[llvm-cov] Separate presentation logic from formatting logic, NFC

This makes it easier to add renderers for new kinds of output formats.

- Define and document a pure-virtual coverage rendering interface.
- Move the text-based rendering logic into its a new file.
- Re-work the API to better reflect the presentation/formatting split.

llvm-svn: 273767

1 files changed, 193 insertions, 0 deletions

diff --git a/llvm/tools/llvm-cov/SourceCoverageViewText.cpp b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
new file mode 100644
index 00000000000..a7cb5075583
--- /dev/null
+++ b/llvm/tools/llvm-cov/SourceCoverageViewText.cpp
@@ -0,0 +1,193 @@
+//===- SourceCoverageViewText.cpp - A text-based code coverage view -------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the text-based coverage renderer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SourceCoverageViewText.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+
+using namespace llvm;
+
+namespace {
+
+constexpr unsigned LineCoverageColumnWidth = 7;
+constexpr unsigned LineNumberColumnWidth = 5;
+
+/// \brief Get the width of the leading columns.
+unsigned getCombinedColumnWidth(const CoverageViewOptions &Opts) {
+  return (Opts.ShowLineStats ? LineCoverageColumnWidth + 1 : 0) +
+         (Opts.ShowLineNumbers ? LineNumberColumnWidth + 1 : 0);
+}
+
+/// \brief The width of the line that is used to divide between the view and
+/// the subviews.
+unsigned getDividerWidth(const CoverageViewOptions &Opts) {
+  return getCombinedColumnWidth(Opts) + 4;
+}
+
+} // anonymous namespace
+
+void SourceCoverageViewText::renderSourceName(raw_ostream &OS) {
+  getOptions().colored_ostream(OS, raw_ostream::CYAN) << getSourceName()
+                                                      << ":\n";
+}
+
+void SourceCoverageViewText::renderLinePrefix(raw_ostream &OS,
+                                              unsigned ViewDepth) {
+  for (unsigned I = 0; I < ViewDepth; ++I)
+    OS << "  |";
+}
+
+void SourceCoverageViewText::renderViewDivider(raw_ostream &OS,
+                                               unsigned ViewDepth) {
+  assert(ViewDepth != 0 && "Cannot render divider at top level");
+  renderLinePrefix(OS, ViewDepth - 1);
+  OS.indent(2);
+  unsigned Length = getDividerWidth(getOptions());
+  for (unsigned I = 0; I < Length; ++I)
+    OS << '-';
+  OS << '\n';
+}
+
+void SourceCoverageViewText::renderLine(
+    raw_ostream &OS, LineRef L,
+    const coverage::CoverageSegment *WrappedSegment,
+    CoverageSegmentArray Segments, unsigned ExpansionCol, unsigned ViewDepth) {
+  StringRef Line = L.Line;
+  unsigned LineNumber = L.LineNo;
+
+  Optional<raw_ostream::Colors> Highlight;
+  SmallVector<std::pair<unsigned, unsigned>, 2> HighlightedRanges;
+
+  // The first segment overlaps from a previous line, so we treat it specially.
+  if (WrappedSegment && WrappedSegment->HasCount && WrappedSegment->Count == 0)
+    Highlight = raw_ostream::RED;
+
+  // Output each segment of the line, possibly highlighted.
+  unsigned Col = 1;
+  for (const auto *S : Segments) {
+    unsigned End = std::min(S->Col, static_cast<unsigned>(Line.size()) + 1);
+    colored_ostream(OS, Highlight ? *Highlight : raw_ostream::SAVEDCOLOR,
+                    getOptions().Colors && Highlight, /*Bold=*/false,
+                    /*BG=*/true)
+        << Line.substr(Col - 1, End - Col);
+    if (getOptions().Debug && Highlight)
+      HighlightedRanges.push_back(std::make_pair(Col, End));
+    Col = End;
+    if (Col == ExpansionCol)
+      Highlight = raw_ostream::CYAN;
+    else if (S->HasCount && S->Count == 0)
+      Highlight = raw_ostream::RED;
+    else
+      Highlight = None;
+  }
+
+  // Show the rest of the line.
