commit 5f39475bb51f48182180e34e4310edb650bea462
author michajlo <michajlo@google.com> Fri Oct 06 23:51:10 2017 +0200
committer Klaus Aehlig <aehlig@google.com> Sat Oct 07 11:07:24 2017 +0200
tree 5871871083d066c96e4cd23e267acda933c9f01e
parent 38da0c2e6e082964e32e8646439cdec7cd50808f

Reduce iterator usage on hot code paths

Micro-optimize a few hot code paths which have a habit of iterating over short O(1)-access
lists.

RELNOTES: None
PiperOrigin-RevId: 171347524

src/main/java/com/google/devtools/build/lib/syntax/Parser.java

diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
index 979c63b..6d45726 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
@@ -481,7 +481,7 @@
 
   // funcall_suffix ::= '(' arg_list? ')'
   private Expression parseFuncallSuffix(int start, Expression function) {
-    List<Argument.Passed> args = Collections.emptyList();
+    ImmutableList<Argument.Passed> args = ImmutableList.of();
     expect(TokenKind.LPAREN);
     int end;
     if (token.kind == TokenKind.RPAREN) {
@@ -509,8 +509,8 @@
   }
 
   // arg_list ::= ( (arg ',')* arg ','? )?
-  private List<Argument.Passed> parseFuncallArguments() {
-    List<Argument.Passed> arguments = parseFunctionArguments(this::parseFuncallArgument);
+  private ImmutableList<Argument.Passed> parseFuncallArguments() {
+    ImmutableList<Argument.Passed> arguments = parseFunctionArguments(this::parseFuncallArgument);
     try {
       Argument.validateFuncallArguments(arguments);
     } catch (Argument.ArgumentException e) {