[llvm] [llvm-objdump] Add the --visualize-jumps option (PR #74858)

[Jonathan Thackray via llvm-commits]

================
@@ -503,5 +506,188 @@ SourcePrinter::SourcePrinter(const object::ObjectFile *Obj,
   Symbolizer.reset(new symbolize::LLVMSymbolizer(SymbolizerOpts));
 }
 
+// TODO Light/dark shades? 256-color terminals?
+const raw_ostream::Colors LineColors[] = {
+    raw_ostream::RED,  raw_ostream::GREEN,   raw_ostream::YELLOW,
+    raw_ostream::BLUE, raw_ostream::MAGENTA, raw_ostream::CYAN,
+};
+
+raw_ostream::Colors ControlFlowPrinter::PickColor() {
+  if (!OutputMode.color_enabled())
+    return raw_ostream::RESET;
+  auto Ret = LineColors[NextColorIdx];
+  NextColorIdx =
+      (NextColorIdx + 1) % (sizeof(LineColors) / sizeof(LineColors[0]));
+  return Ret;
+}
+
+void ControlFlowPrinter::addEdge(uint64_t From, uint64_t To) {
+  auto It = Targets.find(To);
+  if (It == Targets.end())
+    It = Targets.insert(std::make_pair(To, ControlFlowTarget(To, PickColor())))
+             .first;
+  It->second.addSource(From);
+}
+
+void ControlFlowPrinter::finalise() {
+  if (!OutputMode.enabled()) {
+    setControlFlowColumnWidth(0);
+    return;
+  }
+
+  SmallVector<ControlFlowTarget *> SortedTargets;
+  for (auto &[Addr, Info] : Targets) {
+    SortedTargets.push_back(&Info);
+  }
+  std::sort(SortedTargets.begin(), SortedTargets.end(),
+            [](ControlFlowTarget *LHS, ControlFlowTarget *RHS) {
+              return LHS->Length() < RHS->Length();
+            });
+
+  // FIXME This is O(n^3) in the worst case, can we do better?
+  for (auto &T : SortedTargets) {
+    int Column = 0;
+    for (;; ++Column)
+      if (!std::any_of(SortedTargets.begin(), SortedTargets.end(),
+                       [T, Column](ControlFlowTarget *T2) {
+                         return T != T2 && T2->Column == Column &&
+                                T->Overlaps(*T2);
+                       }))
+        break;
+    T->Column = Column;
+    MaxColumn = std::max(MaxColumn, Column);
+  }
+
+  setControlFlowColumnWidth(MaxColumn * 2 + 4);
+}
+
+const char *ControlFlowPrinter::getLineChar(LineChar C) const {
+  bool IsASCII = !OutputMode.unicode_enabled();
+  switch (C) {
+  case LineChar::Horiz:
+    return IsASCII ? "-" : u8"\u2500";
+  case LineChar::Vert:
+    return IsASCII ? "|" : u8"\u2502";
+  case LineChar::TopCorner:
+    return IsASCII ? "/" : u8"\u256d";
+  case LineChar::BottomCorner:
+    return IsASCII ? "\\" : u8"\u2570";
+  case LineChar::Tee:
+    return IsASCII ? "+" : u8"\u251c";
+  case LineChar::Arrow:
+    return ">";
+  }
+  llvm_unreachable("Unhandled LineChar enum");
+}
+
+#define C(id) getLineChar(LineChar::id)
----------------
jthackray wrote:

Nit: would prefer not to have a #define if possible

https://github.com/llvm/llvm-project/pull/74858