1 files changed, 95 insertions, 0 deletions
diff --git a/src/common/pretty_binary.cc b/src/common/pretty_binary.cc
new file mode 100644
index 000000000..d58b0fb6e
--- /dev/null
+++ b/src/common/pretty_binary.cc
@@ -0,0 +1,95 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "pretty_binary.h"
+#include <stdexcept>
+#include <sstream>
+
+std::string pretty_binary_string_reverse(const std::string& pretty)
+{
+  size_t i = 0;
+  auto raise = [&](size_t failpos) {
+    std::ostringstream ss;
+    ss << "invalid char at pos " << failpos << " of " << pretty;
+    throw std::invalid_argument(ss.str());
+  };
+  auto hexdigit = [&](unsigned char c) -> int32_t {
+    if (c >= '0' && c <= '9') return c - '0';
+    if (c >= 'a' && c <= 'f') return c - 'a' + 10;
+    if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+    return -1;
+  };
+  auto require = [&](unsigned char c) {
+    if (i >= pretty.length() || pretty[i] != c) {
+      raise(i);
+    }
+    ++i;
+  };
+  std::string bin;
+  if (pretty.empty())
+    return bin;
+  bin.reserve(pretty.length());
+  bool strmode;
+  switch (pretty[0]) {
+    case '\'':
+      ++i;
+      strmode = true;
+      break;
+    case '0':
+      ++i;
+      require('x');
+      if (i == pretty.length()) {
+	raise(i);
+      }
+      strmode = false;
+      break;
+    default:
+      raise(0);
+  }
+  for (; i < pretty.length();) {
+    if (strmode) {
+      if (pretty[i] == '\'') {
+	if (i + 1 < pretty.length() && pretty[i + 1] == '\'') {
+	  bin.push_back('\'');
+	  i += 2;
+	} else {
+	  ++i;
+	  strmode = false;
+	  if (i + 1 < pretty.length()) {
+	    require('0');
+	    require('x');
+	    if (i == pretty.length()) {
+	      raise(i);
+	    }
+	  }
+	}
+      } else {
+	bin.push_back(pretty[i]);
+	++i;
+      }
+    } else {
+      if (pretty[i] != '\'') {
+	int32_t hex0 = hexdigit(pretty[i]);
+	if (hex0 < 0) {
+	  raise(i);
+	}
+	++i;
+	if (i >= pretty.length()) {
+	  raise(i);
+	}
+	int32_t hex1 = hexdigit(pretty[i]);
+	if (hex1 < 0) {
+	  raise(i);
+	}
+	bin.push_back(hex0 * 0x10 + hex1);
+	++i;
+      } else {
+	strmode = true;
+	++i;
+      }
+    }
+  }
+  if (strmode)
+    raise(i);
+  return bin;
+}