On Fri, Feb 15, 2019 at 02:18:44AM +0000, Ramsay Jones wrote: > On 14/02/2019 23:34, Luc Van Oostenryck wrote: > > From: Uwe Kleine-König <uwe@xxxxxxxxxxxxxxxxx> > > > > Debian build scripts pass CFLAGS in the environment. > > However, this is ignored by Sparse's Makefile since 'CFLAGS' > > is unconditionaly initialized. > > > > Fix this by initializing CFLAGS to their default value using '?='. > > Do the same for PKG_CONFIG, CHECKER, CHECKER_FLAGS and > > DESTDIR, BINDIR, MANDIR & MAN1DIR. > > > > Note: It's useless to try to do the same for CC, LD & AR since > > they're builtin variables so '?= ...' is a no-op for them > > (unless make is called with -R). > > BTW, I have seen (a long time ago) an ugly hack to try and > get around this 'special behaviour' of the variables from > make's built-in database. It is very ugly, ... Yes, for a few seconds I considered using $(origin) after having realized that "CC ?= gcc" was useless but indeed, it's very ugly. > Suppose you wanted to set 'CC ?= gcc' in the Makefile, but > because CC is 'special', you don't get the 'use the value > from the environment if set, else default to this value'. It seemed logical to allow CC, LD & AR to be configurable from the environment, like CFLAGS is now. But it's already possible to do it via the command line (and personnaly, I always do this via a local config file like local.mk). > $ make CC=cmd fred > make: cmd: Command not found > Makefile:128: Your system does not have libxml, disabling c2xml > Makefile:150: Your system does not have gtk3/gtk2, disabling test-inspect > Makefile:183: Your system does not have llvm, disabling sparse-llvm > CC is cmd, origin: command line > $ > > $ CC=env make fred > env: unrecognised option '--print-file-name=' > Try 'env --help' for more information. > Makefile:128: Your system does not have libxml, disabling c2xml > Makefile:150: Your system does not have gtk3/gtk2, disabling test-inspect > Makefile:183: Your system does not have llvm, disabling sparse-llvm > CC is env, origin: environment > $ > > [Note: the 'make: cmd: Command not found' and similar message > about the 'env' invocation comes from the '$(shell $(CC) ...)' > further down the makefile (see line 100, setting GCC_BASE).] > > Hmm, it may be possible to create a define ... :-P Well, a "2>/dev/null" could be added but I think it's preferable to have these kind of messages. Best regards, -- Luc
