SCons out of source build仅适用于可执行程序，而不适用于目标文件

Question

I have the following SCons configuration:

current_directory
|-<.cpp files>
|-<.h files>
|-SConstruct
|-SConscript
|-bin
  |-<empty>

I want to build my source files and put the executable and the object files into the bin directory.

This is what I have in my SConstruct file:

SConscript('SConscript', variant_dir='bin', duplicate=0)

While in the SConsript file I have:

debug_environment.Program(target = 'SsaTest', src_files, LIBS=libraries, LIBPATH=libraries_path)

When I build using scons command I get the SsaTest executable in the bin directory (as desired), but the object files are left in the current directory.

How can I have the .o files be built in the bin directory as well?

Many thanks.

EDIT: Complete SConscript file (forgive me for the xxx s)

import os

# This is correctly Exported()
Import('debug_flags')

# Paths to header files
headers_paths = ['#/../../xxx/include/',
                 '#/../../../xxx/include/',
                 '#/../../xxx/include/',
                 '#/../../xxx/include/',
                 '#/../../xxx/include/']

# Path to source files
src_folder = '#./'

# Source files list
src_files = ['xxx.cpp',
             'xxx.cpp',
             'xxx.cpp',
             'xxx.cpp',
             'xxx.cpp']

# Prepend the relative path to each source file name
src_files = [src_folder + filename for filename in src_files]

libraries = ['xxx', 'xxx', 'xxx', 'xxx', 'xxx', 'xxx', 'xxx', 'xxx']

libraries_path = ['#/../../xxx/lib',
                  '#/../../../xxx/bin', 
                  '#/../lib', 
                  '#/../../xxx/lib', 
                  '#/../../xxx/lib', 
                  '#/../../xxx/lib']

# Debug environment
debug_environment = Environment(CC = 'g++', CCFLAGS=debug_flags, ENV = os.environ, CPPPATH=headers_paths); 
# Executable build command
debug_environment.Program(target = 'SsaTest', src_files, LIBS=libraries, LIBPATH=libraries_path)

Answer 1

Using '#' with source files not recommended, because you have your situation, scons can't correctly process it with variant dirs and how result create object files in directory where sources placed.

So, i tryed to build your example with same configuration and have no troubles:

#SConsctruct
SConscript('SConscript', variant_dir='bin', duplicate=0)

#SConscript
src_files = Glob('*.cpp')
debug_environment = Environment()
debug_environment.Program('SsaTest', src_files)

So, all object files are generated in bin directory.

Finally, you have no troubles with relation dirs with sources files then using variant dirs. But include dirs are depended from variant dirs. Configuration for example :

build
app
--SConscript
--src
----*.h
----*.cpp
SConstruct

#SConstruct
rootEnv = Environment()
Export('rootEnv')
SConscript('app/SConscript', variant_dir='build', duplicate=0)

You SConscript will be looking like it:

Import('rootEnv')
env = rootEnv.Clone()
env.Append(CPPPATH = ['#app/src'])
env.Program('app', Glob('src/*.cpp'))

'#app/src' - where # is very important when using variant dir, because if would be app/src, build command will be looking: '-Ibuild/app/src' (adding variant dir before include path). But adding '#' command will be looking correctly : '-Iapp/src'.

Answer 2

One thing that sticks out in your SConscript is how you are prepending the path to each source file with #./ .

# Path to source files
src_folder = '#./'

Why do you use the dot in that path, its not necessary? Try with the following #/ like you do with the rest of the paths, like this:

# Path to source files
src_folder = '#/'

Another option would be to put the source files and the respective SConscript in its own subdirectory. Its not real clear why you have a SConstruct, SConscript, and the source files all in one directory. Either create a subdir, or consider removing the SConscript if its not necessary.

In the SConscript() function call in the SConstruct, refer to the variant_dir as "#bin" and not "bin". Not sure if this will help, but its better practice.

Ive seen this behaviour before using the Repository() SCons function to reference the source files as mentioned here .

Also, this is off-topic, but if your include and library paths (headers_paths and libraries_path variables) are outside of the project directory structure, you may consider using absolute paths instead. Personally I find it rather ugly to use relative paths with several ../ paths.