From 8184afea12f67ecd864dbc0f15f228dc1f603b85 Mon Sep 17 00:00:00 2001
From: Steve Karg <steve@kargs.net>
Date: Fri, 25 Aug 2023 15:15:32 -0500
Subject: [PATCH] Chore/make test parallel build limits (#480)

* re-enable parallel build for CMake unit tests, but limited to ncores on supported OSes. Using MAKEFLAGS in .bashrc to set the '-j' flag size causes problem for Makefile build of BACnet library which doesn't tolerate parallel builds.  Using "-j" without limits for CMake of unit tests overwhelms my lesser endowed build machines.

---------

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>
---
 test/Makefile | 47 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/test/Makefile b/test/Makefile
index 6ac6ab53..4a446f42 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -14,17 +14,53 @@ BUILD_DIR=build
 CTEST_OPTIONS := --quiet --output-on-failure
 CTEST_OPTIONS += --output-junit test-results.xml
 
+# determine the compile environment name
+ifeq ($(OS),Windows_NT)
+SYS := $(shell gcc -dumpmachine)
+ifneq (, $(findstring mingw, $(SYS)))
+UNAME_S := MinGW
+else ifneq (, $(findstring cygwin, $(SYS)))
+UNAME_S := Cygwin
+else
+UNAME_S := Windows
+endif
+else
+UNAME_S := $(shell uname -s)
+UNAME_S := $(patsubst BSD%,BSD,$(UNAME_S))
+endif
+
+# unlimited parallel makefile jobs can 
+# overwhelm builders with limited resources
+# set job limits based on number of core processors
+ifeq (${JOBS},)
+  ifeq ($(UNAME_S),Windows)
+    JOBS = "-j %NUMBER_OF_PROCESSORS%"
+  endif
+  ifeq ($(UNAME_S),Linux)
+    JOBS = "-j $(nproc)"
+  endif
+  ifeq ($(UNAME_S),Darwin)
+    JOBS = "-j $(sysctl -n hw.ncpu)"
+  endif
+  ifeq ($(UNAME_S),BSD)
+    JOBS = "-j $(sysctl -n hw.ncpu)"
+  endif
+  ifeq ($(UNAME_S),MinGW)
+    JOBS = "-j"
+  endif
+endif
+
 .PHONY: test
 test:
 	[ -d $(BUILD_DIR) ] || mkdir -p $(BUILD_DIR)
 	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && cmake .. && cd ..
-	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && cmake --build . --clean-first && cd ..
+	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && cmake --build . $(JOBS) --clean-first && cd ..
 	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && ctest $(CTEST_OPTIONS)
 	[ -d $(BUILD_DIR) ] && $(MAKE) -C $(BUILD_DIR) lcov
 
 .PHONY: retest
 retest:
-	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && cmake --build . && cd ..
+	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && cmake --build . $(JOBS) && cd ..
 	[ -d $(BUILD_DIR) ] && cd $(BUILD_DIR) && ctest $(CTEST_OPTIONS)
 	[ -d $(BUILD_DIR) ] && $(MAKE) -C $(BUILD_DIR) lcov
 
@@ -32,6 +68,13 @@ retest:
 report:
 	[ -d $(BUILD_DIR) ] && cat $(BUILD_DIR)/Testing/Temporary/LastTest*.log
 
+.PHONY: env
+env:
+	@echo "Makefile environment variables"
+	@echo "UNAME_S=$(UNAME_S)"
+	@echo "JOBS=$(JOBS)"
+	@echo "BUILD_DIR=$(BUILD_DIR)"
+
 .PHONY: clean
 clean:
 	-rm -rf $(BUILD_DIR)