build-webkit: Perl "use of uninitialized value $previousContents"

https://bugs.webkit.org/show_bug.cgi?id=185776

Reviewed by Michael Catanzaro.

Fixes an issue where reading an empty cached argument file would cause
Perl "uninitialized value" warnings of the form:
    Use of uninitialized value $previousContents in chomp at C:/WebKit-BuildWorker/wincairo-wkl-debug/build/Tools/Scripts/webkitdirs.pm line 1969.
    Use of uninitialized value $previousContents in string ne at C:/WebKit-BuildWorker/wincairo-wkl-debug/build/Tools/Scripts/webkitdirs.pm line 1972.

* Scripts/webkitdirs.pm:
(isCachedArgumentfileOutOfDate):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@233388 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index 4399bf7..1a9bd72 100644 (file)
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,5 +1,20 @@
 2018-06-29  Daniel Bates  <dabates@apple.com>
 
+        build-webkit: Perl "use of uninitialized value $previousContents"
+        https://bugs.webkit.org/show_bug.cgi?id=185776
+
+        Reviewed by Michael Catanzaro.
+
+        Fixes an issue where reading an empty cached argument file would cause
+        Perl "uninitialized value" warnings of the form:
+            Use of uninitialized value $previousContents in chomp at C:/WebKit-BuildWorker/wincairo-wkl-debug/build/Tools/Scripts/webkitdirs.pm line 1969.
+            Use of uninitialized value $previousContents in string ne at C:/WebKit-BuildWorker/wincairo-wkl-debug/build/Tools/Scripts/webkitdirs.pm line 1972.
+
+        * Scripts/webkitdirs.pm:
+        (isCachedArgumentfileOutOfDate):
+
+2018-06-29  Daniel Bates  <dabates@apple.com>
+
         Perl uninitialized value $isEnabled when running build-jsc using a CMake build
         https://bugs.webkit.org/show_bug.cgi?id=187208
 

diff --git a/Tools/Scripts/webkitdirs.pm b/Tools/Scripts/webkitdirs.pm
index ea3fca3..8dadf43 100755 (executable)
--- a/Tools/Scripts/webkitdirs.pm
+++ b/Tools/Scripts/webkitdirs.pm
@@ -2028,7 +2028,7 @@ sub isCachedArgumentfileOutOfDate($@)
     }
 
     open(CONTENTS_FILE, $filename);
-    chomp(my $previousContents = <CONTENTS_FILE>);
+    chomp(my $previousContents = <CONTENTS_FILE> || "");
     close(CONTENTS_FILE);
 
     if ($previousContents ne $currentContents) {