8187520: Add --disable-java-warnings-as-errors configure option

Reviewed-by: shade, erikj

make/Docs.gmk

@@ -92,10 +92,6 @@ REFERENCE_TAGS := $(JAVADOC_TAGS)
 JAVADOC_DISABLED_DOCLINT_WARNINGS := missing
 JAVADOC_DISABLED_DOCLINT_PACKAGES := org.w3c.* javax.smartcardio
 
-# Allow overriding on the command line
-# (intentionally sharing name with the javac option)
-JAVA_WARNINGS_ARE_ERRORS ?= -Werror
-
 # The initial set of options for javadoc
 JAVADOC_OPTIONS := -use -keywords -notimestamp \
     -serialwarn -encoding ISO-8859-1 -docencoding UTF-8 -breakiterator \
@@ -322,7 +318,9 @@ define SetupApiDocsGenerationBody
   # Ignore the doclint warnings in certain packages
   $1_OPTIONS += -Xdoclint/package:$$(call CommaList, $$(addprefix -, \
       $$(JAVADOC_DISABLED_DOCLINT_PACKAGES)))
-  $1_OPTIONS += $$(JAVA_WARNINGS_ARE_ERRORS)
+  ifeq ($$(JAVA_WARNINGS_AS_ERRORS), true)
+    $1_OPTIONS += -Werror
+  endif
 
   $1_DOC_TITLE := $$($1_LONG_NAME)<br>Version $$(VERSION_SPECIFICATION) API \
       Specification

make/autoconf/configure.ac

@@ -261,6 +261,7 @@ JDKOPT_ENABLE_DISABLE_CDS_ARCHIVE_COH
 JDKOPT_ENABLE_DISABLE_COMPATIBLE_CDS_ALIGNMENT
 JDKOPT_SETUP_MACOSX_SIGNING
 JDKOPT_SETUP_SIGNING_HOOK
+JDKOPT_SETUP_JAVA_WARNINGS
 
 ################################################################################
 #

make/autoconf/jdk-options.m4

@@ -988,6 +988,18 @@ AC_DEFUN([JDKOPT_SETUP_SIGNING_HOOK],
   AC_SUBST(SIGNING_HOOK)
 ])
 
+################################################################################
+#
+# Setup how javac should handle warnings.
+#
+AC_DEFUN([JDKOPT_SETUP_JAVA_WARNINGS],
+[
+  UTIL_ARG_ENABLE(NAME: java-warnings-as-errors, DEFAULT: true,
+      RESULT: JAVA_WARNINGS_AS_ERRORS,
+      DESC: [consider java warnings to be an error])
+  AC_SUBST(JAVA_WARNINGS_AS_ERRORS)
+])
+
 ################################################################################
 #
 # fallback linker

make/autoconf/spec.gmk.template

@@ -517,6 +517,7 @@ DISABLED_WARNINGS_CXX := @DISABLED_WARNINGS_CXX@
 
 # A global flag (true or false) determining if native warnings are considered errors.
 WARNINGS_AS_ERRORS := @WARNINGS_AS_ERRORS@
+JAVA_WARNINGS_AS_ERRORS := @JAVA_WARNINGS_AS_ERRORS@
 
 CFLAGS_CCACHE := @CFLAGS_CCACHE@
 ADLC_LANGSTD_CXXFLAGS := @ADLC_LANGSTD_CXXFLAGS@

make/common/JavaCompilation.gmk

@@ -264,15 +264,16 @@ define SetupJavaCompilationBody
     $$(error Invalid value for COMPILER in SetupJavaCompilation for $1: '$$($1_COMPILER)')
   endif
 
-  # Allow overriding on the command line
-  JAVA_WARNINGS_ARE_ERRORS ?= -Werror
-
   # Tell javac to do exactly as told and no more
   PARANOIA_FLAGS := -implicit:none -Xprefer:source -XDignore.symbol.file=true -encoding ascii
 
-  $1_FLAGS += -g -Xlint:all $$($1_TARGET_RELEASE) $$(PARANOIA_FLAGS) $$(JAVA_WARNINGS_ARE_ERRORS)
+  $1_FLAGS += -g -Xlint:all $$($1_TARGET_RELEASE) $$(PARANOIA_FLAGS)
   $1_FLAGS += $$($1_JAVAC_FLAGS)
 
+  ifeq ($$(JAVA_WARNINGS_AS_ERRORS), true)
+    $1_FLAGS += -Werror
+  endif
+
   ifneq ($$($1_DISABLED_WARNINGS), )
     $1_FLAGS += -Xlint:$$(call CommaList, $$(addprefix -, $$($1_DISABLED_WARNINGS)))
   endif