I cloned the riscv-tools repository (master branch) and followed the build procedure. Everything went fine.
Then I tried compiling the hello world program for a RV32IM instruction set, doing this:
riscv64-unknown-elf-gcc -m32 -march=RV32IM -o hello hello.c -save-temps
I used options save-temps to keep the intermediate files. (hello.s, hello.i, hello.o)
Everything is OK so far, I can run the hello world program with:
spike pk hello
Hello world!
Now I wanted to take a look at the assembly code for this program. I did the following and I do get the assembly code into hello.dump
riscv64-unknown-elf-objdump -D -S -l -F hello.o > hello.o.dump
Now what I would be interested to see is the assembly code without pseudo instructions and with the non ABI-register names.
It appears to be possible to get that, when I do:
riscv64-unknown-elf-objdump --target-help
I get this:
The following RISC-V-specific disassembler options are supported for use
with the -M switch (multiple options should be separated by commas):
numeric Print numeric reigster names, rather than ABI names.
no-aliases Disassemble only into canonical instructions, rather
than into pseudoinstructions.
However when I try adding these options, it does not work.
riscv64-unknown-elf-objdump -D -S -l -F -Mno-aliases hello.o > hello.o.dump
Unrecognized disassembler option: no-aliases
riscv64-unknown-elf-objdump -D -S -l -F -Mnumeric hello.o > hello.o.dump
Unrecognized disassembler option: numeric
riscv64-unknown-elf-objdump -D -S -l -F -Mnumeric,no-aliases hello.o > hello.o.dump
Unrecognized disassembler option: numeric
Unrecognized disassembler option: no-aliases
Is it a command syntax error or is it just not supported yet by the disassembler?
I can reproduce this and get the same error message. However, riscv64-unknown-elf-objdump returns 0 and the output file does contain an assembler dump without pseudoinstructions and/or with numeric register names, as requested by the option. So it seems like this is working as expected, it just also outputs an irritating error message.
The riscv-tools repo has not been updated since Feb. I also tried this with a build of a more recent version of riscv-gnu-toolchain and here I don't get the error message. So I'd say this is a non-critical bug that already has been fixed in riscv-gnu-toolchain and thus it will be fixed in riscv-tools as soon as riscv-gnu-toolchain is updated there.
You are right, I do get the error message, but when I look at the assembler dump, the numeric register names and the non-pseudo instructions are visible in the file.
Thanks for pointing out that this is just an misleading error message beeing printed...
Related
We are trying to compile this by following instructions in the readme. I must say that we are not specialists with C at all, we are students of a web development bootcamp and trying to do our last project.
It's a command line tool to calculate ephemerides of multiple celestial bodies, and as you can read in the setup in the readme file, it need to download certain data from the internet, and then compile.
All is done through the setup.sh script.
So, we have tried:
In Windows 10 ubuntu WSL terminal
If we type $./setup or $./prettymake, after download the data, gives the error:
$mkfifo: cannot create fifo 'stderr': Operation not supported
$mkdir -p obj obj/argparse obj/coreUtils obj/ephemCalc obj/listTools obj/mathsTools obj/settings
cc -Wall -Wno-format-truncation -Wno-unknown-pragmas -g -c -I /mnt/d/reboot/ephemeris-compute-de430/src -O3 -D DEBUG=0 -D MEMDEBUG1=0 -D MEMDEBUG2=0 -fopenmp -D DCFVERSION=\"2.0\" -D DATE=\"09/06/2019\" -D PATHLINK=\"/\" -D SRCDIR=\"/mnt/d/reboot/ephemeris-compute-de430/src/\" src/ephemCalc/constellations.c -o obj/ephemCalc/constellations.o
If we do it with $sudo ./setup, the error printed is:
$mkfifo: cannot create fifo 'stderr': Operation not supported
$cat: stderr: No such file or directory
$mkdir -p obj obj/argparse obj/coreUtils obj/ephemCalc obj/listTools obj/mathsTools obj/settings
cc -Wall -Wno-format-truncation -Wno-unknown-pragmas -g -c -I /mnt/d/reboot/ephemeris-compute-de430/src -O3 -D DEBUG=0 -D MEMDEBUG1=0 -D MEMDEBUG2=0 -fopenmp -D DCFVERSION=\"2.0\" -D DATE=\"09/06/2019\" -D PATHLINK=\"/\" -D SRCDIR=\"/mnt/d/reboot/ephemeris-compute-de430/src/\" src/ephemCalc/constellations.c -o obj/ephemCalc/constellations.o
In macOS terminal
If we type $./prettymake, gives the error:
$mkdir -p obj obj/argparse obj/coreUtils obj/ephemCalc obj/listTools obj/mathsTools obj/settings
cc -Wall -Wno-format-truncation -Wno-unknown-pragmas -g -c -I /Users/rominaelorrietalopez/Documents/Descargas2/ephemeris-compute-de430-master/src -O3 -D DEBUG=0 -D MEMDEBUG1=0 -D MEMDEBUG2=0 -fopenmp -D DCFVERSION=\"2.0\" -D DATE=\"09/06/2019\" -D PATHLINK=\"/\" -D SRCDIR=\"/Users/rominaelorrietalopez/Documents/Descargas2/ephemeris-compute-de430-master/src/\" src/argparse/argparse.c -o obj/argparse/argparse.o
$clang: error: unsupported option '-fopenmp'
$make: *** [obj/argparse/argparse.o] Error 1
We have tried certain things to no avail, like granting permissions and what not, but have no idea what to do next.
