Proposal for fixing issue #1784 (Spice throws error at midline semicolon comments)

src/db/db/dbNetlistSpiceReader.cc

@@ -54,7 +54,7 @@ read_param_card (tl::Extractor &ex, const db::Netlist *netlist, std::map<std::st
   //  taken from:
   //    https://nmg.gitlab.io/ngspice-manual/circuitdescription/paramparametricnetlists/paramline.html
 
-  while (! ex.at_end ()) {
+  while (! NetlistSpiceReader::at_eol (ex)) {
 
     std::string name;
     ex.read_word (name);
@@ -333,7 +333,7 @@ read_name (tl::Extractor &ex, const db::Netlist *netlist)
 {
   std::string n;
   ex.read_word_or_quoted (n, allowed_name_chars);
-  return netlist->normalize_name (n);
+  return netlist->normalize_name (NetlistSpiceReader::unescape_name (n));
 }
 
 class SpiceCircuitDict
@@ -610,7 +610,7 @@ SpiceCircuitDict::get_line ()
         std::string path_or_libname;
 
         ex.read_word_or_quoted (path_or_libname, allowed_name_chars);
-        if (! ex.at_end ()) {
+        if (! NetlistSpiceReader::at_eol (ex)) {
 
           std::string libname;
           ex.read_word_or_quoted (libname, allowed_name_chars);
@@ -648,7 +648,7 @@ SpiceCircuitDict::get_line ()
 
         ex.expect_end ();
 
-      } else if (ex.at_end () || ex.test ("*")) {
+      } else if (NetlistSpiceReader::at_eol (ex)) {
 
         //  skip empty and comment lines
 
@@ -680,7 +680,7 @@ SpiceCircuitDict::read_card ()
 
   } else if (ex.test_without_case (".global")) {
 
-    while (! ex.at_end ()) {
+    while (! NetlistSpiceReader::at_eol (ex)) {
       std::string n = mp_delegate->translate_net_name (read_name (ex, mp_netlist));
       if (m_global_net_names.find (n) == m_global_net_names.end ()) {
         m_global_nets.push_back (n);
@@ -766,7 +766,7 @@ SpiceCircuitDict::read_card ()
 void
 SpiceCircuitDict::read_options (tl::Extractor &ex)
 {
-  while (! ex.at_end ()) {
+  while (! NetlistSpiceReader::at_eol (ex)) {
 
     std::string n;
     ex.read_word_or_quoted (n, allowed_name_chars);
@@ -780,7 +780,7 @@ SpiceCircuitDict::read_options (tl::Extractor &ex)
       } else {
         //  skip until end or next space
         ex.skip ();
-        while (! ex.at_end () && ! isspace (*ex)) {
+        while (! NetlistSpiceReader::at_eol (ex) && ! isspace (*ex)) {
           ++ex;
         }
       }
@@ -1345,4 +1345,106 @@ void NetlistSpiceReader::read (tl::InputStream &stream, db::Netlist &netlist)
   }
 }
 
