16 files changed, 442 insertions, 0 deletions
diff --git a/tools/build/Build.include b/tools/build/Build.include
new file mode 100644
index 000000000000..4c8daaccb82a
--- /dev/null
+++ b/tools/build/Build.include
@@ -0,0 +1,81 @@
+###
+# build: Generic definitions
+#
+#  Lots of this code have been borrowed or heavily inspired from parts
+#  of kbuild code, which is not credited, but mostly developed by:
+#
+#  Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
+#  Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
+#
+
+###
+# Convenient variables
+comma   := ,
+squote  := '
+
+###
+# Name of target with a '.' as filename prefix. foo/bar.o => foo/.bar.o
+dot-target = $(dir $@).$(notdir $@)
+
+###
+# filename of target with directory and extension stripped
+basetarget = $(basename $(notdir $@))
+
+###
+# The temporary file to save gcc -MD generated dependencies must not
+# contain a comma
+depfile = $(subst $(comma),_,$(dot-target).d)
+
+###
+# Check if both arguments has same arguments. Result is empty string if equal.
+arg-check = $(strip $(filter-out $(cmd_$(1)), $(cmd_$@)) \
+                    $(filter-out $(cmd_$@),   $(cmd_$(1))) )
+
+###
+# Escape single quote for use in echo statements
+escsq = $(subst $(squote),'\$(squote)',$1)
+
+# Echo command
+# Short version is used, if $(quiet) equals `quiet_', otherwise full one.
+echo-cmd = $(if $($(quiet)cmd_$(1)),\
+           echo '  $(call escsq,$($(quiet)cmd_$(1)))';)
+
+###
+# Replace >$< with >$$< to preserve $ when reloading the .cmd file
+# (needed for make)
+# Replace >#< with >\#< to avoid starting a comment in the .cmd file
+# (needed for make)
+# Replace >'< with >'\''< to be able to enclose the whole string in '...'
+# (needed for the shell)
+make-cmd = $(call escsq,$(subst \#,\\\#,$(subst $$,$$$$,$(cmd_$(1)))))
+
+###
+# Find any prerequisites that is newer than target or that does not exist.
+# PHONY targets skipped in both cases.
+any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
+
+###
+# if_changed_dep  - execute command if any prerequisite is newer than
+#                   target, or command line has changed and update
+#                   dependencies in the cmd file
+if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)),         \
+	@set -e;                                                   \
+	$(echo-cmd) $(cmd_$(1));                                   \
+	cat $(depfile) > $(dot-target).cmd;                        \
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' >> $(dot-target).cmd)
+
+# if_changed      - execute command if any prerequisite is newer than
+#                   target, or command line has changed
+if_changed = $(if $(strip $(any-prereq) $(arg-check)),             \
+	@set -e;                                                   \
+	$(echo-cmd) $(cmd_$(1));                                   \
+	printf '%s\n' 'cmd_$@ := $(make-cmd)' > $(dot-target).cmd)
+
+###
+# C flags to be used in rule definitions, includes:
+# - depfile generation
+# - global $(CFLAGS)
+# - per target C flags
+# - per object C flags
+# - BUILD_STR macro to allow '-D"$(variable)"' constructs
+c_flags = -Wp,-MD,$(depfile),-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))
diff --git a/tools/build/Documentation/Build.txt b/tools/build/Documentation/Build.txt
new file mode 100644
index 000000000000..00ad2d608727
--- /dev/null
+++ b/tools/build/Documentation/Build.txt
@@ -0,0 +1,139 @@
+Build Framework
+===============
+
+The perf build framework was adopted from the kernel build system, hence the
+idea and the way how objects are built is the same.
+
+Basically the user provides set of 'Build' files that list objects and
+directories to nest for specific target to be build.
+
+Unlike the kernel we don't have a single build object 'obj-y' list that where
+we setup source objects, but we support more. This allows one 'Build' file to
+carry a sources list for multiple build objects.
