From e4195e2e120f657353732dd0ad2d16b2b650b75b Mon Sep 17 00:00:00 2001
From: Jonathan Anderson <jonathan@FreeBSD.org>
Date: Tue, 1 Nov 2016 21:27:42 +0000
Subject: [PATCH] Add rules to build LLVM IR binaries and libraries.

Running `make libfoo.ll` or `make libfoo.bc` within a library directory
will now give us an LLVM IR version of the library, and `make foo.full.ll`
or `make foo.full.bc` will give us an IR version of a binary.

As part of this change, we add an LLVM_LINK variable to sys.mk that can be
specified/overridden using an external toolchain.

Reviewed by:	bdrewery, brooks
Approved by:	rwatson (mentor)
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D8388
---
 Makefile.inc1        |  4 ++--
 share/mk/bsd.lib.mk  | 14 +++++++++++++-
 share/mk/bsd.prog.mk | 21 +++++++++++++++++----
 share/mk/sys.mk      |  2 ++
 4 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/Makefile.inc1 b/Makefile.inc1
index 931af3134669..2b00ff1422b8 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -543,8 +543,8 @@ HMAKE+=		PATH=${TMPPATH} METALOG=${METALOG} -DNO_ROOT
 
 CROSSENV+=	CC="${XCC} ${XCFLAGS}" CXX="${XCXX} ${XCXXFLAGS} ${XCFLAGS}" \
 		CPP="${XCPP} ${XCFLAGS}" \
-		AS="${XAS}" AR="${XAR}" LD="${XLD}" NM=${XNM} \
-		OBJCOPY="${XOBJCOPY}" \
+		AS="${XAS}" AR="${XAR}" LD="${XLD}" LLVM_LINK="${XLLVM_LINK}" \
+		NM=${XNM} OBJCOPY="${XOBJCOPY}" \
 		RANLIB=${XRANLIB} STRINGS=${XSTRINGS} \
 		SIZE="${XSIZE}"
 
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
index 0126a020e999..1fab97cf9e8d 100644
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -78,7 +78,7 @@ CTFFLAGS+= -g
 
 # prefer .s to a .c, add .po, remove stuff not used in the BSD libraries
 # .pico used for PIC object files
-.SUFFIXES: .out .o .po .pico .S .asm .s .c .cc .cpp .cxx .C .f .y .l .ln
+.SUFFIXES: .out .o .bc .ll .po .pico .S .asm .s .c .cc .cpp .cxx .C .f .y .l .ln
 
 .if !defined(PICFLAG)
 .if ${MACHINE_CPUARCH} == "sparc64"
@@ -199,6 +199,18 @@ lib${LIB_PRIVATE}${LIB}_p.a: ${POBJS}
 	${RANLIB} ${RANLIBFLAGS} ${.TARGET}
 .endif
 
+.if defined(LLVM_LINK)
+BCOBJS=		${OBJS:.o=.bco} ${STATICOBJS:.o=.bco}
+LLOBJS=		${OBJS:.o=.llo} ${STATICOBJS:.o=.llo}
+CLEANFILES+=	${BCOBJS} ${LLOBJS}
+
+lib${LIB_PRIVATE}${LIB}.bc: ${BCOBJS}
+	${LLVM_LINK} -o ${.TARGET} ${BCOBJS}
+
+lib${LIB_PRIVATE}${LIB}.ll: ${LLOBJS}
+	${LLVM_LINK} -S -o ${.TARGET} ${LLOBJS}
+.endif
+
 .if defined(SHLIB_NAME) || \
     defined(INSTALL_PIC_ARCHIVE) && defined(LIB) && !empty(LIB)
 SOBJS+=		${OBJS:.o=.pico}
diff --git a/share/mk/bsd.prog.mk b/share/mk/bsd.prog.mk
index deb78a3ded89..43cfb1271a5a 100644
--- a/share/mk/bsd.prog.mk
+++ b/share/mk/bsd.prog.mk
@@ -4,7 +4,7 @@
 .include <bsd.init.mk>
 .include <bsd.compiler.mk>
 
-.SUFFIXES: .out .o .c .cc .cpp .cxx .C .m .y .l .ln .s .S .asm
+.SUFFIXES: .out .o .bc .c .cc .cpp .cxx .C .m .y .l .ll .ln .s .S .asm
 
 # XXX The use of COPTS in modern makefiles is discouraged.
 .if defined(COPTS)
@@ -147,6 +147,19 @@ ${PROGNAME}.debug: ${PROG_FULL}
 	${OBJCOPY} --only-keep-debug ${PROG_FULL} ${.TARGET}
 .endif
 
+.if defined(LLVM_LINK)
+# LLVM bitcode / textual IR representations of the program
+BCOBJS=	${OBJS:.o=.bco}
+LLOBJS=	${OBJS:.o=.llo}
+
+${PROG_FULL}.bc: ${BCOBJS}
+	${LLVM_LINK} -o ${.TARGET} ${BCOBJS}
+
+${PROG_FULL}.ll: ${LLOBJS}
+	${LLVM_LINK} -S -o ${.TARGET} ${LLOBJS}
+
+.endif # defined(LLVM_LINK)
+
 .if	${MK_MAN} != "no" && !defined(MAN) && \
 	!defined(MAN1) && !defined(MAN2) && !defined(MAN3) && \
 	!defined(MAN4) && !defined(MAN5) && !defined(MAN6) && \
@@ -166,14 +179,14 @@ all: all-man
 .endif
 
 .if defined(PROG)
-CLEANFILES+= ${PROG}
+CLEANFILES+= ${PROG} ${PROG}.bc ${PROG}.ll
 .if ${MK_DEBUG_FILES} != "no"
-CLEANFILES+=	${PROG_FULL} ${PROGNAME}.debug
+CLEANFILES+= ${PROG_FULL} ${PROG_FULL}.bc ${PROGNAME}.debug ${PROG_FULL}.ll
 .endif
 .endif
 
 .if defined(OBJS)
-CLEANFILES+= ${OBJS}
+CLEANFILES+= ${OBJS} ${BCOBJS} ${LLOBJS}
 .endif
 
 .include <bsd.libnames.mk>
diff --git a/share/mk/sys.mk b/share/mk/sys.mk
index cc4a1feb61bb..2c3743342018 100644
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@@ -231,6 +231,8 @@ LINTLIBFLAGS	?=	-cghapbxu -C ${LIB}
 MAKE		?=	make
 
 .if !defined(%POSIX)
+LLVM_LINK	?=	llvm-link
+
 LORDER		?=	lorder
 
 NM		?=	nm