Add support for MS Azure MQTT

tutorials/mqtt/mqtt-client/Makefile

@@ -1,27 +1,32 @@
-PROG ?= example                   # Program we are building
-DELETE = rm -rf                   # Command to remove files
-OUT ?= -o $(PROG)                 # Compiler argument for output file
-SOURCES = main.c mongoose.c mongoose_mqtt.c packed_fs.c      # Source code files, packed_fs.c contains ca.pem, which contains CA certs for TLS
-CFLAGS = -W -Wall -Wextra -g -I.  # Build options
+REPO_ROOT ?= ../../..
+PROG ?= example
+DELETE = rm -rf
+OUT ?= -o $(PROG)
+CFLAGS = -W -Wall -Wextra -g -I. -I$(REPO_ROOT)
+SOURCES = main.c mongoose_mqtt.c $(REPO_ROOT)/mongoose.c
 
 # Mongoose build options. See https://mongoose.ws/docs/getting-started/build-options/
-CFLAGS_EXTRA ?= -DMG_TLS=MG_TLS_BUILTIN
+CFLAGS_MONGOOSE += -DMG_TLS=MG_TLS_BUILTIN
 CFLAGS_MONGOOSE += -DMG_ENABLE_LINES=1
 
-ifeq ($(OS),Windows_NT)   # Windows settings. Assume MinGW compiler. To use VC: make CC=cl CFLAGS=/MD OUT=/Feprog.exe
-  PROG ?= example.exe           # Use .exe suffix for the binary
-  CC = gcc                      # Use MinGW gcc compiler
-  CFLAGS += -lws2_32            # Link against Winsock library
-  DELETE = cmd /C del /Q /F /S  # Command prompt command to delete files
-  OUT ?= -o $(PROG)             # Build output
-  MAKE += WINDOWS=1 CC=$(CC)
+# This is for Azure - it just cannot Chacha20
+CFLAGS_MONGOOSE += -DMG_ENABLE_CHACHA20=0
+
+# Windows settings. Assume MinGW compiler.
+# To use VS compiler, run: make CC=cl CFLAGS=/MD OUT=/Feprog.exe
+ifeq ($(OS),Windows_NT)
+  PROG ?= example.exe
+  CC = gcc
+  CFLAGS += -lws2_32
+  DELETE = cmd /C del /Q /F /S
+  OUT ?= -o $(PROG)
 endif
 
-all: $(PROG)              # Default target. Build and run program
+all: $(PROG)
 	$(RUN) ./$(PROG) $(ARGS)
 
-$(PROG): $(SOURCES)       # Build program from sources
+$(PROG): $(SOURCES)
 	$(CC) $(SOURCES) $(CFLAGS) $(CFLAGS_MONGOOSE) $(CFLAGS_EXTRA) $(OUT)
 
-clean:                    # Cleanup. Delete built program and all build artifacts
+clean:
 	$(DELETE) $(PROG) *.o *.obj *.exe *.dSYM mbedtls