[MC] Error on a .zerofill directive in a non-virtual section

On darwin, all virtual sections have zerofill type, and having a
.zerofill directive in a non-virtual section is not allowed. Instead of
asserting, show a nicer error.

In order to use the equivalent of .zerofill in a non-virtual section,
the usage of .zero of .space is required.

This patch replaces the assert with an error.

Differential Revision: https://reviews.llvm.org/D48517

llvm-svn: 336127

1 files changed, 11 insertions, 2 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 681e7e482e7..5398cfea786 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -178,7 +178,8 @@ public:
                              unsigned ByteAlignment) override;
 
   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
-                    uint64_t Size = 0, unsigned ByteAlignment = 0) override;
+                    uint64_t Size = 0, unsigned ByteAlignment = 0,
+                    SMLoc Loc = SMLoc()) override;
 
   void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
                       unsigned ByteAlignment = 0) override;
@@ -749,14 +750,18 @@ void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 }
 
 void MCAsmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
-                                 uint64_t Size, unsigned ByteAlignment) {
+                                 uint64_t Size, unsigned ByteAlignment,
+                                 SMLoc Loc) {
   if (Symbol)
     AssignFragment(Symbol, &Section->getDummyFragment());
 
   // Note: a .zerofill directive does not switch sections.
   OS << ".zerofill ";
 
+  assert(Section->getVariant() == MCSection::SV_MachO &&
+         ".zerofill is a Mach-O specific directive");
   // This is a mach-o specific directive.
+
   const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
   OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
 
@@ -779,7 +784,11 @@ void MCAsmStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
 
   assert(Symbol && "Symbol shouldn't be NULL!");
   // Instead of using the Section we'll just use the shortcut.
+
+  assert(Section->getVariant() == MCSection::SV_MachO &&
+         ".zerofill is a Mach-O specific directive");
   // This is a mach-o specific directive and section.
+
   OS << ".tbss ";
   Symbol->print(OS, MAI);
   OS << ", " << Size;