It seems that it have something to do with the prettymake file:
mkfifo stderr
cat stderr | sed 's/\(.*\)/\1/' &
make $# 2>stderr | sed 's/\(.*\)/\1/'
rm stderr
It's like its trying to create a pipe to save the errors of the compilation but somehow it fails.
Also possibly worth of mention, it have a Makefile associated.
Since the github project does not have Issues, we've contacted the creator via email, but well, we thought maybe someone could help us here too.
Any kind of help would be honestly appreciated, thanks.
A comment from the OP invites me to answer; here it is.
The prettymake script creates a named fifo in order to receive the messages produced by make on its standard error.
A background process (cat) consumes the data from this fifo and sends them to a sed command (see right after) in order to transform these data before writing to standard output.
(note that cat is useless here since sed could have directly read from the named fifo thanks to <)
However, the two sed commands as shown in the question don't do anything since they just capture each line of text (\(.*\)) and repeat them unchanged (\1), thus they could have been omitted.
In this case, the script could just contain make $# 2>&1, it would have produced the same effect.
On a system where creating the named fifo is problematic (old version of WSL apparently), this change in the script should produce the same effect as expected.
Looking at the link provided in the question, we can see that the original prettymake script actually contains transformations in the sed commands in order to display standard output and standard error of the make command with different colours.
I use gcc compiled the hello.c:
dele-MBP:temp ldl$ ls
a.out hello.c
now, when I cat a.out:
$ cat a.out
??????? H__PAGEZERO?__TEXT__text__TEXTP1P?__stubs__TEXT??__stub_helper__TEXT???__cstring__TEXT??__unwind_info__TEXT?H??__DATA__nl_symbol_ptr__DATA__la_symbol_ptr__DATH__LINKEDIT ?"? 0 0h ? 8
P?
/usr/lib/dyldס??;K????t22
?*(?P
8??/usr/lib/libSystem.B.dylib&`)h UH??H?? ?E??}?H?u?H?=5??1ɉE??H?? ]Ð?%?L?yAS?%i?h?????Hello
P44?4
there shows the messy code.
I want to know what type of the a.out? is it assembly language? if is why there have so many ??? or %%%?
There are several intermediate file formats, depending on the compiler system you use. Most systems use the following steps, here shown with GCC as example:
Preprocessed C source (gcc -E test.c -o test.i), but this is before compilation, strictly speaking
Assembly source (gcc -S test.c -o test.s)
Object file containing machine code, not executable because calls to external functions are not resolved (gcc -c test.c -o test.o)
Executable file containing machine code (gcc test.c -o test)
Only the first two steps generate text files that you could read by cat or in a text editor. This is BTW a valuable source for insight. However, you can use objdump to see most informations contained in the other formats. Please read its documentation.
Each step does also all steps before it. So (gcc test.c -o test) generates assembly source and object file in temporary files that are removed automatically. You can watch that process by giving GCC the option -v.
Use gcc --help to see some entry points for further investigations.
There is at lot more to say about this process but it would fill a book.
I have installed eCos OS on a linux system (Ubuntu 13.02). After installation, the eCos files are located in opt/ecos.
As I read the eCos tutorial, I see hello.c is stored in opt/ecos/ecos-3.0/examples/hello.c (And I notice that maybe all main eCos system files store in the ecos-3.0 directory).
I have followed the eCos tutorial found on the official website, but I still cannot successfully compile hello.c.
