qemu/rules.mak
Paolo Bonzini db5adeaa84 build-sys: clean up flags included in the linker command line
Some of the CFLAGS that are discovered during configure, for example
compiler warnings, are being included on the linker command line because
QEMU_CFLAGS is added to it.  Other flags, such as the -m32, appear twice
because they are included in both QEMU_CFLAGS and LDFLAGS.  All this
leads to confusion with respect to what goes in which Makefile variables
(and we have plenty).

So, introduce QEMU_LDFLAGS for flags discovered by configure, following
the lead of QEMU_CFLAGS, and stop adding to it:

1) options that are already in CFLAGS, for example "-g"

2) duplicate options

At the same time, options that _are_ needed by both compiler and linker
must now be added to both QEMU_CFLAGS and QEMU_LDFLAGS, which is clearer.
This is mostly -fsanitize options.  For now, --extra-cflags has this behavior
(but --extra-cxxflags does not).

Meson will not include CFLAGS on the linker command line, do the same in our
build system as well.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:17 +01:00

402 lines
14 KiB
Makefile

# These are used when we want to do substitutions without confusing Make
NULL :=
SPACE := $(NULL) #
COMMA := ,
# Don't use implicit rules or variables
# we have explicit rules for everything
MAKEFLAGS += -rR
# Files with this suffixes are final, don't try to generate them
# using implicit rules
%/trace-events:
%.hx:
%.py:
%.objs:
%.d:
%.h:
%.c:
%.cc:
%.cpp:
%.m:
%.mak:
clean-target:
# Flags for dependency generation
QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(@D)/$(*F).d
# Compiler searches the source file dir first, but in vpath builds
# we need to make it search the build dir too, before any other
# explicit search paths. There are two search locations in the build
# dir, one absolute and the other relative to the compiler working
# directory. These are the same for target-independent files, but
# different for target-dependent ones.
QEMU_LOCAL_INCLUDES = -iquote $(BUILD_DIR)/$(@D) -iquote $(@D)
WL_U := -Wl,-u,
find-symbols = $(if $1, $(sort $(shell $(NM) -P -g $1 | $2)))
defined-symbols = $(call find-symbols,$1,awk '$$2!="U"{print $$1}')
undefined-symbols = $(call find-symbols,$1,awk '$$2=="U"{print $$1}')
# All the .mo objects in -m variables are also added into corresponding -y
# variable in unnest-vars, but filtered out here, when LINK is called.
#
# The .mo objects are supposed to be linked as a DSO, for module build. So here
# they are only used as a placeholders to generate those "archive undefined"
# symbol options (-Wl,-u,$symbol_name), which are the archive functions
# referenced by the code in the DSO.
#
# Also the presence in -y variables will also guarantee they are built before
# linking executables that will load them. So we can look up symbol reference
# in LINK.
#
# This is necessary because the exectuable itself may not use the function, in
# which case the function would not be linked in. Then the DSO loading will
# fail because of the missing symbol.
process-archive-undefs = $(filter-out %.a %.mo,$1) \
$(addprefix $(WL_U), \
$(filter $(call defined-symbols,$(filter %.a, $1)), \
$(call undefined-symbols,$(filter %.mo,$1)))) \
$(filter %.a,$1)
extract-libs = $(strip $(foreach o,$(filter-out %.mo,$1),$($o-libs)))
expand-objs = $(strip $(sort $(filter %.o,$1)) \
$(foreach o,$(filter %.mo,$1),$($o-objs)) \
$(filter-out %.o %.mo,$1))
%.o: %.c
$(call quiet-command,$(CC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
-c -o $@ $<,"CC","$(TARGET_DIR)$@")
%.o: %.rc
