I'm building a package which provides many makefiles, each makefile has hard coded in side something like
CFLAGS = -g -O2 -Wall ...
CXXFLAGS = -g -O2 -Wall ...
I want to discard -g option but I don't want to edit all makefiles (even not automatically with sed or something similar). The configure script which comes with the package doesn't have enable/disable debug option but I can pass it CFLAGS and CXXFLAGS variables and it concatenates their values to the CFLAGS and CXXFLAGS variables respectively which include the -g option.
Is there an option which will discard -g in case it is specified? Something like
gcc -option-im-looking-for -g file.c -o file
Will build the binary file without debug symbols. I don't want to strip the binary, I want it to be created stripped.
You could negate the effect of -g by adding -g0. Saying
gcc -g -g0 foo.c -o file.o
would produce a binary identical to one obtained by saying
gcc foo.c -o foo.o
Quoting man gcc:
-glevel
...
Level 0 produces no debug information at all. Thus, -g0 negates
-g.
You don't need to edit makefiles. Just override the variables on the command line:
$ cat Makefile
CFLAGS = -g -Wall
all:
echo $(CFLAGS)
$ make
echo -g -Wall
-g -Wall
$ make CFLAGS=-Wall
echo -Wall
-Wall
Related
I was building some Cython extensions, and have to link it against a static library (it has CUDA code in them, so have to be static):
running build_ext
building 'k3lib' extension
gcc -pthread -B /home/kelvin/anaconda3/envs/torch/compiler_compat -Wl,--sysroot=/ -Wsign-compare -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -fPIC -I/home/kelvin/repos/tools/include -I/home/kelvin/anaconda3/envs/torch/include/python3.8 -c main.cpp -o build/temp.linux-x86_64-3.8/main.o -O3 -march=native
cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
g++ -pthread -shared -B /home/kelvin/anaconda3/envs/torch/compiler_compat -L/home/kelvin/anaconda3/envs/torch/lib -Wl,-rpath=/home/kelvin/anaconda3/envs/torch/lib -Wl,--no-as-needed -Wl,--sysroot=/ build/temp.linux-x86_64-3.8/main.o /home/kelvin/repos/tools/include/libk2.a -L/home/kelvin/repos/tools/include -lk2 -o build/lib.linux-x86_64-3.8/k3lib.cpython-38-x86_64-linux-gnu.so -static -Wl,-Bstatic -flinker-output=exec
However, Cython's g++ compile command includes the options -shared -fPIC by default. I tried a number of options at the end of the command via this setup file (the static library is at $(LOCAL_INCLUDE)/libk2.a):
includes = [os.getenv("LOCAL_INCLUDE")]
ext_modules = [
Extension("k3lib", sources=["main.pyx"],
libraries=["k2"], include_dirs=includes, library_dirs=includes, language="c++",
extra_compile_args=["-O3", "-march=native"], extra_objects=[f"{includes[0]}/libk2.a"],
extra_link_args=['-static', '-Wl,-Bstatic', '-flinker-output=exec'])
]
#extra_objects=[f"{includes[0]}/libk2.a"]
#extra_link_args=['-static']
setup(name="k3lib", ext_modules=cythonize(ext_modules, language_level="3"))
Still, g++ thinks that I want to build a shared library, and thus the error message. Is there a way to override the -shared option? I'm planning to go into Cython's files and edit them myself, but was wondering is there a simpler way?
Context: I was following this question on SO but can't replicate their success.
I have this standalone C++ code
that I'm trying to wrap in an R
package.
My problem is that I absolutely
want it to be compiled with the
-O3 flag on.
