From 07bab4417d0e08bed86f48dea6d0c68f496b456c Mon Sep 17 00:00:00 2001
From: Dimitry Andric <dim@FreeBSD.org>
Date: Tue, 3 Nov 2020 19:57:28 +0000
Subject: [PATCH] Add WITH_LLVM_CXXFILT option to install llvm-cxxfilt as
 c++filt

Since elftoolchain's cxxfilt is rather far behind on features, and we
ran into several bugs, add an option to use llvm-cxxfilt as an drop-in
replacement.

It supports the same options as elftoolchain cxxfilt, though it doesn't
have support for old ARM (C++ Annotated Reference Manual, not the CPU)
and GNU v2 manglings. But these are irrelevant in 2020.

Note: as we already compile the required libraries as part of libllvm,
this will not add any significant build time either.

PR:		250702
Reviewed by:	emaste, yuri
Differential Revision: https://reviews.freebsd.org/D27071
MFC after:	2 weeks
---
 share/man/man5/src.conf.5                | 4 +++-
 share/mk/src.opts.mk                     | 1 +
 tools/build/options/WITHOUT_LLVM_CXXFILT | 2 ++
 tools/build/options/WITH_LLVM_CXXFILT    | 2 ++
 usr.bin/Makefile                         | 2 ++
 usr.bin/clang/Makefile                   | 5 ++++-
 usr.bin/clang/llvm-cxxfilt/Makefile      | 7 +++++++
 7 files changed, 21 insertions(+), 2 deletions(-)
 create mode 100644 tools/build/options/WITHOUT_LLVM_CXXFILT
 create mode 100644 tools/build/options/WITH_LLVM_CXXFILT

diff --git a/share/man/man5/src.conf.5 b/share/man/man5/src.conf.5
index 90f6a4886bf5..96224e220c1f 100644
--- a/share/man/man5/src.conf.5
+++ b/share/man/man5/src.conf.5
@@ -1,6 +1,6 @@
 .\" DO NOT EDIT-- this file is @generated by tools/build/options/makeman.
 .\" $FreeBSD$
-.Dd September 15, 2020
+.Dd November 3, 2020
 .Dt SRC.CONF 5
 .Os
 .Sh NAME
@@ -919,6 +919,8 @@ Set to disable debugging assertions in LLVM.
 Set to not build the
 .Xr llvm-cov 1
 tool.
+.It Va WITH_LLVM_CXXFILT
+Install LLVM's llvm-cxxfilt as c++filt, instead of ELF Tool Chain's cxxfilt.
 .It Va WITHOUT_LLVM_TARGET_AARCH64
 Set to not build LLVM target support for AArch64.
 The
diff --git a/share/mk/src.opts.mk b/share/mk/src.opts.mk
index d71b05d3ec99..5601b56165f5 100644
--- a/share/mk/src.opts.mk
+++ b/share/mk/src.opts.mk
@@ -210,6 +210,7 @@ __DEFAULT_NO_OPTIONS = \
     GNU_GREP_COMPAT \
     HESIOD \
     LIBSOFT \
+    LLVM_CXXFILT \
     LOADER_FIREWIRE \
     LOADER_VERBOSE \
     LOADER_VERIEXEC_PASS_MANIFEST \
diff --git a/tools/build/options/WITHOUT_LLVM_CXXFILT b/tools/build/options/WITHOUT_LLVM_CXXFILT
new file mode 100644
index 000000000000..e729f6c4c8e0
--- /dev/null
+++ b/tools/build/options/WITHOUT_LLVM_CXXFILT
@@ -0,0 +1,2 @@
+.\" $FreeBSD$
+Install ELF Tool Chain's cxxfilt as c++filt, instead of LLVM's llvm-cxxfilt.
diff --git a/tools/build/options/WITH_LLVM_CXXFILT b/tools/build/options/WITH_LLVM_CXXFILT
new file mode 100644
index 000000000000..e80c0e9c1f35
--- /dev/null
+++ b/tools/build/options/WITH_LLVM_CXXFILT
@@ -0,0 +1,2 @@
+.\" $FreeBSD$
+Install LLVM's llvm-cxxfilt as c++filt, instead of ELF Tool Chain's cxxfilt.
diff --git a/usr.bin/Makefile b/usr.bin/Makefile
index 85ffce06e496..8ea3b1c2bfe3 100644
--- a/usr.bin/Makefile
+++ b/usr.bin/Makefile
@@ -260,7 +260,9 @@ SUBDIR.${MK_TOOLCHAIN}+=	ar
 SUBDIR.${MK_TOOLCHAIN}+=	c89
 SUBDIR.${MK_TOOLCHAIN}+=	c99
 SUBDIR.${MK_TOOLCHAIN}+=	ctags
+.if ${MK_LLVM_CXXFILT} == "no"
 SUBDIR.${MK_TOOLCHAIN}+=	cxxfilt
+.endif
 SUBDIR.${MK_TOOLCHAIN}+=	objcopy
 SUBDIR.${MK_TOOLCHAIN}+=	file2c
 SUBDIR.${MK_TOOLCHAIN}+=	gprof
diff --git a/usr.bin/clang/Makefile b/usr.bin/clang/Makefile
index 68b3c1537d90..6f5a065b9ae7 100644
--- a/usr.bin/clang/Makefile
+++ b/usr.bin/clang/Makefile
@@ -16,6 +16,10 @@ SUBDIR+=	llvm-nm
 SUBDIR+=	llvm-objdump
 SUBDIR+=	llvm-symbolizer
 
+.if ${MK_CLANG_EXTRAS} != "no" || ${MK_LLVM_CXXFILT} != "no"
+SUBDIR+=	llvm-cxxfilt
+.endif
+
 .if ${MK_CLANG_EXTRAS} != "no"
 SUBDIR+=	bugpoint
 SUBDIR+=	llc
@@ -23,7 +27,6 @@ SUBDIR+=	lli
 SUBDIR+=	llvm-as
 SUBDIR+=	llvm-bcanalyzer
 SUBDIR+=	llvm-cxxdump
-SUBDIR+=	llvm-cxxfilt
 SUBDIR+=	llvm-diff
 SUBDIR+=	llvm-dis
 SUBDIR+=	llvm-dwarfdump
diff --git a/usr.bin/clang/llvm-cxxfilt/Makefile b/usr.bin/clang/llvm-cxxfilt/Makefile
index b5aa8b34b8e2..3b452a1f8e12 100644
--- a/usr.bin/clang/llvm-cxxfilt/Makefile
+++ b/usr.bin/clang/llvm-cxxfilt/Makefile
@@ -1,8 +1,15 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 PROG_CXX=	llvm-cxxfilt
 
 SRCDIR=		llvm/tools/llvm-cxxfilt
 SRCS+=		llvm-cxxfilt.cpp
 
+.if ${MK_LLVM_CXXFILT} != "no"
+LINKS=		${BINDIR}/llvm-cxxfilt ${BINDIR}/c++filt
+MLINKS=		llvm-cxxfilt.1 c++filt.1
+.endif
+
 .include "../llvm.prog.mk"