LLVM puts padding bytes in the __gcc_except_tab section after the

GCC_except_table label but before the Lexception, which the FDE references.
This causes problems as the FDE does not point to the start of an LSDA chunk.

Use an unnormalized uleb128 for the call-site table length that includes the
padding.

llvm-svn: 97078

1 files changed, 13 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
index 1299d048e4b..25337cb765b 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfPrinter.cpp
@@ -159,29 +159,37 @@ void DwarfPrinter::EmitSLEB128(int Value, const char *Desc) const {
     Value >>= 7;
     IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
     if (IsMore) Byte |= 0x80;
-    
     Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
   } while (IsMore);
 }
 
 /// EmitULEB128 - emit the specified signed leb128 value.
-void DwarfPrinter::EmitULEB128(unsigned Value, const char *Desc) const {
+void DwarfPrinter::EmitULEB128(unsigned Value, const char *Desc,
+                               unsigned PadTo) const {
   if (Asm->VerboseAsm && Desc)
     Asm->OutStreamer.AddComment(Desc);
  
-  if (MAI->hasLEB128()) {
+  if (MAI->hasLEB128() && PadTo == 0) {
     O << "\t.uleb128\t" << Value;
     Asm->OutStreamer.AddBlankLine();
     return;
   }
   
-  // If we don't have .uleb128, emit as .bytes.
+  // If we don't have .uleb128 or we want to emit padding, emit as .bytes.
   do {
     unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
     Value >>= 7;
-    if (Value) Byte |= 0x80;
+    if (Value || PadTo != 0) Byte |= 0x80;
     Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
   } while (Value);
+
+  if (PadTo)
+    while (PadTo--) {
+      unsigned char Byte = (PadTo ? 0x80 : 0x00);
+      if (Asm->VerboseAsm)
+        Asm->OutStreamer.AddComment("Padding");
+      Asm->OutStreamer.EmitIntValue(Byte, 1, /*addrspace*/0);
+    }
 }