Add support for reading gzip'd input files

Signed-off-by: David Shah <dave@ds0.me>

1 files changed, 40 insertions, 0 deletions

diff --git a/kernel/register.cc b/kernel/register.cc
index 26da96b95..4f1501330 100644
--- a/kernel/register.cc
+++ b/kernel/register.cc
@@ -25,6 +25,26 @@
 #include <stdio.h>
 #include <errno.h>
 
+#ifdef YOSYS_ENABLE_ZLIB
+#include <zlib.h>
+
+PRIVATE_NAMESPACE_BEGIN
+#define GZ_BUFFER_SIZE 8192
+void decompress_gzip(const std::string &filename, std::stringstream &out)
+{
+	char buffer[GZ_BUFFER_SIZE];
+	int bytes_read;
+	gzFile gzf = gzopen(filename.c_str(), "rb");
+	while(!gzeof(gzf)) {
+		bytes_read = gzread(gzf, reinterpret_cast<void *>(buffer), GZ_BUFFER_SIZE);
+		out.write(buffer, bytes_read);
+	}
+	gzclose(gzf);
+}
+PRIVATE_NAMESPACE_END
+
+#endif
+
 YOSYS_NAMESPACE_BEGIN
 
 #define MAX_REG_COUNT 1000
@@ -436,6 +456,26 @@ void Frontend::extra_args(std::istream *&f, std::string &filename, std::vector<s
 				delete ff;
 			else
 				f = ff;
+			// Check for gzip magic
+			unsigned char magic[3];
+			int n = readsome(*ff, reinterpret_cast<char*>(magic), 3);
+			if (n == 3 && magic[0] == 0x1f && magic[1] == 0x8b) {
+#ifdef YOSYS_ENABLE_ZLIB
+				log("Found gzip magic in file `%s', decompressing using zlib.\n", filename.c_str());
+				if (magic[2] != 8)
+					log_cmd_error("gzip file `%s' uses unsupported compression type %02x\n",
+						filename.c_str(), unsigned(magic[2]));
+				delete ff;
+				std::stringstream *df = new std::stringstream();
+				decompress_gzip(filename, *df);
+				f = df;
+#else
+				log_cmd_error("File `%s' is a gzip file, but Yosys is compiled without zlib.\n", filename.c_str());
+#endif
+			} else {
+				ff->clear();
+				ff->seekg(0, std::ios::beg);
+			}
 		}
 		if (f == NULL)
 			log_cmd_error("Can't open input file `%s' for reading: %s\n", filename.c_str(), strerror(errno));