[opt-viewer] Don't Decode HTML bytes for Python 2

Summary:
D36624 added some python3 compatibility. But that fix has a problem..

With python2 (which is specified by `#!/usr/bin/env python2.7`), if the env variables do not specify the UTF8,
and the source file is UTF8 (contains non-ASCII symbols), then the `.decode('utf-8')` causes the following exception:
```
Reading YAML files...
Rendering HTML files...
        8 of 41Traceback (most recent call last):
  File "/build/llvm/tools/opt-viewer/opt-viewer.py", line 277, in <module>
    print_progress)
  File "/build/llvm/tools/opt-viewer/opt-viewer.py", line 213, in generate_report
    should_print_progress)
  File "/build/llvm/tools/opt-viewer/optpmap.py", line 45, in pmap
    result = map(_wrapped_func, func_and_args, *args, **kwargs)
  File "/build/llvm/tools/opt-viewer/optpmap.py", line 25, in _wrapped_func
    return func(argument)
  File "/build/llvm/tools/opt-viewer/opt-viewer.py", line 174, in _render_file
    SourceFileRenderer(source_dir, output_dir, filename).render(remarks)
  File "/build/llvm/tools/opt-viewer/opt-viewer.py", line 125, in render
    self.render_source_lines(self.source_stream, line_remarks)
  File "/build/llvm/tools/opt-viewer/opt-viewer.py", line 79, in render_source_lines
    </tr>'''.format(**locals()), file=self.stream)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xf4' in position 47: ordinal not in range(128)
```
This is similar to https://bugs.llvm.org/show_bug.cgi?id=33548, which was fixed by https://reviews.llvm.org/D37661

Unlike that fix, here, *removing* `.decode('utf-8')` actually fixes it.

Since i assume that the original fix is needed, i simply made
that fix conditional, since for python2 it actually breaks things.

Reviewers: modocache, anemet

Reviewed By: anemet

Subscribers: fhahn, llvm-commits

Differential Revision: https://reviews.llvm.org/D38289

llvm-svn: 315350

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/tools/opt-viewer/opt-viewer.py b/llvm/tools/opt-viewer/opt-viewer.py
index 08fe2d585e9..15e76d65bf3 100755
--- a/llvm/tools/opt-viewer/opt-viewer.py
+++ b/llvm/tools/opt-viewer/opt-viewer.py
@@ -10,6 +10,7 @@ from multiprocessing import cpu_count
 import os.path
 import re
 import shutil
+import sys
 
 from pygments import highlight
 from pygments.lexers.c_cpp import CppLexer
@@ -62,7 +63,11 @@ class SourceFileRenderer:
         html_highlighted = highlight(
             file_text,
             self.cpp_lexer,
-            self.html_formatter).decode('utf-8')
+            self.html_formatter)
+
+        # On Python 3, pygments.highlight() returns a bytes object, not a str.
+        if sys.version_info >= (3, 0):
+          html_highlighted = html_highlighted.decode('utf-8')
 
         # Take off the header and footer, these must be
         #   reapplied line-wise, within the page structure