+
+a) Build framework makefiles
+----------------------------
+
+The build framework consists of 2 Makefiles:
+
+  Build.include
+  Makefile.build
+
+While the 'Build.include' file contains just some generic definitions, the
+'Makefile.build' file is the makefile used from the outside. It's
+interface/usage is following:
+
+  $ make -f tools/build/Makefile srctree=$(KSRC) dir=$(DIR) obj=$(OBJECT)
+
+where:
+
+  KSRC   - is the path to kernel sources
+  DIR    - is the path to the project to be built
+  OBJECT - is the name of the build object
+
+When succefully finished the $(DIR) directory contains the final object file
+called $(OBJECT)-in.o:
+
+  $ ls $(DIR)/$(OBJECT)-in.o
+
+which includes all compiled sources described in 'Build' makefiles.
+
+a) Build makefiles
+------------------
+
+The user supplies 'Build' makefiles that contains a objects list, and connects
+the build to nested directories.
+
+Assume we have the following project structure:
+
+  ex/a.c
+    /b.c
+    /c.c
+    /d.c
+    /arch/e.c
+    /arch/f.c
+
+Out of which you build the 'ex' binary ' and the 'libex.a' library:
+
+  'ex'      - consists of 'a.o', 'b.o' and libex.a
+  'libex.a' - consists of 'c.o', 'd.o', 'e.o' and 'f.o'
+
+The build framework does not create the 'ex' and 'libex.a' binaries for you, it
+only prepares proper objects to be compiled and grouped together.
+
+To follow the above example, the user provides following 'Build' files:
+
+  ex/Build:
+    ex-y += a.o
+    ex-y += b.o
+
+    libex-y += c.o
+    libex-y += d.o
+    libex-y += arch/
+
+  ex/arch/Build:
+    libex-y += e.o
+    libex-y += f.o
+
+and runs:
+
+  $ make -f tools/build/Makefile.build dir=. obj=ex
+  $ make -f tools/build/Makefile.build dir=. obj=libex
+
+which creates the following objects:
+
+  ex/ex-in.o
+  ex/libex-in.o
+
+that contain request objects names in Build files.
+
+It's only a matter of 2 single commands to create the final binaries:
+
+  $ ar  rcs libex.a libex-in.o
+  $ gcc -o ex ex-in.o libex.a
+
+You can check the 'ex' example in 'tools/build/tests/ex' for more details.
+
+b) Rules
+--------
+
+The build framework provides standard compilation rules to handle .S and .c
+compilation.
+
+It's possible to include special rule if needed (like we do for flex or bison
+code generation).
+
+c) CFLAGS
+---------
+
+It's possible to alter the standard object C flags in the following way:
+
+  CFLAGS_perf.o += '...' - alters CFLAGS for perf.o object
+  CFLAGS_gtk += '...'    - alters CFLAGS for gtk build object
+
+This C flags changes has the scope of the Build makefile they are defined in.
+
+
+d) Dependencies
+---------------
+
+For each built object file 'a.o' the '.a.cmd' is created and holds:
+
+  - Command line used to built that object
+    (for each object)
+
+  - Dependency rules generated by 'gcc -Wp,-MD,...'
+    (for compiled object)
+
+All existing '.cmd' files are included in the Build process to follow properly
+the dependencies and trigger a rebuild when necessary.
+
+
+e) Single rules
+---------------
+
+It's possible to build single object file by choice, like:
+
+  $ make util/map.o    # objects
+  $ make util/map.i    # preprocessor
+  $ make util/map.s    # assembly
diff --git a/tools/build/Makefile.build b/tools/build/Makefile.build
new file mode 100644
index 000000000000..ae203f21cc86
--- /dev/null
+++ b/tools/build/Makefile.build
@@ -0,0 +1,97 @@
+###
+# Main build makefile.