+bool NetlistSpiceReader::at_eol (tl::Extractor &ex)
+{
+  //  terminate at end or midline comment
+  return ex.at_end () || ex.test ("*") || ex.test (";");
+}
+
+inline static int hex_num (char c)
+{
+  if (c >= '0' && c <= '9') {
+    return (int (c - '0'));
+  } else if (c >= 'a' && c <= 'f') {
+    return (int (c - 'f') + 10);
+  } else {
+    return -1;
+  }
+}
+
+std::string NetlistSpiceReader::unescape_name (const std::string &n)
+{
+  std::string nn;
+  nn.reserve (n.size ());
+
+  char quote = 0;
+
+  const char *cp = n.c_str ();
+  while (*cp) {
+
+    if (*cp == quote) {
+
+      quote = 0;
+      ++cp;
+
+    } else if (! quote && (*cp == '"' || *cp == '\'')) {
+
+      quote = *cp++;
+
+    } else if (*cp == '\\' && cp[1]) {
+
+      if (tolower (cp[1]) == 'x') {
+
+        cp += 2;
+
+        char c = 0;
+        for (int i = 0; i < 2 && *cp; ++i) {
+          int n = hex_num (*cp);
+          if (n >= 0) {
+            ++cp;
+            c = c * 16 + char (n);
+          } else {
+            break;
+          }
+        }
+
+        nn += c;
+
+      } else {
+        ++cp;
+        nn += *cp++;
+      }
+
+    } else {
+      nn += *cp++;
+    }
+
+  }
+
+  return nn;
+}
+
+std::string NetlistSpiceReader::parse_component (tl::Extractor &ex)
+{
+  const char *cp = ex.skip ();
+  const char *cp0 = cp;
+
+  char quote = 0;
+  unsigned int brackets = 0;
+
+  while (*cp) {
+    if (quote) {
+      if (*cp == quote) {
+        quote = 0;
+      } else if (*cp == '\\' && cp[1]) {
+        ++cp;
+      }
+    } else if ((isspace (*cp) || *cp == '=') && ! brackets) {
+      break;
+    } else if (*cp == '"' || *cp == '\'') {
+      quote = *cp;
+    } else if (*cp == '(') {
+      ++brackets;
+    } else if (*cp == ')') {
+      if (brackets > 0) {
+        --brackets;
+      }
+    }
+    ++cp;
+  }
+
+  ex = tl::Extractor (cp);
+  return std::string (cp0, cp - cp0);
+}
+
 }

src/db/db/dbNetlistSpiceReader.h

@@ -29,6 +29,7 @@
 #include "tlStream.h"
 #include "tlObject.h"
 #include "tlVariant.h"
+#include "tlString.h"
 
 #include <map>
 #include <string>
@@ -63,6 +64,29 @@ public:
     m_strict = s;
   }
 
+  /**
+   *  @brief Returns true, if the extractor is at the end of the line
+   *  "at_eol" is true at the line end or when a midline comment starts.
+   */
+  static bool at_eol (tl::Extractor &ex);
+
+  /**
+   *  @brief Unescapes a name
+   *  Replaces backslash sequences with the true character and removes quotes.
+   */
+  static std::string unescape_name (const std::string &n);
+
+  /**
+   *  @brief Parses a netlist component (net name, expression etc.)
+   *  Scans over the expression or net name and returns a string representing the latter.
+   */
+  static std::string parse_component (tl::Extractor &ex);
+
+  /**
+   *  @brief Reads a component name
+   *  Scans over a component name and returns the
+   */
+
 private:
   tl::weak_ptr<NetlistSpiceReaderDelegate> mp_delegate;
   std::unique_ptr<NetlistSpiceReaderDelegate> mp_default_delegate;

src/db/db/dbNetlistSpiceReaderDelegate.cc

@@ -32,60 +32,6 @@ namespace db
 
 // ------------------------------------------------------------------------------------------------------
 
-inline static int hex_num (char c)
-{
-  if (c >= '0' && c <= '9') {
-    return (int (c - '0'));
-  } else if (c >= 'a' && c <= 'f') {
-    return (int (c - 'f') + 10);
-  } else {
-    return -1;
-  }
-}
-
-static std::string unescape_name (const std::string &n)
-{
-  std::string nn;
-  nn.reserve (n.size ());
-
-  const char *cp = n.c_str ();
-  while (*cp) {
-
-    if (*cp == '\\' && cp[1]) {
-
-      if (tolower (cp[1]) == 'x') {
-
-        cp += 2;
-
-        char c = 0;
-        for (int i = 0; i < 2 && *cp; ++i) {
-          int n = hex_num (*cp);
-          if (n >= 0) {
-            ++cp;
-            c = c * 16 + char (n);
-          } else {
-            break;
-          }
-        }
-
-        nn += c;
-
-      } else {
-        ++cp;
-        nn += *cp++;
-      }
-
-    } else {
-      nn += *cp++;
-    }
-
-  }
-
-  return nn;
-}
-
-// ------------------------------------------------------------------------------------------------------
-
 NetlistSpiceReaderOptions::NetlistSpiceReaderOptions ()
 {
   scale = 1.0;
@@ -147,7 +93,7 @@ bool NetlistSpiceReaderDelegate::wants_subcircuit (const std::string & /*circuit
 
 std::string NetlistSpiceReaderDelegate::translate_net_name (const std::string &nn)
 {
-  return unescape_name (nn);
+  return NetlistSpiceReader::unescape_name (nn);
 }
 
 void NetlistSpiceReaderDelegate::error (const std::string &msg)
@@ -172,45 +118,12 @@ static db::DeviceClass *make_device_class (db::Circuit *circuit, const std::stri
   return cls;
 }
 
