From 7e0751b7c7d9104830b0d96b30bddb9965f150f6 Mon Sep 17 00:00:00 2001
From: Peter Kasting <pkasting@chromium.org>
Date: Thu, 3 Nov 2022 11:40:35 -0700
Subject: [PATCH 1/2] Avoid IWYU warnings on other namespaces for <algorithm>.

This is an extension of the logic already used for other STL headers.
---
 cpplint/cpplint.py          | 35 +++++++++++++++++++----------------
 cpplint/cpplint_unittest.py |  5 +++++
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/cpplint/cpplint.py b/cpplint/cpplint.py
index 704618f..334a127 100755
--- a/cpplint/cpplint.py
+++ b/cpplint/cpplint.py
@@ -5396,12 +5396,10 @@ _RE_PATTERN_STRING = re.compile(r'\bstring\b')
 _re_pattern_headers_maybe_templates = []
 for _header, _templates in _HEADERS_MAYBE_TEMPLATES:
   for _template in _templates:
-    # Match max<type>(..., ...), max(..., ...), but not foo->max, foo.max or
-    # type::max().
+    # Match max<type>(..., ...), max(..., ...), but not foo->max or foo.max.
     _re_pattern_headers_maybe_templates.append(
-        (re.compile(r'[^>.]\b' + _template + r'(<.*?>)?\([^\)]'),
-            _template,
-            _header))
+        (re.compile(r'(?<![>.]\b)' + _template + r'(<.*?>)?\([^\)]'), _template,
+         _header))
 
 # Other scripts may reach in and modify this pattern.
 _re_pattern_templates = []
@@ -5495,6 +5493,18 @@ def UpdateIncludeState(filename, include_dict, io=codecs):
   return True
 
 
+def UpdateRequiredHeadersForLine(patterns, line, linenum, required):
+  for pattern, template, header in patterns:
+    matched = pattern.search(line)
+    if matched:
+      # Don't warn about IWYU in non-STL namespaces:
+      # (We check only the first match per line; good enough.)
+      prefix = line[:matched.start()]
+      if prefix.endswith('std::') or not prefix.endswith('::'):
+        required[header] = (linenum, template)
+  return required
+
+
 def CheckForIncludeWhatYouUse(filename, clean_lines, include_state, error,
                               io=codecs):
   """Reports for missing stl includes.
@@ -5530,22 +5540,15 @@ def CheckForIncludeWhatYouUse(filename, clean_lines, include_state, error,
       if prefix.endswith('std::') or not prefix.endswith('::'):
         required['<string>'] = (linenum, 'string')
 
-    for pattern, template, header in _re_pattern_headers_maybe_templates:
-      if pattern.search(line):
-        required[header] = (linenum, template)
+    required = UpdateRequiredHeadersForLine(_re_pattern_headers_maybe_templates,
+                                            line, linenum, required)
 
     # The following function is just a speed up, no semantics are changed.
     if not '<' in line:  # Reduces the cpu time usage by skipping lines.
       continue
 
-    for pattern, template, header in _re_pattern_templates:
-      matched = pattern.search(line)
-      if matched:
-        # Don't warn about IWYU in non-STL namespaces:
-        # (We check only the first match per line; good enough.)
-        prefix = line[:matched.start()]
-        if prefix.endswith('std::') or not prefix.endswith('::'):
-          required[header] = (linenum, template)
+    required = UpdateRequiredHeadersForLine(_re_pattern_templates, line,
+                                            linenum, required)
 
   # The policy is that if you #include something in foo.h you don't need to
   # include it again in foo.cc. Here, we will look at possible includes.
diff --git a/cpplint/cpplint_unittest.py b/cpplint/cpplint_unittest.py
index 6087d8f..44d243e 100755
--- a/cpplint/cpplint_unittest.py
+++ b/cpplint/cpplint_unittest.py
@@ -968,6 +968,11 @@ class CpplintTest(CpplintTestBase):
           base::hash_map<int, int> foobar;
         """,
         '')
+    self.TestIncludeWhatYouUse(
+        """#include "base/ranges/algorithm.h"
+          base::ranges::copy(foo, bar.begin());
+        """,
+        '')
     self.TestIncludeWhatYouUse(
         """#include "base/foobar.h"
            bool foobar = std::less<int>(0,1);

From f947b7ee504eda7157883bc96d979c7601d0a49f Mon Sep 17 00:00:00 2001
From: Peter Kasting <pkasting@chromium.org>
Date: Mon, 7 Nov 2022 14:14:43 -0800
Subject: [PATCH 2/2] Fix bad regex

---
 cpplint/cpplint.py          | 2 +-
 cpplint/cpplint_unittest.py | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/cpplint/cpplint.py b/cpplint/cpplint.py
index 334a127..81bd9f5 100755
--- a/cpplint/cpplint.py
+++ b/cpplint/cpplint.py
@@ -5398,7 +5398,7 @@ for _header, _templates in _HEADERS_MAYBE_TEMPLATES:
   for _template in _templates:
     # Match max<type>(..., ...), max(..., ...), but not foo->max or foo.max.
     _re_pattern_headers_maybe_templates.append(
-        (re.compile(r'(?<![>.]\b)' + _template + r'(<.*?>)?\([^\)]'), _template,
+        (re.compile(r'(?<![>.])\b' + _template + r'(<.*?>)?\([^\)]'), _template,
          _header))
 
 # Other scripts may reach in and modify this pattern.
diff --git a/cpplint/cpplint_unittest.py b/cpplint/cpplint_unittest.py
index 44d243e..8625718 100755
--- a/cpplint/cpplint_unittest.py
+++ b/cpplint/cpplint_unittest.py
@@ -973,6 +973,11 @@ class CpplintTest(CpplintTestBase):
           base::ranges::copy(foo, bar.begin());
         """,
         '')
+    self.TestIncludeWhatYouUse(
+        """#include "base/foobar.h"
+          void FooBar::Remove(size_t index);
+        """,
+        '')
     self.TestIncludeWhatYouUse(
         """#include "base/foobar.h"
            bool foobar = std::less<int>(0,1);