$(call quiet-command,$(WINDRES) -I. -o $@ $<,"RC","$(TARGET_DIR)$@")
# If we have a CXX we might have some C++ objects, in which case we
# must link with the C++ compiler, not the plain C compiler.
LINKPROG = $(or $(CXX),$(CC))
LINK = $(call quiet-command, $(LINKPROG) $(CFLAGS) $(QEMU_LDFLAGS) -o $@ \
$(call process-archive-undefs, $1) \
$(version-obj-y) $(call extract-libs,$1) $(LIBS),"LINK","$(TARGET_DIR)$@")
%.o: %.S
$(call quiet-command,$(CCAS) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) \
-c -o $@ $<,"CCAS","$(TARGET_DIR)$@")
%.o: %.cc
$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
$(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
-c -o $@ $<,"CXX","$(TARGET_DIR)$@")
%.o: %.cpp
$(call quiet-command,$(CXX) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
$(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
-c -o $@ $<,"CXX","$(TARGET_DIR)$@")
%.o: %.m
$(call quiet-command,$(OBJCC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
$(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) \
-c -o $@ $<,"OBJC","$(TARGET_DIR)$@")
%.o: %.dtrace
$(call quiet-command,dtrace -o $@ -G -s $<,"GEN","$(TARGET_DIR)$@")
DSO_OBJ_CFLAGS := -fPIC -DBUILD_DSO
module-common.o: CFLAGS += $(DSO_OBJ_CFLAGS)
%$(DSOSUF): QEMU_LDFLAGS += $(LDFLAGS_SHARED)
%$(DSOSUF): %.mo
$(call LINK,$^)
@# Copy to build root so modules can be loaded when program started without install
$(if $(findstring /,$@),$(call quiet-command,cp $@ $(subst /,-,$@),"CP","$(subst /,-,$@)"))
LD_REL := $(CC) -nostdlib $(LD_REL_FLAGS)
%.mo:
$(call quiet-command,$(LD_REL) -o $@ $^,"LD","$(TARGET_DIR)$@")
.PHONY: modules
modules:
%$(EXESUF): %.o
$(call LINK,$(filter %.o %.a %.mo, $^))
%.a:
$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^,"AR","$(TARGET_DIR)$@")
# Usage: $(call quiet-command,command and args,"NAME","args to print")
# This will run "command and args", and either:
# if V=1 just print the whole command and args
# otherwise print the 'quiet' output in the format " NAME args to print"
# NAME should be a short name of the command, 7 letters or fewer.
# If called with only a single argument, will print nothing in quiet mode.
quiet-command-run = $(if $(V),,$(if $2,printf " %-7s %s\n" $2 $3 && ))$1
quiet-@ = $(if $(V),,@)
quiet-command = $(quiet-@)$(call quiet-command-run,$1,$2,$3)
# cc-option
# Usage: CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)
cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
>/dev/null 2>&1 && echo OK), $2, $3)
cc-c-option = $(if $(shell $(CC) $1 $2 -c -o /dev/null -xc /dev/null \
>/dev/null 2>&1 && echo OK), $2, $3)
VPATH_SUFFIXES = %.c %.h %.S %.cc %.cpp %.m %.mak %.texi %.sh %.rc Kconfig% %.json.in
set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))
# install-prog list, dir
define install-prog
$(INSTALL_DIR) "$2"
$(INSTALL_PROG) $1 "$2"
$(if $(STRIP),$(STRIP) $(foreach T,$1,"$2/$(notdir $T)"),)
endef
# find-in-path
# Usage: $(call find-in-path, prog)
# Looks in the PATH if the argument contains no slash, else only considers one
# specific directory. Returns an # empty string if the program doesn't exist
# there.
find-in-path = $(if $(findstring /, $1), \
$(wildcard $1), \
$(wildcard $(patsubst %, %/$1, $(subst :, ,$(PATH)))))
# Logical functions (for operating on y/n values like CONFIG_FOO vars)
# Inputs to these must be either "y" (true) or "n" or "" (both false)
# Output is always either "y" or "n".
# Usage: $(call land,$(CONFIG_FOO),$(CONFIG_BAR))
# Logical NOT
lnot = $(if $(subst n,,$1),n,y)
# Logical AND
land = $(if $(findstring yy,$1$2),y,n)
# Logical OR
lor = $(if $(findstring y,$1$2),y,n)
