Merge branch 'cf/compile_warning_as_error' into ccase/r13b04_dev

* cf/compile_warning_as_error:
  Add option -Werror in erlc(1)
  compile: add flag warnings_as_errors to treat warnings as errors
  compile.erl: remove trailing whitespace

OTP-8382  The -Werror option for erlc and the compiler option
          warnings_as_errors will cause warnings to be treated as errors.
          (Thanks to Christopher Faulet.)

3 files changed, 27 insertions, 13 deletions

diff --git a/erts/doc/src/erlc.xml b/erts/doc/src/erlc.xml
index 3859ac8365..1e8960c22c 100644
--- a/erts/doc/src/erlc.xml
+++ b/erts/doc/src/erlc.xml
@@ -4,7 +4,7 @@
 <comref>
   <header>
     <copyright>
-      <year>1997</year><year>2009</year>
+      <year>1997</year><year>2010</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -13,12 +13,12 @@
       compliance with the License. You should have received a copy of the
       Erlang Public License along with this software. If not, it can be
       retrieved online at http://www.erlang.org/.
-    
+
       Software distributed under the License is distributed on an "AS IS"
       basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
       the License for the specific language governing rights and limitations
       under the License.
-    
+
     </legalnotice>
 
     <title>erlc</title>
@@ -104,6 +104,10 @@
           must be quoted. Terms which contain spaces
           must be quoted on all platforms.</p>
       </item>
+      <tag>-W<em>error</em></tag>
+      <item>
+        <p>Makes all warnings into errors.</p>
+      </item>
       <tag>-W<em>number</em></tag>
       <item>
         <p>Sets warning level to <em>number</em>. Default is <c><![CDATA[1]]></c>.
diff --git a/erts/etc/common/erlc.c b/erts/etc/common/erlc.c
index c958fed741..09aca19e6c 100644
--- a/erts/etc/common/erlc.c
+++ b/erts/etc/common/erlc.c
@@ -1,19 +1,19 @@
 /*
  * %CopyrightBegin%
- * 
- * Copyright Ericsson AB 1997-2009. All Rights Reserved.
- * 
+ *
+ * Copyright Ericsson AB 1997-2010. All Rights Reserved.
+ *
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
  * compliance with the License. You should have received a copy of the
  * Erlang Public License along with this software. If not, it can be
  * retrieved online at http://www.erlang.org/.
- * 
+ *
  * Software distributed under the License is distributed on an "AS IS"
  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
  * the License for the specific language governing rights and limitations
  * under the License.
- * 
+ *
  * %CopyrightEnd%
  */
 /*
@@ -310,6 +310,8 @@ main(int argc, char** argv)
 	    case 'W':		/* Enable warnings. */
 		if (strcmp(argv[1]+2, "all") == 0) {
 		    PUSH2("@warn", "999");
+		} else if (strcmp(argv[1]+2, "error") == 0) {
+		    PUSH2("@option", "warnings_as_errors");
 		} else if (isdigit((int)argv[1][2])) {
 		    PUSH2("@warn", argv[1]+2);
 		} else {
@@ -566,6 +568,7 @@ usage(void)
 	{"-pz path", "add path to the end of Erlang's code path"},
 	{"-smp", "compile using SMP emulator"},
 	{"-v", "verbose compiler output"},
+	{"-Werror", "make all warnings into errors"},
 	{"-W0", "disable warnings"},
 	{"-Wnumber", "set warning level to number"},
 	{"-Wall", "enable all warnings"},
diff --git a/erts/test/erlc_SUITE.erl b/erts/test/erlc_SUITE.erl
index 1d944811aa..6b4484b31e 100644
--- a/erts/test/erlc_SUITE.erl
+++ b/erts/test/erlc_SUITE.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 1997-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 -module(erlc_SUITE).
@@ -56,6 +56,13 @@ compile_erl(Config) when is_list(Config) ->
 
     ?line run(Config, Cmd, FileName, "-W0", ["_OK_"]),
 
+    %% Try treating warnings as errors.
+
+    ?line run(Config, Cmd, FileName, "-Werror",
+	      ["compile: warnings being treated as errors\$",
+	       "Warning: function foo/0 is unused\$",
+	       "_ERROR_"]),
+
     %% Check a bad file.
 
     ?line BadFile = filename:join(SrcDir, "erl_test_bad.erl"),