Consider a compile action to have loose headers if it has textual hea…

…ders and loose headers checking is enabled.

Textual headers may loosely include other header files even when layering check is enabled.

PiperOrigin-RevId: 386489066

src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java

@@ -76,6 +76,7 @@
 import com.google.devtools.build.lib.profiler.SilentCloseable;
 import com.google.devtools.build.lib.rules.cpp.CcCommon.CoptsFilter;
 import com.google.devtools.build.lib.rules.cpp.CcToolchainFeatures.FeatureConfiguration;
+import com.google.devtools.build.lib.rules.cpp.CppConfiguration.HeadersCheckingMode;
 import com.google.devtools.build.lib.rules.cpp.IncludeScanner.IncludeScanningHeaderData;
 import com.google.devtools.build.lib.server.FailureDetails.CppCompile;
 import com.google.devtools.build.lib.server.FailureDetails.CppCompile.Code;
@@ -1780,13 +1781,13 @@ public boolean hasLooseHeaders() {
   // Separated into a helper method so that it can be called from CppCompileActionTemplate.
   static boolean hasLooseHeaders(
       CcCompilationContext ccCompilationContext, FeatureConfiguration featureConfiguration) {
-    // Layering check is stricter than hdrs_check = strict, so when it's enabled, there can't be
-    // loose headers.
-    return ccCompilationContext
-            .getHeadersCheckingMode()
-            .equals(CppConfiguration.HeadersCheckingMode.LOOSE)
-        && !(featureConfiguration.isEnabled(CppRuleClasses.LAYERING_CHECK)
-            && featureConfiguration.isEnabled(CppRuleClasses.PARSE_HEADERS));
+    if (ccCompilationContext.getHeadersCheckingMode() != HeadersCheckingMode.LOOSE) {
+      return false;
+    }
+    // Loose headers may still be included via textual_hdrs even if layering check is enabled.
+    return !featureConfiguration.isEnabled(CppRuleClasses.LAYERING_CHECK)
+        || !featureConfiguration.isEnabled(CppRuleClasses.PARSE_HEADERS)
+        || !ccCompilationContext.getTextualHdrs().isEmpty();
   }
 
   public CompileCommandLine getCompileCommandLine() {