[PATCH] D19686: [PowerPC] Fix the EH_SjLj_Setup pseudo.

[Marcin Kościelnicki via llvm-commits]

koriakin created this revision.
koriakin added reviewers: hfinkel, kbarton.
koriakin added a subscriber: llvm-commits.
koriakin set the repository for this revision to rL LLVM.

This instruction is just a control flow marker - it should not
actually exist in the object file.  Unfortunately, nothing catches
it before it gets to AsmPrinter.  If integrated assembler is used,
it's considered to be a normal 4-byte instruction, and emitted as
an all-0 word, crashing the program.  With external assembler,
a comment is emitted.

Fixed by setting Size to 0 and handling it in MCCodeEmitter - this
means the comment will still be emitted if integrated assembler
is not used.

This broke an ASan test, which has been disabled for a long time
as a result (see the discussion on D19657).  We can reenable it
once this lands.


Repository:
  rL LLVM

http://reviews.llvm.org/D19686

Files:
  lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
  lib/Target/PowerPC/PPCInstrInfo.td

Index: lib/Target/PowerPC/PPCInstrInfo.td
===================================================================
--- lib/Target/PowerPC/PPCInstrInfo.td
+++ lib/Target/PowerPC/PPCInstrInfo.td
@@ -1403,7 +1403,7 @@
                           Requires<[In32BitMode]>;
 }
 
-let isBranch = 1, isTerminator = 1 in {
+let isBranch = 1, isTerminator = 1, Size = 0 in {
   def EH_SjLj_Setup : Pseudo<(outs), (ins directbrtarget:$dst),
                         "#EH_SjLj_Setup\t$dst", []>;
 }
Index: lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
===================================================================
--- lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
+++ lib/Target/PowerPC/MCTargetDesc/PPCMCCodeEmitter.cpp
@@ -113,6 +113,8 @@
     // Output the constant in big/little endian byte order.
     unsigned Size = Desc.getSize();
     switch (Size) {
+    case 0:
+      break;
     case 4:
       if (IsLittleEndian) {
         support::endian::Writer<support::little>(OS).write<uint32_t>(Bits);


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