Patch for Review: _Jv_TempUTFString and JV_TEMP_UTF_STRING
Mohan Embar
gnustuff@thisiscool.com
Wed Aug 13 08:23:00 GMT 2003
Hi All,
This patch leverages:
http://gcc.gnu.org/ml/java-patches/2003-q3/msg00371.html
and tries to do this:
http://gcc.gnu.org/ml/java-patches/2003-q3/msg00361.html
Tested on (i686-pc-linux-gnu,i686-pc-linux-gnu), (i686-pc-linux-gnu,i686-pc-mingw32)
and (i686-pc-mingw32,i686-pc-mingw32). The testcase is attached here:
http://gcc.gnu.org/ml/java-patches/2003-q3/msg00371.html
It was tricky to test this since I wanted a standalone testcase
which used functionality inside of jvm.h, but I think I nailed it.
I separated this from the cni.h patch because I'm not sure whether
this will be received with shouts of joy or screams of horror.
-- Mohan
http://www.thisiscool.com/
http://www.animalsong.org/
ChangeLog
2003-08-13 Mohan Embar <gnustuff@thisiscool.com>
* include/jvm.h: New class _Jv_TempUTFString (helper class for
getting a temporary C string from a jstring)
New macro JV_TEMP_UTF_STRING, which leverages _Jv_TempUTFString
but uses a stack buffer if the string length is less than 256
bytes.
Index: include/jvm.h
===================================================================
RCS file: /cvsroot/gcc/gcc/libjava/include/jvm.h,v
retrieving revision 1.56
diff -u -2 -r1.56 jvm.h
--- include/jvm.h 21 Jul 2003 01:54:05 -0000 1.56
+++ include/jvm.h 13 Aug 2003 05:32:44 -0000
@@ -150,4 +150,76 @@
extern jboolean _Jv_equaln (_Jv_Utf8Const *, jstring, jint);
+/* Helper class which converts a jstring to a temporary char*.
+ Uses the supplied buffer, if non-null. Otherwise, allocates
+ the buffer on the heap. Use the JV_TEMP_UTF_STRING macro,
+ which follows, to automatically allocate a stack buffer if
+ the string is small enough. */
+class _Jv_TempUTFString
+{
+public:
+ _Jv_TempUTFString(jstring jstr, char* buf=0);
+ ~_Jv_TempUTFString();
+
+// Accessors
+ operator const char*() const
+ {
+ return buf_;
+ }
+ const char* buf() const
+ {
+ return buf_;
+ }
+ char* buf()
+ {
+ return buf_;
+ }
+
+private:
+ char* buf_;
+ bool heapAllocated_;
+};
+
+inline _Jv_TempUTFString::_Jv_TempUTFString (jstring jstr, char* buf)
+ : buf_(0), heapAllocated_(false)
+{
+ if (!jstr) return;
+ if (buf)
+ buf_ = buf;
+ else
+ {
+ jsize len = JvGetStringUTFLength (jstr);
+ buf_ = (char*) _Jv_Malloc (len+1);
+ heapAllocated_ = true;
+ }
+
+ JvGetStringUTFChars (jstr, buf_);
+}
+
+inline _Jv_TempUTFString::~_Jv_TempUTFString ()
+{
+ if (heapAllocated_)
+ _Jv_Free (buf_);
+}
+
+/* Macro which uses _Jv_TempUTFString. Allocates a stack-based
+ buffer if the string and its null terminator are less than
+ 256 characters in length. Otherwise, a heap-based buffer is
+ used. The parameters to this macro are the variable name
+ which is an instance of _Jv_TempUTFString (above) and a
+ jstring.
+
+ Sample Usage:
+
+ jstring jstr = getAJString();
+ JV_TEMP_UTF_STRING(utfstr, jstr);
+ printf("The string is: %s\n", utfstr.buf());
+
+ */
+#define JV_TEMP_UTF_STRING(utfstr, jstr) \
+ jstring utfstr##thejstr = (jstr); \
+ jsize utfstr##_len = JvGetStringUTFLength (utfstr##thejstr) + 1; \
+ char utfstr##_buf[utfstr##_len <= 256 ? utfstr##_len : 0]; \
+ _Jv_TempUTFString utfstr(utfstr##thejstr, sizeof(utfstr##_buf)==0 ? 0 : utfstr##_buf)
+
// FIXME: remove this define.
#define StringClass java::lang::String::class$
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