
- Subject: cpplib: More lexer work
This removes the backtracking and character peeking framework that was
necessary when logical lines weren't "clean". This should save several
thousand, if not several tens of thousands, of function calls per
translation unit.
Neil.
* cpphash.h (struct cpp_buffer): Remove backup_to.
* cpplex.c (BACKUP, get_effective_char): Die.
(_cpp_skip_block_comment): Assume '*' is location on entry.
(continues_identifier_p): Respect -fno-dollars-in-identifiers.
(IF_NEXT_IS): Update.
(_cpp_lex_direct): Don't use backup_to; look ahead directly.
Index: cpphash.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cpphash.h,v
retrieving revision 1.182
diff -u -p -r1.182 cpphash.h
--- cpphash.h 19 Apr 2003 11:59:43 -0000 1.182
+++ cpphash.h 19 Apr 2003 16:31:26 -0000
@@ -267,8 +267,6 @@ struct cpp_buffer
struct cpp_buffer *prev;
- const unsigned char *backup_to; /* Soon to die. */
-
/* Pointer into the include table; non-NULL if this is a file
buffer. Used for include_next and to record control macros. */
struct include_file *inc;
Index: cpplex.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cpplex.c,v
retrieving revision 1.223
diff -u -p -r1.223 cpplex.c
--- cpplex.c 19 Apr 2003 11:59:43 -0000 1.223
+++ cpplex.c 19 Apr 2003 16:31:27 -0000
@@ -55,11 +55,8 @@ static const struct token_spelling token
#define TOKEN_SPELL(token) (token_spellings[(token)->type].category)
#define TOKEN_NAME(token) (token_spellings[(token)->type].name)
-#define BACKUP() do {buffer->cur = buffer->backup_to;} while (0)
static void add_line_note PARAMS ((cpp_buffer *, const uchar *, unsigned int));
-static cppchar_t get_effective_char PARAMS ((cpp_reader *));
-
static int skip_line_comment PARAMS ((cpp_reader *));
static void skip_whitespace PARAMS ((cpp_reader *, cppchar_t));
static cpp_hashnode *lex_identifier PARAMS ((cpp_reader *));
@@ -246,24 +243,11 @@ _cpp_process_line_notes (pfile, in_comme
}
}
-/* Obtain the next character, after trigraph conversion and skipping
- an arbitrarily long string of escaped newlines. The common case of
- no trigraphs or escaped newlines falls through quickly. On return,
- buffer->backup_to points to where to return to if the character is
- not to be processed. */
-static cppchar_t
-get_effective_char (pfile)
- cpp_reader *pfile;
-{
- cpp_buffer *buffer = pfile->buffer;
-
- buffer->backup_to = buffer->cur;
- return *buffer->cur++;
-}
-
/* Skip a C-style block comment. We find the end of the comment by
seeing if an asterisk is before every '/' we encounter. Returns
- nonzero if comment terminated by EOF, zero otherwise. */
+ nonzero if comment terminated by EOF, zero otherwise.
+
+ Buffer->cur points to the initial asterisk of the comment. */
bool
_cpp_skip_block_comment (pfile)
cpp_reader *pfile;
@@ -271,6 +255,7 @@ _cpp_skip_block_comment (pfile)
cpp_buffer *buffer = pfile->buffer;
cppchar_t c;
+ buffer->cur++;
if (*buffer->cur == '/')
buffer->cur++;
@@ -381,7 +366,7 @@ static bool
continues_identifier_p (pfile)
cpp_reader *pfile;
{
- if (*pfile->buffer->cur != '$')
+ if (*pfile->buffer->cur != '$' || !CPP_OPTION (pfile, dollars_in_ident))
return false;
if (CPP_PEDANTIC (pfile) && !pfile->state.skipping && !pfile->warned_dollar)
@@ -492,8 +477,7 @@ lex_string (pfile, token)
{
cppchar_t c = *buffer->cur++;
- /* In #include-style directives, terminators are not escapable.
- \n can follow the '\\' if the file's last byte is '\\'. */
+ /* In #include-style directives, terminators are not escapable. */
if (c == '\\' && !pfile->state.angled_headers && *buffer->cur != '\n')
buffer->cur++;
else if (c == terminator || c == '\n')
@@ -728,16 +712,14 @@ _cpp_get_fresh_line (pfile)
}
}
-#define IF_NEXT_IS(CHAR, THEN_TYPE, ELSE_TYPE) \
- do { \
- if (get_effective_char (pfile) == CHAR) \
- result->type = THEN_TYPE; \
- else \
- { \
- BACKUP (); \
- result->type = ELSE_TYPE; \
- } \
- } while (0)
+#define IF_NEXT_IS(CHAR, THEN_TYPE, ELSE_TYPE) \
+ do \
+ { \
+ result->type = ELSE_TYPE; \
+ if (*buffer->cur == CHAR) \
+ buffer->cur++, result->type = THEN_TYPE; \
+ } \
+ while (0)
/* Lex a token into pfile->cur_token, which is also incremented, to
get diagnostics pointing to the correct location.
