vk/glsl_scraper: Don't open files until needed

This prevents us from writing an empty file when the compile failed.

diff --git a/src/vulkan/glsl_scraper.py b/src/vulkan/glsl_scraper.py
index 4b99ae0a3e2b17290bc1c638f3d774d0d7e5ee9b..fa62daf5a2b629c1e9da733e5bbfa58fd36645cc 100644 (file)
--- a/src/vulkan/glsl_scraper.py
+++ b/src/vulkan/glsl_scraper.py
@@ -186,8 +186,8 @@ def open_file(name, mode):
    else:
       return open(name, mode)
 
-infile = None
-outfile = sys.stdout
+infname = None
+outfname = '-'
 glslang = 'glslangValidator'
 
 arg_idx = 1
@@ -196,19 +196,20 @@ while arg_idx < len(sys.argv):
       print_usage(0)
    elif sys.argv[arg_idx] == '-o':
       arg_idx += 1
-      outfile = open_file(sys.argv[arg_idx], 'w')
+      outfname = sys.argv[arg_idx]
    elif sys.argv[arg_idx].startswith('--with-glslang='):
       glslang = sys.argv[arg_idx][len('--with-glslang='):]
    else:
-      infile = open_file(sys.argv[arg_idx], 'r')
+      infname = sys.argv[arg_idx]
       break
    arg_idx += 1
 
-if arg_idx < len(sys.argv) - 1 or not infile or not outfile:
+if arg_idx < len(sys.argv) - 1 or not infname or not outfname:
    print_usage(1)
 
-parser = Parser(infile)
-parser.run()
+with open_file(infname, 'r') as infile:
+   parser = Parser(infile)
+   parser.run()
 
 # glslangValidator has an absolutely *insane* interface.  We pretty much
 # have to run in a temporary directory.  Sad day.
@@ -225,12 +226,13 @@ try:
 finally:
    shutil.rmtree(tmpdir)
 
-outfile.write("""\
+with open_file(outfname, 'w') as outfile:
+   outfile.write("""\
 /* ===========================  DO NOT EDIT!  ===========================
  *            This file is autogenerated by glsl_scraper.py.
  */
 
 #include <stdint.h>""")
 
-for shader in parser.shaders:
-   shader.dump_c_code(outfile)
+   for shader in parser.shaders:
+      shader.dump_c_code(outfile)