+  colored_ostream(OS, Highlight ? *Highlight : raw_ostream::SAVEDCOLOR,
+                  getOptions().Colors && Highlight, /*Bold=*/false, /*BG=*/true)
+      << Line.substr(Col - 1, Line.size() - Col + 1);
+  OS << '\n';
+
+  if (getOptions().Debug) {
+    for (const auto &Range : HighlightedRanges)
+      errs() << "Highlighted line " << LineNumber << ", " << Range.first
+             << " -> " << Range.second << '\n';
+    if (Highlight)
+      errs() << "Highlighted line " << LineNumber << ", " << Col << " -> ?\n";
+  }
+}
+
+void SourceCoverageViewText::renderLineCoverageColumn(
+    raw_ostream &OS, const LineCoverageStats &Line) {
+  if (!Line.isMapped()) {
+    OS.indent(LineCoverageColumnWidth) << '|';
+    return;
+  }
+  std::string C = formatCount(Line.ExecutionCount);
+  OS.indent(LineCoverageColumnWidth - C.size());
+  colored_ostream(OS, raw_ostream::MAGENTA,
+                  Line.hasMultipleRegions() && getOptions().Colors)
+      << C;
+  OS << '|';
+}
+
+void SourceCoverageViewText::renderLineNumberColumn(raw_ostream &OS,
+                                                    unsigned LineNo) {
+  SmallString<32> Buffer;
+  raw_svector_ostream BufferOS(Buffer);
+  BufferOS << LineNo;
+  auto Str = BufferOS.str();
+  // Trim and align to the right.
+  Str = Str.substr(0, std::min(Str.size(), (size_t)LineNumberColumnWidth));
+  OS.indent(LineNumberColumnWidth - Str.size()) << Str << '|';
+}
+
+void SourceCoverageViewText::renderRegionMarkers(
+    raw_ostream &OS, CoverageSegmentArray Segments, unsigned ViewDepth) {
+  renderLinePrefix(OS, ViewDepth);
+  OS.indent(getCombinedColumnWidth(getOptions()));
+
+  unsigned PrevColumn = 1;
+  for (const auto *S : Segments) {
+    if (!S->IsRegionEntry)
+      continue;
+    // Skip to the new region.
+    if (S->Col > PrevColumn)
+      OS.indent(S->Col - PrevColumn);
+    PrevColumn = S->Col + 1;
+    std::string C = formatCount(S->Count);
+    PrevColumn += C.size();
+    OS << '^' << C;
+  }
+  OS << '\n';
+
+  if (getOptions().Debug)
+    for (const auto *S : Segments)
+      errs() << "Marker at " << S->Line << ":" << S->Col << " = "
+             << formatCount(S->Count) << (S->IsRegionEntry ? "\n" : " (pop)\n");
+}
+
+unsigned SourceCoverageViewText::renderExpansionView(
+    raw_ostream &OS, ExpansionView &ESV, Optional<LineRef> FirstLine,
+    unsigned ExpansionCol, const coverage::CoverageSegment *WrappedSegment,
+    CoverageSegmentArray LineSegments, unsigned ViewDepth) {
+  unsigned NextExpansionCol = ExpansionCol;
+
+  if (FirstLine.hasValue()) {
+    // Re-render the current line and highlight the expansion range for
+    // this subview.
+    NextExpansionCol = ESV.getStartCol();
+    renderLinePrefix(OS, ViewDepth);
+    OS.indent(getCombinedColumnWidth(getOptions()) + (ViewDepth == 0 ? 0 : 1));
+    renderLine(OS, *FirstLine, WrappedSegment, LineSegments, ExpansionCol,
+               ViewDepth);
+    renderViewDivider(OS, ViewDepth + 1);
+  }
+
+  // Render the child subview.
+  if (getOptions().Debug)
+    errs() << "Expansion at line " << ESV.getLine() << ", " << ESV.getStartCol()
+           << " -> " << ESV.getEndCol() << '\n';
+  ESV.View->print(OS, /*WholeFile=*/false, /*ShowSourceName=*/false,
+                  ViewDepth + 1);
+
+  return NextExpansionCol;
+}
+
+void SourceCoverageViewText::renderInstantiationView(raw_ostream &OS,
+                                                     InstantiationView &ISV,
+                                                     unsigned ViewDepth) {
+  renderViewDivider(OS, ViewDepth);
+  renderLinePrefix(OS, ViewDepth);
+  OS << ' ';
+  ISV.View->print(OS, /*WholeFile=*/false, /*ShowSourceName=*/true, ViewDepth);
+}