So in the src/Makevars file
I put:
PKG_CPPFLAGS = -I../inst/include
PKG_CXXFLAGS = -O3
CXX_STD = CXX11
and still when I install my package on my
machine, I see:
g++ -std=c++0x -I/usr/share/R/include -DNDEBUG -I../inst/include -O3 -fpic -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security -D_FORTIFY_SOURCE=2 -g -c mycppfunctions.cpp -o mycppfunctions.o
g++ -std=c++0x -shared -Wl,-Bsymbolic-functions -Wl,-z,relro -o mycppfunctions.so mycppfunctions.o -L/usr/lib/R/lib -lR
(the dreaded -O2 flag appears to the right)
so my question is: how can I overwrite the
cpp flags used when g++ is invoked by R CMD?
Edit:
Recently, in another package, I found a way to do
something similar for a F77 code (also in an R package).
Basically, by adding this to the Makevars:
PKG_FFLAGS = $(FPICFLAGS) $(SHLIB_FFLAGS)
all: $(SHLIB)
otherf77foo.o: otherf77foo.f
$(F77) $(PGK_FFLAGS) -O3 -pipe -g -c -o otherf77foo.o otherf77foo.f
but I don't know how to do the same for a cpp code...
Edit2:
So, doing this is totally possible. Dirk Eddelbuettel question 'b)' from his answer below
guided me to the solution. So, all I had to do was to
place this in the src/Makevars file:
mycppfoo.o: mycppfoo.cpp
g++ -std=c++0x -I/usr/share/R/include -DNDEBUG -I../inst/include -fpic -g -O3 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security -Werror=format-security -D_FORTIFY_SOURCE=2 -g -c mycppfoo.cpp -o mycppfoo.o
g++ -std=c++0x -shared -Wl,-Bsymbolic-functions -Wl,-z,relro -o mycppfoo.so mycppfoo.o -L/usr/lib/R/lib -lR
and my problem was solved!
You can't (as per a comment by Simon Urbanek on r-devel a while back).
But it should not matter as AFAIK the right-most value wins. And R puts its values to the left, and lets you add your values (eg via CXX_FLAGS from, say, ~/.R/Makevars or PKG_CXXFLAGS from the src/Makevars in your package) to the right.
So just override with -O3 and it should be -O3.
For what it is worth, my current values in ~/.R/Makevars are:
CFLAGS += -O3 -Wall -pipe -pedantic -std=gnu99
CXXFLAGS += -O3 -Wall -pipe -Wno-unused -pedantic
and you could of course throw in -mnative or your specific CPU identifier.
Lastly, if you really wanted you could edit /etc/R/Makeconf but you'd have to do that
after each upgrade of the R package. And as I argue here you do not need to as the scheme suggested here should work.
Edit: In response to your edit:
a) The clear recommendation on r-devel (please check the archives) is that you should avoid Makefile logic if you can. IIRC this echoed in the Writing R Extension manual.
b) You declared a rule to build an .o (object) file from an .f (source) file. Did you try doing the same with cpp instead of f?
Lastly, you have not explained exactly why the world is coming to an end if your file is built with -O2 rather than -O3. You should understand that as an author of source, you can't fully control with which compiler options (let alone compiler versions) people will build your package.
newedit: Okay I'm a fool. It solved the problem for Rcpp (which I don't care about), but it doesn't work for the github.com/ohdsi/cyclops.git package that I do care about. That one still gets -O2 stuck right-most. This is ridiculous. Control over command-line parameters might be the single most important piece of this entire operation. R needs a better build system.
edit: Of course after days of trouble, I figure it out right after posting. My problem was that I was using the CXX_STD = CXX11 flag. Apparently with this flag you need to use CXX11FLAGS += .... So if your Makevars file contains CXX11FLAGS += -O0 -Wall it will correctly put this to the right of the -O2 flag if you're using C++11.
No matter what I do I can't get -O0 to show up on the right. I have the following in my ~/.R/Makevars:
CFLAGS += -O0 -Wall
CXXFLAGS += -O0 -Wall
CPPFLAGS += -O0 -Wall
PKG_CFLAGS += -O0 -Wall
PKG_CXXFLAGS += -O0 -Wall
PKG_CPPFLAGS += -O0 -Wall
I have installed Rcpp from source (as a test...I'm not interested in it directly) using
install.packages(getwd(), repos = NULL, type = "source")
and that did correctly use -O0.
