Don't use the same llvmdeps.rs for every host.

mk/docs.mk

@@ -299,7 +299,8 @@ $(2) += doc/$(1)/index.html
 doc/$(1)/index.html: CFG_COMPILER_HOST_TRIPLE = $(CFG_TARGET)
 doc/$(1)/index.html: $$(LIB_DOC_DEP_$(1)) doc/$(1)/
 	@$$(call E, rustdoc: $$@)
-	$$(Q)$$(RUSTDOC) --cfg dox --cfg stage2 $$<
+	$$(Q)CFG_LLVM_LINKAGE_FILE=$$(LLVM_LINKAGE_PATH_$(CFG_BUILD)) \
+		$$(RUSTDOC) --cfg dox --cfg stage2 $$<
 endef
 
 $(foreach crate,$(DOC_CRATES),$(eval $(call DEF_LIB_DOC,$(crate),DOC_TARGETS)))

mk/llvm.mk

@@ -49,6 +49,12 @@ else
 LLVM_STDCPP_LOCATION_$(1) =
 endif
 
+
+# LLVM linkage:
+LLVM_LINKAGE_PATH_$(1):=$$(abspath $$(RT_OUTPUT_DIR_$(1))/llvmdeps.rs)
+$$(LLVM_LINKAGE_PATH_$(1)): $(S)src/etc/mklldeps.py $$(LLVM_CONFIG_$(1))
+	$(Q)$(CFG_PYTHON) "$$<" "$$@" "$$(LLVM_COMPONENTS)" "$$(CFG_ENABLE_LLVM_STATIC_STDCPP)" \
+		$$(LLVM_CONFIG_$(1))
 endef
 
 $(foreach host,$(CFG_HOST), \
@@ -57,10 +63,14 @@ $(foreach host,$(CFG_HOST), \
 $(foreach host,$(CFG_HOST), \
  $(eval LLVM_CONFIGS := $(LLVM_CONFIGS) $(LLVM_CONFIG_$(host))))
 
-$(S)src/librustc_llvm/llvmdeps.rs: \
-		    $(LLVM_CONFIGS) \
-		    $(S)src/etc/mklldeps.py \
-		    $(MKFILE_DEPS)
-	$(Q)$(CFG_PYTHON) $(S)src/etc/mklldeps.py \
-		"$@" "$(LLVM_COMPONENTS)" "$(CFG_ENABLE_LLVM_STATIC_STDCPP)" \
-		$(LLVM_CONFIGS)
+# This can't be done in target.mk because it's included before this file.
+define LLVM_LINKAGE_DEPS
+$$(TLIB$(1)_T_$(2)_H_$(3))/stamp.rustc_llvm: $$(LLVM_LINKAGE_PATH_$(3))
+endef
+
+$(foreach source,$(CFG_HOST), \
+ $(foreach target,$(CFG_TARGET), \
+  $(eval $(call LLVM_LINKAGE_DEPS,0,$(target),$(source))) \
+  $(eval $(call LLVM_LINKAGE_DEPS,1,$(target),$(source))) \
+  $(eval $(call LLVM_LINKAGE_DEPS,2,$(target),$(source))) \
+  $(eval $(call LLVM_LINKAGE_DEPS,3,$(target),$(source)))))

mk/target.mk

@@ -79,7 +79,8 @@ $$(TLIB$(1)_T_$(2)_H_$(3))/stamp.$(4): \
 	    $$(dir $$@)$$(call CFG_LIB_GLOB_$(2),$(4)))
 	$$(call REMOVE_ALL_OLD_GLOB_MATCHES, \
 	    $$(dir $$@)$$(call CFG_RLIB_GLOB,$(4)))
-	$$(STAGE$(1)_T_$(2)_H_$(3)) \
+	$(Q)CFG_LLVM_LINKAGE_FILE=$$(LLVM_LINKAGE_PATH_$(2)) \
+	    $$(subst @,,$$(STAGE$(1)_T_$(2)_H_$(3))) \
 		$$(RUST_LIB_FLAGS_ST$(1)) \
 		-L "$$(RT_OUTPUT_DIR_$(2))" \
 		-L "$$(LLVM_LIBDIR_$(2))" \
@@ -134,8 +135,6 @@ SNAPSHOT_RUSTC_POST_CLEANUP=$(HBIN0_H_$(CFG_BUILD))/rustc$(X_$(CFG_BUILD))
 
 define TARGET_HOST_RULES
 
-$$(TLIB$(1)_T_$(2)_H_$(3))/stamp.rustc_llvm: $(S)src/librustc_llvm/llvmdeps.rs
-
 $$(TBIN$(1)_T_$(2)_H_$(3))/:
 	mkdir -p $$@
 

src/librustc_llvm/lib.rs

@@ -2214,4 +2214,6 @@ pub unsafe fn static_link_hack_this_sucks() {
 // parts of LLVM that rustllvm depends on aren't thrown away by the linker.
 // Works to the above fix for #15460 to ensure LLVM dependencies that
 // are only used by rustllvm don't get stripped by the linker.
-mod llvmdeps;
+mod llvmdeps {
+    include!(env!("CFG_LLVM_LINKAGE_FILE"))
+}