-static std::string parse_component (tl::Extractor &ex)
-{
-  const char *cp = ex.skip ();
-  const char *cp0 = cp;
-
-  char quote = 0;
-  unsigned int brackets = 0;
-
-  while (*cp) {
-    if (quote) {
-      if (*cp == quote) {
-        quote = 0;
-      } else if (*cp == '\\' && cp[1]) {
-        ++cp;
-      }
-    } else if ((isspace (*cp) || *cp == '=') && ! brackets) {
-      break;
-    } else if (*cp == '"' || *cp == '\'') {
-      quote = *cp;
-    } else if (*cp == '(') {
-      ++brackets;
-    } else if (*cp == ')') {
-      if (brackets > 0) {
-        --brackets;
-      }
-    }
-    ++cp;
-  }
-
-  ex = tl::Extractor (cp);
-  return std::string (cp0, cp - cp0);
-}
-
 void NetlistSpiceReaderDelegate::parse_element_components (const std::string &s, std::vector<std::string> &strings, std::map<std::string, tl::Variant> &pv, const std::map<std::string, tl::Variant> &variables)
 {
   tl::Extractor ex (s.c_str ());
   bool in_params = false;
 
-  while (! ex.at_end ()) {
+  while (! NetlistSpiceReader::at_eol (ex)) {
 
     if (ex.test_without_case ("params:")) {
 
@@ -235,7 +148,7 @@ void NetlistSpiceReaderDelegate::parse_element_components (const std::string &s,
           ex.error (tl::to_string (tr ("Invalid syntax for parameter assignment - needs keyword followed by '='")));
         }
 
-        std::string comp_name = parse_component (ex);
+        std::string comp_name = NetlistSpiceReader::parse_component (ex);
         comp_name = mp_netlist ? mp_netlist->normalize_name (comp_name) : tl::to_upper_case (comp_name);
 
         //  resolve variables if string type

src/db/unit_tests/dbNetlistReaderTests.cc

@@ -914,6 +914,25 @@ TEST(25_dismiss_top_level)
   );
 }
 
+TEST(26_comments)
+{
+  db::Netlist nl;
+
+  std::string path = tl::combine_path (tl::combine_path (tl::testdata (), "algo"), "nreader26.cir");
+
+  db::NetlistSpiceReader reader;
+  tl::InputStream is (path);
+  reader.read (is, nl);
+
+  EXPECT_EQ (nl.to_string (),
+    "circuit TOP (A=A,B=B);\n"
+    "  device NMOS '1' (S=A,G=B,D=A,B=B) (L=100,W=100,AS=0,AD=0,PS=0,PD=0);\n"
+    "  device NMOS '2' (S='\\\\A',G='NET\"Q\"',D=A,B='NET[0]') (L=100,W=100,AS=0,AD=0,PS=0,PD=0);\n"
+    "  device NMOS 'FET[1]' (S='\\\\A',G='NET\"Q\"',D=AAA,B='NET[0]') (L=100,W=1.7,AS=0,AD=0,PS=0,PD=0);\n"
+    "end;\n"
+  );
+}
+
 TEST(100_ExpressionParser)
 {
   std::map<std::string, tl::Variant> vars;

testdata/algo/nreader26.cir

@@ -0,0 +1,14 @@
+* Test: dismiss empty top level circuit
+; a comment
+
+.subckt top a b 
+m1 a b a b nmos  * a comment
+m2 a 'net"q"' \\a net[0] nmos  * a comment
+mfet\[1\] \a\x41a "net\"q\"" "\\a" net\[0\] nmos w=1.7u ; a comment
+.ends
+
+* this triggered generation of a top level circuit
+.param p1 17 ; a comment
+
+.end    ; a comment
+