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authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 11:12:46 -0600
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-14 11:12:46 -0600
commit3b7b3e6ec5f56118046594d3c62469e7d1d0aadd (patch)
tree3a6eb410ee27b660b7c085c81619f9e69fb5f0fa /Documentation
parente3b1fd56f175526db42ae94c457f29c2fa810aca (diff)
parent164f0d2efaaef835473e74b162eae750341d6a8c (diff)
Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild updates from Michal Marek: - make clean also considers $(extra-m) and $(extra-) to be consistent - cleanup and fixes in scripts/Makefile.host - allow to override the name of the Python 2 executable with make PYTHON=... (only needed for ia64 in practice) - option to split debugingo into *.dwo files to save disk space if the compiler supports it (CONFIG_DEBUG_INFO_SPLIT) - option to use dwarf4 debuginfo if the compiler supports it (CONFIG_DEBUG_INFO_DWARF4) - fix for disabling certain warnings with clang - fix for unneeded rebuild with dash when a command contains backslashes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: Fix handling of backslashes in *.cmd files kbuild, LLVMLinux: Supress warnings unless W=1-3 Kbuild: Add a option to enable dwarf4 v2 kbuild: Support split debug info v4 kbuild: allow to override Python command name kbuild: clean-up and bug fix of scripts/Makefile.host kbuild: clean up scripts/Makefile.host kbuild: drop shared library support from Makefile.host kbuild: fix a bug of C++ host program handling kbuild: fix a typo in scripts/Makefile.host scripts/Makefile.clean: clean also $(extra-m) and $(extra-)
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kbuild/makefiles.txt39
1 files changed, 8 insertions, 31 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index c600e2f44a62..764f5991a3fc 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -23,11 +23,10 @@ This document describes the Linux kernel Makefiles.
=== 4 Host Program support
--- 4.1 Simple Host Program
--- 4.2 Composite Host Programs
- --- 4.3 Defining shared libraries
- --- 4.4 Using C++ for host programs
- --- 4.5 Controlling compiler options for host programs
- --- 4.6 When host programs are actually built
- --- 4.7 Using hostprogs-$(CONFIG_FOO)
+ --- 4.3 Using C++ for host programs
+ --- 4.4 Controlling compiler options for host programs
+ --- 4.5 When host programs are actually built
+ --- 4.6 Using hostprogs-$(CONFIG_FOO)
=== 5 Kbuild clean infrastructure
@@ -643,29 +642,7 @@ Both possibilities are described in the following.
Finally, the two .o files are linked to the executable, lxdialog.
Note: The syntax <executable>-y is not permitted for host-programs.
---- 4.3 Defining shared libraries
-
- Objects with extension .so are considered shared libraries, and
- will be compiled as position independent objects.
- Kbuild provides support for shared libraries, but the usage
- shall be restricted.
- In the following example the libkconfig.so shared library is used
- to link the executable conf.
-
- Example:
- #scripts/kconfig/Makefile
- hostprogs-y := conf
- conf-objs := conf.o libkconfig.so
- libkconfig-objs := expr.o type.o
-
- Shared libraries always require a corresponding -objs line, and
- in the example above the shared library libkconfig is composed by
- the two objects expr.o and type.o.
- expr.o and type.o will be built as position independent code and
- linked as a shared library libkconfig.so. C++ is not supported for
- shared libraries.
-
---- 4.4 Using C++ for host programs
+--- 4.3 Using C++ for host programs
kbuild offers support for host programs written in C++. This was
introduced solely to support kconfig, and is not recommended
@@ -688,7 +665,7 @@ Both possibilities are described in the following.
qconf-cxxobjs := qconf.o
qconf-objs := check.o
---- 4.5 Controlling compiler options for host programs
+--- 4.4 Controlling compiler options for host programs
When compiling host programs, it is possible to set specific flags.
The programs will always be compiled utilising $(HOSTCC) passed
@@ -716,7 +693,7 @@ Both possibilities are described in the following.
When linking qconf, it will be passed the extra option
"-L$(QTDIR)/lib".
---- 4.6 When host programs are actually built
+--- 4.5 When host programs are actually built
Kbuild will only build host-programs when they are referenced
as a prerequisite.
@@ -747,7 +724,7 @@ Both possibilities are described in the following.
This will tell kbuild to build lxdialog even if not referenced in
any rule.
---- 4.7 Using hostprogs-$(CONFIG_FOO)
+--- 4.6 Using hostprogs-$(CONFIG_FOO)
A typical pattern in a Kbuild file looks like this: