colourised errors

misc/_murphi2c

@@ -3,6 +3,7 @@
 # Zsh completion script for Murphi2C
 
 _arguments \
+  '--colour[enable or disable ANSI colour codes]: :(auto off on)' \
   '--header[generate a C header]' \
   '--help[display help information]' \
   {--output,-o}'[path to write source/header to]:filename:_files' \

misc/_murphi2murphi

@@ -3,6 +3,7 @@
 # Zsh completion script for Murphi2Murphi
 
 _arguments \
+  '--colour[enable or disable ANSI colour codes]: :(auto off on)' \
   '--decompose-complex-comparisons[expand array and record equality tests]' \
   '--explicit-semicolons[add omitted semicolons]' \
   '--help[display help information]' \

misc/_murphi2smv

@@ -3,6 +3,7 @@
 # Zsh completion script for Murphi2SMV
 
 _arguments \
+  '--colour[enable or disable ANSI colour codes]: :(auto off on)' \
   '--help[display help information]' \
   {--numeric-type,-n}'[target numeric type]:TYPE' \
   {--output,-o}'[path to write SMV to]:filename:_files' \

misc/_murphi2xml

@@ -3,6 +3,7 @@
 # Zsh completion script for Murphi2XML
 
 _arguments \
+  '--colour[enable or disable ANSI colour codes]: :(auto off on)' \
   '--help[display help information]' \
   {--output,-o}'[path to write XML to]:filename:_files' \
   '--version[output version information]' \

murphi2c/doc/murphi2c.1

@@ -23,6 +23,12 @@ See
 .BR rumur(1)
 for more information about Rumur or Murphi.
 .SH OPTIONS
+\fB\-\-colour\fR [\fBauto\fR | \fBoff\fR | \fBon\fR]
+.RS
+Enable or disable the use of ANSI colour codes in error messages. The default is
+\fBauto\fR, to auto-detect based on whether the stderr is a TTY.
+.RE
+.PP
 \fB\-\-header\fR
 .RS
 Generate a C header, as opposed to a source file.

murphi2c/src/check.cc

@@ -11,76 +11,46 @@ namespace {
 class Check : public ConstTraversal {
 
 public:
-  bool ok = true;
-
-  void visit_choose(const Choose &) final {
-    if (ok) {
-      std::cerr << "choose rules are not supported\n";
-      ok = false;
-    }
+  void visit_choose(const Choose &n) final {
+    throw Error("choose rules are not supported", n.loc);
   }
 
-  void visit_ismember(const IsMember &) final {
-    if (ok) {
-      std::cerr << "ismember expressions are not supported\n";
-      ok = false;
-    }
+  void visit_ismember(const IsMember &n) final {
+    throw Error("ismember expressions are not supported", n.loc);
   }
 
-  void visit_isundefined(const IsUndefined &) final {
-    if (ok) {
-      std::cerr << "isundefined expressions are not supported\n";
-      ok = false;
-    }
+  void visit_isundefined(const IsUndefined &n) final {
+    throw Error("isundefined expressions are not supported", n.loc);
   }
 
-  void visit_multiset(const Multiset &) final {
-    if (ok) {
-      std::cerr << "multiset types are not supported\n";
-      ok = false;
-    }
+  void visit_multiset(const Multiset &n) final {
+    throw Error("multiset types are not supported", n.loc);
   }
 
-  void visit_multisetadd(const MultisetAdd &) final {
-    if (ok) {
-      std::cerr << "multiset types are not supported\n";
-      ok = false;
-    }
+  void visit_multisetadd(const MultisetAdd &n) final {
+    throw Error("multiset types are not supported", n.loc);
   }
 
-  void visit_multisetcount(const MultisetCount &) final {
-    if (ok) {
-      std::cerr << "multiset types are not supported\n";
-      ok = false;
-    }
+  void visit_multisetcount(const MultisetCount &n) final {
+    throw Error("multiset types are not supported", n.loc);
   }
 
-  void visit_multisetremove(const MultisetRemove &) final {
-    if (ok) {
-      std::cerr << "multiset types are not supported\n";
-      ok = false;
-    }
+  void visit_multisetremove(const MultisetRemove &n) final {
+    throw Error("multiset types are not supported", n.loc);
   }
 
-  void visit_multisetremovepred(const MultisetRemovePred &) final {
-    if (ok) {
-      std::cerr << "multiset types are not supported\n";
-      ok = false;
-    }
+  void visit_multisetremovepred(const MultisetRemovePred &n) final {
+    throw Error("multiset types are not supported", n.loc);
   }
 