With my current configuration, I end up getting three different -O0's to the left and final -O2 on the right. Has anyone else run into this problem?
The software I'm installing is at github.com/ohdsi/cyclops.git, though I'm not sure what that would be important.
I’m running Netbeans 7.4 on Mavericks. In order to be able to use gdb, compilation with the -ggdb flag seems to be necessary. However, even though I specify it through the Project’s Properties/Additional Options wizard, Netbeans also emits -g during compilation. Unfortunately, it turns out that this behavior has an adverse effect when the debugging session commences. Is there any way to force Netbeans not to also emit -g?
Output during compilation:
g++ -m64 -ggdb -c -g -Werror -std=c++11 -MMD -MP -MF "build/Debug/macport_GNU-MacOSX/main.o.d" -o build/Debug/macport_GNU-MacOSX/main.o main.cpp
mkdir -p dist/Debug/macport_GNU-MacOSX
g++ -m64 -ggdb -o dist/Debug/macport_GNU-MacOSX/executable build/Debug/macport_GNU-MacOSX/main.o
Alexander.Simon#oracle.com responded here [1] to set "Development Mode" to "No Flags", then specify -ggdb in the "Additional Options".
1 - https://netbeans.org/projects/cnd/lists/users/archive/2014-02/message/12
I am trying to compile a program consisting of two source files:
wildcardtrie.h, wildcardtrie.cpp
using a Makefile. However, when I run GDB to debug, I get the following error:
Reading symbols from /home/meric/Documents/Random/SectionLeading/wildcardtrie...(no debugging symbols found)...done.
I have tried a number of different compiler flags, none of which worked. The thing that perplexes me is that I have used a nearly identical Makefile in other programs and missing symbols has never been a problem. I have included the Makefile below:
CC=g++
CFLAGS = -g -ggdb g++ -O0 -Wall -Wfloat-equal -Wtype-limits -Wpointer-arith -Wlogical- op -fno-diagnostics-show-option
LDFLAGS = -g -ggdb -std=c++0x
programs = wildcardtrie
all : $(programs)
clean:
rm -f $(programs) core *.o
.PHONY: clean all
I have tried removing '-g' and '-ggdb' in the compiler and linker flags, but nothing seems to work. When I call 'make', I get the following output on the terminal:
g++ -c -o wildcardtrie.o wildcardtrie.cpp
g++ -g -ggdb -std=c++0x wildcardtrie.o -o wildcardtrie
Any help would be greatly appreciated!
g++ -c -o wildcardtrie.o wildcardtrie.cpp
This clearly shows that -g is not on your compile line (which is exactly the cause of your problem).
To get -g there, either add it to CXXFLAGS (this is the preferred solution), or just write the compile rule explicitly (instead of relying on built-in make rule):
wildcardtrie.o: wildcardtrie.cpp
$(CC) $(CFLAGS) -o wildcardtrie.o wildcardtrie.cpp
I Have a LD_PRELOAD file. On what OS and conditions i should compile this preload to work on most systems (Unix/Linux). The most wanted are FreeBSD, Ubuntu, CenstOS, Solaris.
Thanks!
You need to compile it into a shared library. Here's how I typically compile mine:
libt.so: t.lo
g++ -fPIC -O3 -W -Wall -shared -Wl,-export-dynamic -o $# $^ -lc
t.lo: t.cc
g++ -c -fPIC -O3 -W -Wall $^ -o $#
Then to use it, you add the library to the LD_PRELOAD environment variable before launching that file. If you do it this way from the bash command line:
LD_PRELOAD=libt.so executable_name -and args
then, it will only set it for that command line run, and not affect any other programs you launch afterwards.