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

[Kyungwoo Lee via llvm-commits]

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@@ -0,0 +1,188 @@
+//===- 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/DenseMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSet.h"
+#include "llvm/DebugInfo/GSYM/ExtractRanges.h"
+#include "llvm/Support/YAMLParser.h"
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+namespace llvm {
+class DataExtractor;
+class raw_ostream;
+class StringTableBuilder;
+class CachedHashStringRef;
+
+namespace yaml {
+struct CallSiteYAML;
+struct FunctionYAML;
+struct FunctionsYAML;
+} // namespace yaml
+
+namespace gsym {
+class FileWriter;
+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,
+  };
+
+  /// The return address of the call site.
+  uint64_t ReturnAddress;
+
+  /// 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.
+  /// \param BaseAddr The base address for decoding (unused here but included
+  /// for consistency).
+  ///
+  /// \returns A CallSiteInfo or an error describing the issue.
+  static llvm::Expected<CallSiteInfo>
+  decode(DataExtractor &Data, uint64_t &Offset, uint64_t BaseAddr);
+
+  /// 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.
+  /// \param BaseAddr The base address for decoding (unused here but included
+  /// for consistency).
+  ///
+  /// \returns A CallSiteInfoCollection or an error describing the issue.
+  static llvm::Expected<CallSiteInfoCollection> decode(DataExtractor &Data,
+                                                       uint64_t BaseAddr);
+
+  /// 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;
+};
+
+bool operator==(const CallSiteInfoCollection &LHS,
+                const CallSiteInfoCollection &RHS);
+
+bool operator==(const CallSiteInfo &LHS, const CallSiteInfo &RHS);
+
+class CallSiteInfoLoader {
+public:
+  /// Constructor that initializes the CallSiteInfoLoader with necessary data
+  /// structures.
+  ///
+  /// \param StringOffsetMap A reference to a DenseMap that maps existing string
+  /// offsets to CachedHashStringRef. \param StrTab A reference to a
+  /// StringTableBuilder used for managing looking up and creating new strings.
+  /// \param StringStorage A reference to a StringSet for storing the data for
+  /// generated strings.
+  CallSiteInfoLoader(DenseMap<uint64_t, CachedHashStringRef> &StringOffsetMap,
+                     StringTableBuilder &StrTab, StringSet<> &StringStorage)
+      : StringOffsetMap(StringOffsetMap), StrTab(StrTab),
+        StringStorage(StringStorage) {}
+
+  /// Loads call site information from a YAML file and populates the provided
+  /// FunctionInfo vector.
+  ///
+  /// 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);
+
+private:
+  /// Retrieves an existing string from the StringOffsetMap using the provided
+  /// offset.
+  ///
+  /// \param offset A 32-bit unsigned integer representing the offset of the
+  /// string.
+  ///
+  /// \returns A StringRef corresponding to the string for the given offset.
+  ///
+  /// \note This method asserts that the offset exists in the StringOffsetMap.
+  StringRef stringFromOffset(uint32_t offset) const;
+
+  /// Obtains the offset corresponding to a given string in the StrTab. If the
+  /// string does not already exist, it is created.
+  ///
+  /// \param str A StringRef representing the string for which the offset is
+  /// requested.
+  ///
+  /// \returns A 32-bit unsigned integer representing the offset of the string.
+  uint32_t offsetFromString(StringRef str);
----------------
kyulee-com wrote:

```suggestion
  uint32_t offsetFromString(StringRef Str);
```

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