I'm working on adding some functionality to the storage manager module in Postgresql.
I have added few source files already to the smgr folder, and I was able to have the Make system includes them by adding their names to the OBJS list in the Makefile inside the smgr folder. (i.e. When I add A.c, I would add A.o to the OBJS list).
That was working fine. Now I'm trying to add a new file hdfs_test.c to the project. The problem with this file is that it requires some extra directives in its compilation command (-I and -L directives).
The gcc command is:
gcc hdfs_test.c -I/HDFS_HOME/hdfs/src/c++/libhdfs -I/usr/lib/jvm/default-java/include -L/HDFS_HOME/hdfs/src/c++/libhdfs -L/HDFS_HOME/build/c++/Linux-i386-32/lib -L/usr/lib/jvm/default-java/jre/lib/i386/server -ljvm -lhdfs -o hdfs_test
Therefore, simply adding hdfs_test.o to the OBJS list doesn't work.
I tried editing the Makefile to look like this:
OBJS = md.o smgr.o smgrtype.o A.o B.o hdfs_test.o
MyRule1 : hdfs_test.c
gcc tati.c -c -I/diskless/taljab1/Workspace/HDFS_Append/hdfs/src/c++/libhdfs -I/usr/lib/jvm/default-java/include -L/diskless/taljab1/Workspace/HDFS_Append/hdfs/src/c++/libhdfs -L/diskless/taljab1/Workspace/HDFS_Append/build/c++/Linux-i386-32/lib -L/usr/lib/jvm/default-java/jre/lib/i386/server -ljvm -lhdfs
but it didn't work out, and I kept getting errors message of the Make trying to compile hdfs_test.c without including the directives.
How do I enforce the Make to include my compilation directives for hdfs_test.c ?
Thanks
You don't need to pass -l and -L at compile time, only at link time. At compile time only -I (include path) directives are required to help the compiler find any extra headers.
You should compile your source file to a .o file, same as all the others. Then add the -L and -l directives to the link command line when the linker is invoked to create the postgres executable. That means all you need to edit in src/backend/storage/smgr/Makefile is the OBJS line to add your output object, as you've already done below. Remove your custom rule, it's unnecessary as well as incorrect.
Just add your extra libraries to the $(LIBS) make variable and add your -L paths to $(LDFLAGS) via src/Makefile.global. src/Makefile.global is generated by configure from src/Makefile.global.in so you actually need to modify configure's behavior to add your includes, library paths and libraries. Don't edit configure directly either; edit configure.in and re-generate it with autoconf.
Yes, GNU Autotools is sometimes referred to as autohell for a reason. It's a bit ... interesting ... to work with sometimes, and there can be a lot of indirection involved in doing simple things.
Related
I have created a Yocto autotools project in Eclipse (based on a Hello World project).
I wanted to separate my code into a number of libs and then link them in a form of static libs (.a) to my project.
Now I have one app and a number of static libs. However, no matter what I try I can't get my code to compile. Each separate lib compiles and produces a .a file, but my app doesn't.
After searching the web I have a possible solution - add a direct link to my static libs:
MyApp_CPPFLAGS="-I$LOCATION"
MyApp_LDADD="/home/xxx/workspace/MyApp/Encoding2/Debug/libEncoding2.a"
This is my Makefile.am file, where libEncoding2.a exist in that path.
The error I get is:
make[2]: *** No rule to make target `"/home/xxx/workspace/MyApp/Encoding2/Debug/libEncoding2.a"', needed by `MyApp'. Stop.
I already built the lib so I am not sure why a make try is even needed.
Any help will be appreciated.
Because you use static library in your recipes, you can make a soft link to the library in your project source folder, i.e., hello-world-0.1, using following command to link to your static library
ln -s /home/xxx/workspace/MyApp/Encoding2/Debug/libEncoding2.a
and then edit your bb file, hello-world_0.1.bb, adding the source path to your URL
SRC_URI = " \
file://libEncoding2.a \
file://hello-world.c \
"
and in the do_compile block, using follow command to compile your project
do_compile() {
${CC} hello-world.c libEncoding.a -o hello-world
}
do_install() {
install -d ${D}${bindir}/Hello
install -m 0755 enet ${D}${bindir}/Hello
}
After you bitbake your project
bitbake hello-world
and run mkefidisk.sh, you can find the hello-world in /usr/bin/Hello/hello-world. Hope this hint can help you.
BTW, I am not familiar with autotools, I just use make to bitbake the recipes. And your static library should also be created in Yocto not in Eclipse I think. So I think your path for the static library maybe not correct, it should locate in ~/yocto/build/tmp/... or some where like this. In my case, it was located in ln -s ~/yocto/build/tmp/sysroots/intel-corei7-64/usr/lib/libEncoding.a depends on your target environment.
