Refactor fetching file/line info from DWARFContext to simplify the

code and allow better code reuse. Make the code a bit more conforming
to LLVM code style.
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162895 91177308-0d34-0410-b5e6-96231b3b80d8

lib/DebugInfo/DWARFContext.cpp

@@ -145,75 +145,93 @@ namespace {
   };
 }
 
-DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t offset) {
+DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
   if (CUs.empty())
     parseCompileUnits();
 
-  DWARFCompileUnit *i = std::lower_bound(CUs.begin(), CUs.end(), offset,
-                                         OffsetComparator());
-  if (i != CUs.end())
-    return &*i;
+  DWARFCompileUnit *CU = std::lower_bound(CUs.begin(), CUs.end(), Offset,
+                                          OffsetComparator());
+  if (CU != CUs.end())
+    return &*CU;
   return 0;
 }
 
-DILineInfo DWARFContext::getLineInfoForAddress(uint64_t address,
-    DILineInfoSpecifier specifier) {
+DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
   // First, get the offset of the compile unit.
-  uint32_t cuOffset = getDebugAranges()->findAddress(address);
+  uint32_t CUOffset = getDebugAranges()->findAddress(Address);
   // Retrieve the compile unit.
-  DWARFCompileUnit *cu = getCompileUnitForOffset(cuOffset);
-  if (!cu)
+  return getCompileUnitForOffset(CUOffset);
+}
+
+static bool getFileNameForCompileUnit(
+    DWARFCompileUnit *CU, const DWARFDebugLine::LineTable *LineTable,
+    uint64_t FileIndex, bool NeedsAbsoluteFilePath, std::string &FileName) {
+  if (CU == 0 ||
+      LineTable == 0 ||
+      !LineTable->getFileNameByIndex(FileIndex, NeedsAbsoluteFilePath,
+                                     FileName))
+    return false;
+  if (NeedsAbsoluteFilePath && sys::path::is_relative(FileName)) {
+    // We may still need to append compilation directory of compile unit.
+    SmallString<16> AbsolutePath;
+    if (const char *CompilationDir = CU->getCompilationDir()) {
+      sys::path::append(AbsolutePath, CompilationDir);
+    }
+    sys::path::append(AbsolutePath, FileName);
+    FileName = AbsolutePath.str();
+  }
+  return true;
+}
+
+bool
+DWARFContext::getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
+                                            uint64_t Address,
+                                            bool NeedsAbsoluteFilePath,
+                                            std::string &FileName,
+                                            uint32_t &Line, uint32_t &Column) {
+  // Get the line table for this compile unit.
+  const DWARFDebugLine::LineTable *LineTable = getLineTableForCompileUnit(CU);
+  if (!LineTable)
+    return false;
+  // Get the index of row we're looking for in the line table.
+  uint32_t RowIndex = LineTable->lookupAddress(Address);
+  if (RowIndex == -1U)
+    return false;
+  // Take file number and line/column from the row.
+  const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
+  if (!getFileNameForCompileUnit(CU, LineTable, Row.File,
+                                 NeedsAbsoluteFilePath, FileName))
+    return false;
+  Line = Row.Line;
+  Column = Row.Column;
+  return true;
+}
+
+DILineInfo DWARFContext::getLineInfoForAddress(uint64_t Address,
+    DILineInfoSpecifier Specifier) {
+  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
+  if (!CU)
     return DILineInfo();
-  SmallString<16> fileName("<invalid>");
-  SmallString<16> functionName("<invalid>");
-  uint32_t line = 0;
-  uint32_t column = 0;
-  if (specifier.needs(DILineInfoSpecifier::FunctionName)) {
-    const DWARFDebugInfoEntryMinimal *function_die =
-        cu->getFunctionDIEForAddress(address);
-    if (function_die) {
-      if (const char *name = function_die->getSubprogramName(cu))
-        functionName = name;
+  std::string FileName = "<invalid>";
+  std::string FunctionName = "<invalid>";
+  uint32_t Line = 0;
+  uint32_t Column = 0;
+  if (Specifier.needs(DILineInfoSpecifier::FunctionName)) {
+    const DWARFDebugInfoEntryMinimal *FunctionDIE =
+        CU->getFunctionDIEForAddress(Address);
+    if (FunctionDIE) {
+      if (const char *Name = FunctionDIE->getSubprogramName(CU))
+        FunctionName = Name;
     }
   }
-  if (specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
-    // Get the line table for this compile unit.
-    const DWARFDebugLine::LineTable *lineTable = getLineTableForCompileUnit(cu);
-    if (lineTable) {
-      // Get the index of the row we're looking for in the line table.
-      uint32_t rowIndex = lineTable->lookupAddress(address);
-      if (rowIndex != -1U) {
-        const DWARFDebugLine::Row &row = lineTable->Rows[rowIndex];
-        // Take file/line info from the line table.
-        const DWARFDebugLine::FileNameEntry &fileNameEntry =
-            lineTable->Prologue.FileNames[row.File - 1];
-        fileName = fileNameEntry.Name;
-        if (specifier.needs(DILineInfoSpecifier::AbsoluteFilePath) &&
-            sys::path::is_relative(fileName.str())) {
-          // Append include directory of file (if it is present in line table)
-          // and compilation directory of compile unit to make path absolute.
-          const char *includeDir = 0;
-          if (uint64_t includeDirIndex = fileNameEntry.DirIdx) {
-            includeDir = lineTable->Prologue
-                         .IncludeDirectories[includeDirIndex - 1];
-          }
-          SmallString<16> absFileName;
-          if (includeDir == 0 || sys::path::is_relative(includeDir)) {
-            if (const char *compilationDir = cu->getCompilationDir())
-              sys::path::append(absFileName, compilationDir);
-          }
-          if (includeDir) {
-            sys::path::append(absFileName, includeDir);
-          }
-          sys::path::append(absFileName, fileName.str());
-          fileName = absFileName;
-        }
-        line = row.Line;
-        column = row.Column;
-      }
-    }
+  if (Specifier.needs(DILineInfoSpecifier::FileLineInfo)) {
+    const bool NeedsAbsoluteFilePath =
+        Specifier.needs(DILineInfoSpecifier::AbsoluteFilePath);
+    getFileLineInfoForCompileUnit(CU, Address, NeedsAbsoluteFilePath,
+                                  FileName, Line, Column);
   }
-  return DILineInfo(fileName, functionName, line, column);
+  return DILineInfo(StringRef(FileName), StringRef(FunctionName),
+                    Line, Column);
 }
 
