dont fail if cargo not found

Author: Ruohan Yan

chipyard.mk

@@ -14,15 +14,28 @@ CYCLOTRON_RS_SRCS = $(shell find $(CYCLOTRON_SRC_DIR)/src -name "*.rs")
 CYCLOTRON_CARGO_FILES = $(CYCLOTRON_SRC_DIR)/Cargo.toml \
 			$(wildcard $(CYCLOTRON_SRC_DIR)/Cargo.lock)
 
+# detect cargo at parse time
+HAVE_CARGO := $(shell command -v cargo >/dev/null 2>&1 && echo 1 || echo 0)
+
 .PHONY: cyclotron
+ifeq ($(HAVE_CARGO),1)
+
 cyclotron: $(CYCLOTRON_LIB)
 
 $(CYCLOTRON_LIB): $(CYCLOTRON_RS_SRCS) $(CYCLOTRON_CARGO_FILES)
 	cd $(CYCLOTRON_SRC_DIR) && cargo build # --release
 
-EXTRA_SIM_REQS += | $(CYCLOTRON_LIB)
+EXTRA_SIM_REQS    += | $(CYCLOTRON_LIB)
 EXTRA_SIM_LDFLAGS += -L$(CYCLOTRON_BUILD_DIR) -Wl,-rpath,$(CYCLOTRON_BUILD_DIR) -lcyclotron
 
+else
+
+# no cargo: don't try to build or link it
+cyclotron:
+	@echo "cargo not found; skipping cyclotron build/link"
+
+endif
+
 EXT_INCDIRS += \
 	$(base_dir)/generators/radiance/src/main/resources/vsrc/cvfpu/src/common_cells/include \