Merge remote-tracking branch 'origin/master' into coerce-string

1 files changed, 65 insertions, 128 deletions

diff --git a/src/libutil/error.cc b/src/libutil/error.cc
index cf4f4a56f..7f7c27267 100644
--- a/src/libutil/error.cc
+++ b/src/libutil/error.cc
@@ -9,9 +9,9 @@ namespace nix {
 
 const std::string nativeSystem = SYSTEM;
 
-void BaseError::addTrace(std::optional<ErrPos> e, hintformat hint, bool frame)
+void BaseError::addTrace(std::shared_ptr<AbstractPos> && e, hintformat hint, bool frame)
 {
-    err.traces.push_front(Trace { .pos = e, .hint = hint, .frame = frame });
+    err.traces.push_front(Trace { .pos = std::move(e), .hint = hint, .frame = frame });
 }
 
 // c++ std::exception descendants must have a 'const char* what()' function.
@@ -30,91 +30,46 @@ const std::string & BaseError::calcWhat() const
 
 std::optional<std::string> ErrorInfo::programName = std::nullopt;
 
-std::ostream & operator<<(std::ostream & os, const hintformat & hf)
+std::ostream & operator <<(std::ostream & os, const hintformat & hf)
 {
     return os << hf.str();
 }
 
-std::string showErrPos(const ErrPos & errPos)
+std::ostream & operator <<(std::ostream & str, const AbstractPos & pos)
 {
-    if (errPos.line > 0) {
-        if (errPos.column > 0) {
-            return fmt("%d:%d", errPos.line, errPos.column);
-        } else {
-            return fmt("%d", errPos.line);
-        }
-    }
-    else {
-        return "";
-    }
+    pos.print(str);
+    str << ":" << pos.line;
+    if (pos.column > 0)
+        str << ":" << pos.column;
+    return str;
 }
 
-std::optional<LinesOfCode> getCodeLines(const ErrPos & errPos)
+std::optional<LinesOfCode> AbstractPos::getCodeLines() const
 {
-    if (errPos.line <= 0)
+    if (line == 0)
         return std::nullopt;
 
-    if (errPos.origin == foFile) {
-        LinesOfCode loc;
-        try {
-            // FIXME: when running as the daemon, make sure we don't
-            // open a file to which the client doesn't have access.
-            AutoCloseFD fd = open(errPos.file.c_str(), O_RDONLY | O_CLOEXEC);
-            if (!fd) return {};
-
-            // count the newlines.
-            int count = 0;
-            std::string line;
-            int pl = errPos.line - 1;
-            do
-            {
-                line = readLine(fd.get());
-                ++count;
-                if (count < pl)
-                    ;
-                else if (count == pl)
-                    loc.prevLineOfCode = line;
-                else if (count == pl + 1)
-                    loc.errLineOfCode = line;
-                else if (count == pl + 2) {
-                    loc.nextLineOfCode = line;
-                    break;
-                }
-            } while (true);
-            return loc;
-        }
-        catch (EndOfFile & eof) {
-            if (loc.errLineOfCode.has_value())
-                return loc;
-            else
-                return std::nullopt;
-        }
-        catch (std::exception & e) {
-            return std::nullopt;
-        }
-    } else {
-        std::istringstream iss(errPos.file);
+    if (auto source = getSource()) {
+
+        std::istringstream iss(*source);
         // count the newlines.
         int count = 0;
-        std::string line;
-        int pl = errPos.line - 1;
+        std::string curLine;
+        int pl = line - 1;
 
         LinesOfCode loc;
 
-        do
-        {
-            std::getline(iss, line);
+        do {
+            std::getline(iss, curLine);
             ++count;
             if (count < pl)
-            {
                 ;
-            }
             else if (count == pl) {
-                loc.prevLineOfCode = line;
+                loc.prevLineOfCode = curLine;
             } else if (count == pl + 1) {
-                loc.errLineOfCode = line;
+                loc.errLineOfCode = curLine;
             } else if (count == pl + 2) {
-                loc.nextLineOfCode = line;
+                loc.nextLineOfCode = curLine;
                 break;
             }
 
@@ -124,12 +79,14 @@ std::optional<LinesOfCode> getCodeLines(const ErrPos & errPos)
 
         return loc;
     }
+
+    return std::nullopt;
 }
 
 // print lines of code to the ostream, indicating the error column.
 void printCodeLines(std::ostream & out,
     const std::string & prefix,
-    const ErrPos & errPos,
+    const AbstractPos & errPos,
     const LinesOfCode & loc)
 {
     // previous line of code.
@@ -176,32 +133,6 @@ void printCodeLines(std::ostream & out,
     }
 }
 
