On 03.12.2019 12:04, Roger Pau Monné wrote: > On Tue, Dec 03, 2019 at 11:03:31AM +0100, Jan Beulich wrote: >> Furthermore I think this moving around of logic (which imo >> would better remain at the bottom of the file, well out of >> sight) is only the second best solution to the issue. The >> reason I didn't notice the breakage was because I had noticed >> what made me create the patch in question only while putting >> together a change moving out the majority of the as-option-add >> invocations, primarily with the goal of not having the >> compiler invoked over and over just to calculate CFLAGS. I >> didn't post this change yet simply because I wanted to give it >> some more (local) testing. > > Looks like an improvement, but how do you plan to achieve the same? > > Are there some compiler/assembler hints available at build time about > which features are supported?
No, I'm changing the mechanism altogether. The various HAVE_AS_* will be put in a generated header file instead. Its generation (obviously) happens with CFLAGS already in final shape. >> Another reason to keep this at the bottom of the file is that >> other CFLAGS additions wouldn't have happened yet at the >> place the checks live now. > > Right, but it's unlikely that CFLAGS can influence whether the > internal assembler is capable of building Xen or not, while it's IMO > more likely that using the internal or an external assembler can lead > to a different set of CFLAGS (as CFLAGS also include options that > affect the assembler). For simple checks against insns being known I agree. But already something like # Set up the assembler include path properly for older toolchains. CFLAGS += -Wa,-I$(BASEDIR)/include could make a difference, if a more complex check involved including some other file. Jan _______________________________________________ Xen-devel mailing list Xenemail@example.com https://lists.xenproject.org/mailman/listinfo/xen-devel