I have been tooling around with autotools for the past couple of days, and finally have made significant progress. One problem I am having is that I have two libraries that need to be compiled before the main application code. I'm not quite sure how to do this. My directory structure is below and a snippet from my configure.ac as well.
AC_CONFIG_FILES([Makefile
src/Makefile
gtkworkbook/Makefile
csv/Makefile])
AC_OUTPUT
I need the csv/Makefile and gtkworkbook/Makefile to both be compiled before src/Makefile; is there any way to specify this? Right now I am getting an error about the library (csv) not existing during the application compile process.
The order of items in AC_CONFIG_FILES() does not affect the build order. If you're using automake, which I assume you are, it will traverse your directory tree in the order that you list directories in each Makefile.am's SUBDIRS list.
That being said, you should have the order of items in AC_CONFIG_FILES() mirror the build order, for consistency/maintainability.
Example of how your toplevel Makefile.am's SUBDIRS to build in the desired order:
SUBDIRS = csv gtkworkbook src
Also, for this simple case you don't need both AC_CONFIG_FILES() and AC_OUTPUT(). You can pass your list directory to AC_OUTPUT():
AC_OUTPUT([
Makefile
src/Makefile
gtkworkbook/Makefile
csv/Makefile
])
Related
I'm facing the following scenario:
Existing project which uses cmake
External 3rdparty library which only comes with Makefiles
The difference of my situation compared to existing questions is that I don't need to have cmake to build the 3rdparty library via the Makefile. Instead, the 3rdparty library provides a library.mk Makefile which has variables like LIB_SRCS and LIB_INCS containing all source and header files required to compile the library.
My idea is to include the library.mk into the project's CMakeLists.txt and then adding those $(LIB_SRCS) and $(LIB_INCS) to target_sources().
My question: How can I include library.mk into the existing CMakeLists.txt to get access to the $(LIB_SRCS) and $(LIB_INCS) for adding them to target_sources()? I'm looking for something like this:
include("/path/to/library.mk") # Somehow include the library's `library.mk` to expose variables to cmake.
add_executable(my_app)
target_sources(
my_app
PRIVATE
main.c
$(LIB_SRCS) # Add 3rd-party library source files
$(LIB_INCS) # Add 3rd-party library header files
)
Using include() does not work as the library.mk is not a CMake list/file.
Since you can't be sure that your target system will even have Make on it, the only option is to parse the strings out of the .mk file, which might be easy if the variables are set directly as a list of filenames, or really hard if they are set with expansions of other variables, conditionals, etc. Do this with FILE(STRINGS) cmake doc.
Your plan will only work if the Makefiles are trivial, and do not set important compiler flags, define preprocessor variables, modify the include directory, etc. And if they really are trivial, skip the parsing, and just do something like aux_source_directory(<dir> <variable>) to collect all the sources from the library directory.
You might also consider building and maintaining a CMakeLists.txt for this third-party library. Do the conversion once, and store it as a branch off of the "vendor" main branch in your version control system. Whenever you update, update the vendor branch from upstream, and merge or rebase your modifications. Or just store it in your existing project, referring to the source directory of the 3rd-party stuff.
It seem to me that scons targets are being generated not in declaration sequence. My problem is, I need to generate some code first, I'm using protoc to process a my.proto file into .h and .cc file, I need some pseudo code like this(what should the working code look like?)
import os
env=Environment(ENV=os.environ,LIBPATH='/usr/local/lib')
env.ShellExecute('protoc', '--outdir=. --out-lang=cpp', 'my.proto')//produces my.cc
myObj=Object('my.cc')//should wait until 'my.cc' is generated by protoc
Dependency(myObj, 'my.cc')
mainObj=Object('main.cpp')
My question is:
How to specify this ShellExecution of protoc in SConstruct/SConscript?
How to make sure that the compilation of 'main.cpp' depends on the existence of 'my.cc', in another word, wait until 'my.cc' is generated and then execute?
Your observations and assumptions are correct, SCons will not execute the single build commands in the order that you list them in the SConstruct files. It will run them based on the dependencies of the targets and source files in your build, either defined implicitly (header includes in C++, for example) or explicitly (via the Depends() method).
So you have to define and setup your dependencies correctly, such that SCons delivers the output that you want. For the special protoc case in your example, a special Builder exists that will help you to get the dependency graph right. It is available in our ToolsIndex, where also support for a variety of other languages and dialects can be found.
These special builders will emit the correct target nodes, e.g. when given a *.proto input file, and SCons is then able to automatically detect the dependency between the protoc input file and your main program if you say something like:
env=Environment(tools=['default','protoc'])
env.Protoc([], "test.proto")
env.Program('main', ['main.cpp'] + Glob('*.cc'))
The Glob('*.cc') will detect your *.cc files, coming out of the protoc Tool, and include them as dependencies for your final target main.
You can always write your own Builders and Emitters in SCons, which is the canonical way of making new tools/toolchains known to SCons dependency analysis. In the UserGuide, sect. "18 Writing Your Own Builders", and especially our ToolsForFools Guide you can find more infos about this.
