[llvm] [GSYM] Callsites: Add data format support and loading from YAML (PR #109781)

[Ellis Hoag via llvm-commits]

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+//===- CallSiteInfo.h -------------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_DEBUGINFO_GSYM_CALLSITEINFO_H
+#define LLVM_DEBUGINFO_GSYM_CALLSITEINFO_H
+
+#include "llvm/ADT/BitmaskEnum.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/Support/Error.h"
+#include <vector>
+
+namespace llvm {
+class DataExtractor;
+class raw_ostream;
+
+namespace yaml {
+struct FunctionsYAML;
+} // namespace yaml
+
+namespace gsym {
+class FileWriter;
+class GsymCreator;
+struct FunctionInfo;
+struct CallSiteInfo {
+  enum Flags : uint8_t {
+    None = 0,
+    // This flag specifies that the call site can only call a function within
+    // the same link unit as the call site.
+    InternalCall = 1 << 0,
+    // This flag specifies that the call site can only call a function outside
+    // the link unit that the call site is in.
+    ExternalCall = 1 << 1,
+
+    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue*/ ExternalCall),
+  };
+
+  /// The return offset of the call site - relative to the function start.
+  uint64_t ReturnOffset = 0;
+
+  /// Offsets into the string table for function names regex patterns.
+  std::vector<uint32_t> MatchRegex;
+
+  /// Bitwise OR of CallSiteInfo::Flags values
+  uint8_t Flags = CallSiteInfo::Flags::None;
+
+  /// Decode a CallSiteInfo object from a binary data stream.
+  ///
+  /// \param Data The binary stream to read the data from.
+  /// \param Offset The current offset within the data stream.
+  /// \returns A CallSiteInfo or an error describing the issue.
+  static llvm::Expected<CallSiteInfo> decode(DataExtractor &Data,
+                                             uint64_t &Offset);
+
+  /// Encode this CallSiteInfo object into a FileWriter stream.
+  ///
+  /// \param O The binary stream to write the data to.
+  /// \returns An error object that indicates success or failure.
+  llvm::Error encode(FileWriter &O) const;
+};
+
+struct CallSiteInfoCollection {
+  std::vector<CallSiteInfo> CallSites;
+
+  /// Decode a CallSiteInfoCollection object from a binary data stream.
+  ///
+  /// \param Data The binary stream to read the data from.
+  /// \returns A CallSiteInfoCollection or an error describing the issue.
+  static llvm::Expected<CallSiteInfoCollection> decode(DataExtractor &Data);
+
+  /// Encode this CallSiteInfoCollection object into a FileWriter stream.
+  ///
+  /// \param O The binary stream to write the data to.
+  /// \returns An error object that indicates success or failure.
+  llvm::Error encode(FileWriter &O) const;
+};
+
+class CallSiteInfoLoader {
+public:
+  /// Constructor that initializes the CallSiteInfoLoader with necessary data
+  /// structures.
+  ///
+  /// \param GCreator A reference to the GsymCreator.
+  CallSiteInfoLoader(GsymCreator &GCreator) : GCreator(GCreator) {}
+
+  /// This method reads the specified YAML file, parses its content, and updates
+  /// the `Funcs` vector with call site information based on the YAML data.
+  ///
+  /// \param Funcs A reference to a vector of FunctionInfo objects to be
+  /// populated.
+  /// \param YAMLFile A StringRef representing the path to the YAML
+  /// file to be loaded.
+  /// \returns An `llvm::Error` indicating success or describing any issues
+  /// encountered during the loading process.
+  llvm::Error loadYAML(std::vector<FunctionInfo> &Funcs, StringRef YAMLFile);
----------------
ellishg wrote:

I see. If you were storing pointers then I think you could use `ArrayRef`, but that would be wasteful to create.

You should be able to use `const std::vector<FunctionInfo> &`, though.

https://github.com/llvm/llvm-project/pull/109781