android: crazy_linker: Minor polish on tests.

Tiny refactor of the C source generating Python functions.
No bugfix / feature at all. But the result of calling
'updated_auto_generated_sources.sh' doesn't need to be
fixed by 'git cl format' anymore.

- Prevent trailing whitespace on commented lines produced
  by CSourceForComments().

- More consistent output from CSourceForIntegerHexArray()
  and CSourceForConstCharArray() by using a common
  CSourceForArrayData() function that takes a lambda to
  format individual values.

R=pasko@chromium.org, agrieve@chromium.org
BUG=NONE

Change-Id: Ifc9c5c175a3432acb5ce3d7918259c4ee294dd04
Reviewed-on: https://chromium-review.googlesource.com/c/1297423Reviewed-by: David Turner <digit@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Commit-Queue: David Turner <digit@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602331}

third_party/android_crazy_linker/src/src/crazy_linker_elf_hash_table_test_data.h

@@ -35,15 +35,15 @@ namespace testing {
 // Buckets: 2, 8, 1, 3
 //
 static const char kTestElfStringTable[145] = {
-    '\0','i','s','n','a','n','\0','f','r','e','e','l','o','c','a','l','\0',
-    'h','c','r','e','a','t','e','_','\0','g','e','t','o','p','t','_','l','o',
-    'n','g','_','o','n','l','\0','e','n','d','r','p','c','e','n','\0','p',
-    't','h','r','e','a','d','_','m','u','t','e','x','_','l','o','c','k','\0',
-    'i','s','i','n','f','\0','s','e','t','r','l','i','m','i','\0','g','e',
-    't','s','p','e','n','\0','u','m','o','u','n','\0','s','t','r','s','i',
-    'g','n','a','\0','l','i','s','t','x','a','t','t','\0','g','e','t','t',
-    'y','e','n','\0','u','s','e','l','i','b','\0','c','f','s','e','t','i',
-    's','p','e','e','d','\0','\0'};
+    '\0','i','s','n','a','n','\0','f','r','e','e','l','o','c','a','l','\0','h',
+    'c','r','e','a','t','e','_','\0','g','e','t','o','p','t','_','l','o','n',
+    'g','_','o','n','l','\0','e','n','d','r','p','c','e','n','\0','p','t','h',
+    'r','e','a','d','_','m','u','t','e','x','_','l','o','c','k','\0','i','s',
+    'i','n','f','\0','s','e','t','r','l','i','m','i','\0','g','e','t','s','p',
+    'e','n','\0','u','m','o','u','n','\0','s','t','r','s','i','g','n','a','\0',
+    'l','i','s','t','x','a','t','t','\0','g','e','t','t','y','e','n','\0','u',
+    's','e','l','i','b','\0','c','f','s','e','t','i','s','p','e','e','d','\0',
+    '\0'};
 
 // Auto-generated macro used to list all symbols
 // XX must be a macro that takes the following parameters:

third_party/android_crazy_linker/src/src/crazy_linker_gnu_hash_table_test_data.h

@@ -50,15 +50,15 @@ namespace testing {
 //   also as:  0x010142a022120001 0x48040a04c81cc00d
 //
 static const char kTestGnuStringTable[145] = {
-    '\0','c','f','s','e','t','i','s','p','e','e','d','\0','s','t','r','s',
-    'i','g','n','a','\0','h','c','r','e','a','t','e','_','\0','e','n','d',
-    'r','p','c','e','n','\0','u','s','e','l','i','b','\0','g','e','t','t',
-    'y','e','n','\0','u','m','o','u','n','\0','f','r','e','e','l','o','c',
-    'a','l','\0','l','i','s','t','x','a','t','t','\0','i','s','n','a','n',
-    '\0','i','s','i','n','f','\0','s','e','t','r','l','i','m','i','\0','g',
-    'e','t','s','p','e','n','\0','p','t','h','r','e','a','d','_','m','u','t',
-    'e','x','_','l','o','c','k','\0','g','e','t','o','p','t','_','l','o','n',
-    'g','_','o','n','l','\0','\0'};
+    '\0','c','f','s','e','t','i','s','p','e','e','d','\0','s','t','r','s','i',
+    'g','n','a','\0','h','c','r','e','a','t','e','_','\0','e','n','d','r','p',
+    'c','e','n','\0','u','s','e','l','i','b','\0','g','e','t','t','y','e','n',
+    '\0','u','m','o','u','n','\0','f','r','e','e','l','o','c','a','l','\0','l',
+    'i','s','t','x','a','t','t','\0','i','s','n','a','n','\0','i','s','i','n',
+    'f','\0','s','e','t','r','l','i','m','i','\0','g','e','t','s','p','e','n',
+    '\0','p','t','h','r','e','a','d','_','m','u','t','e','x','_','l','o','c',
+    'k','\0','g','e','t','o','p','t','_','l','o','n','g','_','o','n','l','\0',
+    '\0'};
 
