Fix PR18381 - print a minimal diagnostic rather than assert on unresolved .secidx...

[oota-llvm.git] / lib / MC / WinCOFFObjectWriter.cpp

diff --git a/lib/MC/WinCOFFObjectWriter.cpp b/lib/MC/WinCOFFObjectWriter.cpp
index d9ca86d8af93d08cf41351f14bf5c23becd6ae3a..b68e69f2eb3419d28318633c4da6981f07fd028f 100644 (file)
--- a/lib/MC/WinCOFFObjectWriter.cpp
+++ b/lib/MC/WinCOFFObjectWriter.cpp
@@ -351,7 +351,7 @@ object_t *WinCOFFObjectWriter::createCOFFEntity(StringRef Name,
 /// and creates the associated COFF section staging object.
 void WinCOFFObjectWriter::DefineSection(MCSectionData const &SectionData) {
   assert(SectionData.getSection().getVariant() == MCSection::SV_COFF
-    && "Got non COFF section in the COFF backend!");
+    && "Got non-COFF section in the COFF backend!");
   // FIXME: Not sure how to verify this (at least in a debug build).
   MCSectionCOFF const &Sec =
     static_cast<MCSectionCOFF const &>(SectionData.getSection());
@@ -636,6 +636,11 @@ void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
 
   const MCSymbol &Symbol = Target.getSymA()->getSymbol();
   const MCSymbol &A = Symbol.AliasedSymbol();
+  if (!Asm.hasSymbolData(A))
+    Asm.getContext().FatalError(
+        Fixup.getLoc(),
+        Twine("symbol '") + A.getName() + "' can not be undefined");
+
   MCSymbolData &A_SD = Asm.getSymbolData(A);
 
   MCSectionData const *SectionData = Fragment->getParent();
@@ -648,14 +653,25 @@ void WinCOFFObjectWriter::RecordRelocation(const MCAssembler &Asm,
 
   COFFSection *coff_section = SectionMap[&SectionData->getSection()];
   COFFSymbol *coff_symbol = SymbolMap[&A_SD.getSymbol()];
-  const MCSymbolRefExpr *SymA = Target.getSymA();
   const MCSymbolRefExpr *SymB = Target.getSymB();
-  const bool CrossSection = SymB &&
-    &SymA->getSymbol().getSection() != &SymB->getSymbol().getSection();
+  bool CrossSection = false;
 
-  if (Target.getSymB()) {
-    const MCSymbol *B = &Target.getSymB()->getSymbol();
+  if (SymB) {
+    const MCSymbol *B = &SymB->getSymbol();
     MCSymbolData &B_SD = Asm.getSymbolData(*B);
+    if (!B_SD.getFragment())
+      Asm.getContext().FatalError(
+          Fixup.getLoc(),
+          Twine("symbol '") + B->getName() +
+              "' can not be undefined in a subtraction expression");
+
+    if (!A_SD.getFragment())
+      Asm.getContext().FatalError(
+          Fixup.getLoc(),
+          Twine("symbol '") + Symbol.getName() +
+              "' can not be undefined in a subtraction expression");
+
+    CrossSection = &Symbol.getSection() != &B->getSection();
 
     // Offset of the symbol in the section
     int64_t a = Layout.getSymbolOffset(&B_SD);
@@ -845,7 +861,8 @@ void WinCOFFObjectWriter::WriteObject(MCAssembler &Asm,
 
   Header.PointerToSymbolTable = offset;
 
-  Header.TimeDateStamp = sys::TimeValue::now().toEpochTime();
+  // We want a deterministic output. It looks like GNU as also writes 0 in here.
+  Header.TimeDateStamp = 0;
 
   // Write it all to disk...
   WriteFileHeader(Header);