This patch removes the implicit build of all shared libraries a target
depends on. Targets only depend on the respective ABIs instead. This
alleviates the need to locally build complex shared libraries (think of
Qt) when developing applications. Instead, application developers can
use binary depot archives.
The implementation splits the mk/lib.mk file into three files:
- mk/a.mk for building one static library (.lib.a)
- mk/so.mk for building one shared object (.lib.so)
- mk/abi.mk for building one ABI stub (.abi.so)
Furthermore, the commit moves messages and the collection of build
artifacts to var/libdeps, triggers the build of kernel-specific
ld-<kernel>.lib.so, and prunes the lib-dependency tree at ABIs.
Fixes#5061
The build system automatically announces the names of shared libraries
as build artifacts. However, in rare cases, it is required to manually
define them. In particular, the 'ld' stub library plays no role at runtime
and should not be integrated into the boot image.
This patch adds a customization hook following the same pattern as used
for target.mk files, namely the BUILD_ARTIFACTS variable. If defined,
its value is taken as the list of boot artifacts generated by the
library-description file.
Issue #4368
This patch adds special handling for lib/<libname> arguments to the
build system, which supersedes the former LIB=<libname> mechanism.
Whereas the old mechanism was limited to a single library, the new
convention allows multiple library arguments, similar to regular
targets. The change brings the two immediate benefits.
First, the streamlining of library and target arguments allows for the
building of libraries via the 'build' command of the run tool.
Second, it alleviates the need for pseudo target.mk files for building
shared libraries that have no direct dependencies, in particular VFS
plugins.
Since this change eases the explicit creation of shared libraries
from run scripts, we may reconsider the automatic implicit building
of shared libraries driven by targets. E.g., while developing a Qt
application, a run script could import the Qt libraries from the
depot and combine those with the developed (fresh built) target without
triggering the build of the Qt libraries in the build directory.
When issueing 'make' without arguments, all targets are built. This
patch applies this behavior to libraries as well, thereby removing the
need for the base/src/lib/target.mk pseudo target as used by the CI
tools to build all libraries.
Note that target.mk files located under src/lib/ are no longer
reachable. Therefore, all run scripts that used to trigger the
build of a shared library via a pseudo target must be adapted.
E.g., 'build lib/vfs/tap' must be replaced by 'build lib/vfs_tap'.
With this patch, the LIB=<libname> option is no longer supported.
Fixes#4599
This patch applies the existing "privatization" of transitive
shared-library dependencies from static lib dependencies to shared lib
dependencies. It thereby improves the consistency of binaries created in
a regular build directory with binaries created in depot archives.
Issue #4408
The former ldso-startup static library (now called ldso_so_support) is
used to spice each shared object/library with local support code for the
dynamic linker (execution of static constructors and ARM-EABI).
Therefore, the library must be statically linked to each dynamic
library.
As a result recipes for dynamic libraries must always depend on the "so"
API, which makes ldso_so_support.mk and so_support.c available
independent of "base". Additionally, ldso_so_support is also provided in
the libc API to cut the dependency early for libc/posix libraries.
Issue #3720
The <build-dir>/bin/ directory used to contain symbolic links to the
unstripped build results. However, since the upcoming depot tool
extracts the content of binary archives from bin/, the resulting
archives would contain overly large unstripped binaries, which is
undesired. On the other hand, always stripping the build results is not
a good option either because we rely of symbol information during
debugging.
This patch changes the installation of build results such that a new
'debug/' directory is populated besides the existing 'bin/' directory.
The debug directory contains symbolic links to the unstripped build
results whereas the bin directory contains stripped binaries that are
palatable for packaging (depot tool) and for assembling boot images (run
tool).
This patch make the ABI mechanism available to shared libraries other
than Genode's dynamic linker. It thereby allows us to introduce
intermediate ABIs at the granularity of shared libraries. This is useful
for slow-moving ABIs such as the libc's interface but it will also
become handy for the package management.
To implement the feature, the build system had to be streamlined a bit.
In particular, archive dependencies and shared-lib dependencies are now
handled separately, and the global list of 'SHARED_LIBS' is no more.
Now, the variable with the same name holds the per-target list of shared
libraries used by the target.
This patch removes the component_entry_point library, which used to
proved a hook for the libc to intercept the call of the
'Component::construct' function. The mechansim has several shortcomings
(see the discussion in the associated issue) and was complex. So we
eventually discarded the approach in favor of the explicit handling of
the startup.
A regular Genode component provides a 'Component::construct' function,
which is determined by the dynamic linker via a symbol lookup.
For the time being, the dynamic linker falls back to looking up a 'main'
function if no 'Component::construct' function could be found.
The libc provides an implementation of 'Component::construct', which
sets up the libc's task handling and finally call the function
'Libc::Component::construct' from the context of the appllication task.
This function is expected to be provided by the libc-using application.
Consequently, Genode components that use the libc have to implement the
'Libc::Component::construct' function.
The new 'posix' library provides an implementation of
'Libc::Component::construct' that calls a main function. Hence, POSIX
programs that merely use the POSIX API merely have to add 'posix' to the
'LIBS' declaration in their 'target.mk' file. Their execution starts at
'main'.
Issue #2199
This patch decouples the kernel-specific implementation of the dynamic
linker from its kernel-agnostic binary interface. The name of the
kernel-specific dynamic linker binary now corresponds to the kernel,
e.g., 'ld-linux.lib.so' or 'ld-nova.lib.so'. Applications are no longer
linked directly against a concrete instance of the dynamic linker but
against a shallow stub called 'ld.lib.so'. This stub contains nothing
but the symbols provided by the dynamic linker. It thereby represents
the Genode ABI.
At system-integration time, the kernel-specific run/boot_dir back ends
integrate the matching the kernel-specific variant of the dynamic linker
as 'ld.lib.so' into the boot image.
The ABI symbol file for the dynamic linker is located at
'base/lib/symbols/ld'. It contains the joint ABI of all supported
architectures. The new utility 'tool/abi_symbols' eases the creation of
such an ABI symbol file for a given shared library. Its result should be
manually inspected and edited as needed.
The patch removes the 'syscall' library from 'base_libs.mk' to avoid
polluting the kernel-agnostic ABI with kernel-specific interfaces.
Issue #2190
Issue #2195
Previously, ports that were needed for a scenario and that were not
prepared or outdated, triggered one assertion each during the second
build stage. The commit slots a mechanism in ahead that gathers all
these ports during the first build stage and reports them in form of a
list before the second build stage is entered. This list can be used
directly as argument for tool/ports/prepare_port to prepare respectively
update the ports. If, however, this mechanism is not available, for
example because a target is build without the first build stage, the old
assertion still prevents the target from running into troubles with a
missing port.
Fixes#1872
Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:
repos/base/include/spec
repos/base/mk/spec
repos/base/lib/mk/spec
repos/base/src/core/spec
...
Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.
Fix#1673
The new 'select_from_ports' function allows a target description file to
query the path to an installed port. All ports are stored in a central
location specified as CONTRIB_DIR. By default, CONTRIB_DIR is defined
as '<genode-dir>/contrib'. Ports of 3rd-party source code are managed
using the tools at '<genode-dir>/tool/ports/'.
Issue #1082
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