 // Auto-generated macro used to list all symbols
 // XX must be a macro that takes the following parameters:

third_party/android_crazy_linker/src/tests/pylib/source_utils.py

@@ -32,6 +32,43 @@ r'''
 #endif  // {guard_macro_name}'''
 )
 
+def CSourceForArrayData(values, formatter, margin=4, width=80):
+  """Turn an array of values into a C source array data definition.
+
+  Args:
+    values: Array of input values.
+    formatter: Formatting function, applied to each input value to get a
+      C-source description of the value.
+    margin: Left-side margin / indentation level.
+    width: Maximum line width.
+  Returns:
+    A string containing the data definition as a C source fragment.
+  """
+  read_pos = 0
+  read_len = len(values)
+  write_pos = margin
+  line_start = ' ' * margin
+  # Account for the margin + one final comma.
+  max_width = width - margin - 1
+  out = ''
+  while read_pos < read_len:
+    out += line_start
+    write_pos = 0
+    comma = ''
+    while read_pos < read_len:
+      item = comma + formatter(values[read_pos])
+      if write_pos + len(item) > max_width:
+        break  # Too long, break line before this item.
+      out += item
+      read_pos += 1
+      write_pos += len(item)
+      comma = ','
+    if read_pos == read_len:
+      break
+    out += ',\n'
+  return out
+
+
 def CSourceForIntegerHexArray(values, num_bits, margin=4, width=80):
   """Turn an array of integers into a C source array data definition.
 
@@ -44,23 +81,22 @@ def CSourceForIntegerHexArray(values, num_bits, margin=4, width=80):
     A string containing the data definition as a C source fragment.
   """
   chars_per_word = num_bits / 4
-  # Account for 0x prefix + one space + one comma
-  max_items_per_line = (width - margin - 2) / (4 + chars_per_word)
-  line_start = ' ' * (margin - 1)
-  slen = len(values)
-  n = 0
-  format_str = ' 0x%%0%dx,' % chars_per_word
-  out = ''
-  while n < slen:
-    out += line_start
-    n2 = min(n + max_items_per_line, slen)
-    while n < n2:
-      out += format_str % values[n]
-      n += 1
-    out += '\n';
+  format_str = ' 0x%%0%dx' % chars_per_word
+  out = CSourceForArrayData(values, lambda x: format_str % x,
+                            margin - 1, width)
+  out += ',\n'
   return out
 
 
+def _FormatChar(ch):
+  """Convert a character into its C source description."""
+  code = ord(ch)
+  if code < 32 or code > 127:
+    return "'\\%d'" % code
+  else:
+    return "'%s'" % ch
+
+
 def CSourceForConstCharArray(chars, variable_name, margin=4, width=80):
   """Return C source fragment for static const char C array.
 
@@ -70,35 +106,8 @@ def CSourceForConstCharArray(chars, variable_name, margin=4, width=80):
   Returns:
     A new string holding a C source fragment for the array definition.
   """
-  slen = len(chars)
-  out = 'static const char %s[%d] = {\n' % (variable_name, slen)
-  line_start = ' ' * margin
-  # Allow for margin + 4 spaces on the right.
-  max_width = width - margin - 4
-  rpos = 0
-  wpos = margin + 1
-  while rpos < slen:
-    out += line_start
-    wpos = 0
-    comma = ''
-    while rpos < slen and wpos < max_width:
-      ch = chars[rpos]
-      code = ord(ch)
-      if code < 32 or code > 127:
-        ch = "'\\%d'" % code
-      else:
-        ch = "'%s'" % ch
-      ch = comma + ch
-      if wpos + len(ch) > max_width: # Too long, break line before this char.
-        break
-      out += ch
-      rpos += 1
-      wpos += len(ch)
-      comma = ','
-    if rpos == slen:
-      break
-    out += ',\n'
-
+  out = 'static const char %s[%d] = {\n' % (variable_name, len(chars))
+  out += CSourceForArrayData(chars, _FormatChar, margin, width)
   out += '};\n'
   return out
 
@@ -107,7 +116,12 @@ def CSourceForComments(lines):
   """Wrap the content of |lines| instead into C++ comments."""
   out = ''
   for line in lines.split('\n'):
+    line = line.rstrip()
+    if line:
       out += '// %s\n' % line
+    else:
+      out += '//\n'
+
   return out
 
 
@@ -116,6 +130,7 @@ def CSourceBeginAutoGeneratedHeader(script_name, guard_macro_name):
       script_name=script_name,
       guard_macro_name=guard_macro_name)
 
+
 def CSourceEndAutoGeneratedHeader(script_name, guard_macro_name):
   return _AUTO_GENERATED_HEADER_END_TEMPLATE.format(
       script_name=script_name,