diff --git a/lib/clang/clang.pre.mk b/lib/clang/clang.pre.mk
--- a/lib/clang/clang.pre.mk
+++ b/lib/clang/clang.pre.mk
@@ -5,3 +5,4 @@
 CLANG_SRCS=	${LLVM_BASE}/clang
 
 CLANG_TBLGEN?=	clang-tblgen
+CLANG_TBLGEN_BIN!= which ${CLANG_TBLGEN}
diff --git a/lib/clang/headers/Makefile b/lib/clang/headers/Makefile
--- a/lib/clang/headers/Makefile
+++ b/lib/clang/headers/Makefile
@@ -214,6 +214,8 @@
 GENINCS+=	riscv_${hdr:H}.h
 .endfor
 
+${GENINCS}: ${CLANG_TBLGEN_BIN}
+
 CLEANFILES=	${GENINCS} ${GENINCS:C/$/.d/}
 
 .include <bsd.prog.mk>
diff --git a/lib/clang/libclang/Makefile b/lib/clang/libclang/Makefile
--- a/lib/clang/libclang/Makefile
+++ b/lib/clang/libclang/Makefile
@@ -1037,13 +1037,6 @@
 	    -o ${.TARGET} ${CLANG_SRCS}/include/clang/Basic/riscv_vector.td
 TGHDRS+=	clang/Basic/riscv_vector_builtin_sema.inc
 
-clang/Driver/Options.inc: ${CLANG_SRCS}/include/clang/Driver/Options.td
-	${LLVM_TBLGEN} -gen-opt-parser-defs \
-	    -I ${LLVM_SRCS}/include -I ${CLANG_SRCS}/include/clang/Driver \
-	    -d ${.TARGET:C/$/.d/} -o ${.TARGET} \
-	    ${CLANG_SRCS}/include/clang/Driver/Options.td
-TGHDRS+=	clang/Driver/Options.inc
-
 clang/Parse/AttrParserStringSwitches.inc: \
 	${CLANG_SRCS}/include/clang/Basic/Attr.td
 	${CLANG_TBLGEN} -gen-clang-attr-parser-string-switches \
@@ -1121,10 +1114,25 @@
 	    ${CLANG_SRCS}/lib/Sema/OpenCLBuiltins.td
 TGHDRS+=	OpenCLBuiltins.inc
 
+${TGHDRS}: ${CLANG_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
 
+clang/Driver/Options.inc: ${CLANG_SRCS}/include/clang/Driver/Options.td
+	${LLVM_TBLGEN} -gen-opt-parser-defs \
+	    -I ${LLVM_SRCS}/include -I ${CLANG_SRCS}/include/clang/Driver \
+	    -d ${.TARGET:C/$/.d/} -o ${.TARGET} \
+	    ${CLANG_SRCS}/include/clang/Driver/Options.td
+LTGHDRS+=	clang/Driver/Options.inc
+
+${LTGHDRS}: ${LLVM_TBLGEN_BIN}
+
+DEPENDFILES+=	${LTGHDRS:C/$/.d/}
+DPSRCS+=	${LTGHDRS}
+CLEANFILES+=	${LTGHDRS} ${LTGHDRS:C/$/.d/}
+
 .include "../clang.build.mk"
 
 INTERNALLIB=
diff --git a/lib/clang/liblldb/Makefile b/lib/clang/liblldb/Makefile
--- a/lib/clang/liblldb/Makefile
+++ b/lib/clang/liblldb/Makefile
@@ -701,6 +701,7 @@
 SRCS+=		Version/Version.cpp
 
 LLDB_TBLGEN?=	lldb-tblgen
+LLDB_TBLGEN_BIN!= which ${LLDB_TBLGEN}
 
 CommandOptions.inc: ${LLDB_SRCS}/source/Commands/Options.td
 	${LLDB_TBLGEN} -gen-lldb-option-defs \
@@ -728,6 +729,8 @@
 TGHDRS+=	${path:T}PropertiesEnum.inc
 .endfor
 
