@@ -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:
@@ -20,16 +20,6 @@
# Will compile qconf as a C++ program, and menu as a C program.
# They are linked as C++ code to the executable qconf
-# hostprogs-y := conf
-# conf-objs := conf.o libkconfig.so
-# libkconfig-objs := expr.o type.o
-# Will create a shared library named libkconfig.so that consists of
-# expr.o and type.o (they are both compiled as C code and the object files
-# are made as position independent code).
-# conf.c is compiled as a C program, and conf.o is linked together with
-# libkconfig.so as the executable conf.
-# Note: Shared libraries consisting of C++ files are not supported
-
__hostprogs := $(sort $(hostprogs-y) $(hostprogs-m))
# C code
@@ -52,15 +42,6 @@ host-cxxmulti := $(foreach m,$(__hostprogs),$(if $($(m)-cxxobjs),$(m)))
# C++ Object (.o) files compiled from .cc files
host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
-# Shared libaries (only .c supported)
-# Shared libraries (.so) - all .so files referenced in "xxx-objs"
-host-cshlib := $(sort $(filter %.so, $(host-cobjs)))
-# Remove .so files from "xxx-objs"
-host-cobjs := $(filter-out %.so,$(host-cobjs))
-
-#Object (.o) files used by the shared libaries
-host-cshobjs := $(sort $(foreach m,$(host-cshlib),$($(m:.so=-objs))))
-
# output directory for programs/.o files
# hostprogs-y := tools/build may have been specified. Retrieve directory
host-objdirs := $(foreach f,$(__hostprogs), $(if $(dir $(f)),$(dir $(f))))
@@ -82,8 +63,6 @@ host-cmulti := $(addprefix $(obj)/,$(host-cmulti))
host-cobjs := $(addprefix $(obj)/,$(host-cobjs))
host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti))
host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs))
-host-cshlib := $(addprefix $(obj)/,$(host-cshlib))
-host-cshobjs := $(addprefix $(obj)/,$(host-cshobjs))
host-objdirs := $(addprefix $(obj)/,$(host-objdirs))
obj-dirs += $(host-objdirs)
@@ -124,7 +103,7 @@ quiet_cmd_host-cmulti = HOSTLD $@
cmd_host-cmulti = $(HOSTCC) $(HOSTLDFLAGS) -o $@ \
$(addprefix $(obj)/,$($(@F)-objs)) \
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cmulti): $(obj)/%: $(host-cobjs) $(host-cshlib) FORCE
+$(host-cmulti): $(obj)/%: $(host-cobjs) FORCE
$(call if_changed,host-cmulti)
# Create .o file from a single .c file
@@ -141,7 +120,7 @@ quiet_cmd_host-cxxmulti = HOSTLD $@
$(foreach o,objs cxxobjs,\
$(addprefix $(obj)/,$($(@F)-$(o)))) \
$(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cxxmulti): $(obj)/%: $(host-cobjs) $(host-cxxobjs) $(host-cshlib) FORCE
+$(host-cxxmulti): $(obj)/%: $(host-cobjs) $(host-cxxobjs) FORCE
$(call if_changed,host-cxxmulti)
# Create .o file from a single .cc (C++) file
@@ -150,21 +129,5 @@ quiet_cmd_host-cxxobjs = HOSTCXX $@
$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
$(call if_changed_dep,host-cxxobjs)
-# Compile .c file, create position independent .o file
-# host-cshobjs -> .o
-quiet_cmd_host-cshobjs = HOSTCC -fPIC $@
- cmd_host-cshobjs = $(HOSTCC) $(hostc_flags) -fPIC -c -o $@ $<
-$(host-cshobjs): $(obj)/%.o: $(src)/%.c FORCE
- $(call if_changed_dep,host-cshobjs)
-
-# Link a shared library, based on position independent .o files
-# *.o -> .so shared library (host-cshlib)
-quiet_cmd_host-cshlib = HOSTLLD -shared $@
- cmd_host-cshlib = $(HOSTCC) $(HOSTLDFLAGS) -shared -o $@ \
- $(addprefix $(obj)/,$($(@F:.so=-objs))) \
- $(HOST_LOADLIBES) $(HOSTLOADLIBES_$(@F))
-$(host-cshlib): $(obj)/%: $(host-cshobjs) FORCE
- $(call if_changed,host-cshlib)
-
targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\
- $(host-cxxmulti) $(host-cxxobjs) $(host-cshlib) $(host-cshobjs)
+ $(host-cxxmulti) $(host-cxxobjs)
The shared library feature in Makefile.host is no longer used. Rip it off to keep the build infrastucture simple. Update Documentation/kbuild/makefiles.txt too. The section "4.3 Definition shared libraries" should be removed and the following sections should be re-numbered. Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com> Suggested-by: Sam Ravnborg <sam@ravnborg.org> --- Changes in v3: - Update Documentation/kbuild/makefile.txt Changes in v2: - Newly added Documentation/kbuild/makefiles.txt | 39 +++++++--------------------------- scripts/Makefile.host | 43 +++----------------------------------- 2 files changed, 11 insertions(+), 71 deletions(-)