ack/lang/cem/cemcom/replace.c
1986-03-10 13:07:55 +00:00

159 lines
3.5 KiB
C

/* $Header$ */
/* PREPROCESSOR: MACRO-TEXT REPLACEMENT ROUTINES */
#include "nopp.h"
#ifndef NOPP
#include "debug.h" /* UF */
#include "pathlength.h" /* UF */
#include "strsize.h" /* UF */
#include "string.h"
#include "alloc.h"
#include "idf.h"
#include "input.h"
#include "macro.h"
#include "arith.h"
#include "LLlex.h"
#include "class.h"
#include "assert.h"
#include "interface.h"
EXPORT int
replace(idef)
struct idf *idef;
{
/* replace() is called by the lexical analyzer to perform
macro replacement. "idef" is the description of the
identifier which leads to the replacement. If the
optional actual parameters of the macro are OK, the text
of the macro is prepared to serve as an input buffer,
which is pushed onto the input stack.
replace() returns 1 if the replacement succeeded and 0 if
some error has occurred.
*/
register char c;
register char flags = idef->id_macro->mc_flag;
char **actpars, **getactuals();
char *reptext, *macro2buffer();
int size;
if (idef->id_macro->mc_nps != -1) { /* with parameter list */
LoadChar(c);
c = skipspaces(c);
if (c != '(') { /* no replacement if no () */
lexerror("(warning) macro %s needs arguments",
idef->id_text);
PushBack();
return 0;
}
actpars = getactuals(idef); /* get act.param. list */
}
if (flags & PREDEF) { /* don't replace this one... */
return 0;
}
if (flags & FUNC) { /* this macro leads to special action */
macro_func(idef);
}
/* create and input buffer */
reptext = macro2buffer(idef, actpars, &size);
InsertText(reptext, size);
return 1;
}
PRIVATE
macro_func(idef)
struct idf *idef;
{
/* macro_func() performs the special actions needed with some
macros. These macros are __FILE__ and __LINE__ which
replacement texts must be evaluated at the time they are
used.
*/
static char FilNamBuf[PATHLENGTH];
/* This switch is very blunt... */
switch (idef->id_text[2]) {
case 'F' : /* __FILE__ */
FilNamBuf[0] = '"';
strcpy(&FilNamBuf[1], FileName);
strcat(FilNamBuf, "\"");
idef->id_macro->mc_text = FilNamBuf;
idef->id_macro->mc_length = strlen(FilNamBuf);
break;
case 'L' : /* __LINE__ */
idef->id_macro->mc_text = itos(LineNumber);
idef->id_macro->mc_length = 1;
break;
default :
crash("(macro_func) illegal macro %s\n", idef->id_text);
}
}
PRIVATE char *
macro2buffer(idef, actpars, siztext)
struct idf *idef;
char **actpars;
int *siztext;
{
/* Macro2buffer() turns the macro replacement text, as it is
stored, into an input buffer, while each occurrence of the
non-ascii formal parameter mark is replaced by its
corresponding actual parameter specified in the actual
parameter list actpars. A pointer to the beginning of the
constructed text is returned, while *siztext is filled
with its length.
If there are no parameters, this function behaves
the same as strcpy().
*/
register int size = 8;
register char *text = Malloc(size);
register pos = 0;
register char *ptr = idef->id_macro->mc_text;
text[pos++] = '\0'; /* allow pushback */
while (*ptr) {
if (*ptr & FORMALP) { /* non-asc formal param. mark */
register int n = *ptr++ & 0177;
register char *p;
ASSERT(n != 0);
/* copy the text of the actual parameter
into the replacement text
*/
for (p = actpars[n - 1]; *p; p++) {
text[pos++] = *p;
if (pos == size) {
text = Srealloc(text, size += RSTRSIZE);
}
}
}
else {
text[pos++] = *ptr++;
if (pos == size) {
text = Srealloc(text, size += RSTRSIZE);
}
}
}
text[pos] = '\0';
*siztext = pos;
return text;
}
#endif NOPP