[DebugLine] Don't try to guess the path style

In r368879 I made an attempt to guess the path style from the files in
the line table. After some consideration I now think this is a poor
idea. This patch undoes that behavior and instead adds an optional
argument to specify the path style. This allows us to make that decision
elsewhere where we have more information. In case of LLDB based on the
Unit.

llvm-svn: 369072

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

@@ -178,11 +178,10 @@ ParseLLVMLineTable(lldb_private::DWARFContext &context,
   return *line_table;
 }
 
-static FileSpecList
-ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
-                              const llvm::DWARFDebugLine::Prologue &prologue,
-                              llvm::StringRef compile_dir = {},
-                              FileSpec first_file = {}) {
+static FileSpecList ParseSupportFilesFromPrologue(
+    const lldb::ModuleSP &module,
+    const llvm::DWARFDebugLine::Prologue &prologue, FileSpec::Style style,
+    llvm::StringRef compile_dir = {}, FileSpec first_file = {}) {
   FileSpecList support_files;
   support_files.Append(first_file);
 
@@ -191,8 +190,8 @@ ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
     std::string original_file;
     if (!prologue.getFileNameByIndex(
             idx, compile_dir,
-            llvm::DILineInfoSpecifier::FileLineInfoKind::Default,
-            original_file)) {
+            llvm::DILineInfoSpecifier::FileLineInfoKind::Default, original_file,
+            style)) {
       // Always add an entry so the indexes remain correct.
       support_files.EmplaceBack();
       continue;
@@ -202,18 +201,14 @@ ParseSupportFilesFromPrologue(const lldb::ModuleSP &module,
     if (!prologue.getFileNameByIndex(
             idx, compile_dir,
             llvm::DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
-            remapped_file)) {
+            remapped_file, style)) {
       // Always add an entry so the indexes remain correct.
-      support_files.EmplaceBack(original_file,
-                                FileSpec::GuessPathStyle(original_file)
-                                    .getValueOr(FileSpec::Style::native));
+      support_files.EmplaceBack(original_file, style);
       continue;
     }
 
     module->RemapSourceFile(llvm::StringRef(original_file), remapped_file);
-    support_files.EmplaceBack(remapped_file,
-                              FileSpec::GuessPathStyle(remapped_file)
-                                  .getValueOr(FileSpec::Style::native));
+    support_files.EmplaceBack(remapped_file, style);
   }
 
   return support_files;
@@ -893,8 +888,8 @@ SymbolFileDWARF::GetTypeUnitSupportFiles(DWARFTypeUnit &tu) {
                      "SymbolFileDWARF::GetTypeUnitSupportFiles failed to parse "
                      "the line table prologue");
     } else {
-      list =
-          ParseSupportFilesFromPrologue(GetObjectFile()->GetModule(), prologue);
+      list = ParseSupportFilesFromPrologue(GetObjectFile()->GetModule(),
+                                           prologue, tu.GetPathStyle());
     }
   }
   return list;
@@ -1013,7 +1008,7 @@ bool SymbolFileDWARF::ParseLineTable(CompileUnit &comp_unit) {
   }
 
   comp_unit.SetSupportFiles(ParseSupportFilesFromPrologue(
-      comp_unit.GetModule(), line_table->Prologue,
+      comp_unit.GetModule(), line_table->Prologue, dwarf_cu->GetPathStyle(),
       dwarf_cu->GetCompilationDirectory().GetCString(), FileSpec(comp_unit)));
 
   return true;

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugLine.h

@@ -18,6 +18,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
 #include "llvm/Support/MD5.h"
+#include "llvm/Support/Path.h"
 #include <cstdint>
 #include <map>
 #include <string>
@@ -128,9 +129,11 @@ class DWARFDebugLine {
 
     bool hasFileAtIndex(uint64_t FileIndex) const;
 
-    bool getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
-                            DILineInfoSpecifier::FileLineInfoKind Kind,
-                            std::string &Result) const;
+    bool
+    getFileNameByIndex(uint64_t FileIndex, StringRef CompDir,
+                       DILineInfoSpecifier::FileLineInfoKind Kind,
+                       std::string &Result,
+                       sys::path::Style Style = sys::path::Style::native) const;
 
     void clear();
     void dump(raw_ostream &OS, DIDumpOptions DumpOptions) const;

llvm/lib/DebugInfo/DWARF/DWARFDebugLine.cpp

@@ -16,7 +16,6 @@
 #include "llvm/DebugInfo/DWARF/DWARFRelocMap.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Format.h"
-#include "llvm/Support/Path.h"
 #include "llvm/Support/WithColor.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -1041,28 +1040,9 @@ static bool isPathAbsoluteOnWindowsOrPosix(const Twine &Path) {
          sys::path::is_absolute(Path, sys::path::Style::windows);
 }
 
-/// If given an absolute path, guess the path style.
-static sys::path::Style GuessPathStyle(StringRef Path) {
-  bool Posix = sys::path::is_absolute(Path, sys::path::Style::posix);
-  bool Windows = sys::path::is_absolute(Path, sys::path::Style::windows);
-  // This is a relative path.
-  if (!Posix && !Windows)
-    return sys::path::Style::native;
-  // This is a valid absolute path for both Windows and Posix.
-  if (Posix && Windows)
-    return sys::path::Style::native;
-  if (Posix)
-    return sys::path::Style::posix;
-  if (Windows)
-    return sys::path::Style::windows;
-
-  llvm_unreachable("All combinations should have been handled.");
-}
-
-bool DWARFDebugLine::Prologue::getFileNameByIndex(uint64_t FileIndex,
-                                                  StringRef CompDir,
-                                                  FileLineInfoKind Kind,
-                                                  std::string &Result) const {
+bool DWARFDebugLine::Prologue::getFileNameByIndex(
+    uint64_t FileIndex, StringRef CompDir, FileLineInfoKind Kind,
+    std::string &Result, sys::path::Style Style) const {
   if (Kind == FileLineInfoKind::None || !hasFileAtIndex(FileIndex))
     return false;
   const FileNameEntry &Entry = getFileNameEntry(FileIndex);
@@ -1088,11 +1068,11 @@ bool DWARFDebugLine::Prologue::getFileNameByIndex(uint64_t FileIndex,
     // We know that FileName is not absolute, the only way to have an
     // absolute path at this point would be if IncludeDir is absolute.
     if (!CompDir.empty() && !isPathAbsoluteOnWindowsOrPosix(IncludeDir))
-      sys::path::append(FilePath, GuessPathStyle(CompDir), CompDir);
+      sys::path::append(FilePath, Style, CompDir);
   }
 
   // sys::path::append skips empty strings.
-  sys::path::append(FilePath, GuessPathStyle(IncludeDir), IncludeDir, FileName);
+  sys::path::append(FilePath, Style, IncludeDir, FileName);
   Result = FilePath.str();
   return true;
 }