+#
+#  Lots of this code have been borrowed or heavily inspired from parts
+#  of kbuild code, which is not credited, but mostly developed by:
+#
+#  Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
+#  Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
+#
+
+PHONY := __build
+__build:
+
+ifeq ($(V),1)
+  quiet =
+else
+  quiet=quiet_
+endif
+
+build-dir := $(srctree)/tools/build
+
+# Generic definitions
+include $(build-dir)/Build.include
+
+# Init all relevant variables used in build files so
+# 1) they have correct type
+# 2) they do not inherit any value from the environment
+subdir-y     :=
+obj-y        :=
+subdir-y     :=
+subdir-obj-y :=
+
+# Build definitions
+build-file := $(dir)/Build
+include $(build-file)
+
+# Compile command
+quiet_cmd_cc_o_c = CC       $@
+      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
+
+# Link agregate command
+# If there's nothing to link, create empty $@ object.
+quiet_cmd_ld_multi = LD       $@
+      cmd_ld_multi = $(if $(strip $(obj-y)),\
+		       $(LD) -r -o $@ $(obj-y),rm -f $@; $(AR) rcs $@)
+
+# Build rules
+$(OUTPUT)%.o: %.c FORCE
+	$(call if_changed_dep,cc_o_c)
+
+$(OUTPUT)%.o: %.S FORCE
+	$(call if_changed_dep,cc_o_c)
+
+# Gather build data:
+#   obj-y        - list of build objects
+#   subdir-y     - list of directories to nest
+#   subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
+obj-y        := $($(obj)-y)
+subdir-y     := $(patsubst %/,%,$(filter %/, $(obj-y)))
+obj-y        := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
+subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
+
+# '$(OUTPUT)/dir' prefix to all objects
+prefix       := $(subst ./,,$(OUTPUT)$(dir)/)
+obj-y        := $(addprefix $(prefix),$(obj-y))
+subdir-obj-y := $(addprefix $(prefix),$(subdir-obj-y))
+
+# Final '$(obj)-in.o' object
+in-target := $(prefix)$(obj)-in.o
+
+PHONY += $(subdir-y)
+
+$(subdir-y):
+	@$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)
+
+$(sort $(subdir-obj-y)): $(subdir-y) ;
+
+$(in-target): $(obj-y) FORCE
+	$(call rule_mkdir)
+	$(call if_changed,ld_multi)
+
+__build: $(in-target)
+	@:
+
+PHONY += FORCE
+FORCE:
+
+# Include all cmd files to get all the dependency rules
+# for all objects included
+targets   := $(wildcard $(sort $(obj-y) $(in-target)))
+cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
+
+ifneq ($(cmd_files),)
+  include $(cmd_files)
+endif
+
+.PHONY: $(PHONY)
diff --git a/tools/build/tests/ex/Build b/tools/build/tests/ex/Build
new file mode 100644
index 000000000000..0e6c3e6767e6
--- /dev/null
+++ b/tools/build/tests/ex/Build
@@ -0,0 +1,8 @@
+ex-y += ex.o
+ex-y += a.o
+ex-y += b.o
+ex-y += empty/
+
+libex-y += c.o
+libex-y += d.o
+libex-y += arch/
diff --git a/tools/build/tests/ex/Makefile b/tools/build/tests/ex/Makefile
new file mode 100644
index 000000000000..52d2476073a3
--- /dev/null
+++ b/tools/build/tests/ex/Makefile
@@ -0,0 +1,23 @@
+export srctree := ../../../..