Depending on whether you're using libtool or not, you should have either a noinst_LTLIBRARIES or noinst_LIBRARIES list of targets, respectively. This should only include the name of your library (libEncoding2.la or libEncoding2.a.)
You should never use a full path for this, and you should not quote Make variables, so what you were looking for is
MyApp_CPPFLAGS = -I$LOCATION
MyApp_LDADD = libEncoding2.la # or .a
And that would work.
But on the other hand it seems like you should take some time to understand how autotools work, as it might not be what you're looking for. With a grain of salt you can take my Autotools Mythbuster as a starting point.
I have a Coq project with its libraries organised into subdirectories, something like:
…/MyProj/Auxiliary/Aux.v
…/MyProj/Main/Main.v (imports Auxiliary/Aux.v)
When I compile the files, I expect to do so from working directory MyProj (via a makefile). But I also want to work on the files using Proof General/Coqtop, in which case the working directory is by default the directory in which the file lives.
But this means that the LoadPath is different between the two contexts, and so the logical path needed for the library import is different. How do I set up the coqc invocation, the LoadPath, and the import declarations so that they work in both contexts?
Each approach I have tried, something goes wrong. For instance, if I compile Aux.v by invoking
coqc -R "." "MyProj" Auxiliary/Aux.v
and import it in Main.v as
Require Import MyProj.Auxiliary.Aux.
then this works when I compile Main.v with
coqc -R "." "MyProj" Main/Main.v
but fails in Coqtop, with Error: Cannot find library MyProj.Auxiliary.Aux in loadpath. On the other hand, if before the Require Import I add
Add LoadPath ".." as MyProj.
then this works in Coqtop, but fails under coqc -R "." "MyProj" Main/Main.v, with
Error: The file […]/MyProj/Auxiliary/Aux.vo contains library
MyProj.Auxiliary.Aux and not library MyProj.MyProj.Auxiliary.Aux
I’m looking for a solution that’s robust for a library that’s shared with collaborators (and hopefully eventually with users), so in particular it can’t use absolute file paths. The best I have found for now is to add emacs local variables to set the LoadPath up when Proof General invokes Coqtop:
((coq-mode . ((coq-prog-args . ("-R" ".." "MyProj" "-emacs")))))
but this (a) seems a little hacky, and (b) only works for Proof General, not in Coqide or plain Coqtop. Is there a better solution?
Allow me to side-step your question by suggesting an alternative process, hinted at by Tiago.
Assuming that your project's tree looks like this:
MyProj/Auxiliary/Aux.v
MyProj/Main/Main.v
In MyProj, write a _CoqProject file listing all your Coq files
-R . ProjectName
Auxiliary/Aux.v
Main/Main.v
When you open one of these Coq files, emacs will look for the _CoqProject and do-the-right-thing (tm).
As shown by Tiago, coq_makefile will also give you a Makefile for free.
I know you explicitly asked for something that works across different platforms, but there's already a Proof-General-specific solution that is less hacky than the one you have. Proof General has a special variable called coq-load-path that you can set with local variables, much like you did for coq-prog-args. The advantage is that you don't have to worry about any other arguments that need to be passed to coqtop (such as -emacs in your example). Thus, your .dir-locals.el file could have a line like this:
((coq-mode . ((coq-load-path . ((".." "MyProj"))))))
Unfortunately, I am not aware of anything that works across platforms, although I'm pretty sure that something specific for CoqIDE must exist. If this is the case, maybe you could set up a script to keep these configuration files updated across different platforms?
If you use coq_makefile you can install the library in your system.
Without OPAM
To initialize your project:
coq_makefile -f _CoqProject -o Makefile
Share your library with other projects:
make install
With OPAM
Assuming you have OPAM installed, you can use coq-shell to help you take care of dependencies.
To setup your project:
coq_shell_url="https://raw.githubusercontent.com/gares/opam-coq-shell/master/src/opam-coq"
curl -s "${coq_shell_url}" | bash /dev/stdin init 8.4 # Install Coq and its dependencies
eval `opam config env --switch=coq-shell-8.4` # Setup the environment
coq_makefile -f _CoqProject -o Makefile # Generates the makefile
opam pin add coq:YOURLIBRARY . # Add your library to OPAM
When you update your library you should do:
opam upgrade coq:YOURLIBRARY
Here is an example of a project that uses the OPAM method:
https://bitbucket.org/cogumbreiro/aniceto-coq/src
I use Eclipse + ARM plugin to build my projects. When I needed to use in my project the StemWin library, I configured my IDE to use external library.
I set
Preferences -> C/C++ General -> Paths and Symbols
I added in "Library Paths" the link to my folder includes library.
I also added the name of my library in tab "Library".
I checked the settings in the compiler tab and I ascertained all should be good.
