Test infra: expose CFLAGS_NO_ARCH for use by test custom build rules

[tfiala]

Summary

The TestUniversal.py test was attempting to build its own CFLAGS unreliably. Essentially it just wanted the prevailing CFLAGS without the arch spec.

This change does the following:

• introduces a new makefile variable CFLAGS_NO_ARCH, which custom build rules can use to grab the prevailing CFLAGS for the build without the arch-specific flags, and
• uses this new flag in TestUniversal.py's Makefile, eliminating the divergence it had from the CFLAGS used for standard test inferiors.

[labath]

I am not that excited by this, but I don't see a much better way to achieve the result. :)
Possibly I'd consider making the variable name positive (instead of CFLAGS_NO_DEBUG, have a INCLUDES var, and then the test can use $(INCLUDES) $(TRIPLE_CFLAGS)).

Python/lldbsuite/test/make/Makefile.rules

197

Are you sure this won't actually be missed on darwin for other tests? -archi386 does not seem to be a valid argument to clang (you need the space here).

[tfiala]

I am not that excited by this, but I don't see a much better way to achieve the result. :)
Possibly I'd consider making the variable name positive (instead of CFLAGS_NO_DEBUG, have a INCLUDES var, and then the test can use $(INCLUDES) $(TRIPLE_CFLAGS)).

Jim and I tried a few different ways to skin this. The actual problem shows up on some CI downstream from here, where we need (but fail to get) the isysroot settings. Those are built with a few more variables that have not yet moved up into the Makefile rules in LLVM.org.

The other way to skin this, since it is a macOS only test, is to strip out the arch flags in the TestUniversal Makefile. This approach would work both here and downstream since it doesn't require accessing Makefile variables that don't exist here.

I'll come back with something slightly different here.

Python/lldbsuite/test/make/Makefile.rules

197

Hmm I ran it through x86_64 and that worked. I didn't try i386. I'll give that a shot. If it blows up, I'll have a look at why a space is needed in one case and not the other on the macOS clang. Thanks for highlighting. (It looked like a meaningless divergence that I thought perhaps came from code motion over time).

[tfiala]

@jingham, there may be some reconciliation needed between here and swift-lldb.

I'm bowing out of this one.

Python/lldbsuite/test/macosx/universal/Makefile

 CC ?= clang
 
+all: testit
+
+LEVEL = ../../make
+
+C_SOURCES := main.c
+
+include $(LEVEL)/Makefile.rules
+
+
 testit: testit.i386 testit.x86_64
   lipo -create -o testit testit.i386 testit.x86_64
 
 testit.i386: testit.i386.o
   $(CC) -arch i386 -o testit.i386 testit.i386.o
 
 testit.x86_64: testit.x86_64.o
   $(CC) -arch x86_64 -o testit.x86_64 testit.x86_64.o
 
 testit.i386.o: main.c
-  $(CC) -g -O0 -arch i386 -c -o testit.i386.o main.c
+  $(CC) $(CFLAGS_NO_ARCH) -arch i386 -c -o testit.i386.o main.c
 
 testit.x86_64.o: main.c
-  $(CC) -g -O0 -arch x86_64 -c -o testit.x86_64.o main.c
+  $(CC) $(CFLAGS_NO_ARCH) -arch x86_64 -c -o testit.x86_64.o main.c
 
-clean:
+clean::
   rm -rf $(wildcard testit* *~)

Python/lldbsuite/test/make/Makefile.rules

ifneq (,$(findstring clang,$(CC)))
    LIMIT_DEBUG_INFO_FLAGS += -flimit-debug-info
    NO_LIMIT_DEBUG_INFO_FLAGS += -fno-limit-debug-info
    MODULE_DEBUG_INFO_FLAGS += -gmodules
 endif
 
 DEBUG_INFO_FLAG ?= -g
 
 CFLAGS ?= $(DEBUG_INFO_FLAG) -O0 -fno-builtin
-ifeq "$(OS)" "Darwin"
-  CFLAGS += $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES) $(CFLAGS_EXTRAS) -I$(LLDB_BASE_DIR)include
-else
-  CFLAGS += $(ARCHFLAG)$(ARCH) $(FRAMEWORK_INCLUDES) $(CFLAGS_EXTRAS) -I$(LLDB_BASE_DIR)include
-endif
+CFLAGS += $(FRAMEWORK_INCLUDES) $(CFLAGS_EXTRAS) -I$(LLDB_BASE_DIR)include -include $(THIS_FILE_DIR)test_common.h $(TRIPLE_CFLAGS)
+CFLAGS_NO_ARCH := $(CFLAGS)
 
-CFLAGS += -include $(THIS_FILE_DIR)test_common.h $(TRIPLE_CFLAGS)
+CFLAGS += $(ARCHFLAG)$(ARCH)
 
 # Use this one if you want to build one part of the result without debug information:
 ifeq "$(OS)" "Darwin"
   CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG) $(ARCH) $(FRAMEWORK_INCLUDES) $(CFLAGS_EXTRAS) $(TRIPLE_CFLAGS)
 else
   CFLAGS_NO_DEBUG = -O0 $(ARCHFLAG)$(ARCH) $(FRAMEWORK_INCLUDES) $(CFLAGS_EXTRAS) $(TRIPLE_CFLAGS)
 endif