[llvm] r362290 - Extend the DWARFExpression address handling to support 16-bit addresses

[Dylan McKay via llvm-commits]

Author: dylanmckay
Date: Sat Jun  1 02:18:26 2019
New Revision: 362290

URL: http://llvm.org/viewvc/llvm-project?rev=362290&view=rev
Log:
Extend the DWARFExpression address handling to support 16-bit addresses

This allows the DWARFExpression class to handle addresses without
crashing on targets with 16-bit pointers like AVR.

This is required in order to generate assembly from clang via the '-S'
flag.

This fixes an error with the following message:

clang: llvm/include/llvm/DebugInfo/DWARF/DWARFExpression.h:132: llvm::DWARFExpression::DWARFExpression(llvm::DataExtractor, uint16_t, uint8_t):
       Assertion `AddressSize == 8 || AddressSize == 4' failed.

Added:
    llvm/trunk/test/MC/AVR/dwarf-asm-no-code.s
Modified:
    llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFExpression.h
    llvm/trunk/lib/DebugInfo/DWARF/DWARFExpression.cpp

Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFExpression.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFExpression.h?rev=362290&r1=362289&r2=362290&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFExpression.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFExpression.h Sat Jun  1 02:18:26 2019
@@ -129,7 +129,7 @@ public:
 
   DWARFExpression(DataExtractor Data, uint16_t Version, uint8_t AddressSize)
       : Data(Data), Version(Version), AddressSize(AddressSize) {
-    assert(AddressSize == 8 || AddressSize == 4);
+    assert(AddressSize == 8 || AddressSize == 4 || AddressSize == 2);
   }
 
   iterator begin() const { return iterator(this, 0); }

Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFExpression.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFExpression.cpp?rev=362290&r1=362289&r2=362290&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFExpression.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFExpression.cpp Sat Jun  1 02:18:26 2019
@@ -155,17 +155,21 @@ bool DWARFExpression::Operation::extract
     case Operation::SizeAddr:
       if (AddressSize == 8) {
         Operands[Operand] = Data.getU64(&Offset);
-      } else {
-        assert(AddressSize == 4);
+      } else if (AddressSize == 4) {
         Operands[Operand] = Data.getU32(&Offset);
+      } else {
+        assert(AddressSize == 2);
+        Operands[Operand] = Data.getU16(&Offset);
       }
       break;
     case Operation::SizeRefAddr:
       if (getRefAddrSize(AddressSize, Version) == 8) {
         Operands[Operand] = Data.getU64(&Offset);
-      } else {
-        assert(getRefAddrSize(AddressSize, Version) == 4);
+      } else if (getRefAddrSize(AddressSize, Version) == 4) {
         Operands[Operand] = Data.getU32(&Offset);
+      } else {
+        assert(getRefAddrSize(AddressSize, Version) == 2);
+        Operands[Operand] = Data.getU16(&Offset);
       }
       break;
     case Operation::SizeLEB:

Added: llvm/trunk/test/MC/AVR/dwarf-asm-no-code.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AVR/dwarf-asm-no-code.s?rev=362290&view=auto
==============================================================================
--- llvm/trunk/test/MC/AVR/dwarf-asm-no-code.s (added)
+++ llvm/trunk/test/MC/AVR/dwarf-asm-no-code.s Sat Jun  1 02:18:26 2019
@@ -0,0 +1,19 @@
+// RUN: llvm-mc < %s -triple=avr -filetype=obj -o %t -g -fdebug-compilation-dir=/tmp
+// RUN: llvm-dwarfdump -v %t | FileCheck -check-prefix DWARF %s
+// RUN: llvm-objdump -r %t | FileCheck -check-prefix RELOC %s
+
+// If there is no code in an assembly file, no debug info is produced
+
+.section .data, "aw"
+a:
+.long 42
+
+// DWARF: ELF32-avr
+// DWARF-NOT: contents:
+// DWARF: .debug_line contents:
+
+// RELOC-NOT: RELOCATION RECORDS FOR [.rel.debug_info]:
+
+// RELOC-NOT: RELOCATION RECORDS FOR [.rel.debug_ranges]:
+
+// RELOC-NOT: RELOCATION RECORDS FOR [.rel.debug_aranges]: