simplify COFF module assembly test and move it to Object

[pcc]

llvm/test/Object/X86/coff-asm.ll

3–4

Don't you just need these two lines to test your change? The change makes it so that llvm-nm doesn't crash on this input, right?

[inglorion]

llvm/test/Object/X86/coff-asm.ll

3–4

llvm-nm doesn't crash here (or in the next invocation, for that matter) even without D57073. Does it use RecordStreamer? My impression was the crashing code path is only invoked when reading in module assembly in ModuleSymbolTable.

[pcc]

llvm/test/Object/X86/coff-asm.ll

3–4

It should be using RecordStreamer via IRObjectFile.

My mistake, I didn't notice that you were calling llc here. You should be able to reproduce the problem by running llvm-nm on the file that you're calling %t.thinlto.bc here.

[inglorion]

Simpler test. This crashes without D57073 and passes with D57073.

[inglorion]

Re-upload only the test change.

[pcc]

LGTM, thanks!

[inglorion]

Thank you!

llvm/lib/Object/RecordStreamer.h

void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
                        bool) override;
   void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
   void EmitZerofill(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
                     unsigned ByteAlignment, SMLoc Loc = SMLoc()) override;
   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                         unsigned ByteAlignment) override;
+
+  // Ignore COFF-specific directives; we do not need any information from them,
+  // but the default implementation of these methods crashes, so we override
+  // them with versions that do nothing.
+  void BeginCOFFSymbolDef(const MCSymbol *Symbol) override {}
+  void EmitCOFFSymbolStorageClass(int StorageClass) override {}
+  void EmitCOFFSymbolType(int Type) override {}
+  void EndCOFFSymbolDef() override {}
+
   /// Record .symver aliases for later processing.
   void emitELFSymverDirective(StringRef AliasName,
                               const MCSymbol *Aliasee) override;
 
   // Emit ELF .symver aliases and ensure they have the same binding as the
   // defined symbol they alias with.
   void flushSymverDirectives();
 

llvm/test/Object/X86/coff-asm.ll

+; Check that llvm-nm doesn't crash on COFF-specific assembly directives
+; (PR36789).
+
+; RUN: llvm-as %s -o %t.bc
+; RUN: llvm-nm %t.bc
+
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.0.24210"
+
+module asm ".text"
+module asm ".def foo; .scl 2; .type 32; .endef"
+module asm "foo:"
+module asm "  ret"