+export CC      := gcc
+export LD      := ld
+export AR      := ar
+
+build := -f $(srctree)/tools/build/Makefile.build dir=. obj
+ex: ex-in.o libex-in.o
+	gcc -o $@ $^
+
+ex.%: FORCE
+	make -f $(srctree)/tools/build/Makefile.build dir=. $@
+
+ex-in.o: FORCE
+	make $(build)=ex
+
+libex-in.o: FORCE
+	make $(build)=libex
+
+clean:
+	find . -name '*.o' -delete -o -name '\.*.cmd' -delete -o -name '\.*.d' -delete
+	rm -f ex ex.i ex.s
+
+.PHONY: FORCE
diff --git a/tools/build/tests/ex/a.c b/tools/build/tests/ex/a.c
new file mode 100644
index 000000000000..851762798c83
--- /dev/null
+++ b/tools/build/tests/ex/a.c
@@ -0,0 +1,5 @@
+
+int a(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/arch/Build b/tools/build/tests/ex/arch/Build
new file mode 100644
index 000000000000..55506189efae
--- /dev/null
+++ b/tools/build/tests/ex/arch/Build
@@ -0,0 +1,2 @@
+libex-y += e.o
+libex-y += f.o
diff --git a/tools/build/tests/ex/arch/e.c b/tools/build/tests/ex/arch/e.c
new file mode 100644
index 000000000000..beaa4a1d7ba8
--- /dev/null
+++ b/tools/build/tests/ex/arch/e.c
@@ -0,0 +1,5 @@
+
+int e(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/arch/f.c b/tools/build/tests/ex/arch/f.c
new file mode 100644
index 000000000000..7c3e9e9da5b7
--- /dev/null
+++ b/tools/build/tests/ex/arch/f.c
@@ -0,0 +1,5 @@
+
+int f(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/b.c b/tools/build/tests/ex/b.c
new file mode 100644
index 000000000000..c24ff9ca9a97
--- /dev/null
+++ b/tools/build/tests/ex/b.c
@@ -0,0 +1,5 @@
+
+int b(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/c.c b/tools/build/tests/ex/c.c
new file mode 100644
index 000000000000..e216d0217499
--- /dev/null
+++ b/tools/build/tests/ex/c.c
@@ -0,0 +1,5 @@
+
+int c(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/d.c b/tools/build/tests/ex/d.c
new file mode 100644
index 000000000000..80dc0f06151b
--- /dev/null
+++ b/tools/build/tests/ex/d.c
@@ -0,0 +1,5 @@
+
+int d(void)
+{
+	return 0;
+}
diff --git a/tools/build/tests/ex/empty/Build b/tools/build/tests/ex/empty/Build
new file mode 100644
index 000000000000..e69de29bb2d1
--- /dev/null
+++ b/tools/build/tests/ex/empty/Build
diff --git a/tools/build/tests/ex/ex.c b/tools/build/tests/ex/ex.c
new file mode 100644
index 000000000000..dc42eb2e1a67
--- /dev/null
+++ b/tools/build/tests/ex/ex.c
@@ -0,0 +1,19 @@
+
+int a(void);
+int b(void);
+int c(void);
+int d(void);
+int e(void);
+int f(void);
+
+int main(void)
+{
+	a();
+	b();
+	c();
+	d();
+	e();
+	f();
+
+	return 0;
+}
diff --git a/tools/build/tests/run.sh b/tools/build/tests/run.sh
new file mode 100755
index 000000000000..5494f8ea7567
--- /dev/null
+++ b/tools/build/tests/run.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+function test_ex {
+	make -C ex V=1 clean > ex.out 2>&1
+	make -C ex V=1 >> ex.out 2>&1
+
+	if [ ! -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	make -C ex V=1 clean > /dev/null 2>&1
+	rm -f ex.out
+}
+
+function test_ex_suffix {
+	make -C ex V=1 clean > ex.out 2>&1
+
+	# use -rR to disable make's builtin rules
+	make -rR -C ex V=1 ex.o >> ex.out 2>&1
+	make -rR -C ex V=1 ex.i >> ex.out 2>&1
+	make -rR -C ex V=1 ex.s >> ex.out 2>&1
+
+	if [ -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	if [ ! -f ./ex/ex.o -o ! -f ./ex/ex.i -o ! -f ./ex/ex.s ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	make -C ex V=1 clean > /dev/null 2>&1
+	rm -f ex.out
+}
+echo -n Testing..
+
+test_ex
+test_ex_suffix
+
+echo OK
diff --git a/tools/perf/MANIFEST b/tools/perf/MANIFEST
index fbbfdc39271d..11ccbb22ea2b 100644
--- a/tools/perf/MANIFEST
+++ b/tools/perf/MANIFEST
@@ -1,5 +1,6 @@
 tools/perf
 tools/scripts
+tools/build
 tools/lib/traceevent
 tools/lib/api
 tools/lib/symbol/kallsyms.c