When I tried to build my project I got an error from linker:
cannot find -lMyLib.a Hello C/C++ Problem
I double checked the name of my library and link, all are correct. This is the output of my linker:
arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -L"C:\lib"
-T"C:\arm_toolchain\stm32_workspace\Hello\LinkerScript.ld" -Wl,
-Map=output.map -Wl,--gc-sections -o "Hello.elf" #"objects.list" -lMyLib.a
What should I do from here?
I faced the same problem before.
-l:STemWin526_CM4_GCC.a
-L"C:\Edu_Workspace\STM32F4\stm32f4_bsp_template\Drivers\Middlewares\ST\STemWin\Lib"
Above are my working settings.
With -l:<archive file name> the colon : is important for archive file linking.
And -L will contain library path.
Also for stemwin make sure to compile with hardware floating point
-mfloat-abi=hard -mfpu=fpv4-sp-d16
the convention for the -l option of the linker (say you give -lMyLib.a as a linker option) is to search for a library file with "lib" prepended to the given name and .a (or .so) appended, i.e. your command line searches for a file libMyLib.a.{a,so} which is probably not how it's named.
Either you rename your library according to this convention or give it to the linker command line omitting -l (provided your IDE allows you to do so).
Looks like the problem is in -lMyLib.a which means you're trying to link a static library as a dynamic one.
To link a static lib you have to use its path as with ordinary .o files: ... /path/to/MyLib.a
and the resulting command line should look something like
arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -L"C:\lib" -T"C:\arm_toolchain\stm32_workspace\Hello\LinkerScript.ld" -Wl,-Map=output.map -Wl,--gc-sections -o "Hello.elf" #"objects.list" /path/to/MyLib.a
UPDATE:
Although it might fix the issue, turns out it's not true:
-llibrary
-l library
...
Normally the files found this way are library files—archive files whose members are object files. The linker handles an archive file by scanning through it for members which define symbols that have so far been referenced but not defined. But if the file that is found is an ordinary object file, it is linked in the usual fashion. The only difference between using an -l option and specifying a file name is that -l surrounds library with ‘lib’ and ‘.a’ and searches several directories.
(https://gcc.gnu.org/onlinedocs/gcc/Link-Options.html)
Something like this:
cmake --get-variable=MY_CMAKE_VARIABLE
The variable may exist in an included CMake file.
If you have an existing cache file, you can do:
grep MY_CMAKE_VARIABLE CMakeCache.txt
If you do not yet have a cache file and you want to see what options there are in a CMakeLists.txt file, you can do (in a different directory since this will write a cache file):
cmake -L /path/to/CMakeLists.txt | grep MY_CMAKE_VARIABLE
which will return to you something like
<VARIABLE>:<TYPE>=<VALUE>
If it is an advanced variable, add the -A flag to the same command and it will include advanced variables. Of course, if you only want the value, you can do:
cmake -L /path/to/CMakeLists.txt | grep MY_CMAKE_VARIABLE | cut -d "=" -f2
EDIT
For example, with a CMakeLists.txt that is:
cmake_minimum_required(VERSION 2.8)
project(test)
include(otherFile.txt)
set(MY_VAR "Testing" CACHE STRING "")
And where otherFile.txt is:
set(MY_OTHER_VAR "Hi" CACHE STRING "")
The command (run from another directory):
cmake -L ../cmaketest
Gives:
-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
-- Check for working C compiler: /usr/bin/gcc
-- Check for working C compiler: /usr/bin/gcc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - 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
-- Configuring done
-- Generating done
-- Build files have been written to: /home/tgallagher/cmaketest-build
-- Cache values
CMAKE_BUILD_TYPE:STRING=
CMAKE_INSTALL_PREFIX:PATH=/usr/local
MY_OTHER_VAR:STRING=Hi
MY_VAR:STRING=Testing
So, it does show variables from other files. It should parse the entire build. The issue though is that it will not show any variables that are not marked with CACHE. And it will not show any that are cached INTERNAL, and will only show ADVANCED if -LA is used instead of -L.
If your variables are marked as INTERNAL or not CACHE'd at all, then there is no method within CMake to pull it out. But, non-CACHE'd variables are meant to be transient, so I'm not sure why you would need them outside of a build environment anyway.
Use:
cmake -LA -N /path/to/project
to get a listing of all cache values. The -N is important; it prevents cmake from trying to generate any build files, and just shows you what's in the cache.
If the variable you want is not something you're setting, but something from the defaults, you can use
cmake --system-information
And grep that. Note it does seem to take a second or two which seems kinda slow.
If for example you're trying to do this to configure your cmake vars in the first place, it avoids getting the cart out in front of the horse. :)
You can also pass this a file name. So you can try only generating it if it doesn't exist, and parse the file if it does (to save that 1-2 seconds).
