Improve public header file checking

tools/gn/c_include_iterator_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/c_include_iterator.h"
+#include "tools/gn/input_file.h"
+#include "tools/gn/location.h"
+
+namespace {
+
+bool RangeIs(const LocationRange& range,
+             int line, int begin_char, int end_char) {
+  return range.begin().line_number() == line &&
+         range.end().line_number() == line &&
+         range.begin().char_offset() == begin_char &&
+         range.end().char_offset() == end_char;
+}
+
+}  // namespace
 
 TEST(CIncludeIterator, Basic) {
   std::string buffer;
   buffer.append("// Some comment\n");
   buffer.append("\n");
   buffer.append("#include \"foo/bar.h\"\n");
   buffer.append("\n");
   buffer.append("#include <stdio.h>\n");
   buffer.append("\n");
   buffer.append(" #include \"foo/baz.h\"\n");  // Leading whitespace
   buffer.append("#include \"la/deda.h\"\n");
   buffer.append("#import \"weird_mac_import.h\"\n");
   buffer.append("\n");
   buffer.append("void SomeCode() {\n");
 
-  CIncludeIterator iter(buffer);
+  InputFile file(SourceFile("//foo.cc"));
+  file.SetContents(buffer);
+
+  CIncludeIterator iter(&file);
 
   base::StringPiece contents;
-  EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+  LocationRange range;
+  EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_EQ("foo/bar.h", contents);
-  EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+  EXPECT_TRUE(RangeIs(range, 3, 11, 20)) << range.begin().Describe(true);
+
+  EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_EQ("foo/baz.h", contents);
-  EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+  EXPECT_TRUE(RangeIs(range, 7, 12, 21)) << range.begin().Describe(true);
+
+  EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_EQ("la/deda.h", contents);
-  EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+  EXPECT_TRUE(RangeIs(range, 8, 11, 20)) << range.begin().Describe(true);
+
+  EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_EQ("weird_mac_import.h", contents);
-  EXPECT_FALSE(iter.GetNextIncludeString(&contents));
+  EXPECT_TRUE(RangeIs(range, 9, 10, 28)) << range.begin().Describe(true);
+
+  EXPECT_FALSE(iter.GetNextIncludeString(&contents, &range));
 }
 
 // Tests that we don't search for includes indefinitely.
 TEST(CIncludeIterator, GiveUp) {
   std::string buffer;
   for (size_t i = 0; i < 1000; i++)
     buffer.append("x\n");
   buffer.append("#include \"foo/bar.h\"\n");
 
+  InputFile file(SourceFile("//foo.cc"));
+  file.SetContents(buffer);
+
   base::StringPiece contents;
+  LocationRange range;
 
-  CIncludeIterator iter(buffer);
-  EXPECT_FALSE(iter.GetNextIncludeString(&contents));
+  CIncludeIterator iter(&file);
+  EXPECT_FALSE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_TRUE(contents.empty());
 }
 
 // Don't count blank lines, comments, and preprocessor when giving up.
 TEST(CIncludeIterator, DontGiveUp) {
   std::string buffer;
   for (size_t i = 0; i < 1000; i++)
     buffer.push_back('\n');
   for (size_t i = 0; i < 1000; i++)
     buffer.append("// comment\n");
   for (size_t i = 0; i < 1000; i++)
     buffer.append("#preproc\n");
   buffer.append("#include \"foo/bar.h\"\n");
 
+  InputFile file(SourceFile("//foo.cc"));
+  file.SetContents(buffer);
+
   base::StringPiece contents;
+  LocationRange range;
 
-  CIncludeIterator iter(buffer);
-  EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+  CIncludeIterator iter(&file);
+  EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
   EXPECT_EQ("foo/bar.h", contents);
 }
 
 // Tests that we'll tolerate some small numbers of non-includes interspersed
 // with real includes.
 TEST(CIncludeIterator, TolerateNonIncludes) {
   const size_t kSkip = CIncludeIterator::kMaxNonIncludeLines - 2;
   const size_t kGroupCount = 100;
 
   std::string include("foo/bar.h");
 
   // Allow a series of includes with blanks in between.
   std::string buffer;
   for (size_t group = 0; group < kGroupCount; group++) {
     for (size_t i = 0; i < kSkip; i++)
       buffer.append("foo\n");
     buffer.append("#include \"" + include + "\"\n");
   }
 
+  InputFile file(SourceFile("//foo.cc"));
+  file.SetContents(buffer);
+
   base::StringPiece contents;
+  LocationRange range;
 
-  CIncludeIterator iter(buffer);
+  CIncludeIterator iter(&file);
   for (size_t group = 0; group < kGroupCount; group++) {
-    EXPECT_TRUE(iter.GetNextIncludeString(&contents));
+    EXPECT_TRUE(iter.GetNextIncludeString(&contents, &range));
     EXPECT_EQ(include, contents.as_string());
   }
-  EXPECT_FALSE(iter.GetNextIncludeString(&contents));
+  EXPECT_FALSE(iter.GetNextIncludeString(&contents, &range));
 }