>From b92cb72f08908a718da05318975545e988bfdaf9 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam@xxxxxxxxxxxx>
Date: Mon, 9 Jun 2014 18:03:22 +0200
Subject: [PATCH] kbuild: move cc_c_o logic to a shell script
The amount of makefile magic required when building a
.o file from a .c file had grown far too much.
Move all the logic to a shell script where it is much
easier to follow the sequence and thus easier to debug/enhance.
This transition has following impact on the current functionality:
- We no longer rebuild the kernel if the source for recordmount is changed
The source filehas not changed for a couple of years
- A shortcut to build symtypes files is lost. It was never
supported by the top-level Makefile anyway
Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
---
The final link of vmlinux was moved out to a shell script
resulting in some much more readable code.
Try to do the same for .c => .o rule.
I would like someone with more shell-foo than me to review the
shell script.
Sam
scripts/Makefile.build | 115 ++++--------------------------
scripts/kcc.sh | 187 +++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 202 insertions(+), 100 deletions(-)
create mode 100644 scripts/kcc.sh
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 003bc26..3497a7c 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -158,14 +158,9 @@ __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
@:
# Linus' kernel sanity checking tool
-ifneq ($(KBUILD_CHECKSRC),0)
- ifeq ($(KBUILD_CHECKSRC),2)
- quiet_cmd_force_checksrc = CHECK $<
- cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
- else
- quiet_cmd_checksrc = CHECK $<
- cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
- endif
+ifeq ($(KBUILD_CHECKSRC),2)
+quiet_cmd_force_checksrc = CHECK $<
+ cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
endif
# Do section mismatch analysis for each module/built-in.o
@@ -219,108 +214,28 @@ cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
$(obj)/%.i: $(src)/%.c FORCE
$(call if_changed_dep,cc_i_c)
-cmd_gensymtypes = \
- $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
- $(GENKSYMS) $(if $(1), -T $(2)) \
- $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
- $(if $(KBUILD_PRESERVE),-p) \
- -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
-
-quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
-cmd_cc_symtypes_c = \
- set -e; \
- $(call cmd_gensymtypes,true,$@) >/dev/null; \
- test -s $@ || rm -f $@
-
-$(obj)/%.symtypes : $(src)/%.c FORCE
- $(call cmd,cc_symtypes_c)
-
-# C (.c) files
-# The C file is compiled and updated dependency information is generated.
-# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
-
-quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
-
-ifndef CONFIG_MODVERSIONS
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
-
-else
-# When module versioning is enabled the following steps are executed:
-# o compile a .tmp_<file>.o from <file>.c
-# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
-# not export symbols, we just rename .tmp_<file>.o to <file>.o and
-# are done.
-# o otherwise, we calculate symbol versions using the good old
-# genksyms on the preprocessed source and postprocess them in a way
-# that they are usable as a linker script
-# o generate <file>.o from .tmp_<file>.o using the linker to
-# replace the unresolved symbols __crc_exported_symbol with
-# the actual value of the checksum generated by genksyms
-
-cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
-cmd_modversions = \
- if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
- $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
- > $(@D)/.tmp_$(@F:.o=.ver); \
- \
- $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
- -T $(@D)/.tmp_$(@F:.o=.ver); \
- rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
- else \
- mv -f $(@D)/.tmp_$(@F) $@; \
- fi;
-endif
-
-ifdef CONFIG_FTRACE_MCOUNT_RECORD
-ifdef BUILD_C_RECORDMCOUNT
-ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
- RECORDMCOUNT_FLAGS = -w
-endif
-# Due to recursion, we must skip empty.o.
-# The empty.o file is created in the make process in order to determine
-# the target endianness and word size. It is made before all other C
-# files, including recordmcount.
-sub_cmd_record_mcount = \
- if [ $(@) != "scripts/mod/empty.o" ]; then \
- $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
- fi;
-recordmcount_source := $(srctree)/scripts/recordmcount.c \
- $(srctree)/scripts/recordmcount.h
-else
-sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
- "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
- "$(if $(CONFIG_64BIT),64,32)" \
- "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
- "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
- "$(if $(part-of-module),1,0)" "$(@)";
-recordmcount_source := $(srctree)/scripts/recordmcount.pl
-endif
-cmd_record_mcount = \
- if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
- $(sub_cmd_record_mcount) \
- fi;
-endif
-
define rule_cc_o_c
- $(call echo-cmd,checksrc) $(cmd_checksrc) \
- $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
- $(cmd_modversions) \
- $(call echo-cmd,record_mcount) \
- $(cmd_record_mcount) \
- scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
- $(dot-target).tmp; \
- rm -f $(depfile); \
+ $(CONFIG_SHELL) $(srctree)/scripts/kcc.sh \
+ $< $@ $(depfile) \
+ $(if $(part-of-module),m,b) \
+ "$(echo-why)" \
+ $(c_flags); \
+ scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
+ $(dot-target).tmp; \
+ rm -f $(depfile); \
mv -f $(dot-target).tmp $(dot-target).cmd
endef
+# cmd_cc_o_c is required by if_changed_rule to detect changes in options
+cmd_cc_o_c = $(CC) $(c_flags)
# Built-in and composite module parts
-$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(obj)/%.o: $(src)/%.c FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
# Single-part modules are special since we need to mark them in $(MODVERDIR)
-$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
+$(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
$(call cmd,force_checksrc)
$(call if_changed_rule,cc_o_c)
@{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
diff --git a/scripts/kcc.sh b/scripts/kcc.sh
new file mode 100644
index 0000000..2b0bad6
--- /dev/null
+++ b/scripts/kcc.sh
@@ -0,0 +1,187 @@
+#!/bin/sh
+# kernel wrapper for cc
+# In the simple case we just call cc with the supplied arguments.