@@ -853,8 +835,8 @@ _cpp_lex_direct (pfile)
case '/':
/* A potential block or line comment. */
comment_start = buffer->cur;
- c = get_effective_char (pfile);
-
+ c = *buffer->cur;
+
if (c == '*')
{
if (_cpp_skip_block_comment (pfile))
@@ -880,12 +862,12 @@ _cpp_lex_direct (pfile)
}
else if (c == '=')
{
+ buffer->cur++;
result->type = CPP_DIV_EQ;
break;
}
else
{
- BACKUP ();
result->type = CPP_DIV;
break;
}
@@ -908,178 +890,136 @@ _cpp_lex_direct (pfile)
break;
}
- c = get_effective_char (pfile);
- if (c == '=')
- result->type = CPP_LESS_EQ;
- else if (c == '<')
- IF_NEXT_IS ('=', CPP_LSHIFT_EQ, CPP_LSHIFT);
- else if (c == '?' && CPP_OPTION (pfile, cplusplus))
- IF_NEXT_IS ('=', CPP_MIN_EQ, CPP_MIN);
- else if (c == ':' && CPP_OPTION (pfile, digraphs))
+ result->type = CPP_LESS;
+ if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_LESS_EQ;
+ else if (*buffer->cur == '<')
{
- result->type = CPP_OPEN_SQUARE;
- result->flags |= DIGRAPH;
+ buffer->cur++;
+ IF_NEXT_IS ('=', CPP_LSHIFT_EQ, CPP_LSHIFT);
}
- else if (c == '%' && CPP_OPTION (pfile, digraphs))
+ else if (*buffer->cur == '?' && CPP_OPTION (pfile, cplusplus))
{
- result->type = CPP_OPEN_BRACE;
- result->flags |= DIGRAPH;
+ buffer->cur++;
+ IF_NEXT_IS ('=', CPP_MIN_EQ, CPP_MIN);
}
- else
+ else if (CPP_OPTION (pfile, digraphs))
{
- BACKUP ();
- result->type = CPP_LESS;
+ if (*buffer->cur == ':')
+ {
+ buffer->cur++;
+ result->flags |= DIGRAPH;
+ result->type = CPP_OPEN_SQUARE;
+ }
+ else if (*buffer->cur == '%')
+ {
+ buffer->cur++;
+ result->flags |= DIGRAPH;
+ result->type = CPP_OPEN_BRACE;
+ }
}
break;
case '>':
- c = get_effective_char (pfile);
- if (c == '=')
- result->type = CPP_GREATER_EQ;
- else if (c == '>')
- IF_NEXT_IS ('=', CPP_RSHIFT_EQ, CPP_RSHIFT);
- else if (c == '?' && CPP_OPTION (pfile, cplusplus))
- IF_NEXT_IS ('=', CPP_MAX_EQ, CPP_MAX);
- else
+ result->type = CPP_GREATER;
+ if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_GREATER_EQ;
+ else if (*buffer->cur == '>')
{
- BACKUP ();
- result->type = CPP_GREATER;
+ buffer->cur++;
+ IF_NEXT_IS ('=', CPP_RSHIFT_EQ, CPP_RSHIFT);
+ }
+ else if (*buffer->cur == '?' && CPP_OPTION (pfile, cplusplus))
+ {
+ buffer->cur++;
+ IF_NEXT_IS ('=', CPP_MAX_EQ, CPP_MAX);
}
break;
case '%':
- c = get_effective_char (pfile);
- if (c == '=')
- result->type = CPP_MOD_EQ;
- else if (CPP_OPTION (pfile, digraphs) && c == ':')
+ result->type = CPP_MOD;
+ if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_MOD_EQ;
+ else if (CPP_OPTION (pfile, digraphs))
{
- result->flags |= DIGRAPH;
- result->type = CPP_HASH;
- if (get_effective_char (pfile) == '%')
+ if (*buffer->cur == ':')
{
- const unsigned char *pos = buffer->cur;
-
- if (get_effective_char (pfile) == ':')
- result->type = CPP_PASTE;
- else
- buffer->cur = pos - 1;
+ buffer->cur++;
+ result->flags |= DIGRAPH;
+ result->type = CPP_HASH;
+ if (*buffer->cur == '%' && buffer->cur[1] == ':')
+ buffer->cur += 2, result->type = CPP_PASTE;
+ }
+ else if (*buffer->cur == '>')
+ {
+ buffer->cur++;
+ result->flags |= DIGRAPH;
+ result->type = CPP_CLOSE_BRACE;
}
- else
- BACKUP ();
- }
- else if (CPP_OPTION (pfile, digraphs) && c == '>')
- {
- result->flags |= DIGRAPH;
- result->type = CPP_CLOSE_BRACE;
- }
- else
- {
- BACKUP ();
- result->type = CPP_MOD;
}
break;
case '.':
result->type = CPP_DOT;
- c = get_effective_char (pfile);
- if (c == '.')
