lldb/source/Utility/DiagnosticsRendering.cpp

   1 //===-- DiagnosticsRendering.cpp ------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "lldb/Utility/DiagnosticsRendering.h"
  10 #include <cstdint>
  11
  12 using namespace lldb_private;
  13 using namespace lldb;
  14
  15 namespace lldb_private {
  16
  17 char DiagnosticError::ID;
  18
  19 lldb::ErrorType DiagnosticError::GetErrorType() const {
  20   return lldb::eErrorTypeExpression;
  21 }
  22
  23 static llvm::raw_ostream &PrintSeverity(Stream &stream,
  24                                         lldb::Severity severity) {
  25   llvm::HighlightColor color;
  26   llvm::StringRef text;
  27   switch (severity) {
  28   case lldb::eSeverityError:
  29     color = llvm::HighlightColor::Error;
  30     text = "error: ";
  31     break;
  32   case lldb::eSeverityWarning:
  33     color = llvm::HighlightColor::Warning;
  34     text = "warning: ";
  35     break;
  36   case lldb::eSeverityInfo:
  37     color = llvm::HighlightColor::Remark;
  38     text = "note: ";
  39     break;
  40   }
  41   return llvm::WithColor(stream.AsRawOstream(), color, llvm::ColorMode::Enable)
  42          << text;
  43 }
  44
  45 void RenderDiagnosticDetails(Stream &stream,
  46                              std::optional<uint16_t> offset_in_command,
  47                              bool show_inline,
  48                              llvm::ArrayRef<DiagnosticDetail> details) {
  49   if (details.empty())
  50     return;
  51
  52   if (!offset_in_command) {
  53     for (const DiagnosticDetail &detail : details) {
  54       PrintSeverity(stream, detail.severity);
  55       stream << detail.rendered << '\n';
  56     }
  57     return;
  58   }
  59
  60   // Since there is no other way to find this out, use the color
  61   // attribute as a proxy for whether the terminal supports Unicode
  62   // characters.  In the future it might make sense to move this into
  63   // Host so it can be customized for a specific platform.
  64   llvm::StringRef cursor, underline, vbar, joint, hbar, spacer;
  65   if (stream.AsRawOstream().colors_enabled()) {
  66     cursor = "˄";
  67     underline = "˜";
  68     vbar = "│";
  69     joint = "╰";
  70     hbar = "─";
  71     spacer = " ";
  72   } else {
  73     cursor = "^";
  74     underline = "~";
  75     vbar = "|";
  76     joint = "";
  77     hbar = "";
  78     spacer = "";
  79   }
  80
  81   // Partition the diagnostics.
  82   std::vector<DiagnosticDetail> remaining_details, other_details,
  83       hidden_details;
  84   for (const DiagnosticDetail &detail : details) {
  85     if (!show_inline || !detail.source_location) {
  86       other_details.push_back(detail);
  87       continue;
  88     }
  89     if (detail.source_location->hidden) {
  90       hidden_details.push_back(detail);
  91       continue;
  92     }
  93     if (!detail.source_location->in_user_input) {
  94       other_details.push_back(detail);
  95       continue;
  96     }
  97
  98     remaining_details.push_back(detail);
  99   }
 100
 101   // Sort the diagnostics.
 102   auto sort = [](std::vector<DiagnosticDetail> &ds) {
 103     std::stable_sort(ds.begin(), ds.end(), [](auto &d1, auto &d2) {
 104       auto l1 = d1.source_location.value_or(DiagnosticDetail::SourceLocation{});
 105       auto l2 = d2.source_location.value_or(DiagnosticDetail::SourceLocation{});
 106       return std::tie(l1.line, l1.column) < std::tie(l2.line, l2.column);
 107     });
 108   };
 109   sort(remaining_details);
 110   sort(other_details);
 111   sort(hidden_details);
 112
 113   // Print a line with caret indicator(s) below the lldb prompt + command.
 114   const size_t padding = *offset_in_command;
 115   stream << std::string(padding, ' ');
 116   {
 117     size_t x_pos = 1;
 118     for (const DiagnosticDetail &detail : remaining_details) {
 119       auto &loc = *detail.source_location;
 120
 121       if (x_pos > loc.column)
 122         continue;
 123
 124       stream << std::string(loc.column - x_pos, ' ') << cursor;
 125       x_pos = loc.column + 1;
 126       for (unsigned i = 0; i + 1 < loc.length; ++i) {
 127         stream << underline;
 128         x_pos += 1;
 129       }
 130     }
 131   }
 132   stream << '\n';
 133
 134   // Reverse the order within groups of diagnostics that are on the same column.
 135   auto group = [](std::vector<DiagnosticDetail> &details) {
 136     for (auto it = details.begin(), end = details.end(); it != end;) {
 137       auto eq_end = std::find_if(it, end, [&](const DiagnosticDetail &d) {
 138         return d.source_location->column != it->source_location->column;
 139       });
 140       std::reverse(it, eq_end);
 141       it = eq_end;
 142     }
 143   };
 144   group(remaining_details);
 145
 146   // Work through each detail in reverse order using the vector/stack.
 147   bool did_print = false;
 148   for (auto detail = remaining_details.rbegin();
 149        detail != remaining_details.rend();
 150        ++detail, remaining_details.pop_back()) {
 151     // Get the information to print this detail and remove it from the stack.
 152     // Print all the lines for all the other messages first.
 153     stream << std::string(padding, ' ');
 154     size_t x_pos = 1;
 155     for (auto &remaining_detail :
 156          llvm::ArrayRef(remaining_details).drop_back(1)) {
 157       uint16_t column = remaining_detail.source_location->column;
 158       // Is this a note with the same column as another diagnostic?
 159       if (column == detail->source_location->column)
 160         continue;
 161
 162       if (column >= x_pos) {
 163         stream << std::string(column - x_pos, ' ') << vbar;
 164         x_pos = column + 1;
 165       }
 166     }
 167
 168     uint16_t column = detail->source_location->column;
 169     // Print the line connecting the ^ with the error message.
 170     if (column >= x_pos)
 171       stream << std::string(column - x_pos, ' ') << joint << hbar << spacer;
 172
 173     // Print a colorized string based on the message's severity type.
 174     PrintSeverity(stream, detail->severity);
 175
 176     // Finally, print the message and start a new line.
 177     stream << detail->message << '\n';
 178     did_print = true;
 179   }
 180
 181   // Print the non-located details.
 182   for (const DiagnosticDetail &detail : other_details) {
 183     PrintSeverity(stream, detail.severity);
 184     stream << detail.rendered << '\n';
 185     did_print = true;
 186   }
 187
 188   // Print the hidden details as a last resort.
 189   if (!did_print)
 190     for (const DiagnosticDetail &detail : hidden_details) {
 191       PrintSeverity(stream, detail.severity);
 192       stream << detail.rendered << '\n';
 193     }
 194 }
 195
 196 } // namespace lldb_private