Add lookup functions for efficient lookups of addresses when using GsymReader classes.

Summary:
Lookup functions are designed to not fully decode a FunctionInfo, LineTable or InlineInfo, they decode only what is needed into a LookupResult object. This allows lookups to avoid costly memory allocations and avoid parsing large amounts of information one a suitable match is found.

LookupResult objects contain the address that was looked up, the concrete function address range, the name of the concrete function, and a list of source locations. One for each inline function, and one for the concrete function. This allows one address to turn into multiple frames and improves the signal you get when symbolicating addresses in GSYM files.

Reviewers: labath, aprantl

Subscribers: mgorny, hiraditya, llvm-commits, lldb-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70993

1 files changed, 68 insertions, 0 deletions

diff --git a/llvm/lib/DebugInfo/GSYM/LookupResult.cpp b/llvm/lib/DebugInfo/GSYM/LookupResult.cpp
new file mode 100644
index 00000000000..7b7ee8c3d79
--- /dev/null
+++ b/llvm/lib/DebugInfo/GSYM/LookupResult.cpp
@@ -0,0 +1,68 @@
+//===- LookupResult.cpp -------------------------------------------------*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DebugInfo/GSYM/LookupResult.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+using namespace gsym;
+
+std::string LookupResult::getSourceFile(uint32_t Index) const {
+  std::string Fullpath;
+  if (Index < Locations.size()) {
+    if (!Locations[Index].Dir.empty()) {
+      if (Locations[Index].Base.empty()) {
+        Fullpath = Locations[Index].Dir;
+      } else {
+        llvm::SmallString<64> Storage;
+        llvm::sys::path::append(Storage, Locations[Index].Dir,
+                                Locations[Index].Base);
+        Fullpath.assign(Storage.begin(), Storage.end());
+      }
+    } else if (!Locations[Index].Base.empty())
+      Fullpath = Locations[Index].Base;
+  }
+  return Fullpath;
+}
+
+raw_ostream &llvm::gsym::operator<<(raw_ostream &OS, const SourceLocation &SL) {
+  OS << SL.Name << " @ ";
+  if (!SL.Dir.empty()) {
+    OS << SL.Dir;
+    if (SL.Dir.contains('\\') and not SL.Dir.contains('/'))
+      OS << '\\';
+    else
+      OS << '/';
+  }
+  if (SL.Base.empty())
+    OS << "<invalid-file>";
+  else
+    OS << SL.Base;
+  OS << ':' << SL.Line;
+  return OS;
+}
+
+raw_ostream &llvm::gsym::operator<<(raw_ostream &OS, const LookupResult &LR) {
+  OS << HEX64(LR.LookupAddr) << ": ";
+  auto NumLocations = LR.Locations.size();
+  for (size_t I = 0; I < NumLocations; ++I) {
+    if (I > 0) {
+      OS << '\n';
+      OS.indent(20);
+    }
+    const bool IsInlined = I + 1 != NumLocations;
+    OS << LR.Locations[I];
+    if (IsInlined)
+      OS << " [inlined]";
+  }
+  OS << '\n';
+  return OS;
+}