-  void visit_union(const Union &) final {
-    if (ok) {
-      std::cerr << "union types are not supported\n";
-      ok = false;
-    }
+  void visit_union(const Union &n) final {
+    throw Error("union types are not supported", n.loc);
   }
 };
 
 } // namespace
 
-bool check(const Node &n) {
+void check(const Node &n) {
   Check c;
   c.dispatch(n);
-  return c.ok;
 }

murphi2c/src/check.h

@@ -2,6 +2,7 @@
 
 #include <rumur/rumur.h>
 
-// validate the given AST contains no idioms that cannot be handled by murphi2c,
-// and return false if any are found
-bool check(const rumur::Node &n);
+/// validate the given AST contains no idioms that cannot be handled by murphi2c
+///
+/// Throws `rumur::Error` if anything is found that cannot be handled.
+void check(const rumur::Node &n);

murphi2c/src/main.cc

@@ -7,7 +7,9 @@
 #include "resources.h"
 #include <cassert>
 #include <cstddef>
+#include <cstdio>
 #include <cstdlib>
+#include <cstring>
 #include <fstream>
 #include <getopt.h>
 #include <iostream>
@@ -17,25 +19,25 @@
 #include <string>
 #include <sys/stat.h>
 #include <unistd.h>
-#include <utility>
 #include <vector>
 
-// a pair of input streams
-using dup_t =
-    std::pair<std::shared_ptr<std::istream>, std::shared_ptr<std::istream>>;
-
-static std::string in_filename = "<stdin>";
-static dup_t in;
+static const char *in_filename = "<stdin>";
+static std::shared_ptr<std::istream> in;
 static std::shared_ptr<std::ostream> out;
 
 // output C source? (as opposed to C header)
 static bool source = true;
 
+/// use colour in error messages?
+static enum { AUTO, ON, OFF } color = AUTO;
+
 static void parse_args(int argc, char **argv) {
 
   for (;;) {
     static struct option options[] = {
         // clang-format off
+        { "color",      required_argument, 0, 132 },
+        { "colour",     required_argument, 0, 132 },
         { "header",     no_argument,       0, 128 },
         { "help",       no_argument,       0, 'h' },
         { "output",     required_argument, 0, 'o' },
@@ -89,6 +91,20 @@ static void parse_args(int argc, char **argv) {
       std::cout << "Murphi2C version " << rumur_get_version() << '\n';
       exit(EXIT_SUCCESS);
 
+    case 132: // --color, --colour
+      if (strcmp(optarg, "auto") == 0) {
+        color = AUTO;
+      } else if (strcmp(optarg, "on") == 0) {
+        color = ON;
+      } else if (strcmp(optarg, "off") == 0) {
+        color = OFF;
+      } else {
+        std::cerr << "invalid --colour argument \"" << optarg << "\"\n"
+                  << "valid arguments are \"auto\", \"off\", and \"on\"\n";
+        exit(EXIT_FAILURE);
+      }
+      break;
+
     default:
       std::cerr << "unexpected error\n";
       exit(EXIT_FAILURE);
@@ -112,43 +128,114 @@ static void parse_args(int argc, char **argv) {
     in_filename = argv[optind];
 
     auto i = std::make_shared<std::ifstream>(in_filename);
-    auto j = std::make_shared<std::ifstream>(in_filename);
-    if (!i->is_open() || !j->is_open()) {
+    if (!i->is_open()) {
       std::cerr << "failed to open " << in_filename << '\n';
       exit(EXIT_FAILURE);
     }
-    in = dup_t(i, j);
+    in = i;
   }
 }
 
-static dup_t make_stdin_dup() {
+static std::shared_ptr<std::istream> make_stdin_buf() {
 
   // read stdin into memory
   auto buffer = std::make_shared<std::stringstream>();
   *buffer << std::cin.rdbuf();
 
-  // duplicate the buffer
-  auto copy = std::make_shared<std::istringstream>(buffer->str());
+  return buffer;
+}
+
+static bool use_colors() {
+  if (color == AUTO)
+    color = isatty(STDERR_FILENO) ? ON : OFF;
+  return color == ON;
+}
+
+static const char *bold() {
+  if (use_colors())
+    return "\033[1m";
+  return "";
+}
+
+static const char *green() {
+  if (use_colors())
+    return "\033[32m";
+  return "";
+}
+
+static const char *red() {
+  if (use_colors())
+    return "\033[31m";
+  return "";
+}
+
+static const char *reset() {
+  if (use_colors())
+    return "\033[0m";
+  return "";
+}
 
