build: disable most built-in implicit make rules

Clear `.SUFFIXES:` to reduce unnecessary filesystem lookups.

Overall, this appears to reduce the amount of implicit rule searches by
~62% for the default build and by ~96% for the "man" target (as an
example):

    $ git checkout master >/dev/null 2>&1
    $ git show --pretty='%h %ai %s' -s
    a8f01a383 2023-06-20 05:26:23 +0000 Merge pull request #5859 from kmk3/build-remove-retpoline
    $ ./configure >/dev/null
    $ make clean >/dev/null && make --debug=i -j 4     | grep -F 'Trying implicit' | wc -l
    6798
    $ make clean >/dev/null && make --debug=i -j 4 man | grep -F 'Trying implicit' | wc -l
    1085
    # (with this commit applied)
    $ make clean >/dev/null && make --debug=i -j 4     | grep -F 'Trying implicit' | wc -l
    2535
    $ make clean >/dev/null && make --debug=i -j 4 man | grep -F 'Trying implicit' | wc -l
    42

Environment: GNU make 4.4.1-2 on Artix Linux.

Commands used to search and replace:

    $ git ls-files -z -- '*Makefile*' | xargs -0 -I '{}' sh -c \
      "printf '%s\n' \"\$(sed '1s/^/.SUFFIXES:\n/' '{}')\" >'{}'"

See also commit f48886f25 ("build: mark most phony targets as such",
2023-02-01) / PR #5637.

30 files changed, 30 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index 49c97c382..1d1d81566 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = .
 -include config.mk
 
diff --git a/src/bash_completion/Makefile b/src/bash_completion/Makefile
index bd447857e..516805886 100644
--- a/src/bash_completion/Makefile
+++ b/src/bash_completion/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/etc-cleanup/Makefile b/src/etc-cleanup/Makefile
index 10c28cd76..c8a12476e 100644
--- a/src/etc-cleanup/Makefile
+++ b/src/etc-cleanup/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fbuilder/Makefile b/src/fbuilder/Makefile
index ad73e8960..7595f0775 100644
--- a/src/fbuilder/Makefile
+++ b/src/fbuilder/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fcopy/Makefile b/src/fcopy/Makefile
index 27054627c..e2956fdd1 100644
--- a/src/fcopy/Makefile
+++ b/src/fcopy/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fids/Makefile b/src/fids/Makefile
index 44ea396d7..901cbb470 100644
--- a/src/fids/Makefile
+++ b/src/fids/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/firecfg/Makefile b/src/firecfg/Makefile
index 05cc088f4..59b713f1b 100644
--- a/src/firecfg/Makefile
+++ b/src/firecfg/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/firejail/Makefile b/src/firejail/Makefile
index 47edc5ac6..53bccf843 100644
--- a/src/firejail/Makefile
+++ b/src/firejail/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/firemon/Makefile b/src/firemon/Makefile
index 433e4267d..e0059aee5 100644
--- a/src/firemon/Makefile
+++ b/src/firemon/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fldd/Makefile b/src/fldd/Makefile
index 0c127af55..86693a76c 100644
--- a/src/fldd/Makefile
+++ b/src/fldd/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnet/Makefile b/src/fnet/Makefile
index 91de109fa..8efc6d26b 100644
--- a/src/fnet/Makefile
+++ b/src/fnet/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnetfilter/Makefile b/src/fnetfilter/Makefile
index 506d287ab..2be8311ae 100644
--- a/src/fnetfilter/Makefile
+++ b/src/fnetfilter/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnettrace-dns/Makefile b/src/fnettrace-dns/Makefile
index 36542f567..bbd4772e2 100644
--- a/src/fnettrace-dns/Makefile
+++ b/src/fnettrace-dns/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnettrace-icmp/Makefile b/src/fnettrace-icmp/Makefile
index 12ae42e9a..0d26dc2fc 100644
--- a/src/fnettrace-icmp/Makefile
+++ b/src/fnettrace-icmp/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnettrace-sni/Makefile b/src/fnettrace-sni/Makefile
index 8d9a437d5..554741fc8 100644
--- a/src/fnettrace-sni/Makefile
+++ b/src/fnettrace-sni/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fnettrace/Makefile b/src/fnettrace/Makefile
index 952036ad3..94381d299 100644
--- a/src/fnettrace/Makefile
+++ b/src/fnettrace/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fsec-optimize/Makefile b/src/fsec-optimize/Makefile
index ce65f4719..4941f13b1 100644
--- a/src/fsec-optimize/Makefile
+++ b/src/fsec-optimize/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fsec-print/Makefile b/src/fsec-print/Makefile
index cbe061d45..78e87a93f 100644
--- a/src/fsec-print/Makefile
+++ b/src/fsec-print/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fseccomp/Makefile b/src/fseccomp/Makefile
index 1b8d0bb48..461179f4d 100644
--- a/src/fseccomp/Makefile
+++ b/src/fseccomp/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/ftee/Makefile b/src/ftee/Makefile
index 2f26ab900..0c27b4cbc 100644
--- a/src/ftee/Makefile
+++ b/src/ftee/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/fzenity/Makefile b/src/fzenity/Makefile
index aeb862d9b..a17a9252f 100644
--- a/src/fzenity/Makefile
+++ b/src/fzenity/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/jailcheck/Makefile b/src/jailcheck/Makefile
index e3b84fbf3..23cd9c1a9 100644
--- a/src/jailcheck/Makefile
+++ b/src/jailcheck/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/lib/Makefile b/src/lib/Makefile
index f5b92e389..a7b093048 100644
--- a/src/lib/Makefile
+++ b/src/lib/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/libpostexecseccomp/Makefile b/src/libpostexecseccomp/Makefile
index 62e167b73..dfd8eb318 100644
--- a/src/libpostexecseccomp/Makefile
+++ b/src/libpostexecseccomp/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/libtrace/Makefile b/src/libtrace/Makefile
index d45b3e2f6..8b14a4335 100644
--- a/src/libtrace/Makefile
+++ b/src/libtrace/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/libtracelog/Makefile b/src/libtracelog/Makefile
index bfc5adddc..ac48264df 100644
--- a/src/libtracelog/Makefile
+++ b/src/libtracelog/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/man/Makefile b/src/man/Makefile
index bff4c30d0..197f76192 100644
--- a/src/man/Makefile
+++ b/src/man/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/profstats/Makefile b/src/profstats/Makefile
index 47b39e76c..b4cb1a6f7 100644
--- a/src/profstats/Makefile
+++ b/src/profstats/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/src/zsh_completion/Makefile b/src/zsh_completion/Makefile
index c68ed2d72..cc811ae99 100644
--- a/src/zsh_completion/Makefile
+++ b/src/zsh_completion/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ../..
 -include $(ROOT)/config.mk
 
diff --git a/test/Makefile b/test/Makefile
index 2f023b8b1..08462c09b 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -1,3 +1,4 @@
+.SUFFIXES:
 ROOT = ..
 -include $(ROOT)/config.mk