Bug 1747298 - Use CXX for Cargo linking when necessary. r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D135219

build/cargo-linker

@@ -17,6 +17,22 @@
 #   and not quoting it ensures that each of those arguments is passed
 #   as a separate argument to the actual LD.
 #
+# * In rare cases, we also need MOZ_CARGO_WRAP_LD_CXX, which is the
+#   equivalent of CXX, when linking C++ code. Usually, this should
+#   simply work by the use of CC and -lstdc++ (added by cc-rs).
+#   However, in the case of sanitizer runtimes, there is a separate
+#   runtime for C and C++ and linking C++ code with the C runtime can
+#   fail if the requested feature is in the C++ runtime only (bug 1747298).
+#
 # $@ is doubly quoted for the eval. See bug 1418598.
 
-eval ${MOZ_CARGO_WRAP_LD} ${MOZ_CARGO_WRAP_LDFLAGS} '"$@"'
+WRAP_LD=${MOZ_CARGO_WRAP_LD}
+for opt; do
+  case "$opt" in
+  -lc++|-lstdc++)
+    WRAP_LD=${MOZ_CARGO_WRAP_LD_CXX};
+    break;
+    ;;
+  esac
+done
+eval ${WRAP_LD} ${MOZ_CARGO_WRAP_LDFLAGS} '"$@"'

config/makefiles/rust.mk

@@ -318,8 +318,10 @@ cargo_linker_env_var := CARGO_TARGET_$(call varize,$(RUST_TARGET))_LINKER
 
 export MOZ_CARGO_WRAP_LDFLAGS
 export MOZ_CARGO_WRAP_LD
+export MOZ_CARGO_WRAP_LD_CXX
 export MOZ_CARGO_WRAP_HOST_LDFLAGS
 export MOZ_CARGO_WRAP_HOST_LD
+export MOZ_CARGO_WRAP_HOST_LD_CXX
 # Exporting from make always exports a value. Setting a value per-recipe
 # would export an empty value for the host recipes. When not doing a
 # cross-compile, the --target for those is the same, and cargo will use
@@ -382,16 +384,22 @@ $(TARGET_RECIPES) $(HOST_RECIPES): MOZ_CARGO_WRAP_HOST_LDFLAGS:=$(HOST_LDFLAGS)
 
 ifeq (,$(filter clang-cl,$(CC_TYPE)))
 $(TARGET_RECIPES): MOZ_CARGO_WRAP_LD:=$(CC)
+$(TARGET_RECIPES): MOZ_CARGO_WRAP_LD_CXX:=$(CXX)
 else
 $(TARGET_RECIPES): MOZ_CARGO_WRAP_LD:=$(LINKER)
+$(TARGET_RECIPES): MOZ_CARGO_WRAP_LD_CXX:=$(LINKER)
 endif
 
 ifeq (,$(filter clang-cl,$(HOST_CC_TYPE)))
 $(HOST_RECIPES): MOZ_CARGO_WRAP_LD:=$(HOST_CC)
+$(HOST_RECIPES): MOZ_CARGO_WRAP_LD_CXX:=$(HOST_CXX)
 $(TARGET_RECIPES) $(HOST_RECIPES): MOZ_CARGO_WRAP_HOST_LD:=$(HOST_CC)
+$(TARGET_RECIPES) $(HOST_RECIPES): MOZ_CARGO_WRAP_HOST_LD_CXX:=$(HOST_CXX)
 else
 $(HOST_RECIPES): MOZ_CARGO_WRAP_LD:=$(HOST_LINKER)
+$(HOST_RECIPES): MOZ_CARGO_WRAP_LD_CXX:=$(HOST_LINKER)
 $(TARGET_RECIPES) $(HOST_RECIPES): MOZ_CARGO_WRAP_HOST_LD:=$(HOST_LINKER)
+$(TARGET_RECIPES) $(HOST_RECIPES): MOZ_CARGO_WRAP_HOST_LD_CXX:=$(HOST_LINKER)
 endif
 
 ifdef RUST_LIBRARY_FILE

taskcluster/scripts/misc/wr-macos-cross-build-setup.sh

@@ -55,5 +55,6 @@ export AR="${CLANGDIR}/bin/llvm-ar"
 # the right arguments to the linker when invoked by cargo is nigh impossible
 # without this.
 export MOZ_CARGO_WRAP_LD="${CC}"
+export MOZ_CARGO_WRAP_LD_CXX="${CXX}"
 export MOZ_CARGO_WRAP_LDFLAGS="${TARGET_CFLAGS}"
 export CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="${GECKO_PATH}/build/cargo-linker"