+${TGHDRS}: ${LLDB_TBLGEN_BIN}
+
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
 
diff --git a/lib/clang/libllvm/Makefile b/lib/clang/libllvm/Makefile
--- a/lib/clang/libllvm/Makefile
+++ b/lib/clang/libllvm/Makefile
@@ -2128,6 +2128,8 @@
 TGHDRS+=	X86GenSubtargetInfo.inc
 .endif # MK_LLVM_TARGET_X86
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/lib/clang/llvm.pre.mk b/lib/clang/llvm.pre.mk
--- a/lib/clang/llvm.pre.mk
+++ b/lib/clang/llvm.pre.mk
@@ -5,3 +5,4 @@
 LLVM_SRCS=	${LLVM_BASE}/llvm
 
 LLVM_TBLGEN?=	llvm-tblgen
+LLVM_TBLGEN_BIN!= which ${LLVM_TBLGEN}
diff --git a/usr.bin/clang/lld/Makefile b/usr.bin/clang/lld/Makefile
--- a/usr.bin/clang/lld/Makefile
+++ b/usr.bin/clang/lld/Makefile
@@ -95,6 +95,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/lldb-server/Makefile b/usr.bin/clang/lldb-server/Makefile
--- a/usr.bin/clang/lldb-server/Makefile
+++ b/usr.bin/clang/lldb-server/Makefile
@@ -37,6 +37,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/lldb/Makefile b/usr.bin/clang/lldb/Makefile
--- a/usr.bin/clang/lldb/Makefile
+++ b/usr.bin/clang/lldb/Makefile
@@ -30,6 +30,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-cxxfilt/Makefile b/usr.bin/clang/llvm-cxxfilt/Makefile
--- a/usr.bin/clang/llvm-cxxfilt/Makefile
+++ b/usr.bin/clang/llvm-cxxfilt/Makefile
@@ -21,6 +21,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-dwarfutil/Makefile b/usr.bin/clang/llvm-dwarfutil/Makefile
--- a/usr.bin/clang/llvm-dwarfutil/Makefile
+++ b/usr.bin/clang/llvm-dwarfutil/Makefile
@@ -18,6 +18,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-nm/Makefile b/usr.bin/clang/llvm-nm/Makefile
--- a/usr.bin/clang/llvm-nm/Makefile
+++ b/usr.bin/clang/llvm-nm/Makefile
@@ -19,6 +19,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-objcopy/Makefile b/usr.bin/clang/llvm-objcopy/Makefile
--- a/usr.bin/clang/llvm-objcopy/Makefile
+++ b/usr.bin/clang/llvm-objcopy/Makefile
@@ -23,6 +23,8 @@
 TGHDRS+=	${hdr}.inc
 .endfor
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-objdump/Makefile b/usr.bin/clang/llvm-objdump/Makefile
--- a/usr.bin/clang/llvm-objdump/Makefile
+++ b/usr.bin/clang/llvm-objdump/Makefile
@@ -26,6 +26,8 @@
 TGHDRS+=	${hdr}.inc
 .endfor
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-readobj/Makefile b/usr.bin/clang/llvm-readobj/Makefile
--- a/usr.bin/clang/llvm-readobj/Makefile
+++ b/usr.bin/clang/llvm-readobj/Makefile
@@ -30,6 +30,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-size/Makefile b/usr.bin/clang/llvm-size/Makefile
--- a/usr.bin/clang/llvm-size/Makefile
+++ b/usr.bin/clang/llvm-size/Makefile
@@ -19,6 +19,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-strings/Makefile b/usr.bin/clang/llvm-strings/Makefile
--- a/usr.bin/clang/llvm-strings/Makefile
+++ b/usr.bin/clang/llvm-strings/Makefile
@@ -17,6 +17,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}
diff --git a/usr.bin/clang/llvm-symbolizer/Makefile b/usr.bin/clang/llvm-symbolizer/Makefile
--- a/usr.bin/clang/llvm-symbolizer/Makefile
+++ b/usr.bin/clang/llvm-symbolizer/Makefile
@@ -20,6 +20,8 @@
 	    -o ${.TARGET} ${TDFILE}
 TGHDRS+=	${INCFILE}
 
+${TGHDRS}: ${LLVM_TBLGEN_BIN}
+
 DEPENDFILES+=	${TGHDRS:C/$/.d/}
 DPSRCS+=	${TGHDRS}
 CLEANFILES+=	${TGHDRS} ${TGHDRS:C/$/.d/}