- {
- const unsigned char *pos = buffer->cur;
-
- if (get_effective_char (pfile) == '.')
- result->type = CPP_ELLIPSIS;
- else
- buffer->cur = pos - 1;
- }
- /* All known character sets have 0...9 contiguous. */
- else if (ISDIGIT (c))
+ if (ISDIGIT (*buffer->cur))
{
- buffer->cur--;
result->type = CPP_NUMBER;
lex_number (pfile, &result->val.str);
}
- else if (c == '*' && CPP_OPTION (pfile, cplusplus))
- result->type = CPP_DOT_STAR;
- else
- BACKUP ();
+ else if (*buffer->cur == '.' && buffer->cur[1] == '.')
+ buffer->cur += 2, result->type = CPP_ELLIPSIS;
+ else if (*buffer->cur == '*' && CPP_OPTION (pfile, cplusplus))
+ buffer->cur++, result->type = CPP_DOT_STAR;
break;
case '+':
- c = get_effective_char (pfile);
- if (c == '+')
- result->type = CPP_PLUS_PLUS;
- else if (c == '=')
- result->type = CPP_PLUS_EQ;
- else
- {
- BACKUP ();
- result->type = CPP_PLUS;
- }
+ result->type = CPP_PLUS;
+ if (*buffer->cur == '+')
+ buffer->cur++, result->type = CPP_PLUS_PLUS;
+ else if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_PLUS_EQ;
break;
case '-':
- c = get_effective_char (pfile);
- if (c == '>')
+ result->type = CPP_MINUS;
+ if (*buffer->cur == '>')
{
+ buffer->cur++;
result->type = CPP_DEREF;
- if (CPP_OPTION (pfile, cplusplus))
- {
- if (get_effective_char (pfile) == '*')
- result->type = CPP_DEREF_STAR;
- else
- BACKUP ();
- }
- }
- else if (c == '-')
- result->type = CPP_MINUS_MINUS;
- else if (c == '=')
- result->type = CPP_MINUS_EQ;
- else
- {
- BACKUP ();
- result->type = CPP_MINUS;
+ if (*buffer->cur == '*' && CPP_OPTION (pfile, cplusplus))
+ buffer->cur++, result->type = CPP_DEREF_STAR;
}
+ else if (*buffer->cur == '-')
+ buffer->cur++, result->type = CPP_MINUS_MINUS;
+ else if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_MINUS_EQ;
break;
case '&':
- c = get_effective_char (pfile);
- if (c == '&')
- result->type = CPP_AND_AND;
- else if (c == '=')
- result->type = CPP_AND_EQ;
- else
- {
- BACKUP ();
- result->type = CPP_AND;
- }
+ result->type = CPP_AND;
+ if (*buffer->cur == '&')
+ buffer->cur++, result->type = CPP_AND_AND;
+ else if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_AND_EQ;
break;
case '|':
- c = get_effective_char (pfile);
- if (c == '|')
- result->type = CPP_OR_OR;
- else if (c == '=')
- result->type = CPP_OR_EQ;
- else
- {
- BACKUP ();
- result->type = CPP_OR;
- }
+ result->type = CPP_OR;
+ if (*buffer->cur == '|')
+ buffer->cur++, result->type = CPP_OR_OR;
+ else if (*buffer->cur == '=')
+ buffer->cur++, result->type = CPP_OR_EQ;
break;
case ':':
- c = get_effective_char (pfile);
- if (c == ':' && CPP_OPTION (pfile, cplusplus))
- result->type = CPP_SCOPE;
- else if (c == '>' && CPP_OPTION (pfile, digraphs))
+ result->type = CPP_COLON;
+ if (*buffer->cur == ':' && CPP_OPTION (pfile, cplusplus))
+ buffer->cur++, result->type = CPP_SCOPE;
+ else if (*buffer->cur == '>' && CPP_OPTION (pfile, digraphs))
{
+ buffer->cur++;
result->flags |= DIGRAPH;
result->type = CPP_CLOSE_SQUARE;
- }
- else
- {
- BACKUP ();
- result->type = CPP_COLON;
}
break;