Why can't I compile with OpenBSD? - c

Question

My program used to compile fine with OpenBSD before I added the lemon parser. Now it compiles on Linux but on OpenBSD I get an error I don't understand.
$ cmake ..
-- The C compiler identification is GNU 4.2.1
-- The CXX compiler identification is GNU 4.2.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/dac/test/openshell/build
$ make
Scanning dependScanning dependencies of target shell
[ 28%] Building C object CMakeFiles/shell.dir/main.c.o
/home/dac/test/openshell/main.c: In function 'main':
/home/dac/test/openshell/main.c:788: warning: implicit declaration of function 'add_history'
/home/dac/test/openshell/main.c: In function 'command':
/home/dac/test/openshell/main.c:573: warning: passing argument 1 of 'expandVariable' discards qualifiers from pointer target type
cc: -ledit: linker input file unused because linking not done
cc: -lncurses: linker input file unused because linking not done
cc: -lcurses: linker input file unused because linking not done
cc: -ltermcap: linker input file unused because linking not done
[ 42%] Building C object CMakeFiles/shell.dir/shellparser.c.o
/home/dac/test/openshell/shellparser.c:280: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:288: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:288: error: initializer element is not constant
/home/dac/test/openshell/shellparser.c:288: error: (near initialization for 'yyRuleName[0]')
/home/dac/test/openshell/shellparser.c: In function 'yy_destructor':
/home/dac/test/openshell/shellparser.c:370: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:370: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: In function 'yyStackOverflow':
/home/dac/test/openshell/shellparser.c:551: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:551: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: At top level:
/home/dac/test/openshell/shellparser.c:609: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:609: warning: missing braces around initializer
/home/dac/test/openshell/shellparser.c:609: warning: (near initialization for 'yyRuleInfo[0]')
/home/dac/test/openshell/shellparser.c:609: error: initializer element is not constant
/home/dac/test/openshell/shellparser.c:609: error: (near initialization for 'yyRuleInfo[0].lhs')
/home/dac/test/openshell/shellparser.c: In function 'yy_reduce':
/home/dac/test/openshell/shellparser.c:664: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:664: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: In function 'yy_parse_failed':
/home/dac/test/openshell/shellparser.c:710: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:710: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: In function 'yy_syntax_error':
/home/dac/test/openshell/shellparser.c:726: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:726: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: In function 'yy_accept':
/home/dac/test/openshell/shellparser.c:745: error: expected expression before '%' token
/home/dac/test/openshell/shellparser.c:745: warning: statement with no effect
/home/dac/test/openshell/shellparser.c: At top level:
/home/dac/test/openshell/shellparser.c:918: error: expected identifier or '(' before string constant
/home/dac/test/openshell/shellparser.c:929: error: expected identifier or '(' before ',' token
Why is is happening and what can I do about it? Did I forget to include a library? My cmake file is
cmake_minimum_required(VERSION 3.0)
project(shell.test)
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -L/usr/local/include/ -L/usr/include -std=c99 -pedantic -O3 -g -Wall -pedantic -ledit -lncurses -lcurses -ltermcap")
include_directories(/usr/local/include/ /usr/include)
link_directories(/usr/lib)
link_directories(/usr/local/lib)
add_executable(shell main.c shellparser.c errors.c util.c)
target_link_libraries(shell edit readline)
add_custom_target(shellparser DEPENDS ${CMAKE_SOURCE_DIR}/shellparser.c)
add_custom_command(OUTPUT ${CMAKE_SOURCE_DIR}/shellparser.c COMMAND lemon -s ${CMAKE_SOURCE_DIR}/shellparser.y DEPENDS ${CMAKE_SOURCE_DIR}/shellparser.y)
add_dependencies(shell shellparser)
set_property(TARGET shell PROPERTY C_STANDARD 99)$
On Ubuntu I can build it successfully:
$ git clone http://github.com/montao/openshell
Cloning into 'openshell'...
remote: Counting objects: 1439, done.
remote: Compressing objects: 100% (184/184), done.
remote: Total 1439 (delta 124), reused 0 (delta 0), pack-reused 1255
Receiving objects: 100% (1439/1439), 405.08 KiB | 117.00 KiB/s, done.
Resolving deltas: 100% (973/973), done.
Checking connectivity... done.
dac#dac-Latitude-E7450:~/montao/test$ cd openshell/
dac#dac-Latitude-E7450:~/montao/test/openshell$ mkdir build
dac#dac-Latitude-E7450:~/montao/test/openshell$ cd build/
dac#dac-Latitude-E7450:~/montao/test/openshell/build$ cmake ..
-- The C compiler identification is GNU 5.3.1
-- The CXX compiler identification is GNU 5.3.1
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/dac/montao/test/openshell/build
dac#dac-Latitude-E7450:~/montao/test/openshell/build$ make
Scanning dependencies of target shellparser
[ 14%] Generating ../shellparser.c
Parser statistics:
terminal symbols................... 9
non-terminal symbols............... 3
total symbols...................... 12
rules.............................. 8
states............................. 14
conflicts.......................... 0
action table entries............... 32
total table size (bytes)........... 100
[ 14%] Built target shellparser
Scanning dependencies of target shell
[ 28%] Building C object CMakeFiles/shell.dir/main.c.o
/home/dac/montao/test/openshell/main.c: In function ‘free_pipeline’:
/home/dac/montao/test/openshell/main.c:337:6: note: the ABI of passing struct with a flexible array member has changed in GCC 4.4
void free_pipeline(struct pipeline pipe) {
^
[ 42%] Building C object CMakeFiles/shell.dir/shellparser.c.o
[ 57%] Building C object CMakeFiles/shell.dir/errors.c.o
[ 71%] Building C object CMakeFiles/shell.dir/util.c.o
/home/dac/montao/test/openshell/util.c: In function ‘make_args’:
/home/dac/montao/test/openshell/util.c:1100:52: warning: operation on ‘jc’ may be undefined [-Wsequence-point]
char *str = concat((char *) *retArgv[jc++], (char *) *retArgv[jc]);
^
/home/dac/montao/test/openshell/util.c:1100:19: warning: unused variable ‘str’ [-Wunused-variable]
char *str = concat((char *) *retArgv[jc++], (char *) *retArgv[jc]);
^
[ 85%] Linking C executable shell
[100%] Built target shell
No matter what I do, the error is there when I compile with OpenBSD. I tried everything.

Answer 1

I haven't used OpenBSD but this could be caused by an "ancient" GCC 4.2.1 which was released 18 July 2007. On Ubuntu it's compiled with more recent GCC.
In fact if you check dependencies of project you want to build
Dependencies: editline, ncurses, C99
And C99 support in gcc
C99 is substantially completely supported as of GCC 4.5 (with -std=c99 -pedantic-errors used; -fextended-identifiers also needed to enable extended identifiers before GCC 5)

Answer 2

I can compile it like this with OpenBSD 5.9
gcc -std=c99 shellparser.c main.c util.c errors.c -ledit -ltermcap
IF I first generate the shellparser.c with Linux and copy the file to OpenBSD, then the above works to build for OpenBSD. But I still can't generate the C from the grammar with OpenBSD, there comes a compilation error. I can recreate the compilation error on Ubuntu and I'm still looking for what causes the diff in the generated C when I run lemon shellparser.y