My makefile makes use of auto-generated dependencies. To do this, I have in my top-level makefile something similar to:
# Makefile
include target1.deps
include target2.deps
all: target2.deps
cat $^
target2.deps: target1.deps
target1.deps:
echo "target2.deps:" > $#
echo " touch target2.deps" >> $#
Initially, target1.deps and target2.deps do not exist. When make is first instantiated, it parses the entire Makefile and searches for a way to generate these include files. After building them, it reinvokes itself, causing the Makefile to be reparsed and the include files to be included this time. At least, that's my understanding.
The issue is that when I run the above Makefile, Make first builds target1.deps, then executes the body of the all rule, never having built or included target2.deps. This causes cat to error: cat: target2.deps: No such file or directory
This seems like a contradiction to me. I explicitly tell Make that all depends on target2.deps, but it attempts to execute the rule before satisfying its prerequisites!
The intended behavior is that target1.deps should be built and included, then target2.deps should be built and included using the rule contained within target1.deps, and then all should be run. How do I achieve this?
Context: Since this is weirdly abstract, here's my goal: I have a target index.html, which gets generated from a template index.html.in, but I don't know anything about its dependencies. I need to find out (a) which files I need to create before building index.html and (b) which files index.html will depend on at runtime.
For example index.html includes some inline css that's pulled out of global.css - I need to therefore build global.css before building index.html. On the other hand, index.html links to about.html, so after I build index.html I want to also build about.html. I call the former "build dependencies" and the latter "runtime dependencies". So my makefile looks something like this:
include index.html.build_deps
include index.html.runtime_deps
all: index.html $(runtime_deps_index.html)
%.build_deps: %.in
./extract_build_deps %< -o %#
%.runtime_deps: %
./extract_runtime_deps %< -o %#
%: %.in
./compile_template %< -o $#
What I want to happen is for Make to follow these steps:
Build index.html.build_deps
Include index.html.build_deps
Build global.css (now a known prerequisite of index.html)
Build index.html
Build index.html.runtime_deps
Include index.html.runtime_deps
Build about.html (contained inside $(runtime_deps_index.html) included from index.html.runtime_deps)
Target all is reached
What actually happens:
Make sees that index.html.build_deps can be directly build from index.html.in; does so.
Make sees that index.html.runtime_deps can be built from index.html, can be built from index.html.in.
Make builds index.html. It errors because global.css hasn't yet been built.
If Make had included index.html.build_deps after building that, then it would be aware of the global.css dependency. But because it tries to build all include files before expanding any of them, it's unaware of the dependency. I want to add a dependency "index.html.runtime_deps depends on index.html.build_deps having been included, but I'm not sure how to specify such a dependency.
#Dario is correct. To be a bit more specific, these are the steps make will follow here:
Read the makefile.
Try to build target1.deps.
Find a target target1.deps and execute the recipe.
The recipe succeeds, but make observes that the file target1.deps still does not exist, so make doesn't mark the target as updated.
Try to build target2.deps.
There's a target for it that depends on target1.deps, which make already built, but there's no recipe for it so make doesn't mark target2.deps as updated (since it was never updated, as far as make can tell--it didn't run any recipe to update it).
So, make decides none of the included makefiles were actually updated and it won't re-exec.
Then make wants to build all; it sees that all depends on target2.deps but make already considered that target and decided it didn't need to be rebuilt, so now make is done with all its work.
You can run make -d and follow along with the decisions make takes.
I'm creating a makefile to build an existing project. We're using GNU Make 4, but the compiler doesn't automatically generate dependency information so I'm trying to determine the best way to specify dependencies for code that includes header files which in turn may include header files. Due to the complexity of the codebase, I think it will be unrealistic to traverse the entire #include tree, gather up all the header files, and then specify them for each source file.
One solution is to create makefile definitions of each header file and its direct dependencies, then create a recipe for a header file that touches that header file to trigger the recompile of the source that includes it:
a123.o: a123.c header1.h
header1.h: header2.h
header2.h: header3.h
# Recipes
%.o:
# compile command for building a .o
%.h:
#touch $#
This seems to work; if header3.h changes, then the %.h recipe updates header2.h's timestamp, which causes header1.h's timestamp to be updated, which causes a123.o to be rebuilt.
However, it seems messy, with all the touching, plus it seems odd to create a recipe for a source file that isn't directly compiled. Is this the correct way to do this sort of thing, or is there a cleaner approach? Please note that I simplified my question; in reality several languages are in use with different file extensions, the compiler isn't GCC, and the output isn't a .o file. But the logic is exactly the same.
I have 2 libraries that share same source files:
# src/lib_mt/Makefile.am:
libppb_la_SOURCES = rphs_mt.c timer_mt.c
# src/sipplib/Makefile.am:
libsipp_a_SOURCES = ../lib_mt/rphs_mt.c ../lib_mt/timer_mt.c
Each source file compiled twice. First for lib_mt with -fPIC, second for sipplib without -fPIC.
Object files for each library created in corresponding directory.
Eventually subdir-objects becomes default. How to keep current behavior for these 2 source files? Some explicit rule maybe?
There is no way to disable that the moment it becomes the default. What you can do instead is migrate this to a non-recursive Automake buildsystem. At that point, it will know that there are different targets compiling the same source files with different flags (it requires AC_PROG_CC_C_O to be called in configure.ac.)
Alternatively, the hacky version is to create a src/sipplib/rphs_mt.c file that only contains
#include "../libmt/rphs_mt.c"
so that it is actually a separate build target.