debian: Include SPIR-V (*.spv) outputs in libclc package

This adds the following to the libclc-12 package:

/usr/lib/clc/spirv64-mesa3d-.spv
/usr/lib/clc/spirv-mesa3d-.spv

Since Debian buster & Ubuntu 18.04 don't have the llvm-spirv package,
they cannot support this feature. Therefore, as suggested by tjaalton,
we make the control Build-Depends for spirv dependencies include
"| hello".

This causes the simple "hello world" package to be installed on these
older distros, which is small and unrelated to llvm. Then, in
debian/rules, we check to see if llvm-spirv is installed.

Note that sbuild must use `--resolve-alternatives` for these older
distributions, or sbuild won't search for the "hello" alternatives in
the Build-Depends.

Signed-off-by: Jordan Justen <jljusten@debian.org>

debian/changelog

@@ -1,7 +1,7 @@
 llvm-toolchain-12 (1:12.0.1-5) unstable; urgency=medium
 
   [ Jordan Justen ]
-  * libclc: Include libclc spir-v outputs (used by Mesa opencl)
+  * Include SPIR-V (*.spv) outputs in libclc package
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Tue, 17 Aug 2021 10:19:22 +0200
 

debian/control

@@ -19,7 +19,9 @@ Build-Depends: debhelper (>= 9.0), cmake, chrpath, texinfo, sharutils,
     ocaml-findlib [amd64 arm64 armhf ppc64el s390x],
     libctypes-ocaml-dev [amd64 arm64 armhf ppc64el s390x],
     dh-exec, dh-ocaml [amd64 arm64 armhf ppc64el s390x],
-    libpfm4-dev [linux-any], python3-setuptools, libz3-dev
+    libpfm4-dev [linux-any], python3-setuptools, libz3-dev,
+    llvm-spirv | hello, spirv-tools | hello
+# "| hello" is for older buster/bionic distros without spirv support
 Build-Conflicts: oprofile, ocaml
 Standards-Version: 4.2.1
 Homepage: https://www.llvm.org/

debian/libclc-X.Y.install.in

@@ -1 +1,2 @@
 usr/lib/clc/*.bc
+#spv usr/lib/clc/*.spv

debian/patches/libclc-llvm-spirv.diff

@@ -0,0 +1,13 @@
+diff --git a/libclc/CMakeLists.txt b/libclc/CMakeLists.txt
+index b8b5ceff086c..5964468358f2 100644
+--- a/libclc/CMakeLists.txt
++++ b/libclc/CMakeLists.txt
+@@ -95,7 +95,7 @@ find_program( LLVM_CLANG clang PATHS ${LLVM_BINDIR} NO_DEFAULT_PATH )
+ find_program( LLVM_AS llvm-as PATHS ${LLVM_BINDIR} NO_DEFAULT_PATH )
+ find_program( LLVM_LINK llvm-link PATHS ${LLVM_BINDIR} NO_DEFAULT_PATH )
+ find_program( LLVM_OPT opt PATHS ${LLVM_BINDIR} NO_DEFAULT_PATH )
+-find_program( LLVM_SPIRV llvm-spirv PATHS ${LLVM_BINDIR} NO_DEFAULT_PATH )
++find_program( LLVM_SPIRV llvm-spirv PATHS ${LLVM_BINDIR})
+ 
+ # Print toolchain
+ message( "clang: ${LLVM_CLANG}" )

debian/patches/series

@@ -144,3 +144,5 @@ lld-use-link-atomic-i386.diff
 D99501-ignore-lto-auto.diff
 scan-build-py-fix-analyze-path.diff
 scan-build-py-fix-default-bin.diff
+
+libclc-llvm-spirv.diff

debian/rules

@@ -132,6 +132,17 @@ else
 	control_vars = '-Vdep:devlibs=libstdc++6-$(GCC_VERSION)-dev'
 endif
 
+ifeq ($(shell which llvm-spirv),)
+LLVM_SPIRV_INSTALLED = no
+else
+LLVM_SPIRV_INSTALLED = yes
+endif
+
+LIBCLC_TARGETS_TO_BUILD="amdgcn--;amdgcn--amdhsa;r600--;nvptx--;nvptx64--;nvptx--nvidiacl;nvptx64--nvidiacl"
+ifeq ($(LLVM_SPIRV_INSTALLED),yes)
+	LIBCLC_TARGETS_TO_BUILD := $(LIBCLC_TARGETS_TO_BUILD)";spirv-mesa3d-;spirv64-mesa3d-"
+endif
+
 # Disabled:
 #  Host compiler does not support '-fuse-ld=lld'
 # USE_LLD_ARCHS := amd64
@@ -361,6 +372,12 @@ preconfigure:
 		fi; \
 	fi
 
+	# Conditionally enable *.spv files. Debian buster and Ubuntu 18.04
+	# don't have llvm-spirv to create the *.spv files.
+	if test "$(LLVM_SPIRV_INSTALLED)" = "yes"; then \
+		sed -i -e "s|#spv\ ||g" debian/libclc-$(LLVM_VERSION).install; \
+	fi
+
 # Override this two targets. They are trying to manage the .in conversion for me
 override_dh_ocamlinit:
 override_dh_ocamlclean:
@@ -541,7 +558,7 @@ debian-libclc-build:
 	-DCMAKE_INSTALL_DATADIR=lib \
 	-DCMAKE_INSTALL_INCLUDEDIR=include \
 	-DLLVM_CONFIG=$(CURDIR)/$(TARGET_BUILD_STAGE2)/bin/llvm-config \
-	-DLIBCLC_TARGETS_TO_BUILD="amdgcn--;amdgcn--amdhsa;r600--;nvptx--;nvptx64--;nvptx--nvidiacl;nvptx64--nvidiacl"; \
+	-DLIBCLC_TARGETS_TO_BUILD=$(LIBCLC_TARGETS_TO_BUILD); \
 	make $(NJOBS) $(VERBOSE)
 	touch $@