Rewrite CppHelper linkopts expansion to take a list and return a list

Progress on #2475.

PiperOrigin-RevId: 170187908

2 files changed, 26 insertions, 19 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
index c945a72ae7..343d3c7dd0 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcCommon.java
@@ -127,17 +127,17 @@ public final class CcCommon {
    */
   public ImmutableList<String> getLinkopts() {
     Preconditions.checkState(hasAttribute("linkopts", Type.STRING_LIST));
-    List<String> ourLinkopts = ruleContext.attributes().get("linkopts", Type.STRING_LIST);
-    List<String> result = new ArrayList<>();
+    Iterable<String> ourLinkopts = ruleContext.attributes().get("linkopts", Type.STRING_LIST);
+    List<String> result;
     if (ourLinkopts != null) {
       boolean allowDashStatic = !cppConfiguration.forceIgnoreDashStatic()
           && (cppConfiguration.getDynamicMode() != DynamicMode.FULLY);
-      for (String linkopt : ourLinkopts) {
-        if (linkopt.equals("-static") && !allowDashStatic) {
-          continue;
-        }
-        CppHelper.expandAttribute(ruleContext, result, "linkopts", linkopt, true);
+      if (!allowDashStatic) {
+        ourLinkopts = Iterables.filter(ourLinkopts, (v) -> !"-static".equals(v));
       }
+      result = CppHelper.expandLinkopts(ruleContext, "linkopts", ourLinkopts);
+    } else {
+      result = ImmutableList.of();
     }
 
     if (ApplePlatform.isApplePlatform(cppConfiguration.getTargetCpu())
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
index 21714bbf33..83649b6267 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppHelper.java
@@ -199,20 +199,27 @@ public class CppHelper {
    * (if attemptLabelExpansion == {@code true} and it does not look like make
    * variable or flag) or tokenizes and expands make variables.
    */
-  public static void expandAttribute(RuleContext ruleContext,
-      List<String> result, String attrName, String attrValue, boolean attemptLabelExpansion) {
-    if (attemptLabelExpansion && CppHelper.isLinkoptLabel(attrValue)) {
-      if (!CppHelper.expandLabel(ruleContext, result, attrValue)) {
-        ruleContext.attributeError(attrName, "could not resolve label '" + attrValue + "'");
+  public static List<String> expandLinkopts(
+      RuleContext ruleContext, String attrName, Iterable<String> values) {
+    List<String> result = new ArrayList<>();
+    ConfigurationMakeVariableContext makeVariableContext =
+        ruleContext.getConfigurationMakeVariableContext(
+            ImmutableList.of(new CcFlagsSupplier(ruleContext)));
+    for (String value : values) {
+      if (isLinkoptLabel(value)) {
+        if (!expandLabel(ruleContext, result, value)) {
+          ruleContext.attributeError(attrName, "could not resolve label '" + value + "'");
+        }
+      } else {
+        ruleContext
+            .tokenizeAndExpandMakeVars(
+                result,
+                attrName,
+                value,
+                makeVariableContext);
       }
-    } else {
-      ruleContext.tokenizeAndExpandMakeVars(
-          result,
-          attrName,
-          attrValue,
-          ruleContext.getConfigurationMakeVariableContext(
-              ImmutableList.of(new CcFlagsSupplier(ruleContext))));
     }
+    return result;
   }
 
   /**