clang: install clang-scan-deps

clang-scan-deps is used to generate dependency information from C++20
modules according to proposed standard ISO/IEC WG21 P1689R5[0].  It is
required by common build tools (e.g., CMake) to build C++ sources
that use modules.

Since this is a core build tool, install it by default, not gated
behind MK_CLANG_EXTRAS.

[0] https://www.open-std.org/JTC1/SC22/WG21/docs/papers/2022/p1689r5.html

MFC after:	3 days
Reviewed by:	kevans, dim
Approved by:	kevans (mentor)
Requested by:	jbo
Differential Revision:	https://reviews.freebsd.org/D51044

lib/clang/libclang/Makefile

@@ -841,6 +841,11 @@ SRCS_MIN+=	Tooling/ArgumentsAdjusters.cpp
 SRCS_MIN+=	Tooling/CommonOptionsParser.cpp
 SRCS_MIN+=	Tooling/CompilationDatabase.cpp
 SRCS_MIN+=	Tooling/Core/Replacement.cpp
+SRCS_MIN+=	Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+SRCS_MIN+=	Tooling/DependencyScanning/DependencyScanningService.cpp
+SRCS_MIN+=	Tooling/DependencyScanning/DependencyScanningTool.cpp
+SRCS_MIN+=	Tooling/DependencyScanning/DependencyScanningWorker.cpp
+SRCS_MIN+=	Tooling/DependencyScanning/ModuleDepCollector.cpp
 SRCS_MIN+=	Tooling/ExpandResponseFilesCompilationDatabase.cpp
 SRCS_MIN+=	Tooling/FileMatchTrie.cpp
 SRCS_MIN+=	Tooling/GuessTargetAndModeCompilationDatabase.cpp
@@ -848,6 +853,7 @@ SRCS_MIN+=	Tooling/Inclusions/HeaderIncludes.cpp
 SRCS_MIN+=	Tooling/Inclusions/IncludeStyle.cpp
 SRCS_MIN+=	Tooling/InterpolatingCompilationDatabase.cpp
 SRCS_MIN+=	Tooling/JSONCompilationDatabase.cpp
+SRCS_MIN+=	Tooling/LocateToolCompilationDatabase.cpp
 SRCS_MIN+=	Tooling/Refactoring.cpp
 SRCS_MIN+=	Tooling/RefactoringCallbacks.cpp
 SRCS_MIN+=	Tooling/Tooling.cpp

usr.bin/clang/Makefile

@@ -5,6 +5,10 @@ SUBDIR+=	clang
 .endif
 
 .if !defined(TOOLS_PREFIX)
+.if ${MK_CLANG} != "no"
+SUBDIR+=	clang-scan-deps
+.endif
+
 # LLVM binutils are needed to support features such as LTO, so we build them
 # by default if clang is enabled. If MK_LLVM_BINUTILS is set, we also use them
 # as the default binutils (ar,nm,addr2line, etc.).

usr.bin/clang/clang-scan-deps/Makefile

@@ -0,0 +1,26 @@
+.include <src.opts.mk>
+
+PROG_CXX=	clang-scan-deps
+MAN=
+
+SRCDIR=		clang/tools/clang-scan-deps
+SRCS+=		ClangScanDeps.cpp \
+		clang-scan-deps-driver.cpp
+
+.include "${SRCTOP}/lib/clang/clang.pre.mk"
+
+CFLAGS+=	-I${.OBJDIR}
+TDFILE=		Opts.td
+INCFILE=	${TDFILE:.td=.inc}
+GENOPT=		-gen-opt-parser-defs
+
+${INCFILE}: ${TDFILE}
+	${LLVM_TBLGEN} ${GENOPT} -I ${LLVM_SRCS}/include -d ${.TARGET:C/$/.d/} \
+	    -o ${.TARGET} ${.ALLSRC}
+TGHDRS+=	${INCFILE}
+
+DEPENDFILES+=	${TGHDRS:C/$/.d/}
+DPSRCS+=	${TGHDRS}
+CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
+
+.include "../clang.prog.mk"

usr.bin/clang/clang-scan-deps/clang-scan-deps-driver.cpp

@@ -0,0 +1,18 @@
+//===-- driver-template.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/LLVMDriver.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Support/InitLLVM.h"
+
+int clang_scan_deps_main(int argc, char **, const llvm::ToolContext &);
+
+int main(int argc, char **argv) {
+  llvm::InitLLVM X(argc, argv);
+  return clang_scan_deps_main(argc, argv, {argv[0], nullptr, false});
+}