# Logical XOR (note that this is the inverse of leqv)
lxor = $(if $(filter $(call lnot,$1),$(call lnot,$2)),n,y)
# Logical equivalence (note that leqv "","n" is true)
leqv = $(if $(filter $(call lnot,$1),$(call lnot,$2)),y,n)
# Logical if: like make's $(if) but with an leqv-like test
lif = $(if $(subst n,,$1),$2,$3)
# String testing functions: inputs to these can be any string;
# the output is always either "y" or "n". Leading and trailing whitespace
# is ignored when comparing strings.
# String equality
eq = $(if $(subst $2,,$1)$(subst $1,,$2),n,y)
# String inequality
ne = $(if $(subst $2,,$1)$(subst $1,,$2),y,n)
# Emptiness/non-emptiness tests:
isempty = $(if $1,n,y)
notempty = $(if $1,y,n)
# Generate files with tracetool
TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py
# Generate timestamp files for .h include files
config-%.h: config-%.h-timestamp
@cmp $< $@ >/dev/null 2>&1 || cp $< $@
config-%.h-timestamp: config-%.mak $(SRC_PATH)/scripts/create_config
$(call quiet-command, sh $(SRC_PATH)/scripts/create_config < $< > $@,"GEN","$(TARGET_DIR)config-$*.h")
.PHONY: clean-timestamp
clean-timestamp:
rm -f *.timestamp
clean: clean-timestamp
# will delete the target of a rule if commands exit with a nonzero exit status
.DELETE_ON_ERROR:
# save-vars
# Usage: $(call save-vars, vars)
# Save each variable $v in $vars as save-vars-$v, save their object's
# variables, then clear $v. saved-vars-$v contains the variables that
# where saved for the objects, in order to speedup load-vars.
define save-vars
$(foreach v,$1,
$(eval save-vars-$v := $(value $v))
$(eval saved-vars-$v := $(foreach o,$($v), \
$(if $($o-cflags), $o-cflags $(eval save-vars-$o-cflags := $($o-cflags))$(eval $o-cflags := )) \
$(if $($o-libs), $o-libs $(eval save-vars-$o-libs := $($o-libs))$(eval $o-libs := )) \
$(if $($o-objs), $o-objs $(eval save-vars-$o-objs := $($o-objs))$(eval $o-objs := ))))
$(eval $v := ))
endef
# load-vars
# Usage: $(call load-vars, vars, add_var)
# Load the saved value for each variable in @vars, and the per object
# variables.
# Append @add_var's current value to the loaded value.
define load-vars
$(eval $2-new-value := $(value $2))
$(foreach v,$1,
$(eval $v := $(value save-vars-$v))
$(foreach o,$(saved-vars-$v),
$(eval $o := $(save-vars-$o)) $(eval save-vars-$o := ))
$(eval save-vars-$v := )
$(eval saved-vars-$v := ))
$(eval $2 := $(value $2) $($2-new-value))
endef
# fix-paths
# Usage: $(call fix-paths, obj_path, src_path, vars)
# Add prefix @obj_path to all objects in @vars, and add prefix @src_path to all
# directories in @vars.
define fix-paths
$(foreach v,$3,
$(foreach o,$($v),
$(if $($o-libs),
$(eval $1$o-libs := $($o-libs)))
$(if $($o-cflags),
$(eval $1$o-cflags := $($o-cflags)))
$(if $($o-objs),
$(eval $1$o-objs := $(addprefix $1,$($o-objs)))))
$(eval $v := $(addprefix $1,$(filter-out %/,$($v))) \
$(addprefix $2,$(filter %/,$($v)))))
endef
# unnest-var-recursive
# Usage: $(call unnest-var-recursive, obj_prefix, vars, var)
#
# Unnest @var by including subdir Makefile.objs, while protect others in @vars
# unchanged.
#
# @obj_prefix is the starting point of object path prefix.
#
define unnest-var-recursive
$(eval dirs := $(sort $(filter %/,$($3))))
$(eval $3 := $(filter-out %/,$($3)))
$(foreach d,$(dirs:%/=%),
$(call save-vars,$2)
$(eval obj := $(if $1,$1/)$d)
$(eval -include $(SRC_PATH)/$d/Makefile.objs)
$(call fix-paths,$(if $1,$1/)$d/,$d/,$2)
$(call load-vars,$2,$3)
$(call unnest-var-recursive,$1,$2,$3))
endef
