[lldb] Implement SymbolFile::GetCompileOptions

Implement SymbolFile::GetCompileOptions, which returns a map from
compilation units to compilation arguments associated with that unit.

Differential Revision: https://reviews.llvm.org/D147748

Author: augusto2112

lldb/include/lldb/Symbol/SymbolFile.h

@@ -30,6 +30,7 @@
 
 #include <mutex>
 #include <optional>
+#include <unordered_map>
 
 #if defined(LLDB_CONFIGURATION_DEBUG)
 #define ASSERT_MODULE_LOCK(expr) (expr->AssertModuleLock())
@@ -435,9 +436,20 @@ class SymbolFile : public PluginInterface {
 
   virtual lldb::TypeSP CopyType(const lldb::TypeSP &other_type) = 0;
 
+  /// Returns a map of compilation unit to the compile option arguments
+  /// associated with that compilation unit.
+  std::unordered_map<lldb::CompUnitSP, Args> GetCompileOptions() {
+    std::unordered_map<lldb::CompUnitSP, Args> args;
+    GetCompileOptions(args);
+    return args;
+  }
+
 protected:
   void AssertModuleLock();
 
+  virtual void GetCompileOptions(
+      std::unordered_map<lldb::CompUnitSP, lldb_private::Args> &args) {}
+
 private:
   SymbolFile(const SymbolFile &) = delete;
   const SymbolFile &operator=(const SymbolFile &) = delete;

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

@@ -4255,3 +4255,30 @@ Status SymbolFileDWARF::CalculateFrameVariableError(StackFrame &frame) {
   return Status("no variable information is available in debug info for this "
                 "compile unit");
 }
+
+void SymbolFileDWARF::GetCompileOptions(
+    std::unordered_map<lldb::CompUnitSP, lldb_private::Args> &args) {
+
+  const uint32_t num_compile_units = GetNumCompileUnits();
+
+  for (uint32_t cu_idx = 0; cu_idx < num_compile_units; ++cu_idx) {
+    lldb::CompUnitSP comp_unit = GetCompileUnitAtIndex(cu_idx);
+    if (!comp_unit)
+      continue;
+
+    DWARFUnit *dwarf_cu = GetDWARFCompileUnit(comp_unit.get());
+    if (!dwarf_cu)
+      continue;
+
+    const DWARFBaseDIE die = dwarf_cu->GetUnitDIEOnly();
+    if (!die)
+      continue;
+
+    const char *flags = die.GetAttributeValueAsString(DW_AT_APPLE_flags, NULL);
+
+    if (!flags)
+      continue;
+    args.insert({comp_unit, Args(flags)});
+  }
+}
+

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

@@ -523,6 +523,9 @@ class SymbolFileDWARF : public lldb_private::SymbolFileCommon {
 
   void InitializeFirstCodeAddress();
 
+  void GetCompileOptions(
+      std::unordered_map<lldb::CompUnitSP, lldb_private::Args> &args) override;
+
   lldb::ModuleWP m_debug_map_module_wp;
   SymbolFileDWARFDebugMap *m_debug_map_symfile;
 

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.cpp

@@ -1549,3 +1549,12 @@ Status SymbolFileDWARFDebugMap::CalculateFrameVariableError(StackFrame &frame) {
   }
   return Status();
 }
+
+void SymbolFileDWARFDebugMap::GetCompileOptions(
+    std::unordered_map<lldb::CompUnitSP, lldb_private::Args> &args) {
+
+  ForEachSymbolFile([&](SymbolFileDWARF *oso_dwarf) -> bool {
+    oso_dwarf->GetCompileOptions(args);
+    return false;
+  });
+}

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h

@@ -153,6 +153,9 @@ class SymbolFileDWARFDebugMap : public lldb_private::SymbolFileCommon {
   // Statistics overrides.
   lldb_private::ModuleList GetDebugInfoModules() override;
 
+  void GetCompileOptions(
+      std::unordered_map<lldb::CompUnitSP, lldb_private::Args> &args) override;
+
 protected:
   enum { kHaveInitializedOSOs = (1 << 0), kNumFlags };