This reverts commit 45672c269d.
Because:
* It's very confusing to have cc as LD.
* I don't see what "-nostartfiles -nodefaultlibs" in LDFLAGS are
supposed to do when we use LD directly. It would be simpler to
remove them from our LDFLAGS.
The patch
Make: use gcc as LD
introduced use of GCC wrapper as linker. LD variable references GCC
executable now. But when GCC wrapper s used to build relocatable
loadable objects (ELF executables and modules) then it causes
linking of toolchain default libc and other libraries even when -r
is usd. Another problem is that incorrect multiarch variant is selected
for libraries search and possibly even for LTO or C++ templates
instantiating and other glue code which causes fails during linking
if CFLAGS selects non/default miltiarch variant.
Corresponding CFLAGS are passed to LDMODULEFLAGS and LDELFFLAGS
as well as -nostartfiles -nodefaultlibs options.
Separate line is used to easily find and adjust lines if link
process is changed in future.
Signed-off-by: Pavel Pisa <ppisa@pikron.com>
In the current compilation environment, the recursive assignment(=) for compile
flags will be delayed until every file is actually need to be compile.
For example:
--------------------------------------------------------------------------------
arch/arm/src/Makefile:
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)chip}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)common}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)$(ARCH_SUBDIR)}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(TOPDIR)$(DELIM)sched}
CPPFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CXXFLAGS += $(INCLUDES) $(EXTRAFLAGS)
AFLAGS += $(INCLUDES) $(EXTRAFLAGS)
--------------------------------------------------------------------------------
All compilation options will be included recursively,
which will be delayed until the compilation options are actually used:
tools/Config.mk:
--------------------------------------------------------------------------------
define COMPILE
@echo "CC: $1"
$(Q) $(CC) -c $(CFLAGS) $($(strip $1)_CFLAGS) $1 -o $2
endef
--------------------------------------------------------------------------------
All compile flags to be reexecuted $(INCDIR) as long as one file needs to be compiled,
but in fact, the compilation options have not changed in the current directory.
So the we recommand to change the syntax of assignment
From
Recursive (=)
To
Simple (:=)
In this way, we can ensure that all compilation options are expanded only once and reducing repeated works.
Signed-off-by: chao.an <anchao@xiaomi.com>