-// Enough indent to align with with the `... `
-// prepended to each element of the trace
-#define ELLIPSIS_INDENT "  "
-
-void printAtPos(const ErrPos & pos, std::ostream & out)
-{
-    if (pos) {
-        switch (pos.origin) {
-            case foFile: {
-                out << fmt(ELLIPSIS_INDENT "at " ANSI_WARNING "%s:%s" ANSI_NORMAL ":", pos.file, showErrPos(pos));
-                break;
-            }
-            case foString: {
-                out << fmt(ELLIPSIS_INDENT "at " ANSI_WARNING "«string»:%s" ANSI_NORMAL ":", showErrPos(pos));
-                break;
-            }
-            case foStdin: {
-                out << fmt(ELLIPSIS_INDENT "at " ANSI_WARNING "«stdin»:%s" ANSI_NORMAL ":", showErrPos(pos));
-                break;
-            }
-            default:
-                throw Error("invalid FileOrigin in errPos");
-        }
-    }
-}
-
 static std::string indent(std::string_view indentFirst, std::string_view indentRest, std::string_view s)
 {
     std::string res;
@@ -266,27 +197,8 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
         prefix += ":" ANSI_NORMAL " ";
 
     std::ostringstream oss;
-    oss << einfo.msg << "\n";
-
-    if (einfo.errPos.has_value() && *einfo.errPos) {
-        printAtPos(*einfo.errPos, oss);
-
-        auto loc = getCodeLines(*einfo.errPos);
 
-        // lines of code.
-        if (loc.has_value()) {
-            oss << "\n";
-            printCodeLines(oss, "", *einfo.errPos, *loc);
-        }
-        oss << "\n";
-    }
-
-    auto suggestions = einfo.suggestions.trim();
-    if (! suggestions.suggestions.empty()){
-        oss << "Did you mean " <<
-            suggestions.trim() <<
-            "?" << std::endl;
-    }
+    auto noSource = ANSI_ITALIC " (source not available)" ANSI_NORMAL "\n";
 
     /*
      * Traces
@@ -382,36 +294,61 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
      *
      */
 
+    // Enough indent to align with with the `... `
+    // prepended to each element of the trace
+    auto ellipsisIndent = "  ";
+
     bool frameOnly = false;
     if (!einfo.traces.empty()) {
-        unsigned int count = 0;
-        for (auto iter = einfo.traces.rbegin(); iter != einfo.traces.rend(); ++iter) {
+        size_t count = 0;
+        for (const auto & trace : einfo.traces) {
             if (!showTrace && count > 3) {
-                oss << "\n" << "(truncated)" << "\n";
+                oss << "\n" << ANSI_ITALIC "(stack trace truncated)" ANSI_NORMAL << "\n";
                 break;
             }
 
-            if (iter->hint.str().empty()) continue;
-            if (frameOnly && !iter->frame) continue;
+            if (trace.hint.str().empty()) continue;
+            if (frameOnly && !trace.frame) continue;
 
             count++;
-            frameOnly = iter->frame;
+            frameOnly = trace.frame;
 
-            oss << "\n" << "… " << iter->hint.str() << "\n";
+            oss << "\n" << "… " << trace.hint.str() << "\n";
 
-            if (iter->pos.has_value() && (*iter->pos)) {
+            if (trace.pos) {
                 count++;
-                auto pos = iter->pos.value();
-                printAtPos(pos, oss);
 
-                auto loc = getCodeLines(pos);
-                if (loc.has_value()) {
+                oss << "\n" << ellipsisIndent << ANSI_BLUE << "at " ANSI_WARNING << *trace.pos << ANSI_NORMAL << ":";
+
+                if (auto loc = trace.pos->getCodeLines()) {
+                    oss << "\n";
+                    printCodeLines(oss, "", *trace.pos, *loc);
                     oss << "\n";
-                    printCodeLines(oss, "", pos, *loc);
-                }
-                oss << "\n";
+                } else
+                    oss << noSource;
             }
         }
+        oss << "\n" << prefix;
+    }
+
+    oss << einfo.msg << "\n";
+
+    if (einfo.errPos) {
+        oss << "\n" << ANSI_BLUE << "at " ANSI_WARNING << *einfo.errPos << ANSI_NORMAL << ":";
+
+        if (auto loc = einfo.errPos->getCodeLines()) {
+            oss << "\n";
+            printCodeLines(oss, "", *einfo.errPos, *loc);
+            oss << "\n";
+        } else
+            oss << noSource;
+    }
+
+    auto suggestions = einfo.suggestions.trim();
+    if (!suggestions.suggestions.empty()) {
+        oss << "Did you mean " <<
+            suggestions.trim() <<
+            "?" << std::endl;
     }
 
     out << indent(prefix, std::string(filterANSIEscapes(prefix, true).size(), ' '), chomp(oss.str()));