arnold@emory.UUCP (Arnold D. Robbins {EUCC}) (06/02/86)
This bounced when I tried to send it to mod.sources, so I am just posting.
It was announced in various groups last week.
=============================================================================
Below is a context diff, suitable for use with patch, to the 4.2 BSD /lib/cpp.
It provides two enhancements:
1) Code provided by Doug Gwyn of the Ballistics Research Lab to
implement the recent-SV/ANSI C #elif preprocessor directive. This
code is not dependant on any command line option, since I figure
it is something that everyone will want, and it is something
that will be a standard in the C community. (BTW, the crummy
indentation is my fault, not his -- it follows the current "style".)
2) Code written by me, based loosely on the existing code, to recognize
C++ comments that start with // and continue to the end of line.
This feature must be enabled with the -B command line argument.
("B" is reminiscent of the old B language which had the //
comment, which is where C++ took it back from. Not terribly
mnemonic, I know.)
Those of you with C++ should change your CC shell script to invoke /lib/cpp
with the new -B option.
Enjoy,
Arnold Robbins
CSNET: arnold@emory BITNET: arnold@emoryu1
ARPA: arnold%emory.csnet@csnet-relay.arpa
UUCP: { akgua, decvax, gatech, sb1, sb6, sunatl }!emory!arnold
"All this digital stuff is just a fad. Analog is the way to go."
-- William M. Robbins, 1984
-------- cut here, feed to patch in /usr/src/lib/cpp ------
*** ./README Tue May 27 14:07:10 1986
--- ../ncpp/README Tue May 27 15:28:08 1986
***************
*** 1,6
#
# @(#)README 1.2 8/30/82
#
August 30, 1982
Fixed by Kurt Shoens, UCB
If the "#line n name" occurs, then all future references
--- 1,12 -----
#
# @(#)README 1.2 8/30/82
#
+ May 27, 1985
+ Modified by Arnold Robbins, Emory University Computing Center.
+ With the -B option, will recognize C++ style start with // and go to
+ the end of the line comments. Also added in code from Doug Gwyn of
+ the Ballistics Research Laboratory to implement #elif.
+
August 30, 1982
Fixed by Kurt Shoens, UCB
If the "#line n name" occurs, then all future references
*** ./cpp.c Tue May 27 14:07:09 1986
--- ../ncpp/cpp.c Tue May 27 15:16:12 1986
***************
*** 153,158
STATIC int nd = 1;
STATIC int pflag; /* don't put out lines "# 12 foo.c" */
int passcom; /* don't delete comments */
STATIC int rflag; /* allow macro recursion */
STATIC int ifno;
# define NPREDEF 20
--- 153,159 -----
STATIC int nd = 1;
STATIC int pflag; /* don't put out lines "# 12 foo.c" */
int passcom; /* don't delete comments */
+ int eolcom; /* allow // ... \n comments */
STATIC int rflag; /* allow macro recursion */
STATIC int ifno;
# define NPREDEF 20
***************
*** 185,190
STATIC struct symtab *udfloc;
STATIC struct symtab *incloc;
STATIC struct symtab *ifloc;
STATIC struct symtab *elsloc;
STATIC struct symtab *eifloc;
STATIC struct symtab *ifdloc;
--- 186,192 -----
STATIC struct symtab *udfloc;
STATIC struct symtab *incloc;
STATIC struct symtab *ifloc;
+ STATIC struct symtab *eliloc; /* DAG -- added */
STATIC struct symtab *elsloc;
STATIC struct symtab *eifloc;
STATIC struct symtab *ifdloc;
***************
*** 196,201
STATIC struct symtab *uflloc;
STATIC int trulvl;
STATIC int flslvl;
sayline() {
if (pflag==0) fprintf(fout,"# %d \"%s\"\n", lineno[ifno], fnames[ifno]);
--- 198,205 -----
STATIC struct symtab *uflloc;
STATIC int trulvl;
STATIC int flslvl;
+ #define MAX_IF_NESTING 64 /* DAG -- added (must be at least 6) */
