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/*****************************************************************************
* $Id: get.c,v 1.5 1997/04/06 02:13:52 darren Exp $
*
* Copyright (c) 1996-1997, Darren Hiebert
*
* Contains the high level source read functions (preprocessor directives
* are handled within this level).
*****************************************************************************/
/*============================================================================
= Include files
============================================================================*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "ctags.h"
/*============================================================================
= Data declarations
============================================================================*/
typedef enum { COMMENT_NONE, COMMENT_C, COMMENT_CPLUS } Comment;
/*============================================================================
= Data definitions
============================================================================*/
cppState Cpp = {
0,
{
DRCTV_NONE,
FALSE,
{ 0, 0, "" },
FALSE,
0,
{{FALSE,FALSE}}
}
};
/*============================================================================
= Function prototypes
============================================================================*/
static boolean cppReadDirective __ARGS((int c, char *name));
static boolean cppReadIdentifier __ARGS((int c, tagInfo *const tag));
static boolean pushCppIgnore __ARGS((const boolean ignore, const boolean pathChosen));
static boolean popCppIgnore __ARGS((void));
static boolean prevCppIgnore __ARGS((void));
static boolean setCppIgnore __ARGS((const boolean ignore));
static boolean wasPathChosen __ARGS((void));
static boolean handleDirective __ARGS((const int c));
static Comment isComment __ARGS((void));
static int skipOverCComment __ARGS((void));
static int skipOverCplusComment __ARGS((void));
static int skipToEndOfString __ARGS((void));
static int skipToEndOfChar __ARGS((void));
/*============================================================================
= Function definitions
============================================================================*/
/*----------------------------------------------------------------------------
* Scanning functions
*
* This section handles preprocessor directives. It strips out all
* directives and may emit a tag for #define directives.
*--------------------------------------------------------------------------*/
extern boolean cppOpen( name )
const char *const name;
{
boolean opened;
opened = fileOpen(name);
if (opened)
{
Cpp.ungetch = '\0';
Cpp.directive.state = DRCTV_NONE;
Cpp.directive.accept = TRUE;
Cpp.directive.resolve = FALSE;
Cpp.directive.level = 0;
}
return opened;
}
extern void cppClose()
{
fileClose();
}
/* This puts a character back into the input queue for the source File.
*/
extern void cppUngetc( c )
const int c;
{
Cpp.ungetch = c;
}
/* Reads a directive, whose first character is given by "c", into "name".
*/
static boolean cppReadDirective( c, name )
int c;
char *name;
{
do
{
*name++ = c;
} while (c = fileGetc(), (c != EOF && isalpha(c)));
fileUngetc(c);
*name = '\0'; /* null terminate */
return isspacetab(c);
}
/* Reads an identifier, whose first character is given by "c", into "tag",
* together with the file location and corresponding line number.
*/
static boolean cppReadIdentifier( c, tag )
int c;
tagInfo *const tag;
{
char *name = tag->name;
do
{
*name++ = c;
} while (c = fileGetc(), (c != EOF && isident(c)));
fileUngetc(c);
*name = '\0'; /* null terminate */
tag->location = File.seek;
tag->lineNumber = File.lineNumber;
return (isspace(c) || c == '(');
}
/* Pushes one nesting level for an #if directive, indicating whether or not
* the path should be ignored and whether a path has already been chosen.
*/
static boolean pushCppIgnore( ignore, pathChosen )
const boolean ignore;
const boolean pathChosen;
{
if (Cpp.directive.level < CppNestingLevel - 1)
{
++Cpp.directive.level;
Cpp.directive.ifdef[Cpp.directive.level].ignore = ignore;
Cpp.directive.ifdef[Cpp.directive.level].pathChosen = pathChosen;
}
return cppIgnore();
}
/* Pops one nesting level for an #endif directive.
*/
static boolean popCppIgnore()
{
if (Cpp.directive.level > 0)
--Cpp.directive.level;
return cppIgnore();
}
/* Returns whether or not the parent of this nesting level was ignored.
*/
static boolean prevCppIgnore()
{
boolean ignore;
if (Cpp.directive.level <= 0)
ignore = FALSE;
else
ignore = Cpp.directive.ifdef[Cpp.directive.level - 1].ignore;
return ignore;
}
static boolean setCppIgnore( ignore )
const boolean ignore;
{
return Cpp.directive.ifdef[Cpp.directive.level].ignore = ignore;
}
static boolean wasPathChosen()
{
return Cpp.directive.ifdef[Cpp.directive.level].pathChosen;
}
/* Handles a pre-processor directive whose first character is given by "c".