More detail. When I try to run :
$ export INSTALL_DIR=BASE_DIR/ecos-work/arm_install
$ TARGET-gcc -g -IBASE_DIR/ecos-work/install/include hello.c \
-LBASE_DIR/ecos-work/install/lib -Ttarget.ld -nostdlib
I get the error : TARGET-gcc : command not found
I have tried some other tutorials, but I'm still having issues (too messy to list here).
I am looking for step-by-step instruction on compiling hello.c in eCos system. I see the eCos manual lacking in this area.
Thanks :)
It appears that you've missed a subtle convention in the eCos documentation. Items in italics are provided by you! They are variables.
The documentation mentions this here:
Note: Remember that when this manual shows TARGET-gcc you should use
the full name of the cross compiler, e.g. i386-elf-gcc, arm-elf-gcc,
or sh-elf-gcc. When compiling for the synthetic Linux target, use the
native gcc which must have the features required by eCos.
Replace TARGET with the appropriate value and BASE_DIR with (I think, in your case) /opt/ecos. You should verify the include directory before moving forward:
$ ls -l /opt/ecos/ecos-work/install/include
If that doesn't list directory contents, then you simply need to locate ecos-work
The Ecosconfig on Windows and Linux Quick Start section of the docs has you create the BASE_DIR directory (below is a snippet that I am quoting ... italics will not display).
$ mkdir BASE_DIR/ecos-work
$ cd BASE_DIR/ecos-work
So, this could be the correct invocation.
$ export INSTALL_DIR=/opt/ecos/ecos-work/arm_install
$ arm-elf-gcc -g -I/opt/ecos/ecos-work/install/include hello.c \
-L/opt/ecos/ecos-work/install/lib -Ttarget.ld -nostdlib
you need to do
# source /opt/ecos/ecosenv.sh
Then you can try to compile by changing TARGET=
$ TARGET-gcc -g -IBASE_DIR/ecos-work/install/include hello.c \
-LBASE_DIR/ecos-work/install/lib -Ttarget.ld -nostdlib
I'm trying to use clang++ instead of g++ to create object files that will later be linked by the gnu linker.
I'm am able to do this successfully using native clang++, but when I use clang++ with a plugin, I get a link error:
clang: error: linker command failed with exit code 1 (use -v to see invocation)
That's okay! I just need the object files! However, when I specify -S or -c I do not get any object file, even if I use .o to explicitly specify an output file.
I am unable to do this even with clang's example plugins.
How can I get clang to give an object file?
Much Thanks!
I had this same issue. For me, replacing "-plugin" with "-add-plugin" on my command line fixed the problem. I'm not sure what the difference is or why it worked, but it did.
Also, if you are using "-cc1" on the command line, try removing it and prefixing every plugin specific argument with "-Xclang ", i.e. "clang -Xclang -load -Xclang plugin.so -Xclang -add-plugin -Xclang pluginName". Again, I'm not sure why -cc1 wasn't working for me, but it wasn't and this fixed it.
I would like to know how to generate assembler code from a C program using Unix.
I tried the gcc: gcc -c file.c
I also used firstly cpp and then try as but I'm getting errors.
I'm trying to build an assembler program from 3 different programs
prog1.c prog2.c prog.h
Is it correct to do gcc -S prog1.c prog2.c prog.h?
Seems that is not correct. I don't know if I have to generate the assembler from each of them and then link them
Thanks
According the manual:
`-S'
Stop after the stage of compilation proper; do not assemble. The
output is in the form of an assembler code file for each
non-assembler input file specified.
By default, the assembler file name for a source file is made by
replacing the suffix `.c', `.i', etc., with `.s'.
Input files that don't require compilation are ignored.
so try gcc -S file.c.
From man gcc:
-S Stop after the stage of compilation proper; do not
assemble. The output is an assembler code file for
each non-assembler input file specified.
By default, GCC makes the assembler file name for a
source file by replacing the suffix `.c', `.i',
etc., with `.s'. Use -o to select another name.
GCC ignores any input files that don't require com-
pilation.
If you're using gcc (as it seems) it's gcc -S.
Don't forget to specify the include paths with -I if needed.
gcc -I ../my_includes -S my_file.c
and you'll get my_file.s with the Assembler instructions.
objdump -d also works very nicely, and will give you the assembly listing for the whole binary (exe or shared lib).
This can be a lot clearer than using the compiler generated asm since calls to functions within the same source file can show up not yet resolved to their final locations.
Build your code with -g and you can also add --line and/or --source to the objdump flags.