+ STATIC int ifdone[MAX_IF_NESTING]; /* DAG -- added */
sayline() {
if (pflag==0) fprintf(fout,"# %d \"%s\"\n", lineno[ifno], fnames[ifno]);
***************
*** 379,385
else {++p; break;}
} break;
case '/': for (;;) {
! if (*p++=='*') {/* comment */
if (!passcom) {inp=p-2; dump(); ++flslvl;}
for (;;) {
while (!iscom(*p++));
--- 383,390 -----
else {++p; break;}
} break;
case '/': for (;;) {
! if (*p=='/' && eolcom) {/* C++ style comment to end of line */
! p++;
if (!passcom) {inp=p-2; dump(); ++flslvl;}
for (;;) {
while (*p && *p++ != '\n');
***************
*** 382,387
if (*p++=='*') {/* comment */
if (!passcom) {inp=p-2; dump(); ++flslvl;}
for (;;) {
while (!iscom(*p++));
if (p[-1]=='*') for (;;) {
if (*p++=='/') goto endcom;
--- 387,411 -----
p++;
if (!passcom) {inp=p-2; dump(); ++flslvl;}
for (;;) {
+ while (*p && *p++ != '\n');
+ if (p[-1]=='\n') {
+ p--;
+ goto endcpluscom;
+ } else if (eob(--p)) {
+ if (!passcom) {inp=p; p=refill(p);}
+ else if ((p-inp)>=BUFSIZ) {/* split long comment */
+ inp=p; p=refill(p);
+ } else p=refill(p);
+ } else ++p; /* ignore null byte */
+ }
+ endcpluscom:
+ if (!passcom) {outp=inp=p; --flslvl;}
+ goto newline;
+ break;
+ }
+ else if (*p++=='*') {/* comment */
+ if (!passcom) {inp=p-2; dump(); ++flslvl;}
+ for (;;) {
while (!iscom(*p++));
if (p[-1]=='*') for (;;) {
if (*p++=='/') goto endcom;
***************
*** 430,435
}
} break;
case '\n': {
++lineno[ifno]; if (isslo) {state=LF; return(p);}
prevlf:
state=BEG;
--- 454,460 -----
}
} break;
case '\n': {
+ newline:
++lineno[ifno]; if (isslo) {state=LF; return(p);}
prevlf:
state=BEG;
***************
*** 710,716
#define fasscan() ptrtab=fastab+COFF
#define sloscan() ptrtab=slotab+COFF
! char *
control(p) register char *p; {/* find and handle preprocessor control lines */
register struct symtab *np;
for (;;) {
--- 735,741 -----
#define fasscan() ptrtab=fastab+COFF
#define sloscan() ptrtab=slotab+COFF
! void /* DAG -- bug fix (was (char *)) */
control(p) register char *p; {/* find and handle preprocessor control lines */
register struct symtab *np;
for (;;) {
***************
*** 723,729
if (flslvl==0) {p=doincl(p); continue;}
} else if (np==ifnloc) {/* ifndef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
! if (flslvl==0 && np->value==0) ++trulvl;
else ++flslvl;
} else if (np==ifdloc) {/* ifdef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
--- 748,758 -----
if (flslvl==0) {p=doincl(p); continue;}
} else if (np==ifnloc) {/* ifndef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
! if (flslvl==0)
! if (ifdone[trulvl] = np->value == 0)
! ++trulvl;
! else
! ++flslvl;
else ++flslvl;
} else if (np==ifdloc) {/* ifdef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
***************
*** 727,733
else ++flslvl;
} else if (np==ifdloc) {/* ifdef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
! if (flslvl==0 && np->value!=0) ++trulvl;
else ++flslvl;
} else if (np==eifloc) {/* endif */
if (flslvl) {if (--flslvl==0) sayline();}
--- 756,766 -----
else ++flslvl;
} else if (np==ifdloc) {/* ifdef */
++flslvl; p=skipbl(p); np=slookup(inp,p,0); --flslvl;
! if (flslvl==0)
! if (ifdone[trulvl] = np->value!=0)
! ++trulvl;
! else
! ++flslvl;
else ++flslvl;
} else if (np==eifloc) {/* endif */
if (flslvl) {if (--flslvl==0) sayline();}
***************
*** 731,737
else ++flslvl;
} else if (np==eifloc) {/* endif */
if (flslvl) {if (--flslvl==0) sayline();}
! else if (trulvl) --trulvl;
else pperror("If-less endif",0);
} else if (np==elsloc) {/* else */
if (flslvl) {
--- 764,770 -----
else ++flslvl;
} else if (np==eifloc) {/* endif */
