Merge pull request #47 from xuchenhan-tri/if-constexpr

Fix false positive cpplint

Author: jwnimmer-tri

cpplint/cpplint.py

@@ -3884,11 +3884,11 @@ def CheckBraces(filename, clean_lines, linenum, error):
   # its line, and the line after that should have an indent level equal to or
   # lower than the if. We also check for ambiguous if/else nesting without
   # braces.
-  if_else_match = Search(r'\b(if\s*\(|else\b)', line)
+  if_else_match = Search(r'\b(if\s*(|constexpr)\s*\(|else\b)', line)
   if if_else_match and not Match(r'\s*#', line):
     if_indent = GetIndentLevel(line)
     endline, endlinenum, endpos = line, linenum, if_else_match.end()
-    if_match = Search(r'\bif\s*\(', line)
+    if_match = Search(r'\bif\s*(|constexpr)\s*\(', line)
     if if_match:
       # This could be a multiline if condition, so find the end first.
       pos = if_match.end() - 1

cpplint/cpplint_unittest.py

@@ -3708,6 +3708,21 @@ def testConditionals(self):
           goto fail;""",
         'If/else bodies with multiple statements require braces'
         '  [readability/braces] [4]')
+    self.TestMultiLineLint(
+        """
+        if constexpr (foo)
+          goto fail;
+          goto fail;""",
+        'If/else bodies with multiple statements require braces'
+        '  [readability/braces] [4]')
+    self.TestMultiLineLint(
+        """
+        if constexpr (foo) {
+          bar;
+        } else if constexpr (baz) {
+          qux;
+        }""",
+        '')
     self.TestMultiLineLint(
         """
         if (foo)