Generate a minimal llvm2ice.

Makefile.standalone

 # The following variables will likely need to be modified, depending on where
 # and how you built LLVM & Clang. They can be overridden in a command-line
 # invocation of make, like:
 #
 #   make LLVM_SRC_PATH=<path> LLVM_BIN_PATH=<path> \
 #        LIBCXX_INSTALL_PATH=<path> CLANG_PATH=<path> ...
 #
 
 # LLVM_SRC_PATH is the path to the root of the checked out source code. This
 # directory should contain the configure script, the include/ and lib/
@@ skipping 82 matching lines @@
         IceTargetLoweringX8632.cpp \
         IceTimerTree.cpp \
         IceTranslator.cpp \
         IceTypeConverter.cpp \
         IceTypes.cpp \
         llvm2ice.cpp \
         PNaClTranslator.cpp
 
 OBJS=$(patsubst %.cpp, $(OBJDIR)/%.o, $(SRCS))
 
+
+MINOBJDIR=$(OBJDIR)/min
+
+MINOBJS=$(patsubst %.cpp, $(MINOBJDIR)/%.o, $(SRCS))
+
+MIN_CXXFLAGS = -DBUILD_MIN_LLVM

[Jim Stichnoth, 2014/10/13 16:03:58]

LLVM?

Maybe something like SZ_MINIMAL?

[jvoung (off chromium), 2014/10/13 17:05:08]

SHAVED_ICE

just kidding

[Karl, 2014/10/14 22:54:12]

Done.

+
 # Keep all the first target so it's the default.
-all: $(OBJDIR)/llvm2ice make_symlink
+all: $(OBJDIR)/llvm2ice $(MINOBJDIR)/llvm2ice make_symlink
 
-make_symlink: $(OBJDIR)/llvm2ice
+make_symlink: $(OBJDIR)/llvm2ice $(MINOBJDIR)/llvm2ice

[Jim Stichnoth, 2014/10/13 16:03:58]

I'm not thrilled about the build time doubling.  What do you think about
something like this?

- Set OBJDIR, OPTLEVEL, ASSERTIONS, etc. to something appropriate when MINIMAL
is defined.

- Change run-llvm2ice.py to be able to run FileCheck as part of its execution.

- Change the lit RUN lines accordingly.

- In run-llvm2ice.py, probe the llvm2ice binary and if it is a minimal build
that doesn't support requirements of the test (such as using IceConverter), just
return success without running llvm2ice+FileCheck.

[jvoung (off chromium), 2014/10/13 17:05:08]

If it helps, lit's llvm/utils/lit/lit/TestRunner.py has a "REQUIRES: ..."
keyword (besides "RUN" and "XFAIL"). E.g., "REQUIRES: asserts" and "REQUIRES:
fma3".

I'm not sure exactly how that works, but I think it checks a config file which
could be generated. I think it's similar to how they support per-arch
directories which require the particular backend to be configured-in and built.

[Karl, 2014/10/14 22:54:12]

Made code dependent of command-line flag: "MINIMAL=t".

Also modified so that we now generate llvm2ice.build_atts holding the
corresponding build flags used to build llvm2ice. Added two concepts:

1) The REQUIRES lines to assert that defines when the lit test should be run.
and
2) A conditional %ifX command prefix to only run commands if the corresponding
built attributes are defined. In this case, the lit file  should contain tests
for multiple builds that use the same input. Tests that don't meet the build
conditions quietly succeed by doing nothing.
 

         rm -f llvm2ice
         ln -s $(OBJDIR)/llvm2ice
+        rm -f minllvm2ice
+        ln -s $(MINOBJDIR)/llvm2ice minllvm2ice
 
 .PHONY: all make_symlink
 
 $(OBJDIR)/llvm2ice: $(OBJS)
         $(CXX) $(LDFLAGS) -o $@ $^ $(LLVM_LDFLAGS) -ldl \
                -Wl,-rpath=$(abspath $(LIBCXX_INSTALL_PATH)/lib)
 
 # TODO: Be more precise than "*.h" here and elsewhere.
 $(OBJS): $(OBJDIR)/%.o: src/%.cpp src/*.h src/*.def
         $(CXX) -c $(CXXFLAGS) $< -o $@
 
 $(OBJS): | $(OBJDIR)
 
 $(OBJDIR):
         @mkdir -p $@
 
+$(MINOBJDIR)/llvm2ice: $(MINOBJS)
+        $(CXX) $(MIN_CXXFLAGS) $(LDFLAGS) -o $@ $^ $(LLVM_LDFLAGS) -ldl \
+               -Wl,-rpath=$(abspath $(LIBCXX_INSTALL_PATH)/lib)
+
+$(MINOBJS): $(MINOBJDIR)/%.o: src/%.cpp src/*.h src/*.def
+        $(CXX) -c $(MIN_CXXFLAGS) $(CXXFLAGS) $< -o $@
+
+$(MINOBJS): | $(MINOBJDIR)
+
+$(MINOBJDIR): $(OBJDIR)
+        @mkdir -p $@
+
 check-lit: llvm2ice make_symlink
         LLVM_BIN_PATH=$(LLVM_BIN_PATH) \
         $(LLVM_SRC_PATH)/utils/lit/lit.py -sv tests_lit
 
 check: check-lit
         (cd crosstest; ./runtests.sh)
 
 # TODO: Fix the use of wildcards.
 # Assumes clang-format is within $PATH.
 format:
         clang-format -style=LLVM -i src/*.h src/*.cpp
 
 # Assumes clang-format-diff.py is within $PATH, and that the
 # clang-format it calls is also within $PATH.  This may require adding
 # a component to $PATH, or creating symlinks within some existing
 # $PATH component.  Uses the one in /usr/lib/clang-format/ if it
 # exists.
 ifeq (,$(wildcard /usr/lib/clang-format/clang-format-diff.py))
   CLANG_FORMAT_DIFF = clang-format-diff.py
 else
   CLANG_FORMAT_DIFF = /usr/lib/clang-format/clang-format-diff.py
 endif
 format-diff:
         git diff -U0 `git merge-base HEAD master` | \
         $(CLANG_FORMAT_DIFF) -p1 -style=LLVM -i
 
 clean:
-        rm -rf llvm2ice *.o build/
+        rm -rf llvm2ice minllvm2ice *.o build/