if (flslvl) {if (--flslvl==0) sayline();}
! else if (trulvl) ifdone[--trulvl] = 0; /* DAG */
else pperror("If-less endif",0);
} else if (np==elsloc) {/* else */
if (flslvl) {
***************
*** 735,741
else pperror("If-less endif",0);
} else if (np==elsloc) {/* else */
if (flslvl) {
! if (--flslvl!=0) ++flslvl;
else {++trulvl; sayline();}
}
else if (trulvl) {++flslvl; --trulvl;}
--- 768,774 -----
else pperror("If-less endif",0);
} else if (np==elsloc) {/* else */
if (flslvl) {
! if (--flslvl!=0 || ifdone[trulvl]) ++flslvl;
else {++trulvl; sayline();}
}
else if (trulvl) {++flslvl; --trulvl;}
***************
*** 747,753
} else if (np==ifloc) {/* if */
#if tgp
pperror(" IF not implemented, true assumed", 0);
! if (flslvl==0) ++trulvl; else ++flslvl;
#else
newp=p;
if (flslvl==0 && yyparse()) ++trulvl; else ++flslvl;
--- 780,786 -----
} else if (np==ifloc) {/* if */
#if tgp
pperror(" IF not implemented, true assumed", 0);
! if (flslvl==0) ifdone[trulvl++] = 1; else ++flslvl;
#else
newp=p;
if (flslvl==0)
***************
*** 750,756
if (flslvl==0) ++trulvl; else ++flslvl;
#else
newp=p;
! if (flslvl==0 && yyparse()) ++trulvl; else ++flslvl;
p=newp;
#endif
} else if (np==lneloc) {/* line */
--- 783,796 -----
if (flslvl==0) ifdone[trulvl++] = 1; else ++flslvl;
#else
newp=p;
! if (flslvl==0)
! {
! if (ifdone[trulvl] = yyparse()) /* DAG */
! ++trulvl;
! else
! ++flslvl;
! }
! else ++flslvl;
p=newp;
#endif
} else if (np==eliloc) {/* elif */ /* DAG -- added */
***************
*** 753,758
if (flslvl==0 && yyparse()) ++trulvl; else ++flslvl;
p=newp;
#endif
} else if (np==lneloc) {/* line */
if (flslvl==0 && pflag==0) {
char *cp, *cp2, *savestring();
--- 793,839 -----
else ++flslvl;
p=newp;
#endif
+ } else if (np==eliloc) {/* elif */ /* DAG -- added */
+ #if tgp
+ pperror ( " ELIF not implemented, true assumed", (char *) 0, (char *) 0);
+ if (flslvl)
+ {
+ if (--flslvl == 0 && !ifdeone[trulvl])
+ {
+ ifdone[trulvl++] = 1;
+ sayline():
+ }
+ else
+ ++flslvl;
+ }
+ else if (trulvl)
+ {
+ ++flslvl;
+ --trulvl;
+ }
+ else
+ pperror ( "If-less elif"< (char *) 0, (char *) 0);
+ #else
+ newp = p;
+ if (flslvl)
+ {
+ if (--flslvl == 0 && !ifdone[trulvl] && yyparse())
+ {
+ ifdone[trulvl++] = 1;
+ sayline();
+ }
+ else
+ ++flslvl;
+ }
+ else if (trulvl)
+ {
+ ++flslvl;
+ --trulvl;
+ }
+ else
+ pperror ("If-less elif", (char *) 0, (char *) 0);
+ p = newp;
+ #endif
} else if (np==lneloc) {/* line */
if (flslvl==0 && pflag==0) {
char *cp, *cp2, *savestring();
***************
*** 1067,1072
case 'E': continue;
case 'R': ++rflag; continue;
case 'C': passcom++; continue;
case 'D':
if (predef>prespc+NPREDEF) {
pperror("too many -D options, ignoring %s",argv[i]);
--- 1148,1154 -----
case 'E': continue;
case 'R': ++rflag; continue;
case 'C': passcom++; continue;
+ case 'B': eolcom++; continue;
case 'D':
if (predef>prespc+NPREDEF) {
pperror("too many -D options, ignoring %s",argv[i]);
***************
*** 1141,1146
ifdloc=ppsym("ifdef");
ifnloc=ppsym("ifndef");
ifloc=ppsym("if");
lneloc=ppsym("line");
for (i=sizeof(macbit)/sizeof(macbit[0]); --i>=0; ) macbit[i]=0;
# if unix
--- 1223,1229 -----
ifdloc=ppsym("ifdef");
ifnloc=ppsym("ifndef");
ifloc=ppsym("if");
+ eliloc=ppsym("elif");
lneloc=ppsym("line");
for (i=sizeof(macbit)/sizeof(macbit[0]); --i>=0; ) macbit[i]=0;
# if unix
--
Arnold Robbins
CSNET: arnold@emory BITNET: arnold@emoryu1
ARPA: arnold%emory.csnet@csnet-relay.arpa
UUCP: { akgua, decvax, gatech, sb1, sb6, sunatl }!emory!arnold
"All this digital stuff is just a fad. Analog is the way to go."
-- William M. Robbins, 1984