# unnest-vars
# Usage: $(call unnest-vars, obj_prefix, vars)
#
# @obj_prefix: object path prefix, can be empty, or '..', etc. Don't include
# ending '/'.
#
# @vars: the list of variable names to unnest.
#
# This macro will scan subdirectories's Makefile.objs, include them, to build
# up each variable listed in @vars.
#
# Per object and per module cflags and libs are saved with relative path fixed
# as well, those variables include -libs, -cflags and -objs. Items in -objs are
# also fixed to relative path against SRC_PATH plus the prefix @obj_prefix.
#
# All nested variables postfixed by -m in names are treated as DSO variables,
# and will be built as modules, if enabled.
#
# A simple example of the unnest:
#
# obj_prefix = ..
# vars = hot cold
# hot = fire.o sun.o season/
# cold = snow.o water/ season/
#
# Unnest through a faked source directory structure:
#
# SRC_PATH
# ├── water
# │ └── Makefile.objs──────────────────┐
# │ │ hot += steam.o │
# │ │ cold += ice.mo │
# │ │ ice.mo-libs := -licemaker │
# │ │ ice.mo-objs := ice1.o ice2.o │
# │ └──────────────────────────────┘
# │
# └── season
# └── Makefile.objs──────┐
# │ hot += summer.o │
# │ cold += winter.o │
# └──────────────────┘
#
# In the end, the result will be:
#
# hot = ../fire.o ../sun.o ../season/summer.o
# cold = ../snow.o ../water/ice.mo ../season/winter.o
# ../water/ice.mo-libs = -licemaker
# ../water/ice.mo-objs = ../water/ice1.o ../water/ice2.o
#
# Note that 'hot' didn't include 'water/' in the input, so 'steam.o' is not
# included.
#
define unnest-vars
# In the case of target build (i.e. $1 == ..), fix path for top level
# Makefile.objs objects
$(if $1,$(call fix-paths,$1/,,$2))
# Descend and include every subdir Makefile.objs
$(foreach v, $2,
$(call unnest-var-recursive,$1,$2,$v)
# Pass the .mo-cflags and .mo-libs along to its member objects
$(foreach o, $(filter %.mo,$($v)),
$(foreach p,$($o-objs),
$(if $($o-cflags), $(eval $p-cflags += $($o-cflags)))
$(if $($o-libs), $(eval $p-libs += $($o-libs))))))
# For all %.mo objects that are directly added into -y, just expand them
$(foreach v,$(filter %-y,$2),
$(eval $v := $(foreach o,$($v),$(if $($o-objs),$($o-objs),$o))))
$(foreach v,$(filter %-m,$2),
# All .o found in *-m variables are single object modules, create .mo
# for them
$(foreach o,$(filter %.o,$($v)),
$(eval $(o:%.o=%.mo)-objs := $o))
# Now unify .o in -m variable to .mo
$(eval $v := $($v:%.o=%.mo))
$(eval modules-m += $($v))
# For module build, build shared libraries during "make modules"
# For non-module build, add -m to -y
$(if $(CONFIG_MODULES),
$(foreach o,$($v),
$(eval $($o-objs): CFLAGS += $(DSO_OBJ_CFLAGS))
$(eval $o: $($o-objs)))
$(eval $(patsubst %-m,%-y,$v) += $($v))
$(eval modules: $($v:%.mo=%$(DSOSUF))),
$(eval $(patsubst %-m,%-y,$v) += $(call expand-objs, $($v)))))
# Post-process all the unnested vars
$(foreach v,$2,
$(foreach o, $(filter %.mo,$($v)),
# Find all the .mo objects in variables and add dependency rules
# according to .mo-objs. Report error if not set
$(if $($o-objs),
$(eval $(o:%.mo=%$(DSOSUF)): module-common.o $($o-objs)),
$(error $o added in $v but $o-objs is not set)))
$(shell mkdir -p ./ $(sort $(dir $($v))))
# Include all the .d files
$(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$($v))))
$(eval $v := $(filter-out %/,$($v))))
endef
TEXI2MAN = $(call quiet-command, \
perl -Ww -- $(SRC_PATH)/scripts/texi2pod.pl $(TEXI2PODFLAGS) $< $@.pod && \
$(POD2MAN) --section=$(subst .,,$(suffix $@)) --center=" " --release=" " $@.pod > $@, \
"GEN","$@")
%.1:
$(call TEXI2MAN)
%.7:
$(call TEXI2MAN)
%.8:
$(call TEXI2MAN)
GEN_SUBST = $(call quiet-command, \
sed -e "s!@libexecdir@!$(libexecdir)!g" < $< > $@, \
"GEN","$@")
%.json: %.json.in
$(call GEN_SUBST)