From 261bc561fa30706b51cad2e4b6944cb94d0f6035 Mon Sep 17 00:00:00 2001
From: Akash Levy <akashlevy@gmail.com>
Date: Sun, 5 May 2024 04:21:47 -0700
Subject: [PATCH] Allow for gzip magic in stat

---
 passes/cmds/stat.cc | 107 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 101 insertions(+), 6 deletions(-)

diff --git a/passes/cmds/stat.cc b/passes/cmds/stat.cc
index c2bb72f3b..c8daec062 100644
--- a/passes/cmds/stat.cc
+++ b/passes/cmds/stat.cc
@@ -25,6 +25,65 @@
 #include "kernel/cost.h"
 #include "libs/json11/json11.hpp"
 
+#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);
+}
+
+/*
+An output stream that uses a stringbuf to buffer data internally,
+using zlib to write gzip-compressed data every time the stream is flushed.
+*/
+class gzip_ostream : public std::ostream  {
+public:
+	gzip_ostream() : std::ostream(nullptr)
+	{
+		rdbuf(&outbuf);
+	}
+	bool open(const std::string &filename)
+	{
+		return outbuf.open(filename);
+	}
+private:
+	class gzip_streambuf : public std::stringbuf {
+	public:
+		gzip_streambuf() { };
+		bool open(const std::string &filename)
+		{
+			gzf = gzopen(filename.c_str(), "wb");
+			return gzf != nullptr;
+		}
+		virtual int sync() override
+		{
+			gzwrite(gzf, reinterpret_cast<const void *>(str().c_str()), unsigned(str().size()));
+			str("");
+			return 0;
+		}
+		virtual ~gzip_streambuf()
+		{
+			sync();
+			gzclose(gzf);
+		}
+	private:
+		gzFile gzf = nullptr;
+	} outbuf;
+};
+PRIVATE_NAMESPACE_END
+
+#endif
+
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
@@ -350,13 +409,49 @@ statdata_t hierarchy_worker(std::map<RTLIL::IdString, statdata_t> &mod_stat, RTL
 
 void read_liberty_cellarea(dict<IdString, cell_area_t> &cell_area, string liberty_file)
 {
-	std::ifstream f;
-	f.open(liberty_file.c_str());
+	std::istream *f;
+	std::ifstream *ff = new std::ifstream;
+	ff->open(liberty_file.c_str(), (liberty_file.substr(liberty_file.size() - 3) == ".gz") ? std::ifstream::binary : std::ifstream::in);
 	yosys_input_files.insert(liberty_file);
-	if (f.fail())
-		log_cmd_error("Can't open liberty file `%s': %s\n", liberty_file.c_str(), strerror(errno));
-	LibertyParser libparser(f);
-	f.close();
+	if (ff->fail()) {
+		delete ff;
+		ff = nullptr;
+	}
+	f = ff;
+	if (f != NULL) {
+		// Check for gzip magic
+		unsigned char magic[3];
+		int n = 0;
+		while (n < 3)
+		{
+			int c = ff->get();
+			if (c != EOF) {
+				magic[n] = (unsigned char) c;
+			}
+			n++;
+		}
+		if (n == 3 && magic[0] == 0x1f && magic[1] == 0x8b) {
+#ifdef YOSYS_ENABLE_ZLIB
+			// log("Found gzip magic in file `%s', decompressing using zlib.\n", liberty_file.c_str());
+			if (magic[2] != 8)
+				log_cmd_error("gzip file `%s' uses unsupported compression type %02x\n",
+					liberty_file.c_str(), unsigned(magic[2]));
+			delete ff;
+			std::stringstream *df = new std::stringstream();
+			decompress_gzip(liberty_file, *df);
+			f = df;
+#else
+			log_cmd_error("File `%s' is a gzip file, but Yosys is compiled without zlib.\n", liberty_file.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", liberty_file.c_str(), strerror(errno));
+
+	LibertyParser libparser(*f);
 
 	for (auto cell : libparser.ast->children)
 	{