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build: Allow ./configure CFLAGS=... to override auto-detected flags
1 parent c8a3dc9 commit 7034123

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6 files changed

+93
-56
lines changed

6 files changed

+93
-56
lines changed

‎build/auto.mk‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,54 @@
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# Copyright © Tavian Barnes <[email protected]>
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# SPDX-License-Identifier: 0BSD
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# Makefile that generates gen/auto.mk
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include build/prelude.mk
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include gen/vars.mk
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include gen/early.mk
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include gen/late.mk
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include build/exports.mk
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# Auto-detected flags
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AUTO_FLAGS := \
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gen/flags/std.mk \
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gen/flags/bind-now.mk \
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gen/flags/deps.mk \
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gen/flags/pthread.mk \
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gen/flags/Wformat.mk \
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gen/flags/Wimplicit-fallthrough.mk \
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gen/flags/Wimplicit.mk \
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gen/flags/Wmissing-decls.mk \
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gen/flags/Wmissing-var-decls.mk \
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gen/flags/Wshadow.mk \
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gen/flags/Wsign-compare.mk \
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gen/flags/Wstrict-prototypes.mk \
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gen/flags/Wundef-prefix.mk
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gen/auto.mk: ${AUTO_FLAGS}
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${MSG} "[ GEN] $@"
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@printf '# %s\n' "$@" >$@
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@cat $^ >>$@
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@cat ${^:%=%.log} >gen/flags.log
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${VCAT} $@
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.PHONY: gen/auto.mk
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# Check that the C compiler works at all
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cc::
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@build/cc.sh -q build/empty.c -o gen/.cc.out; \
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ret=$$?; \
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build/msg-if.sh "[ CC ] build/empty.c" test $$ret -eq 0; \
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exit $$ret
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# The short name of the config test
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SLUG = ${@:gen/%.mk=%}
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# The source file to build
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CSRC = build/${SLUG}.c
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# The hidden output file name
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OUT = ${SLUG:flags/%=gen/flags/.%.out}
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${AUTO_FLAGS}: cc
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@${MKDIR} ${@D}
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@build/flags-if.sh ${CSRC} -o ${OUT} >$@ 2>$@.log; \
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build/msg-if.sh "[ CC ] ${SLUG}.c" test $$? -eq 0
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.PHONY: ${AUTO_FLAGS}

‎build/config.mk‎

Lines changed: 15 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -10,8 +10,16 @@ include build/exports.mk
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config: gen/config.mk gen/config.h
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.PHONY: config
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# All the generated makefile fragments
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MKS := \
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gen/vars.mk \
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gen/early.mk \
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gen/auto.mk \
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gen/pkgs.mk \
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gen/late.mk
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# The main configuration file, which includes the others
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gen/config.mk: gen/vars.mk gen/flags.mk gen/pkgs.mk
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gen/config.mk: ${MKS}
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${MSG} "[ GEN] $@"
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@printf '# %s\n' "$@" >$@
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@printf 'include %s\n' $^ >>$@
@@ -36,16 +44,17 @@ gen/vars.mk::
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# Sets the build flags. This depends on vars.mk and uses a recursive make so
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# that the default flags can depend on variables like ${OS}.
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gen/flags.mk: gen/vars.mk
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gen/early.mk gen/late.mk: gen/vars.mk
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@+XMAKEFLAGS="$$MAKEFLAGS" ${MAKE} -sf build/flags.mk $@
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.PHONY: gen/flags.mk
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# Auto-detected build flags
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gen/auto.mk: gen/early.mk gen/late.mk
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@+XMAKEFLAGS="$$MAKEFLAGS" ${MAKE} -sf build/auto.mk $@
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# Auto-detect dependencies and their build flags
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gen/pkgs.mk: gen/flags.mk
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gen/pkgs.mk: gen/auto.mk
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@+XMAKEFLAGS="$$MAKEFLAGS" ${MAKE} -sf build/pkgs.mk $@
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.PHONY: gen/pkgs.mk
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# Compile-time feature detection
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gen/config.h: gen/pkgs.mk
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@+XMAKEFLAGS="$$MAKEFLAGS" ${MAKE} -sf build/header.mk $@
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.PHONY: gen/config.h

‎build/exports.mk‎

Lines changed: 5 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -17,4 +17,9 @@ export XCFLAGS=${_CFLAGS}
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export XLDFLAGS=${_LDFLAGS}
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export XLDLIBS=${_LDLIBS}
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export CONF_CPPFLAGS=${CPPFLAGS} ${EXTRA_CPPFLAGS}
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export CONF_CFLAGS=${CFLAGS} ${EXTRA_CFLAGS}
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export CONF_LDFLAGS=${LDFLAGS} ${EXTRA_LDFLAGS}
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export CONF_LDLIBS=${LDLIBS} ${EXTRA_LDLIBS}
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export XNOLIBS=${NOLIBS}

