[llvm] Add text file support for z/OS back in (PR #209259)

[Aiden Grossman via llvm-commits]

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@@ -65,18 +66,32 @@ def run(argv, stdin, stdout, stderr, cwd):
 
     for filename in filenames:
         path = filename
-        contents = None
         if not os.path.isabs(path):
             path = os.path.join(cwd, path)
-        try:
-            with open(path, "rb") as fileToCat:
-                contents = fileToCat.read()
-        except IOError as error:
-            error.filename = filename
-            stderr.write(str(error).encode())
-            return 1
+
+        contents = None
+        is_text = False
+        if platform.system() == "OS/390":
+            try:
+                with open(path, "r") as fileToCat:
+                    contents = fileToCat.read()
+                    is_text = True
+            except:
+                pass
+
+        if contents is None:
+            try:
+                with open(path, "rb") as fileToCat:
+                    contents = fileToCat.read()
+            except IOError as error:
+                error.filename = filename
+                stderr.write(str(error).encode())
+                return 1
+
         if show_nonprinting:
             contents = convertToCaretAndMNotation(contents)
+        elif is_text:
+            contents = contents.encode()
----------------
boomanaiden154 wrote:

It's unclear to me how this proposal would cause a semantic difference from what the code does now. When we set `is_text`, we're reading in text node, so `.read()` does not read an encoded form and we still only encode once.

https://github.com/llvm/llvm-project/pull/209259