From 12ebe3823b01be256b0834956bc2e117129b32e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 2 Sep 2011 13:27:41 +0200
Subject: erlc_SUITE: Fix arg_overflow/1 test case

In commit be8759e68b337524c056b8bb757ea68c9996d863, a buffer overflow
was fixed in erlc and the erlc_SUITE:arg_overflow/1 test case was
added. That test cases invokes erlc with 10000 -D options, which will
result in 'erl' being invoked with more than 30000 arguments.

On some platforms, the test case will fail for the wrong reason:

* 64-bit Linux kernels before 2.6.23 limit the number of arguments in
an excvp() call to 16383. (See "Number of arguments and maximum length
of one argument" in http://www.in-ulm.de/~mascheck/various/argmax/.)

* The command shell in Windows limits the size of the command line to
8191 characters.

Depending on the platform, pass a different number of -D options
to erlc. Since the size of the options does not matter for this
test case, make the options as short as possible by generating
numbers in base 36.
---
 erts/test/erlc_SUITE.erl | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

(limited to 'erts/test')

diff --git a/erts/test/erlc_SUITE.erl b/erts/test/erlc_SUITE.erl
index 62e0e6813d..2b5cb11f02 100644
--- a/erts/test/erlc_SUITE.erl
+++ b/erts/test/erlc_SUITE.erl
@@ -213,13 +213,34 @@ deep_cwd_1(PrivDir) ->
 arg_overflow(Config) when is_list(Config) ->
     ?line {SrcDir, _OutDir, Cmd} = get_cmd(Config),
     ?line FileName = filename:join(SrcDir, "erl_test_ok.erl"),
-    ?line Args = lists:flatten([ ["-D", integer_to_list(N), "=1 "] ||
-            N <- lists:seq(1,10000) ]),
+    %% Each -D option will be expanded to three arguments when
+    %% invoking 'erl'.
+    ?line NumDOptions = num_d_options(),
+    ?line Args = lists:flatten([ ["-D", integer_to_list(N, 36), "=1 "] ||
+            N <- lists:seq(1, NumDOptions) ]),
     ?line run(Config, Cmd, FileName, Args,
 	      ["Warning: function foo/0 is unused\$",
 	       "_OK_"]),
     ok.
 
+num_d_options() ->
+    case {os:type(),os:version()} of
+	{{win32,_},_} ->
+	    %% The maximum size of a command line in the command
+	    %% shell on Windows is 8191 characters.
+	    %% Each -D option is expanded to "@dv NN 1", i.e.
+	    %% 8 characters. (Numbers up to 1295 can be expressed
+	    %% as two 36-base digits.)
+	    1000;
+	{{unix,linux},Version} when Version < {2,6,23} ->
+	    %% On some older 64-bit versions of Linux, the maximum number
+	    %% of arguments is 16383.
+	    %% See: http://www.in-ulm.de/~mascheck/various/argmax/
+	    5440;
+	{_,_} ->
+	    12000
+    end.
+
 erlc() ->
     case os:find_executable("erlc") of
 	false ->
-- 
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