‎build/flags.mk‎

Lines changed: 13 additions & 48 deletions
Original file line numberDiff line numberDiff line change
@@ -1,7 +1,7 @@
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# Copyright © Tavian Barnes <[email protected]>
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# SPDX-License-Identifier: 0BSD
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4-
# Makefile that generates gen/flags.mk
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# Makefile that generates gen/{early,late}.mk
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include build/prelude.mk
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include gen/vars.mk
@@ -79,32 +79,10 @@ _CFLAGS += ${LTO_CFLAGS,${_LTO}}
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# Configurable flags
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CFLAGS ?= -g -Wall
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# Add the configurable flags last so they can override ours
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_CPPFLAGS += ${CPPFLAGS} ${EXTRA_CPPFLAGS}
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_CFLAGS += ${CFLAGS} ${EXTRA_CFLAGS}
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_LDFLAGS += ${LDFLAGS} ${EXTRA_LDFLAGS}
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# (except LDLIBS, as earlier libs override later ones)
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_LDLIBS := ${LDLIBS} ${EXTRA_LDLIBS} ${_LDLIBS}
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include build/exports.mk
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# Conditionally-supported flags
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AUTO_FLAGS := \
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gen/flags/std.mk \
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gen/flags/bind-now.mk \
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gen/flags/deps.mk \
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gen/flags/pthread.mk \
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gen/flags/Wformat.mk \
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gen/flags/Wimplicit-fallthrough.mk \
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gen/flags/Wimplicit.mk \
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gen/flags/Wmissing-decls.mk \
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gen/flags/Wmissing-var-decls.mk \
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gen/flags/Wshadow.mk \
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gen/flags/Wsign-compare.mk \
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gen/flags/Wstrict-prototypes.mk \
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gen/flags/Wundef-prefix.mk
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gen/flags.mk: ${AUTO_FLAGS}
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# Saves the internal flags
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gen/early.mk::
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${MSG} "[ GEN] $@"
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@printf '# %s\n' "$@" >$@
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@printf '_CPPFLAGS := %s\n' "$$XCPPFLAGS" >>$@
@@ -113,27 +91,14 @@ gen/flags.mk: ${AUTO_FLAGS}
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@printf '_LDLIBS := %s\n' "$$XLDLIBS" >>$@
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@printf 'NOLIBS := %s\n' "$$XNOLIBS" >>$@
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@test "${OS}-${SAN}" != FreeBSD-y || printf 'POSTLINK = elfctl -e +noaslr $$@\n' >>$@
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@cat $^ >>$@
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@cat ${^:%=%.log} >gen/flags.log
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${VCAT} $@
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.PHONY: gen/flags.mk
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121-
# Check that the C compiler works at all
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cc::
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@build/cc.sh -q build/empty.c -o gen/.cc.out; \
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ret=$$?; \
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build/msg-if.sh "[ CC ] build/empty.c" test $$ret -eq 0; \
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exit $$ret
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# The short name of the config test
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SLUG = ${@:gen/%.mk=%}
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# The source file to build
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CSRC = build/${SLUG}.c
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# The hidden output file name
133-
OUT = ${SLUG:flags/%=gen/flags/.%.out}
134-
135-
${AUTO_FLAGS}: cc
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@${MKDIR} ${@D}
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@build/flags-if.sh ${CSRC} -o ${OUT} >$@ 2>$@.log; \
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build/msg-if.sh "[ CC ] ${SLUG}.c" test $$? -eq 0
139-
.PHONY: ${AUTO_FLAGS}
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# Save explicit flags from ./configure separately so they can override the rest
97+
gen/late.mk::
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${MSG} "[ GEN] $@"
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@printf '# %s\n' "$@" >$@
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@printf '_CPPFLAGS += %s\n' "$$CONF_CPPFLAGS" >>$@
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@printf '_CFLAGS += %s\n' "$$CONF_CFLAGS" >>$@
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@printf '_LDFLAGS += %s\n' "$$CONF_LDFLAGS" >>$@
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@printf '_LDLIBS := %s $${_LDLIBS}\n' "$$CONF_LDLIBS" >>$@
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${VCAT} $@

‎build/header.mk‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -5,8 +5,10 @@
55

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include build/prelude.mk
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include gen/vars.mk
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include gen/flags.mk
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include gen/early.mk
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include gen/auto.mk
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include gen/pkgs.mk
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include gen/late.mk
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include build/exports.mk
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# All header fragments we generate

‎build/pkgs.mk‎

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,9 @@
55

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include build/prelude.mk
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include gen/vars.mk
8-
include gen/flags.mk
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include gen/early.mk
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include gen/auto.mk
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include gen/late.mk
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include build/exports.mk
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HEADERS := ${ALL_PKGS:%=gen/with/%.h}

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