If you need get non cached user variable but can't edit original cmake script, you may resort to a trick. Create new CMakeLists.txt file in another directory with the following content:
include(<Path to original CMakeLists.txt>)
message(STATUS "MY_VAR={${MY_VAR}}")
It is quite possible, cmake will made a lot of errors while running in new directory. Relative paths, if used in original script, is definitely a cause for such errors. But cmake will print last value assigned for your variable. Further, filter all errors and warnings using any well known text processor (assume UNIX familiar), for example:
cmake . | sed -n 's/-- MY_VAR={\(.*\)}/\1/p' 2>&1
I use this approach in projects maintenance scripts, it is reliably as long as original CMakeLists.txt has no syntax errors.
-D <var>:<type>=<value>:
When cmake is first run in an empty build tree, it creates a CMakeCache.txt file and populates it with customizable settings for the project. This option may be used to specify a setting that takes priority over the project's default value. The option may be repeated for as many cache entries as desired.
I have different behaviour of compiler, when building project from IDE and from command-line, which I can not explain.
The detailed issue's description is rather big, but it's really simple.
I have a C++ Builder project, which has a PAS-file included (IncludeUnits.pas). This pas-file has several units and inc-files listed. These files are located in separate folders and these folders are listed in library&include paths in project's options.
Folders layout:
C:\Demo\Bin
C:\Demo\Project
C:\Demo\Project\CBuilder5
C:\Demo\Project\Common
C:\Demo\Source
C:\Demo\Source\Common
Bin is output folder, Project/CBuilder5 holds project (bpr-file), Project/Common holds included pas-file (IncludeUnits.pas), Source and Source/Common hold other files (pas&inc). I think that it's pretty usual layout.
C:\Demo\Project\Common\ IncludeUnits.pas :
unit IncludeUnits;
interface
uses
Test;
implementation
end.
C:\Demo\Source\ Test.pas :
unit Test;
interface
{$I Test.inc}
implementation
end.
C:\Demo\Source\Common\ Test.inc :
// this file is empty
If I compile this project from C++ Builder IDE - it will compile fine. C++ Builder IDE doesn't have any additional paths in IDE settings set.
Now, I want to compile it from command-line. First, I issue
bpr2mak.exe MyProject.bpr
command.
This command creates MyProject.mak file, where I can see all paths ("....\Source" and "....\Source\Common" are the paths in question):
...
INCLUDEPATH = $(BCB)\include;$(BCB)\include\vcl;..\Common;..\..\Source;..\..\Source\Common
LIBPATH = $(BCB)\lib\obj;$(BCB)\lib;..\Common;..\..\Source;..\..\Source\Common
...
Now, I run make command:
make.exe -B -f"MyProject.mak"
It gives me the following output:
C:\PROGRA~1\Borland\CBUILD~2\BIN\dcc32 -N2....\Bin -N0....\Bin -$Y+ -$W -$R -v -JPHNE -M -UC:\PROGRA~1\Borland\CBUILD~2\bin..\include;C:\PROGRA~1\Borland\CBUILD~2\bin..\include\vcl;..\Common;..\..\Source;..\..\Source\Common -D_DEBUG;_RTLDLL;NO_STRICT -OC:\PROGRA~1\Borland\CBUILD~2\bin..\include;C:\PROGRA~1\Borland\CBUILD~2\bin..\include\vcl;..\Common;..\..\Source;..\..\Source\Common --BCB ..\Common\IncludeUnits.PAS
Borland Delphi Version 13.0 Copyright (c) 1983,99 Inprise Corporation
C:\Demo\Project\Common\IncludeUnits.pas(1) C:\Demo\Project\Common\IncludeUnits.pas(1) C:\Demo\Project\Common\IncludeUnits.pas(1) C:\Demo\Project\Common\IncludeUnits.pas(6) C:\Demo\Source\Test.pas(1) C:\Demo\Source\Test.pas(5) Fatal: File not found: 'Test.inc'
As you can see - all search path is passed to compiler and the file (Test.inc) is all here - in that Source\Common folder. But still compiler can't find it?
Of course, I run both commands from folder with bpr-file. And changing paths to absolute doesn't help.
Copying Test.inc from Source\Common to Source will help. Changing {$I Test.inc} to {$I Common\Test.inc} will also help.
Why? It seems that I'm missing something. Remember: project have no problems with compiling from IDE, Test.inc is found without copying or changing declaration. Did I miss some switch to make or dcc32?
I found the reason: command line for dcc32 misses -I switch, which specifies paths for include files.
For some reason, bpr2mak doesn't respect this option. Fortunately, it allows you to specify alternate template for conversion bpr -> mak. I edited default template and added "-I" option to it, pass new template to bpr2mak - and it worked.