[DebugInfo] Make offsets of dwarf units 64-bit (19/19).

In the case of LTO, several DWARF units can be emitted in one section.
For an extremely large application, they may exceed the limit of 4GiB
for 32-bit offsets. As it is now possible to emit 64-bit debugging info,
the patch enables storing the larger offsets.

Differential Revision: https://reviews.llvm.org/D87026

diff --git a/llvm/include/llvm/CodeGen/DIE.h b/llvm/include/llvm/CodeGen/DIE.h
index 43ba859..fa554be 100644 (file)
--- a/llvm/include/llvm/CodeGen/DIE.h
+++ b/llvm/include/llvm/CodeGen/DIE.h
@@ -788,7 +788,7 @@ public:
 
   /// Get the absolute offset within the .debug_info or .debug_types section
   /// for this DIE.
-  unsigned getDebugSectionOffset() const;
+  uint64_t getDebugSectionOffset() const;
 
   /// Compute the offset of this DIE and all its children.
   ///
@@ -890,8 +890,8 @@ public:
   ///
   /// \returns Section pointer which can be NULL.
   MCSection *getSection() const { return Section; }
-  void setDebugSectionOffset(unsigned O) { Offset = O; }
-  unsigned getDebugSectionOffset() const { return Offset; }
+  void setDebugSectionOffset(uint64_t O) { Offset = O; }
+  uint64_t getDebugSectionOffset() const { return Offset; }
   DIE &getUnitDie() { return Die; }
   const DIE &getUnitDie() const { return Die; }
 };

diff --git a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
index 5ef4a28..4e45a0f 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AccelTable.cpp
@@ -591,10 +591,14 @@ void llvm::emitDWARF5AccelTable(
 }
 
 void AppleAccelTableOffsetData::emit(AsmPrinter *Asm) const {
+  assert(Die.getDebugSectionOffset() <= UINT32_MAX &&
+         "The section offset exceeds the limit.");
   Asm->emitInt32(Die.getDebugSectionOffset());
 }
 
 void AppleAccelTableTypeData::emit(AsmPrinter *Asm) const {
+  assert(Die.getDebugSectionOffset() <= UINT32_MAX &&
+         "The section offset exceeds the limit.");
   Asm->emitInt32(Die.getDebugSectionOffset());
   Asm->emitInt16(Die.getTag());
   Asm->emitInt8(0);

diff --git a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
index 4ec470b..9b074c8 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DIE.cpp
@@ -194,7 +194,7 @@ DIEAbbrev DIE::generateAbbrev() const {
   return Abbrev;
 }
 
-unsigned DIE::getDebugSectionOffset() const {
+uint64_t DIE::getDebugSectionOffset() const {
   const DIEUnit *Unit = getUnit();
   assert(Unit && "DIE must be owned by a DIEUnit to get its absolute offset");
   return Unit->getDebugSectionOffset() + getOffset();
@@ -662,7 +662,7 @@ void DIEEntry::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 
   case dwarf::DW_FORM_ref_addr: {
     // Get the absolute offset for this DIE within the debug info/types section.
-    unsigned Addr = Entry->getDebugSectionOffset();
+    uint64_t Addr = Entry->getDebugSectionOffset();
     if (const MCSymbol *SectionSym =
             Entry->getUnit()->getCrossSectionRelativeBaseAddress()) {
       AP->emitLabelPlusOffset(SectionSym, Addr, SizeOf(AP, Form), true);

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
index d9004c4..dee0323 100644 (file)
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfFile.cpp
@@ -59,7 +59,7 @@ void DwarfFile::emitUnit(DwarfUnit *TheU, bool UseOffsets) {
 // Compute the size and offset for each DIE.
 void DwarfFile::computeSizeAndOffsets() {
   // Offset from the first CU in the debug info section is 0 initially.
-  unsigned SecOffset = 0;
+  uint64_t SecOffset = 0;
 
   // Iterate over each compile unit and set the size and offsets for each
   // DIE within each compile unit. All offsets are CU relative.
@@ -75,6 +75,9 @@ void DwarfFile::computeSizeAndOffsets() {
     TheU->setDebugSectionOffset(SecOffset);
     SecOffset += computeSizeAndOffsetsForUnit(TheU.get());
   }
+  if (SecOffset > UINT32_MAX && !Asm->isDwarf64())
+    report_fatal_error("The generated debug information is too large "
+                       "for the 32-bit DWARF format.");
 }
 
 unsigned DwarfFile::computeSizeAndOffsetsForUnit(DwarfUnit *TheU) {

diff --git a/llvm/unittests/DebugInfo/DWARF/DwarfGenerator.cpp b/llvm/unittests/DebugInfo/DWARF/DwarfGenerator.cpp
index 5d53c0d..69746dd 100644 (file)
--- a/llvm/unittests/DebugInfo/DWARF/DwarfGenerator.cpp
+++ b/llvm/unittests/DebugInfo/DWARF/DwarfGenerator.cpp
@@ -504,7 +504,7 @@ llvm::Error dwarfgen::Generator::init(Triple TheTriple, uint16_t V) {
 
 StringRef dwarfgen::Generator::generate() {
   // Offset from the first CU in the debug info section is 0 initially.
-  unsigned SecOffset = 0;
+  uint64_t SecOffset = 0;
 
   // Iterate over each compile unit and set the size and offsets for each
   // DIE within each compile unit. All offsets are CU relative.