ext: Replace gzstream with iostream3 from zlib to avoid LGPL

This patch replaces the gzstream zlib wrapper with the iostream3
wrapper provided as part of zlib contributions. The main reason for
the switch is to avoid including LGPL in the default gem5
build. iostream3 is provided under a more permissive license:

The code is provided "as is", with the permission to use, copy,
modify, distribute and sell it for any purpose without fee.

1 files changed, 50 insertions, 0 deletions

diff --git a/ext/iostream3/test.cc b/ext/iostream3/test.cc
new file mode 100644
index 000000000..94235334f
--- /dev/null
+++ b/ext/iostream3/test.cc
@@ -0,0 +1,50 @@
+/*
+ * Test program for gzifstream and gzofstream
+ *
+ * by Ludwig Schwardt <schwardt@sun.ac.za>
+ * original version by Kevin Ruland <kevin@rodin.wustl.edu>
+ */
+
+#include "zfstream.h"
+#include <iostream>      // for cout
+
+int main() {
+
+  gzofstream outf;
+  gzifstream inf;
+  char buf[80];
+
+  outf.open("test1.txt.gz");
+  outf << "The quick brown fox sidestepped the lazy canine\n"
+       << 1.3 << "\nPlan " << 9 << std::endl;
+  outf.close();
+  std::cout << "Wrote the following message to 'test1.txt.gz' (check with zcat or zless):\n"
+            << "The quick brown fox sidestepped the lazy canine\n"
+            << 1.3 << "\nPlan " << 9 << std::endl;
+
+  std::cout << "\nReading 'test1.txt.gz' (buffered) produces:\n";
+  inf.open("test1.txt.gz");
+  while (inf.getline(buf,80,'\n')) {
+    std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n";
+  }
+  inf.close();
+
+  outf.rdbuf()->pubsetbuf(0,0);
+  outf.open("test2.txt.gz");
+  outf << setcompression(Z_NO_COMPRESSION)
+       << "The quick brown fox sidestepped the lazy canine\n"
+       << 1.3 << "\nPlan " << 9 << std::endl;
+  outf.close();
+  std::cout << "\nWrote the same message to 'test2.txt.gz' in uncompressed form";
+
+  std::cout << "\nReading 'test2.txt.gz' (unbuffered) produces:\n";
+  inf.rdbuf()->pubsetbuf(0,0);
+  inf.open("test2.txt.gz");
+  while (inf.getline(buf,80,'\n')) {
+    std::cout << buf << "\t(" << inf.rdbuf()->in_avail() << " chars left in buffer)\n";
+  }
+  inf.close();
+
+  return 0;
+
+}