diff options
| -rw-r--r-- | Documentation/kbuild/makefiles.txt | 39 | ||||
| -rw-r--r-- | scripts/Makefile.host | 43 |
2 files changed, 11 insertions, 71 deletions
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index d567a7c..3ceadbd 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: diff --git a/scripts/Makefile.host b/scripts/Makefile.host index bf44e79..1c2e570 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -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) |
