makefiles: make all, clean and distclean PHONY

Avoid a stat() call for each affected target and also potentially speed
up parallel builds.

From the GNU make manual[1]:

> Phony targets are also useful in conjunction with recursive
> invocations of make (see Recursive Use of make).  In this situation
> the makefile will often contain a variable which lists a number of
> sub-directories to be built.

[...]

> The implicit rule search (see Implicit Rules) is skipped for .PHONY
> targets.  This is why declaring a target as .PHONY is good for
> performance, even if you are not worried about the actual file
> existing.

Commands used to search, replace and cleanup:

    $ find -type f -name '*Makefile.in' -exec sed -i.bak \
      -e 's/^all:/.PHONY: all\nall:/' \
      -e 's/^clean:/.PHONY: clean\nclean:/' \
      -e 's/^distclean:/.PHONY: distclean\ndistclean:/' '{}' +
    $ find -type f -name '*Makefile.in.bak' -exec rm '{}' +

[1]: https://www.gnu.org/software/make/manual/html_node/Phony-Targets.html

1 files changed, 3 insertions, 0 deletions

diff --git a/Makefile.in b/Makefile.in
index 8f399a2ab..bc03ab9ce 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -23,6 +23,7 @@ endif
 
 COMPLETIONDIRS = src/zsh_completion src/bash_completion
 
+.PHONY: all
 all: all_items mydirs $(MAN_TARGET) filters
 APPS = src/firecfg/firecfg src/firejail/firejail src/firemon/firemon src/profstats/profstats src/jailtest/jailtest
 SBOX_APPS = src/fbuilder/fbuilder src/ftee/ftee
@@ -72,6 +73,7 @@ seccomp.mdwx: src/fseccomp/fseccomp
 seccomp.mdwx.32: src/fseccomp/fseccomp
         src/fseccomp/fseccomp memory-deny-write-execute.32 seccomp.mdwx.32
 
+.PHONY: clean
 clean:
         for dir in $$(dirname $(ALL_ITEMS)) $(MYDIRS); do \
                 $(MAKE) -C $$dir clean; \
@@ -91,6 +93,7 @@ clean:
         rm -f test/sysutils/firejail_t*
         cd test/compile; ./compile.sh --clean; cd ../..
 
+.PHONY: distclean
 distclean: clean
         for dir in $$(dirname $(ALL_ITEMS)) $(MYDIRS); do \
                 $(MAKE) -C $$dir distclean; \