Detect incorrect dependencies

Hello,

This is the fifth version of the small patch series to detect incorrect dependencies (i.e a package that depends on another in its .mk file, but that forgets to do so in its Config.in).

Compared to the previous version, this new version:

- Use $($(PKG)_TYPE) and $($(PKG)_KCONFIG)_VAR) instead of target-specific variables, as suggested by Arnout.

- Move the "culprit listing" logic into a separate patch, so that it can be considered separately, suggested by Yann E. Morin.

- Makes some other trivial adjustements suggested by Yann and Arnout.

- Is rebased on top of master.

Thanks,

Thomas

Thomas Petazzoni (2):
pkg-generic: detect incorrectly used package
pkg-generic: improve incorrectly used package detection

 package/pkg-generic.mk | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

2.6.1

In Buildroot, the selection of a package from a Config.in level and from a Makefile level are completely disconnected. This can lead to issues where the build of a package is triggered at the Makefile level due to the package being listed in another package <pkg>_DEPENDENCIES variable, even if that package is not enabled in the configuration.

This has for example been the case recently with python-can having 'python' in its <pkg>_DEPENDENCIES, while python-can could be enabled when Python 3.x is used, in which case the 'python' package should not be built.

To detect such issues more easily, this patch adds a check in the package infrastructure. When the build process of a package is being triggered, we verify that the package is enabled in the configuration. We do this check in the "configure" step, since this step is the first common step between the normal download case and the "local site method" / "package override" case.

---
Changes since v4:
- Use $($(PKG)_KCONFIG_VAR) and $($(PKG)_TYPE) as suggested by Arnout.
- Split the "potential culprit" mechanism into a separate commit, as suggested by Yann.

Changes since v3:
- Add the DEPENDENT_OF mechanism to display which packages are mistakenly depending on a package without selecting it. Suggested and implement by Yann E. Morin.

Changes since v2:
- Only do the check if MAKECMDGOALS is empty, i.e if a "default" build is being done. This allows advanced users to continue doing "make <pkg>" to forcefully build a package even if not enabled in the configuration. Suggested by Peter Korsgaard.
- Add @ in front of the test command so that it doesn't get displayed. Suggested by Peter Korsgaard.
- Improve error message, as suggested by Peter Korsgaard.

Changes since v1:
- Use KCONFIG_VAR in order to make the thing work for toolchain packages, bootloaders and Linux. Issue reported by Vicente.

---
 package/pkg-generic.mk | 10 ++++++++++
 1 file changed, 10 insertions(+)

index 76ec295..a831199 100644
@@ -143,6 +143,16 @@ $(foreach dir,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR)),\
 
 # Configure
 $(BUILD_DIR)/%/.stamp_configured:
+# Only trigger the check for default builds. If the user forces
+# building a package, even if not enabled in the configuration, we
+# want to accept it.
+ifeq ($(MAKECMDGOALS),)
+	@if test "$($(PKG)_TYPE)" = "target" -a -z "$($($(PKG)_KCONFIG_VAR))" ; then \
+		echo "ERROR: A package must have added $($(PKG)_NAME) to its _DEPENDENCIES line but" ; \
+		echo "forgot to add the corresponding select / depends on $($(PKG)_KCONFIG_VAR)." ; \
+		exit 1 ; \
+	fi
+endif
 	@$(call step_start,configure)
 	@$(call MESSAGE,"Configuring")
 	$(foreach hook,$($(PKG)_PRE_CONFIGURE_HOOKS),$(call $(hook))$(sep))

2.6.1

Thomas, All,

On 2015-10-09 11:15 +0200, Thomas Petazzoni spake thusly:

[--SNIP--]

.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'

Hello,

I've applied, after taking into account the comment from Yann (and fixing a minor issue with it: $(1) cannot be used, it should have been $($(PKG)_NAME)).

Thanks!

Thomas

Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

The package infrastructure now detects when a target package is being built even if its corresponding Config.in option is not enabled, and aborts with an error. However, it does not indicate *which* package is improperly depending on the current package without selecting it at the kconfig level.

So, in this commit, in addition to displaying an error, we try to help the user by saying which packages could be the culprit. To achieve this, we register the reverse dependencies of each package in a variable called <pkg>_DEPENDENT_OF, and display this variable for the problematic package when the error is detected. Many thanks to Yann E. Morin for the idea and implementation!

---
 package/pkg-generic.mk | 8 ++++++++
 1 file changed, 8 insertions(+)

index a831199..1266a47 100644
@@ -150,6 +150,8 @@ ifeq ($(MAKECMDGOALS),)
 	@if test "$($(PKG)_TYPE)" = "target" -a -z "$($($(PKG)_KCONFIG_VAR))" ; then \
 		echo "ERROR: A package must have added $($(PKG)_NAME) to its _DEPENDENCIES line but" ; \
 		echo "forgot to add the corresponding select / depends on $($(PKG)_KCONFIG_VAR)." ; \
+		echo "Potential culprits:" ; \
+		for p in $($(PKG)_DEPENDENT_OF) ; do echo " - $$p" ; done ; \
 		exit 1 ; \
 	fi
 endif

@@ -777,6 +779,12 @@ endif # ifneq ($$(call qstrip,$$($(2)_SOURCE)),)
 # configuration
 ifeq ($$($$($(2)_KCONFIG_VAR)),y)
 
+# Store reverse build-dependency information: we add the name of the
+# current package to the <pkg>_DEPENDENT_OF variable of all packages
+# the current package depends on.
+$$(eval $$(foreach d,$$($(2)_FINAL_ALL_DEPENDENCIES),\
+	$$(call UPPERCASE,$$(d))_DEPENDENT_OF += $(1)$$(sep)))
+
 # Ensure the calling package is the declared provider for all the virtual
 # packages it claims to be an implementation of.
 ifneq ($$($(2)_PROVIDES),)

2.6.1

Thomas, All,

On 2015-10-09 11:15 +0200, Thomas Petazzoni spake thusly:

For example, I added;
    BUSYBOX_DEPENDENCIES += exim

ERROR: A package must have added berkeleydb to its _DEPENDENCIES line but forgot to add the corresponding select / depends on BR2_PACKAGE_BERKELEYDB. Potential culprits:
make[1]: *** [.../berkeleydb-5.3.28/.stamp_configured] Error 1
make: *** [_all] Error 2

That's because the real culprit is not directly the cause of the berkeleydb dependency; the depenency chain is two-or-more levels deep.

So, NAK on this patch (even though that was my idea originally, IIRC).

I'll (later!) to find a solution...

Regards,
Yann E. MORIN.

.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
| http://ymorin.is-a-geek.org/ | _/*\_ | / \ HTML MAIL    |   v   conspiracy.  |
'------------------------------^-------^------------------^--------------------'