[clang-format] Switch to case-insensitive header matching and use it to

improve support for LLVM-style include sorting.

This really is a collection of improvements to the rules for LLVM
include sorting:
- We have gmock headers now, so it adds support for those to one of the
  categories.
- LLVM does use 'FooTest.cpp' files to test 'Foo.h' so it adds that
  suffix for finding a main header.
- At times the test file's case may not match the header file's case, so
  switch to case-insensitive regex matching of header names.

With this set of changes, I can't spot any misbehaviors when re-sorting
all of LLVM's unittest '#include' lines.

Thanks to Eric and Daniel for help testing and refining the patch during
review!

Differential Revision: https://reviews.llvm.org/D33932

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@306759 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/unittests/Format/SortIncludesTest.cpp b/unittests/Format/SortIncludesTest.cpp
index c3c56a8130..1128ed829f 100644
--- a/unittests/Format/SortIncludesTest.cpp
+++ b/unittests/Format/SortIncludesTest.cpp
@@ -266,6 +266,29 @@ TEST_F(SortIncludesTest, LeavesMainHeaderFirst) {
                  "a.cc"));
 }
 
+TEST_F(SortIncludesTest, SupportCaseInsensitiveMatching) {
+  // Setup an regex for main includes so we can cover those as well.
+  Style.IncludeIsMainRegex = "([-_](test|unittest))?$";
+
+  // Ensure both main header detection and grouping work in a case insensitive
+  // manner.
+  EXPECT_EQ("#include \"llvm/A.h\"\n"
+            "#include \"b.h\"\n"
+            "#include \"c.h\"\n"
+            "#include \"LLVM/z.h\"\n"
+            "#include \"llvm/X.h\"\n"
+            "#include \"GTest/GTest.h\"\n"
+            "#include \"gmock/gmock.h\"\n",
+            sort("#include \"c.h\"\n"
+                 "#include \"b.h\"\n"
+                 "#include \"GTest/GTest.h\"\n"
+                 "#include \"llvm/A.h\"\n"
+                 "#include \"gmock/gmock.h\"\n"
+                 "#include \"llvm/X.h\"\n"
+                 "#include \"LLVM/z.h\"\n",
+                 "a_TEST.cc"));
+}
+
 TEST_F(SortIncludesTest, NegativePriorities) {
   Style.IncludeCategories = {{".*important_os_header.*", -1}, {".*", 1}};
   EXPECT_EQ("#include \"important_os_header.h\"\n"