*/
static boolean handleDirective( c )
const int c;
{
char *const name = Cpp.directive.tag.name;
const tagScope scope = File.header ? SCOPE_GLOBAL : SCOPE_STATIC;
boolean ignore = FALSE;
switch (Cpp.directive.state)
{
case DRCTV_NONE:
ignore = cppIgnore(); /* ignore characters until newline */
break;
case DRCTV_HASH:
cppReadDirective(c, name);
if (strcmp(name, "define") == 0)
Cpp.directive.state = DRCTV_DEFINE;
else if (strncmp(name, "if", (size_t)2) == 0)
Cpp.directive.state = DRCTV_IF;
else
{
if (strcmp(name, "endif") == 0)
ignore = popCppIgnore();
else if (Cpp.directive.resolve && ! Option.braceFormat)
{
if (strcmp(name, "elif") == 0)
ignore = setCppIgnore(TRUE);
else if (strcmp(name, "else") == 0)
ignore = setCppIgnore(prevCppIgnore() || wasPathChosen());
}
else if (strcmp(name, "elif") == 0 || strcmp(name, "else") == 0)
ignore = setCppIgnore(FALSE);
Cpp.directive.state = DRCTV_NONE;
}
break;
case DRCTV_DEFINE:
cppReadIdentifier(c, &Cpp.directive.tag);
makeDefineTag(&Cpp.directive.tag, scope);
Cpp.directive.state = DRCTV_NONE;
break;
case DRCTV_IF:
if (Option.braceFormat)
ignore = pushCppIgnore(FALSE, TRUE);
else if (c == '0') /* special case: avoid first branch */
ignore = pushCppIgnore(TRUE, FALSE);
else
ignore = pushCppIgnore(cppIgnore(), TRUE);
Cpp.directive.state = DRCTV_NONE;
break;
}
return ignore;
}
/* Called upon reading of a slash ('/') characters, determines whether a
* comment is encountered, and its type.
*/
static Comment isComment()
{
Comment comment;
const int next = fileGetc();
if (next == '*')
comment = COMMENT_C;
else if (next == '/')
comment = COMMENT_CPLUS;
else
{
fileUngetc(next);
comment = COMMENT_NONE;
}
return comment;
}
/* Skips over a C style comment. According to ANSI specification a comment
* is treated as white space, so we perform this subsitution.
*/
static int skipOverCComment()
{
int c = fileGetc();
while (c != EOF)
{
if (c != '*')
c = fileGetc();
else
{
const int next = fileGetc();
if (next != '/')
c = next;
else
{
c = ' '; /* replace comment with space */
break;
}
}
}
return c;
}
/* Skips over a C++ style comment.
*/
static int skipOverCplusComment()
{
int c;
while ((c = fileGetc()) != EOF)
{
if (c == BACKSLASH)
c = fileGetc(); /* throw away next character, too */
else if (c == NEWLINE)
break;
}
return c;
}
/* Skips to the end of a string, returning a special character to
* symbolically represent a generic string.
*/
static int skipToEndOfString()
{
int c;
while ((c = fileGetc()) != EOF)
{
if (c == BACKSLASH)
c = fileGetc(); /* throw away next character, too */
else if (c == DOUBLE_QUOTE)
break;
else if (c == NEWLINE)
{
fileUngetc(c);
break;
}
}
return STRING_SYMBOL; /* symbolic representation of string */
}
/* Skips to the end of the three (possibly four) 'c' sequence, returning a
* special character to symbolically represent a generic character.
*/
static int skipToEndOfChar()
{
int c;
while ((c = fileGetc()) != EOF)
{
if (c == BACKSLASH)
c = fileGetc(); /* throw away next character, too */
else if (c == SINGLE_QUOTE)
break;
else if (c == NEWLINE)
{
fileUngetc(c);
break;
}
}
return CHAR_SYMBOL; /* symbolic representation of character */
}
/* This function returns the next character, stripping out comments,
* C pre-processor directives, and the contents of single and double
* quoted strings. In short, strip anything which places a burden upon
* the tokenizer.
*/
extern int cppGetc()
{
Comment comment = COMMENT_NONE;
boolean directive = FALSE;
boolean ignore = FALSE;
int c;
if (Cpp.ungetch != '\0')
{
c = Cpp.ungetch;
Cpp.ungetch = '\0';
return c; /* return here to avoid re-calling debugPutc() */
}
else do
{
c = fileGetc();
switch (c)
{
case EOF:
ignore = FALSE;
directive = FALSE;
break;
case TAB:
case SPACE:
break; /* ignore most white space */
case NEWLINE:
if (directive && ! ignore)
directive = FALSE;
Cpp.directive.accept = TRUE;
break;
case DOUBLE_QUOTE:
Cpp.directive.accept = FALSE;
c = skipToEndOfString();
break;
case '#':
if (Cpp.directive.accept)
{
directive = TRUE;
Cpp.directive.state = DRCTV_HASH;
Cpp.directive.accept = FALSE;
}
break;
case SINGLE_QUOTE:
Cpp.directive.accept = FALSE;
c = skipToEndOfChar();
break;
case '/':
comment = isComment();
if (comment == COMMENT_C)
c = skipOverCComment();
else if (comment == COMMENT_CPLUS)
{
c = skipOverCplusComment();
if (c == NEWLINE)
fileUngetc(c);
}
else
Cpp.directive.accept = FALSE;
break;
default:
Cpp.directive.accept = FALSE;
if (directive)
{
#ifdef DEBUG
const boolean ignore0 = ignore;
#endif
ignore = handleDirective(c);
#ifdef DEBUG
if (ignore != ignore0)
debugCpp(ignore);
#endif
}
break;
}
} while (directive || ignore);
#ifdef DEBUG
debugPutc(c, DEBUG_CPP);
#endif
return c;
}
/* vi:set tabstop=8 shiftwidth=4: */
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