<s>
Cfront	B-Device
was	O
the	O
original	O
compiler	B-Language
for	O
C++	B-Language
(	O
then	O
known	O
as	O
"	O
C	B-Language
with	O
Classes	O
"	O
)	O
from	O
around	O
1983	O
,	O
which	O
converted	O
C++	B-Language
to	O
C	B-Language
;	O
developed	O
by	O
Bjarne	O
Stroustrup	O
at	O
AT&T	O
Bell	O
Labs	O
.	O
</s>
<s>
The	O
preprocessor	B-General_Concept
did	O
not	O
understand	O
all	O
of	O
the	O
language	O
and	O
much	O
of	O
the	O
code	O
was	O
written	O
via	O
translations	B-Language
.	O
</s>
<s>
Cfront	B-Device
had	O
a	O
complete	O
parser	B-Language
,	O
built	O
symbol	B-Application
tables	I-Application
,	O
and	O
built	O
a	O
tree	B-Application
for	O
each	O
class	O
,	O
function	O
,	O
etc	O
.	O
</s>
<s>
Cfront	B-Device
was	O
based	O
on	O
CPre	O
,	O
a	O
C	B-Language
compiler	B-Language
started	O
in	O
1979	O
.	O
</s>
<s>
As	O
Cfront	B-Device
was	O
written	O
in	O
C++	B-Language
,	O
it	O
was	O
a	O
challenge	O
to	O
bootstrap	B-Application
on	O
a	O
machine	O
without	O
a	O
C++	B-Language
compiler/translator	O
.	O
</s>
<s>
Along	O
with	O
the	O
Cfront	B-Device
C++	B-Language
sources	O
,	O
a	O
special	O
"	O
half-preprocessed	O
"	O
version	O
of	O
the	O
C	B-Language
code	O
resulting	O
from	O
compiling	B-Language
Cfront	B-Device
with	O
itself	O
was	O
also	O
provided	O
.	O
</s>
<s>
This	O
C	B-Language
code	O
was	O
to	O
be	O
compiled	B-Language
with	O
the	O
native	O
C	B-Language
compiler	B-Language
,	O
and	O
the	O
resulting	O
executable	O
could	O
then	O
be	O
used	O
to	O
compile	B-Language
the	O
Cfront	B-Device
C++	B-Language
sources	O
.	O
</s>
<s>
Most	O
of	O
the	O
porting	O
effort	O
in	O
getting	O
Cfront	B-Device
running	O
on	O
a	O
new	O
machine	O
was	O
related	O
to	O
standard	O
I/O	O
.	O
</s>
<s>
Cfront	B-Device
's	O
C++	B-Language
streams	O
were	O
closely	O
tied	O
in	O
with	O
the	O
C	B-Language
library	O
's	O
buffered	O
I/O	O
streams	O
,	O
but	O
there	O
was	O
little	O
interaction	O
with	O
the	O
rest	O
of	O
the	O
C	B-Language
environment	O
.	O
</s>
<s>
The	O
compiler	B-Language
could	O
be	O
ported	O
to	O
most	O
System	B-Operating_System
V	I-Operating_System
derivatives	O
without	O
many	O
changes	O
,	O
but	O
BSD-based	O
systems	O
usually	O
had	O
many	O
more	O
variations	O
in	O
their	O
C	B-Language
libraries	O
and	O
associated	O
stdio	O
structures	O
.	O
</s>
<s>
Cfront	B-Device
defined	O
the	O
language	O
until	O
circa	O
1990	O
,	O
and	O
many	O
of	O
the	O
more	O
obscure	O
corner	O
cases	O
in	O
C++	B-Language
were	O
related	O
to	O
its	O
C++	B-Language
-to-C	O
translation	O
approach	O
.	O
</s>
<s>
A	O
few	O
remnants	O
of	O
Cfront	B-Device
's	O
translation	O
method	O
are	O
still	O
found	O
in	O
today	O
's	O
C++	B-Language
compilers	B-Language
;	O
name	B-Language
mangling	I-Language
was	O
originated	O
by	O
Cfront	B-Device
,	O
as	O
the	O
relatively	O
primitive	O
linkers	B-Application
at	O
the	O
time	O
did	O
not	O
support	O
type	O
information	O
in	O
symbols	O
,	O
and	O
some	O
template	O
instantiation	O
models	O
are	O
derived	O
from	O
Cfront	B-Device
's	O
early	O
efforts	O
.	O
</s>
<s>
C++	B-Language
(	O
and	O
Cfront	B-Device
)	O
was	O
directly	O
responsible	O
for	O
many	O
improvements	O
in	O
Unix	B-Application
linkers	B-Application
and	O
object	B-Application
file	I-Application
formats	I-Application
,	O
as	O
it	O
was	O
the	O
first	O
widely	O
used	O
language	O
which	O
required	O
link-time	B-Application
type	O
checking	O
,	O
weak	O
symbols	O
,	O
and	O
other	O
similar	O
features	O
.	O
</s>
<s>
Cfront	B-Device
4.0	O
was	O
abandoned	O
in	O
1993	O
after	O
a	O
failed	O
attempt	O
to	O
add	O
exception	B-General_Concept
support	O
.	O
</s>
<s>
The	O
C++	B-Language
language	I-Language
had	O
grown	O
beyond	O
its	O
capabilities	O
;	O
however	O
a	O
compiler	B-Language
with	O
similar	O
approach	O
became	O
available	O
later	O
,	O
namely	O
Comeau	B-General_Concept
C/C	I-General_Concept
++	I-General_Concept
.	O
</s>
