qemu/rules.mak
Fam Zheng d24697e182 rules.mak: Force CFLAGS for all objects in DSO
Because of the trick of process-archive-undefs, all .mo objects, even
with --enable-modules, are dependencies of executables.

This breaks CFLAGS propogation because the compiling of module object
will happen too early before building for DSO.

With GCC 5, the linking would fail because .o doesn't have -fPIC. Also,
BUILD_DSO will be missed. (module-common.o will have it, so the stamp
symbol was still liked in .so).

Fix the problem by forcing the CFLAGS on individual .o-cflags during
unnest-vars.

Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Fam Zheng <famz@redhat.com>
Cc: qemu-stable@nongnu.org # 2.3
Message-Id: <1430981715-31465-1-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-08 14:45:11 +02:00

374 lines
14 KiB
Makefile

# 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
%.d:
%.h:
%.c:
%.cc:
%.cpp:
%.m:
%.mak:
# Flags for C++ compilation
QEMU_CXXFLAGS = -D__STDC_LIMIT_MACROS $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wnested-externs -Wold-style-declaration -Wold-style-definition -Wredundant-decls, $(QEMU_CFLAGS))
# Flags for dependency generation
QEMU_DGFLAGS += -MMD -MP -MT $@ -MF $(*D)/$(*F).d
# Same as -I$(SRC_PATH) -I., but for the nested source/object directories
QEMU_INCLUDES += -I$(<D) -I$(@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,$1,$($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_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))
ifeq ($(LIBTOOL),)
LINK = $(call quiet-command, $(LINKPROG) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ \
$(call process-archive-undefs, $1) \
$(version-obj-y) $(call extract-libs,$1) $(LIBS)," LINK $(TARGET_DIR)$@")
else
LIBTOOL += $(if $(V),,--quiet)
%.lo: %.c
$(call quiet-command,$(LIBTOOL) --mode=compile --tag=CC $(CC) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($*.o-cflags) -c -o $@ $<," lt CC $@")
%.lo: %.rc
$(call quiet-command,$(LIBTOOL) --mode=compile --tag=RC $(WINDRES) -I. -o $@ $<,"lt RC $(TARGET_DIR)$@")
%.lo: %.dtrace
$(call quiet-command,$(LIBTOOL) --mode=compile --tag=CC dtrace -o $@ -G -s $<, " lt GEN $(TARGET_DIR)$@")
LINK = $(call quiet-command,\
$(if $(filter %.lo %.la,$1),$(LIBTOOL) --mode=link --tag=CC \
)$(LINKPROG) $(QEMU_CFLAGS) $(CFLAGS) $(LDFLAGS) -o $@ \
$(call process-archive-undefs, $1)\
$(if $(filter %.lo %.la,$1),$(version-lobj-y),$(version-obj-y)) \
$(if $(filter %.lo %.la,$1),$(LIBTOOLFLAGS)) \
$(call extract-libs,$(1:.lo=.o)) $(LIBS),$(if $(filter %.lo %.la,$1),"lt LINK ", " LINK ")"$(TARGET_DIR)$@")
endif
%.asm: %.S
$(call quiet-command,$(CPP) $(QEMU_INCLUDES) $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) -o $@ $<," CPP $(TARGET_DIR)$@")
%.o: %.asm
$(call quiet-command,$(AS) $(ASFLAGS) -o $@ $<," AS $(TARGET_DIR)$@")
%.o: %.cc
$(call quiet-command,$(CXX) $(QEMU_INCLUDES) $(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) -c -o $@ $<," CXX $(TARGET_DIR)$@")
%.o: %.cpp
$(call quiet-command,$(CXX) $(QEMU_INCLUDES) $(QEMU_CXXFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $($@-cflags) -c -o $@ $<," CXX $(TARGET_DIR)$@")
%.o: %.m
$(call quiet-command,$(OBJCC) $(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): 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 -Wl,-r
%.mo:
$(call quiet-command,$(LD_REL) -o $@ $^," LD -r $(TARGET_DIR)$@")
.PHONY: modules
modules:
%$(EXESUF): %.o
$(call LINK,$^)
%.a:
$(call quiet-command,rm -f $@ && $(AR) rcs $@ $^," AR $(TARGET_DIR)$@")
quiet-command = $(if $(V),$1,$(if $(2),@echo $2 && $1, @$1))
# cc-option
# Usage: CFLAGS+=$(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)
VPATH_SUFFIXES = %.c %.h %.S %.cc %.cpp %.m %.mak %.texi %.sh %.rc
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 $(find-string /, $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
$(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.
define save-vars
$(foreach v,$1,
$(eval save-vars-$v := $(value $v))
$(foreach o,$($v),
$(foreach k,cflags libs objs,
$(if $($o-$k),
$(eval save-vars-$o-$k := $($o-$k))
$(eval $o-$k := ))))
$(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))
$(foreach o,$($v),
$(foreach k,cflags libs objs,
$(if $(save-vars-$o-$k),
$(eval $o-$k := $(save-vars-$o-$k))
$(eval save-vars-$o-$k := ))))
$(eval save-vars-$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 'season/' in the input, so 'summer.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 $(addsuffix *.d, $(sort $(dir $($v)))))
$(eval $v := $(filter-out %/,$($v))))
endef