+# But we may check the source with sparse before we call cc.
+# And we may postprocess the source or the .o file to support
+# module versioning and function tracing.
+
+# Error out on error
+set -e
+
+# Print command and execute
+# ${quiet} determine which command to print (if any)
+run()
+{
+ case "${quiet}" in
+ "silent_")
+ shift
+ ;;
+ "quiet_")
+ printf " %s \n" "$1 ${why}"
+ shift
+ ;;
+ *)
+ shift
+ echo "$*"
+ esac
+
+ # Run the command
+ $*
+}
+
+# Calculate symbol versions on the preprocessed source
+# using genksyms and postprocess the output in a way
+# that it is usable as a linker script.
+# Then generate the .o file with the __crc_exported_symbol replaced.
+gen_sym_types()
+{
+ if [ "${KBUILD_SYMTYPES}" = "y" ]; then
+ dump_types="-T $1.symtypes"
+ fi
+
+ if [ "${CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX}" = "y" ]; then
+ mod_prefix="-s _"
+ fi
+
+ if [ "${KBUILD_PRESERVE}" != "" ]; then
+ preserve="-p";
+ if [ -f $1.symref ]; then
+ reference="-r $1.symref"
+ fi
+ fi
+
+ out=$1.ver
+ shift
+
+ ${CPP} -D__GENKSYMS__ $* ${infile} | \
+ ${GENKSYMS} ${dump_types} ${mod_prefix} ${preserve} ${reference} > ${out}
+
+ # Generate <file>.o from .tmp_<file>.o using the linker to
+ # replace the unresolved symbols __crc_exported_symbol with
+ # the actual value of the checksum generated by genksyms
+ ${LD} ${LDFLAGS} -r -o ${outfile} ${tmpfile}.o -T ${out}
+ rm -f ${tmpfile}.o ${out}
+}
+
+# Create __mcount_loc section with pointers to all calls to mcount
+record_mcount()
+{
+ # Due to recursion, we must skip empty.o.
+ # The empty.o file is created in the make process in order to determine
+ # the target endianness and word size. It is made before all other C
+ # files, including recordmcount.
+
+ if [ "$(basename ${outfile})" = "empty.o" ]; then
+ return
+ fi
+
+ if [ "${BUILD_C_RECORDMCOUNT}" != "" ]; then
+ if [ "${RECORDMCOUNT_WARN}" != "" ]; then
+ warn_on_notrace="-w"
+ fi
+
+ ${objtree}/scripts/recordmcount ${warn_on_notrace} ${outfile}
+ else
+
+ mcount=${srctree}/scripts/recordmcount.pl
+ if [ "${CONFIG_CPU_BIG_ENDIAN}" != "" ]; then
+ endian=big
+ else
+ endian=little
+ fi
+ if [ "${CONFIG_64BIT}" != "" ]; then
+ bits=64
+ else
+ bits=32
+ fi
+ if [ "${module}" = "m" ]; then
+ is_module=1
+ else
+ is_module=0
+ fi
+
+ ${mcount} ${ARCH} ${endian} ${bits} "${OBJDUMP}" "${OBJCOPY}" \
+ "${CC} ${KBUILD_CFLAGS}" "${LD}" "${NM}" "${RM}" "${MV}" \
+ ${is_module} ${outfile}
+ fi
+}
+
+# Delete output files in case of error
+trap cleanup SIGHUP SIGINT SIGQUIT SIGTERM ERR
+cleanup()
+{
+ rm -f ${outfile}
+}
+
+#
+#
+# kcc.sh infile outfile depfile {b,m} why {options to cc}
+# where b == built-in, m == module
+
+infile=$1
+shift
+outfile=$1
+shift
+depfile=$1
+shift
+
+# Print [M] for modules
+if [ $1 = m ]; then
+ module=m
+ modtag="[M]"
+else
+ modtag=" "
+fi
+shift
+
+why=$1
+shift
+
+# We need access to CONFIG_ symbols
+case "${KCONFIG_CONFIG}" in
+*/*)
+ . "${KCONFIG_CONFIG}"
+ ;;
+*)
+ # Force using a file from the current directory
+ . "./${KCONFIG_CONFIG}"
+esac
+
+#set -x
+
+# Run sparse (or another checker) on the input file?
+if [ "${KBUILD_CHECKSRC}" = "1" ]; then
+ cmd="${CHECK} ${CHECKFLAGS} $* ${infile}"
+ run "CHECK ${infile}" ${cmd}
+fi
+
+# Have we enabled module versioning?
+if [ "${CONFIG_MODVERSIONS}" = "" ]; then
+ cccmd="${CC} $* -c -o ${outfile} ${infile}"
+ run "CC ${modtag} ${outfile}" ${cccmd}
+else
+ # Module versioning is enabled
+ # If the .o file contains exported symbol calculate symbol versions
+ dir=$(dirname ${outfile})
+ file=$(basename ${outfile})
+ tmpfile=${dir}/.tmp_${file}
+
+ cccmd="${CC} $* -c -o ${tmpfile}.o ${infile}"
+ run "CC ${modtag} ${outfile}" ${cccmd}
+
+ if ${OBJDUMP} -h ${tmpfile}.o | grep -q __ksymtab; then
+ # The .o file contains exported symbols
+ # (contains __ksymtab section)
+ # Calculate symbol versions using genksyms
+ gen_sym_types ${tmpfile} $*
+ else
+ mv -f ${tmpfile}.o ${outfile}
+ fi
+fi
+
+# Do we have to run record_mcount?
+if [ "${CONFIG_FTRACE_MCOUNT_RECORD}" != "" ]; then
+ if [ $(echo $* | grep -c -e "-pg") -gt 0 ]; then
+ record_mcount
+ fi
+fi
--
1.9.3
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