position for stdin, string; (string) for trace; fix tests

Makefile

@@ -17,7 +17,8 @@ makefiles = \
   misc/upstart/local.mk \
   doc/manual/local.mk \
   tests/local.mk \
-  tests/plugins/local.mk
+  tests/plugins/local.mk \
+  src/error-demo/local.mk
 
 -include Makefile.config
 

src/error-demo/error-demo.cc

@@ -118,7 +118,7 @@ int main()
                         "yellow",
                         "values"),
                     .nixCode = NixCode {
-                        .errPos = Pos(problem_file, 40, 13),
+                        .errPos = Pos(foFile, problem_file, 40, 13),
                         .prevLineOfCode = std::nullopt,
                         .errLineOfCode = "this is the problem line of code",
                         .nextLineOfCode = std::nullopt
@@ -132,7 +132,7 @@ int main()
                         "yellow",
                         "values"),
                     .nixCode = NixCode {
-                        .errPos = Pos(problem_file, 40, 13),
+                        .errPos = Pos(foFile, problem_file, 40, 13),
                         .prevLineOfCode = "previous line of code",
                         .errLineOfCode = "this is the problem line of code",
                         .nextLineOfCode = "next line of code",
@@ -147,7 +147,7 @@ int main()
                         "yellow",
                         "values"),
                     .nixCode = NixCode {
-                        .errPos = Pos(problem_file, 40, 13)
+                        .errPos = Pos(foFile, problem_file, 40, 13)
                     }});
 
     // Error with only hint and name..
@@ -155,7 +155,7 @@ int main()
         ErrorInfo { .name = "error name",
                     .hint = hintfmt("hint %1%", "only"),
                     .nixCode = NixCode {
-                        .errPos = Pos(problem_file, 40, 13)
+                        .errPos = Pos(foFile, problem_file, 40, 13)
                     }});
 
     return 0;

src/libexpr/nixexpr.cc

@@ -197,7 +197,22 @@ std::ostream & operator << (std::ostream & str, const Pos & pos)
     if (!pos)
         str << "undefined position";
     else
-        str << (format(ANSI_BOLD "%1%" ANSI_NORMAL ":%2%:%3%") % (string) pos.file % pos.line % pos.column).str();
+    { 
+        auto f = format(ANSI_BOLD "%1%" ANSI_NORMAL ":%2%:%3%");
+        switch (pos.origin) { 
+            case foFile:
+                f % (string) pos.file; 
+                break;
+            case foStdin:
+            case foString:
+                f % "(string)";
+                break;
+            default:
+                throw Error("unhandled Pos origin!");
+        }
+        str << (f % pos.line % pos.column).str();
+    }
+
     return str;
 }
 

src/libutil/error.cc

@@ -58,13 +58,13 @@ void getCodeLines(NixCode &nixCode)
     if (nixCode.errPos.line <= 0) 
         return;
 
-    // check this magic value!
     if (nixCode.errPos.origin == foFile) {
         try {
             AutoCloseFD fd = open(nixCode.errPos.file.c_str(), O_RDONLY | O_CLOEXEC);
             if (!fd)
-                throw SysError("opening file '%1%'", nixCode.errPos.file);
+                logError(SysError("opening file '%1%'", nixCode.errPos.file).info());
-
+            else
+            {
                 // count the newlines.
                 int count = 0;
                 string line;
@@ -87,6 +87,7 @@ void getCodeLines(NixCode &nixCode)
                     }
                 } while (true);
              }
+        }
         catch (EndOfFile &eof) {
             ;
         }
@@ -103,7 +104,6 @@ void getCodeLines(NixCode &nixCode)
         do 
         {
             std::getline(iss, line);
-            // std::cout << "getline result: " << std::getline(iss, line) << std::endl;
             ++count;
             if (count < pl) 
             {
@@ -261,12 +261,12 @@ std::ostream& operator<<(std::ostream &out, const ErrorInfo &einfo)
                 break;
             }
             case foString: {
-                out << fmt("%1%from command line argument", prefix) << std::endl;
+                out << fmt("%1%from command line argument %2%", prefix, showErrPos(einfo.nixCode->errPos)) << std::endl;
                 out << prefix << std::endl;
                 break;
             }
             case foStdin: {
-                out << fmt("%1%from stdin", prefix) << std::endl;
+                out << fmt("%1%from stdin %2%", prefix, showErrPos(einfo.nixCode->errPos)) << std::endl;
                 out << prefix << std::endl;
                 break;
             }
@@ -291,11 +291,12 @@ std::ostream& operator<<(std::ostream &out, const ErrorInfo &einfo)
             printCodeLines(out, prefix, nixcode);
             out << prefix << std::endl;
         }
+    }
 
     // hint
+    if (einfo.hint.has_value()) {
         out << prefix << *einfo.hint << std::endl;
         out << prefix << std::endl;
-
     }
 
     return out;

tests/misc.sh

@@ -16,6 +16,11 @@ nix-env --foo 2>&1 | grep "no operation"
 nix-env -q --foo 2>&1 | grep "unknown flag"
 
 # Eval Errors.
-eval_res=$(nix-instantiate --eval -E 'let a = {} // a; in a.foo' 2>&1 || true)
+eval_arg_res=$(nix-instantiate --eval -E 'let a = {} // a; in a.foo' 2>&1 || true)
-echo $eval_res | grep "(string) (1:15)"
+echo $eval_arg_res | grep "command line argument (1:15)"
-echo $eval_res | grep "infinite recursion encountered"
+echo $eval_arg_res | grep "infinite recursion encountered"
+
+eval_stdin_res=$(echo 'let a = {} // a; in a.foo' | nix-instantiate --eval -E - 2>&1 || true)
+echo $eval_stdin_res | grep "stdin (1:15)"
+echo $eval_stdin_res | grep "infinite recursion encountered"
+