tools: bpftool: harmonise Makefile and Documentation/Makefile

Several minor fixes and harmonisation items for Makefiles:

* Use the same mechanism for verbose/non-verbose output in two files
  ("$(Q)"), for all commands.
* Use calls to "QUIET_INSTALL" and equivalent in Makefile. In
  particular, use "call(descend, ...)" instead of "make -C" to run
  documentation targets.
* Add a "doc-clean" target, aligned on "doc" and "doc-install".
* Make "install" target in Makefile depend on "bpftool".
* Remove condition on DESTDIR to initialise prefix in doc Makefile.
* Remove modification of VPATH based on OUTPUT, it is unused.
* Formatting: harmonise spaces around equal signs.
* Make install path for man pages /usr/local/man instead of
  /usr/local/share/man (respects the Makefile conventions, and the
  latter is usually a symbolic link to the former anyway).
* Do not erase prefix if set by user in bpftool Makefile.
* Fix install target for bpftool: append DESTDIR to install path.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/bpf/bpftool/Documentation/Makefile

@@ -4,11 +4,14 @@ include ../../../scripts/utilities.mak
 INSTALL ?= install
 RM ?= rm -f
 
-# Make the path relative to DESTDIR, not prefix
-ifndef DESTDIR
-prefix ?= /usr/local
+ifeq ($(V),1)
+  Q =
+else
+  Q = @
 endif
-mandir ?= $(prefix)/share/man
+
+prefix ?= /usr/local
+mandir ?= $(prefix)/man
 man8dir = $(mandir)/man8
 
 MAN8_RST = $(wildcard *.rst)
@@ -20,15 +23,16 @@ man: man8
 man8: $(DOC_MAN8)
 
 $(OUTPUT)%.8: %.rst
-	rst2man $< > $@
+	$(QUIET_GEN)rst2man $< > $@
 
 clean:
-	$(call QUIET_CLEAN, Documentation) $(RM) $(DOC_MAN8)
+	$(call QUIET_CLEAN, Documentation)
+	$(Q)$(RM) $(DOC_MAN8)
 
 install: man
-	$(call QUIET_INSTALL, Documentation-man) \
-		$(INSTALL) -d -m 755 $(DESTDIR)$(man8dir); \
-		$(INSTALL) -m 644 $(DOC_MAN8) $(DESTDIR)$(man8dir);
+	$(call QUIET_INSTALL, Documentation-man)
+	$(Q)$(INSTALL) -d -m 755 $(DESTDIR)$(man8dir)
+	$(Q)$(INSTALL) -m 644 $(DOC_MAN8) $(DESTDIR)$(man8dir)
 
 .PHONY: man man8 clean install
 .DEFAULT_GOAL := man

tools/bpf/bpftool/Makefile

@@ -1,25 +1,10 @@
 include ../../scripts/Makefile.include
-
 include ../../scripts/utilities.mak
 
 ifeq ($(srctree),)
 srctree := $(patsubst %/,%,$(dir $(CURDIR)))
 srctree := $(patsubst %/,%,$(dir $(srctree)))
 srctree := $(patsubst %/,%,$(dir $(srctree)))
-#$(info Determined 'srctree' to be $(srctree))
-endif
-
-ifneq ($(objtree),)
-#$(info Determined 'objtree' to be $(objtree))
-endif
-
-ifneq ($(OUTPUT),)
-#$(info Determined 'OUTPUT' to be $(OUTPUT))
-# Adding $(OUTPUT) as a directory to look for source files,
-# because use generated output files as sources dependency
-# for flex/bison parsers.
-VPATH += $(OUTPUT)
-export VPATH
 endif
 
 ifeq ($(V),1)
@@ -28,12 +13,12 @@ else
   Q = @
 endif
 
-BPF_DIR	= $(srctree)/tools/lib/bpf/
+BPF_DIR = $(srctree)/tools/lib/bpf/
 
 ifneq ($(OUTPUT),)
-  BPF_PATH=$(OUTPUT)
+  BPF_PATH = $(OUTPUT)
 else
-  BPF_PATH=$(BPF_DIR)
+  BPF_PATH = $(BPF_DIR)
 endif
 
 LIBBPF = $(BPF_PATH)libbpf.a
@@ -45,7 +30,7 @@ $(LIBBPF)-clean:
 	$(call QUIET_CLEAN, libbpf)
 	$(Q)$(MAKE) -C $(BPF_DIR) OUTPUT=$(OUTPUT) clean >/dev/null
 
-prefix = /usr/local
+prefix ?= /usr/local
 bash_compdir ?= /usr/share/bash-completion/completions
 
 CC = gcc
@@ -55,12 +40,15 @@ CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow
 CFLAGS += -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
 LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
 
+INSTALL ?= install
+RM ?= rm -f
+
 include $(wildcard *.d)
 
 all: $(OUTPUT)bpftool
 
-SRCS=$(wildcard *.c)
-OBJS=$(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
+SRCS = $(wildcard *.c)
+OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
 
 $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
@@ -73,21 +61,26 @@ $(OUTPUT)%.o: %.c
 
 clean: $(LIBBPF)-clean
 	$(call QUIET_CLEAN, bpftool)
-	$(Q)rm -rf $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d
+	$(Q)$(RM) $(OUTPUT)bpftool $(OUTPUT)*.o $(OUTPUT)*.d
 
-install:
-	install -m 0755 -d $(prefix)/sbin
-	install $(OUTPUT)bpftool $(prefix)/sbin/bpftool
-	install -m 0755 -d $(bash_compdir)
-	install -m 0644 bash-completion/bpftool $(bash_compdir)
+install: $(OUTPUT)bpftool
+	$(call QUIET_INSTALL, bpftool)
+	$(Q)$(INSTALL) -m 0755 -d $(DESTDIR)$(prefix)/sbin
+	$(Q)$(INSTALL) $(OUTPUT)bpftool $(DESTDIR)$(prefix)/sbin/bpftool
+	$(Q)$(INSTALL) -m 0755 -d $(DESTDIR)$(bash_compdir)
+	$(Q)$(INSTALL) -m 0644 bash-completion/bpftool $(DESTDIR)$(bash_compdir)
 
 doc:
-	$(Q)$(MAKE) -C Documentation/
+	$(call descend,Documentation)
+
+doc-clean:
+	$(call descend,Documentation,clean)
 
 doc-install:
-	$(Q)$(MAKE) -C Documentation/ install
+	$(call descend,Documentation,install)
 
 FORCE:
 
-.PHONY: all clean FORCE install doc doc-install
+.PHONY: all FORCE clean install
+.PHONY: doc doc-clean doc-install
 .DEFAULT_GOAL := all