-  return dup_t(buffer, copy);
+static const char *white() {
+  if (use_colors())
+    return "\033[37m";
+  return "";
+}
+
+static void print_location(std::istream &src, const rumur::location &location) {
+
+  // the type of position.line and position.column changes across Bison
+  // releases, so avoid some -Wsign-compare warnings by casting them in advance
+  auto loc_line = static_cast<unsigned long>(location.begin.line);
+  auto loc_col = static_cast<unsigned long>(location.begin.column);
+
+  std::string line;
+  unsigned long lineno = 0;
+  while (lineno < loc_line) {
+    if (!std::getline(src, line))
+      return;
+    lineno++;
+  }
+
+  // print the line, and construct an underline indicating the column location
+  std::ostringstream buf;
+  unsigned long col = 1;
+  for (const char &c : line) {
+    if (col == loc_col) {
+      buf << green() << bold() << '^' << reset();
+    } else if (col < loc_col) {
+      if (c == '\t') {
+        buf << '\t';
+      } else {
+        buf << ' ';
+      }
+    }
+    std::cerr << c;
+    col++;
+  }
+  std::cerr << '\n';
+
+  std::cerr << buf.str() << '\n';
 }
 
 int main(int argc, char **argv) {
 
   // parse command line options
   parse_args(argc, argv);
 
-  // if we are reading from stdin, duplicate it so that we can parse it both as
-  // Murphi and for comments
-  if (in.first == nullptr)
-    in = make_stdin_dup();
+  // if we are reading from stdin, duplicate it so that we can seek it
+  if (in == nullptr)
+    in = make_stdin_buf();
 
   // parse input model
   rumur::Ptr<rumur::Model> m;
   try {
-    m = rumur::parse_model(*in.first);
+    m = rumur::parse_model(*in);
   } catch (rumur::Error &e) {
-    std::cerr << e.loc << ":" << e.what() << '\n';
+    std::cerr << white() << bold() << in_filename << ':' << e.loc << ':'
+              << reset() << ' ' << red() << bold() << "error:" << reset() << ' '
+              << white() << bold() << e.what() << reset() << '\n';
+    in->seekg(0);
+    print_location(*in, e.loc);
     return EXIT_FAILURE;
   }
 
@@ -162,13 +249,25 @@ int main(int argc, char **argv) {
     resolve_symbols(*m);
     validate(*m);
   } catch (rumur::Error &e) {
-    std::cerr << e.loc << ":" << e.what() << '\n';
+    std::cerr << white() << bold() << in_filename << ':' << e.loc << ':'
+              << reset() << ' ' << red() << bold() << "error:" << reset() << ' '
+              << white() << bold() << e.what() << reset() << '\n';
+    in->seekg(0);
+    print_location(*in, e.loc);
     return EXIT_FAILURE;
   }
 
   // validate that this model is OK to translate
-  if (!check(*m))
+  try {
+    check(*m);
+  } catch (rumur::Error &e) {
+    std::cerr << white() << bold() << in_filename << ':' << e.loc << ':'
+              << reset() << ' ' << red() << bold() << "error:" << reset() << ' '
+              << white() << bold() << e.what() << reset() << '\n';
+    in->seekg(0);
+    print_location(*in, e.loc);
     return EXIT_FAILURE;
+  }
 
   // name any rules that are unnamed, so they get valid C symbols
   rumur::sanitise_rule_names(*m);
@@ -178,7 +277,8 @@ int main(int argc, char **argv) {
   bool pack = compares_complex_values(*m);
 
   // parse comments from the source code
-  std::vector<rumur::Comment> comments = rumur::parse_comments(*in.second);
+  in->seekg(0);
+  std::vector<rumur::Comment> comments = rumur::parse_comments(*in);
 
   // output code
   if (source) {

murphi2murphi/doc/murphi2murphi.1

@@ -23,6 +23,12 @@ See
 .BR rumur(1)
 for more information about Rumur or Murphi.
 .SH OPTIONS
+\fB\-\-colour\fR [\fBauto\fR | \fBoff\fR | \fBon\fR]
+.RS
+Enable or disable the use of ANSI colour codes in error messages. The default is
+\fBauto\fR, to auto-detect based on whether the stderr is a TTY.
+.RE
+.PP
 \fB\-\-decompose\-complex\-comparisons\fR
 .RS
 Rumur supports comparing values of complex type (records and arrays) with each