[include-cleaner] Dont apply name-match for non-owning headers (#82625)

Author: kadircet

clang-tools-extra/include-cleaner/lib/FindHeaders.cpp

@@ -275,6 +275,12 @@ llvm::SmallVector<Header> headersForSymbol(const Symbol &S,
     // are already ranked in the stdlib mapping.
     if (H.kind() == Header::Standard)
       continue;
+    // Don't apply name match hints to exporting headers. As they usually have
+    // names similar to the original header, e.g. foo_wrapper/foo.h vs
+    // foo/foo.h, but shouldn't be preferred (unless marked as the public
+    // interface).
+    if ((H.Hint & Hints::OriginHeader) == Hints::None)
+      continue;
     if (nameMatch(SymbolName, H))
       H.Hint |= Hints::PreferredHeader;
   }

clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp

@@ -628,5 +628,24 @@ TEST_F(HeadersForSymbolTest, StandardHeaders) {
                            tooling::stdlib::Header::named("<assert.h>")));
 }
 
+TEST_F(HeadersForSymbolTest, ExporterNoNameMatch) {
+  Inputs.Code = R"cpp(
+    #include "exporter/foo.h"
+    #include "foo_public.h"
+  )cpp";
+  Inputs.ExtraArgs.emplace_back("-I.");
+  // Deliberately named as foo_public to make sure it doesn't get name-match
+  // boost and also gets lexicographically bigger order than "exporter/foo.h".
+  Inputs.ExtraFiles["foo_public.h"] = guard(R"cpp(
+    struct foo {};
+  )cpp");
+  Inputs.ExtraFiles["exporter/foo.h"] = guard(R"cpp(
+    #include "foo_public.h" // IWYU pragma: export
+  )cpp");
+  buildAST();
+  EXPECT_THAT(headersForFoo(), ElementsAre(physicalHeader("foo_public.h"),
+                                           physicalHeader("exporter/foo.h")));
+}
+
 } // namespace
 } // namespace clang::include_cleaner