https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100392
Bug ID: 100392
Summary: compiling result of "g++ -E -fdirectives-only" causes
"error: stray ‘#’ in program" if no newline at EOF
Product: gcc
Version: 11.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: preprocessor
Assignee: unassigned at gcc dot gnu.org
Reporter: mst.lo at arcor dot de
Target Milestone: ---
> g++ --version
g++ (GCC) 11.1.1 20210428 (Red Hat 11.1.1-1)
works:
> echo '#include "test.h"' > test.cpp
> printf 'extern const int ksc5601_hangul_to_unicode[2350];\n' > test.h
> g++ -E -fdirectives-only test.cpp -o test.i
> g++ -c test.i
doesn't work:
> echo '#include "test.h"' > test.cpp
> printf 'extern const int ksc5601_hangul_to_unicode[2350];' > test.h
> g++ -E -fdirectives-only test.cpp -o test.i
> g++ -c test.i
In file included from test.cpp:1:
test.h:1:50: error: stray ‘#’ in program
1 | extern const int ksc5601_hangul_to_unicode[2350];
| ^
test.h:1:52: error: expected unqualified-id before numeric constant
1 | extern const int ksc5601_hangul_to_unicode[2350];
|
in a draft of C++11, 2.2 Phases of translation [lex.phases] 1.2 says:
A source file
that is not empty and that does not end in a new-line character, or that ends
in a new-line character
immediately preceded by a backslash character before any such splicing takes
place, shall be processed
as if an additional new-line character were appended to the file.
similar language in
https://github.com/cplusplus/draft/blob/master/source/lex.tex#L97
wheres e.g. in a draft of C99, 5.1.1.2 Translation phases 2. says:
A source file that is not empty shall end in a new-line character,
which shall not be immediately preceded by a backslash character before any
such
splicing takes place.
... so apparently different standards have different requirements here.
i believe this problem didn't occur when using GCC 10 with sccache or icecream,
which use "-E -fdirectives-only" to create a suitable input for distributed
compilation.
