Only use llvm-config for library selection when building against syst…

…em LLVM. (#30459)

base/Makefile

@@ -200,8 +200,15 @@ endif
 endif # WINNT
 
 symlink_libLLVM: $(build_private_libdir)/libLLVM.dylib
+ifneq ($(USE_SYSTEM_LLVM),0)
+LLVM_CONFIG_HOST_LIBS := $(shell $(LLVM_CONFIG_HOST) --libfiles)
+# HACK: llvm-config doesn't correctly point to shared libs on all platforms
+#       https://github.com/JuliaLang/julia/issues/29981
+else
+LLVM_CONFIG_HOST_LIBS := $(shell $(LLVM_CONFIG_HOST) --libdir)/libLLVM.$(SHLIB_EXT)
+endif
 $(build_private_libdir)/libLLVM.dylib:
-	REALPATH=`$(LLVM_CONFIG_HOST) --libfiles` && \
+	REALPATH=$(LLVM_CONFIG_HOST_LIBS) && \
 	$(call resolve_path,REALPATH) && \
 	[ -e "$$REALPATH" ] && \
 	([ ! -e "$@" ] || rm "$@") && \

src/Makefile

@@ -89,7 +89,17 @@ endif
 PUBLIC_HEADER_TARGETS := $(addprefix $(build_includedir)/julia/,$(notdir $(PUBLIC_HEADERS)) $(UV_HEADERS))
 
 ifeq ($(JULIACODEGEN),LLVM)
+ifneq ($(USE_SYSTEM_LLVM),0)
 LLVMLINK += $(shell $(LLVM_CONFIG_HOST) --ldflags --libs --system-libs)
+# HACK: llvm-config doesn't correctly point to shared libs on all platforms
+#       https://github.com/JuliaLang/julia/issues/29981
+else
+ifneq ($(USE_LLVM_SHLIB),1)
+LLVMLINK += $(shell $(LLVM_CONFIG_HOST) --ldflags) $(shell $(LLVM_CONFIG_HOST) --libs $(LLVM_LIBS)) $(shell $(LLVM_CONFIG_HOST) --ldflags) $(shell $(LLVM_CONFIG_HOST) --system-libs 2> /dev/null)
+else
+LLVMLINK += $(shell $(LLVM_CONFIG_HOST) --ldflags) -lLLVM
+endif
+endif
 ifeq ($(USE_LLVM_SHLIB),1)
 FLAGS += -DLLVM_SHLIB
 endif # USE_LLVM_SHLIB == 1