Revert "FROMLIST: rust: add PROCMACROLDFLAGS"

This reverts commit 5ff498e7bc.

Change-Id: I5ba3348d1cca052c7312489904dcab0c66bf6b45
Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Documentation/kbuild/kbuild.rst

@@ -96,13 +96,6 @@ HOSTRUSTFLAGS
 -------------
 Additional flags to be passed to $(HOSTRUSTC) when building host programs.
 
-PROCMACROLDFLAGS
--------------
-Additional flags to be passed when linking Rust proc macros. Since proc macros
-are loaded by rustc at build time, they must be linked in a way that is
-compatible with the rustc toolchain being used. If unset, it defaults to
-$(HOSTLDFLAGS).
-
 HOSTLDFLAGS
 -----------
 Additional flags to be passed when linking host programs.

Makefile

@@ -483,7 +483,6 @@ KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
 		       -I $(srctree)/scripts/include
 KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
 			-Zallow-features= $(HOSTRUSTFLAGS)
-KBUILD_PROCMACROLDFLAGS := $(or $(PROCMACROLDFLAGS),$(HOSTLDFLAGS))
 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 

rust/Makefile

@@ -336,7 +336,7 @@ quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
       cmd_rustc_procmacro = \
 	$(RUSTC_OR_CLIPPY) $(rust_common_flags) \
 		-Clinker-flavor=gcc -Clinker=$(HOSTCC) \
-		-Clink-args='$(call escsq,$(KBUILD_PROCMACROLDFLAGS))' \
+		-Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
 		--emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \
 		--crate-type proc-macro \
 		--crate-name $(patsubst lib%.so,%,$(notdir $@)) $<