 void DWARFContextInMemory::anchor() { }

lib/DebugInfo/DWARFContext.h

@@ -54,9 +54,6 @@ public:
     return &CUs[index];
   }
 
-  /// Return the compile unit that includes an offset (relative to .debug_info).
-  DWARFCompileUnit *getCompileUnitForOffset(uint32_t offset);
-
   /// Get a pointer to the parsed DebugAbbrev object.
   const DWARFDebugAbbrev *getDebugAbbrev();
 
@@ -67,8 +64,8 @@ public:
   const DWARFDebugLine::LineTable *
   getLineTableForCompileUnit(DWARFCompileUnit *cu);
 
-  virtual DILineInfo getLineInfoForAddress(uint64_t address,
-      DILineInfoSpecifier specifier = DILineInfoSpecifier());
+  virtual DILineInfo getLineInfoForAddress(uint64_t Address,
+      DILineInfoSpecifier Specifier = DILineInfoSpecifier());
 
   bool isLittleEndian() const { return IsLittleEndian; }
 
@@ -82,8 +79,22 @@ public:
   static bool isSupportedVersion(unsigned version) {
     return version == 2 || version == 3;
   }
-};
+private:
+  /// Return the compile unit that includes an offset (relative to .debug_info).
+  DWARFCompileUnit *getCompileUnitForOffset(uint32_t Offset);
 
+  /// Return the compile unit which contains instruction with provided
+  /// address.
+  DWARFCompileUnit *getCompileUnitForAddress(uint64_t Address);
+
+  /// Fetches filename, line and column number for given address and
+  /// compile unit. Returns true on success.
+  bool getFileLineInfoForCompileUnit(DWARFCompileUnit *CU,
+                                     uint64_t Address,
+                                     bool NeedsAbsoluteFilePath,
+                                     std::string &FileName,
+                                     uint32_t &Line, uint32_t &Column);
+};
 
 /// DWARFContextInMemory is the simplest possible implementation of a
 /// DWARFContext. It assumes all content is available in memory and stores

lib/DebugInfo/DWARFDebugLine.cpp

@@ -10,6 +10,7 @@
 #include "DWARFDebugLine.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 using namespace llvm;
@@ -513,3 +514,29 @@ DWARFDebugLine::LineTable::lookupAddress(uint64_t address) const {
   }
   return index;
 }
+
+bool
+DWARFDebugLine::LineTable::getFileNameByIndex(uint64_t FileIndex,
+                                              bool NeedsAbsoluteFilePath,
+                                              std::string &Result) const {
+  if (FileIndex == 0 || FileIndex > Prologue.FileNames.size())
+    return false;
+  const FileNameEntry &Entry = Prologue.FileNames[FileIndex - 1];
+  const char *FileName = Entry.Name;
+  if (!NeedsAbsoluteFilePath ||
+      sys::path::is_absolute(FileName)) {
+    Result = FileName;
+    return true;
+  }
+  SmallString<16> FilePath;
+  uint64_t IncludeDirIndex = Entry.DirIdx;
+  // Be defensive about the contents of Entry.
+  if (IncludeDirIndex > 0 &&
+      IncludeDirIndex <= Prologue.IncludeDirectories.size()) {
+    const char *IncludeDir = Prologue.IncludeDirectories[IncludeDirIndex - 1];
+    sys::path::append(FilePath, IncludeDir);
+  }
+  sys::path::append(FilePath, FileName);
+  Result = FilePath.str();
+  return true;
+}

lib/DebugInfo/DWARFDebugLine.h

@@ -12,6 +12,7 @@
 
 #include "llvm/Support/DataExtractor.h"
 #include <map>
+#include <string>
 #include <vector>
 
 namespace llvm {
@@ -174,6 +175,13 @@ public:
     // Returns the index of the row with file/line info for a given address,
     // or -1 if there is no such row.
     uint32_t lookupAddress(uint64_t address) const;
+
+    // Extracts filename by its index in filename table in prologue.
+    // Returns true on success.
+    bool getFileNameByIndex(uint64_t FileIndex,
+                            bool NeedsAbsoluteFilePath,
+                            std::string &Result) const;
+
     void dump(raw_ostream &OS) const;
 
     struct Prologue Prologue;