improved build time by having Python generated code preserve it's modification date when it's content isn't changing

Makefile

@@ -295,8 +295,8 @@ src/conf_templates.c: tbl
 tbl:
 	@echo Generating tables
 	@$(PYTHON) tools/create_hal_tbl.py . $(COMPS)
-	@$(PYTHON) tools/create_config.py conf/template/* > src/conf_templates.c
-	@$(PYTHON) tools/create_cmd.py $(SOURCES) > inc/commandslist.h
+	@$(PYTHON) tools/create_config.py src/conf_templates.c conf/template/*
+	@$(PYTHON) tools/create_cmd.py inc/commandslist.h $(SOURCES)
 
 #build f4 bootloader
 boot:

stm32f303/Makefile

@@ -201,7 +201,7 @@ tbl:
 	@echo Generating tables
 	@$(PYTHON) tools/create_hal_tbl.py stm32f303/ $(COMPS)
 	#shared/comps/*.c src/comps/hw/*.c src/comps/*.c
-	@$(PYTHON) tools/create_cmd.py $(SOURCES) > stm32f303/inc/commandslist.h
+	@$(PYTHON) tools/create_cmd.py stm32f303/inc/commandslist.h $(SOURCES)
 
 # Target: clean project
 #

tools/create_cmd.py

@@ -1,24 +1,29 @@
 #!/usr/bin/env python
 import re
 import sys
+import file_updater
 
 cmd = []
 
-for infile in sys.argv[1:]:
+for infile in sys.argv[2:]:
     with open(infile) as f:
         for line_number, line in enumerate(f):
             match = re.search('COMMAND\("(\w*)", *(\w*), *"([^"]*)"\);', line)
             if match:
                 cmd.append((match.groups(), infile, line_number))
 
-print ("//generated by " + sys.argv[0] + " DO NOT EDIT")
+header = file_updater.FileUpdater(sys.argv[1])
+
+header.write("//generated by " + sys.argv[0] + " DO NOT EDIT\n")
 
 for (name, ptr, doc), file_name, line_number in cmd:
-    print ("extern void " + ptr + "(char *); // found in " + file_name + " line: " + str(line_number + 1))
+    header.write("extern void " + ptr + "(char *); // found in " + file_name + " line: " + str(line_number + 1) + "\n")
 
-print ("\n")
+header.write("\n\n")
 
-print ("cmd_t cmd[] = {")
+header.write("cmd_t cmd[] = {\n")
 for (name, ptr, doc), file_name, line_number in cmd:
-    print ("   {\"" + name + "\", \"" + doc + "\", " + ptr + "}, // found in " + file_name + " line: " + str(line_number + 1))
-print ("};")
+    header.write("   {\"" + name + "\", \"" + doc + "\", " + ptr + "}, // found in " + file_name + " line: " + str(line_number + 1) + "\n")
+header.write("};\n")
+
+header.close()

tools/create_config.py

@@ -2,24 +2,29 @@
 import re
 import sys
 import os
+import file_updater
 
 config = []
 
-for infile in sys.argv[1:]:
+for infile in sys.argv[2:]:
     with open(infile) as f:
         config.append((os.path.splitext(os.path.basename(infile))[0], f.read()))
 
-print ("//generated by " + sys.argv[0] + " DO NOT EDIT\n")
-print ("#include \"config.h\"\n")
-print ("const uint32_t num_of_config_templates = " + str(len(config)) + ";\n")
+code = file_updater.FileUpdater(sys.argv[1])
 
-print ("config_template_t config_templates[] = {")
+code.write("//generated by " + sys.argv[0] + " DO NOT EDIT\n\n")
+code.write("#include \"config.h\"\n\n")
+code.write("const uint32_t num_of_config_templates = " + str(len(config)) + ";\n\n")
+
+code.write("config_template_t config_templates[] = {\n")
 
 for index, (file_name, content) in enumerate(config):
-    print ("{")
-    print (".name = \"" + file_name + "\",")
-    print (".config = \"\\")
+    code.write("{\n")
+    code.write(".name = \"" + file_name + "\",\n")
+    code.write(".config = \"\\\n")
     for line in content.splitlines():
-        print (line + "\\n\\")
-    print ("\"\n},\n")
-print ("};")
+        code.write(line + "\\n\\\n")
+    code.write("\"\n},\n\n")
+code.write("};\n")
+
+code.close()

tools/create_hal_tbl.py

@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 import re
 import sys
+import file_updater
 
 comps = []
 
-header = open(sys.argv[1] + '/inc/hal_tbl.h', 'w')
-code = open(sys.argv[1] + '/src/hal_tbl.c', 'w')
+header = file_updater.FileUpdater(sys.argv[1] + '/inc/hal_tbl.h')
+code   = file_updater.FileUpdater(sys.argv[1] + '/src/hal_tbl.c')
 
 for infile in sys.argv[2:]:
     with open(infile) as f:
@@ -65,7 +66,7 @@ for comp_name, pins, file_name in comps:
     header.write("extern const hal_comp_t " + comp_name + "_comp_struct; // found in " + file_name + "\n")
 
 
-code.write("#include \"hal.h\"\n")
+code.write("#include \"hal.h\"\n\n")
 code.write("//generated by " + sys.argv[0] + " DO NOT EDIT\n\n")
 code.write("const hal_comp_t * comps[] = {\n")
 for comp_name, pins, file_name in comps:

tools/file_updater.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python
+import shutil
+import tempfile
+import filecmp
+
+def copyIfDifferent(src, dst_path):
+    dst = None
+    try:
+        dst = open(dst_path, 'rw+b')
+        src.seek(0)
+        if src.read() == dst.read():
+            return
+        dst.seek(0)
+    except:
+        pass
+    if dst is None:
+        dst = open(dst_path, 'w+b')
+    src.seek(0)
+    shutil.copyfileobj(src, dst)
+
+class FileUpdater:
+    def __init__(self, path):
+        self.filePath = path
+        self.tempFile = tempfile.TemporaryFile(mode='rw+b')
+
+    def __del__(self):
+        if not self.tempFile.closed:
+            self.close()
+
+    def write(self, str):
+        self.tempFile.write(str)
+
+    def close(self):
+        copyIfDifferent(self.tempFile, self.filePath)
+        self.tempFile.close()