Extend support for format strings in Verilog front-end

Signed-off-by: Claire Wolf <claire@symbioticeda.com>

diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 372dcf95c59575c79bd547139352d788700ec974..467afdd8717bdb913cd98cb622cd7c594c5e84a2 100644 (file)
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -64,6 +64,21 @@ std::string AstNode::process_format_str(const std::string &sformat, int next_arg
                                continue;
                        }
 
+                       bool got_len = false;
+                       bool got_zlen = false;
+                       int len_value = 0;
+
+                       while ('0' <= cformat && cformat <= '9')
+                       {
+                               if (!got_len && cformat == '0')
+                                       got_zlen = true;
+
+                               got_len = true;
+                               len_value = 10*len_value + (cformat - '0');
+
+                               cformat = sformat[++i];
+                       }
+
                        // Simplify the argument
                        AstNode *node_arg = nullptr;
 
@@ -74,6 +89,9 @@ std::string AstNode::process_format_str(const std::string &sformat, int next_arg
                                case 'S':
                                case 'd':
                                case 'D':
+                                       if (got_len)
+                                               goto unsupported_format;
+                                       /* fall through */
                                case 'x':
                                case 'X':
                                        if (next_arg >= GetSize(children))
@@ -88,9 +106,12 @@ std::string AstNode::process_format_str(const std::string &sformat, int next_arg
 
                                case 'm':
                                case 'M':
+                                       if (got_len)
+                                               goto unsupported_format;
                                        break;
 
                                default:
+                               unsupported_format:
                                        log_file_error(filename, location.first_line, "System task `%s' called with invalid/unsupported format specifier.\n", str.c_str());
                                        break;
                        }
@@ -104,19 +125,28 @@ std::string AstNode::process_format_str(const std::string &sformat, int next_arg
 
                                case 'd':
                                case 'D':
-                                       {
-                                               char tmp[128];
-                                               snprintf(tmp, sizeof(tmp), "%d", node_arg->bitsAsConst().as_int());
-                                               sout += tmp;
-                                       }
+                                       sout += stringf("%d", node_arg->bitsAsConst().as_int());
                                        break;
 
                                case 'x':
                                case 'X':
                                        {
-                                               char tmp[128];
-                                               snprintf(tmp, sizeof(tmp), "%x", node_arg->bitsAsConst().as_int());
-                                               sout += tmp;
+                                               Const val = node_arg->bitsAsConst();
+
+                                               while (GetSize(val) % 4 != 0)
+                                                       val.bits.push_back(State::S0);
+
+                                               int len = GetSize(val) / 4;
+                                               for (int i = len; i < len_value; i++)
+                                                       sout += got_zlen ? '0' : ' ';
+
+                                               for (int i = len-1; i >= 0; i--) {
+                                                       Const digit = val.extract(4*i, 4);
+                                                       if (digit.is_fully_def())
+                                                               sout += stringf(cformat == 'x' ? "%x" : "%X", digit.as_int());
+                                                       else
+                                                               sout += cformat == 'x' ? "x" : "X";
+                                               }
                                        }
                                        break;