Do you have 0x0A at the end of your text file ?
No:
zira:~> hd tst.c
00000000 69 6e 74 20 6d 61 69 6e 20 28 76 6f 69 64 29 0a |int main
(void).|
00000010 7b 0a 20 20 72 65 74 75 72 6e 20 30 3b 0a 7d 0a |{.
return 0;.}.|
00000020 23 64 65 66 69 6e 65 20 46 4f 4f |#define FOO|
0000002b
And BTW, Clang behaves as expected:
zira:~> clang-4.0 -std=c99 -pedantic tst.c -o tst
tst.c:5:12: warning: no newline at end of file [-Wnewline-eof]
#define FOO
^
1 warning generated.
So, I think that's a bug in GCC. Do you agree?
I agree. C requires non-empty source files to end in an unescaped
new-line character. POSIX further requires that source files be
text files (and defines the term text file as a file organized
into zero or more lines of at most LINE_MAX characters each).
C++ 11 (and later) has a weaker requirement that makes the above
test case valid.
Fascinating. I never would have thought that a zero line length file
would be accepted as valid. However gcc ( older rev 4.9.2 ) will
accept this :
$ printf "int main ( int argc, char* argv[] ) { return 0; }" > tzero.c
$ wc tzero.c
0 12 49 tzero.c
$ hdump -Ax -v -tx1 tzero.c
0: 69 6e 74 20 6d 61 69 6e 20 28 20 69 6e 74 20 61
10: 72 67 63 2c 20 63 68 61 72 2a 20 61 72 67 76 5b
20: 5d 20 29 20 7b 20 72 65 74 75 72 6e 20 30 3b 20
30: 7d
31:
$ /usr/local/gcc4/bin/gcc -m64 -std=c99 -pedantic \
> -D_TS_ERRNO -D_POSIX_PTHREAD_SEMANTICS \
> -D_LARGEFILE64_SOURCE -S -o tzero.s tzero.c
$ cat tzero.s
.file "tzero.c"
.section ".text"
.align 4
.global main
.type main, #function
.proc 04
main:
save %sp, -176, %sp
mov %i0, %g1
stx %i1, [%fp+2183]
st %g1, [%fp+2175]
mov 0, %g1
sra %g1, 0, %g1
mov %g1, %i0
return %i7+8
nop
.size main, .-main
.ident "GCC: (genunix Fri Jan 2 11:56:03 GMT 2015) 4.9.2"
Whereas c99 ( Oracle Studio 12.4 ) rejects the input file :
$ c99 -errfmt=error -erroff=%none -errshort=full \
> -m64 -xmemalign=8s -xnolibmil -Xc -xregs=no%appl -xlibmieee \
> -Qy -xbuiltin=%none -D_TS_ERRNO -D_POSIX_PTHREAD_SEMANTICS \
> -D_LARGEFILE64_SOURCE -S -o tzero.s tzero.c
"tzero.c", line 1: warning: newline not last character in file
I think "zero or more lines of at most LINE_MAX characters each" won't
work. There must be more than "zero lines" in the input. What is the
actual spec?
This is really splitting hairs of course.
Dennis
