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authornormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-01-31 00:41:56 +0000
committernormal <normal@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-01-31 00:41:56 +0000
commitba5aa6066869e80af71fddb0b42d31222f328c97 (patch)
treefec1a3a25d77156c9498a93272fcb7502c8a4cf8
parent4b9a21cdd6881325836ec54d1daca47c9ce4fa02 (diff)
sprintf.c: avoid garbage in common (no exception) case
Format strings which are dynamically-generated will benefit from this. This won't cover exceptions, but exceptions for sprintf should be too uncommon to care about (unlike IO) * sprintf.c (rb_str_format): use rb_str_tmp_frozen_{acquire,release} * test/ruby/test_sprintf.rb (test_no_hidden_garbage): new test git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57473 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r--sprintf.c6
-rw-r--r--test/ruby/test_sprintf.rb10
2 files changed, 14 insertions, 2 deletions
diff --git a/sprintf.c b/sprintf.c
index 4342904..40872c0 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -475,6 +475,7 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
int tainted = 0;
VALUE nextvalue;
VALUE tmp;
+ VALUE orig;
VALUE str;
volatile VALUE hash = Qundef;
@@ -498,7 +499,8 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
if (OBJ_TAINTED(fmt)) tainted = 1;
StringValue(fmt);
enc = rb_enc_get(fmt);
- fmt = rb_str_new4(fmt);
+ orig = fmt;
+ fmt = rb_str_tmp_frozen_acquire(fmt);
p = RSTRING_PTR(fmt);
end = p + RSTRING_LEN(fmt);
blen = 0;
@@ -1196,7 +1198,7 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
}
sprint_exit:
- RB_GC_GUARD(fmt);
+ rb_str_tmp_frozen_release(orig, fmt);
/* XXX - We cannot validate the number of arguments if (digit)$ style used.
*/
if (posarg >= 0 && nextarg < argc) {
diff --git a/test/ruby/test_sprintf.rb b/test/ruby/test_sprintf.rb
index 595bf6d..c80f88b 100644
--- a/test/ruby/test_sprintf.rb
+++ b/test/ruby/test_sprintf.rb
@@ -451,4 +451,14 @@ class TestSprintf < Test::Unit::TestCase
bug = 'https://github.com/mruby/mruby/issues/3347'
assert_equal("!", sprintf("%*c", 0, ?!.ord), bug)
end
+
+ def test_no_hidden_garbage
+ fmt = [4, 2, 2].map { |x| "%0#{x}d" }.join('-') # defeats optimization
+ ObjectSpace.count_objects(res = {}) # creates strings on first call
+ before = ObjectSpace.count_objects(res)[:T_STRING]
+ val = sprintf(fmt, 1970, 1, 1)
+ after = ObjectSpace.count_objects(res)[:T_STRING]
+ assert_equal before + 1, after, 'only new string is the created one'
+ assert_equal '1970-01-01', val
+ end
end