[Assembler] Make fatal assembler errors non-fatal

Currently, if the assembler encounters an error after parsing (such as an
out-of-range fixup), it reports this as a fatal error, and so stops after the
first error. However, for most of these there is an obvious way to recover
after emitting the error, such as emitting the fixup with a value of zero. This
means that we can report on all of the errors in a file, not just the first
one. MCContext::reportError records the fact that an error was encountered, so
we won't actually emit an object file with the incorrect contents.

Differential Revision: http://reviews.llvm.org/D14717

llvm-svn: 253328

1 files changed, 21 insertions, 11 deletions

diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
index 95d7ea7c04a..cfd504e533a 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMMachObjectWriter.cpp
@@ -150,10 +150,12 @@ RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
   // See <reloc.h>.
   const MCSymbol *A = &Target.getSymA()->getSymbol();
 
-  if (!A->getFragment())
-    Asm.getContext().reportFatalError(Fixup.getLoc(),
+  if (!A->getFragment()) {
+    Asm.getContext().reportError(Fixup.getLoc(),
                        "symbol '" + A->getName() +
                        "' can not be undefined in a subtraction expression");
+    return;
+  }
 
   uint32_t Value = Writer->getSymbolAddress(*A, Layout);
   uint32_t Value2 = 0;
@@ -163,10 +165,12 @@ RecordARMScatteredHalfRelocation(MachObjectWriter *Writer,
   if (const MCSymbolRefExpr *B = Target.getSymB()) {
     const MCSymbol *SB = &B->getSymbol();
 
-    if (!SB->getFragment())
-      Asm.getContext().reportFatalError(Fixup.getLoc(),
+    if (!SB->getFragment()) {
+      Asm.getContext().reportError(Fixup.getLoc(),
                          "symbol '" + B->getSymbol().getName() +
                          "' can not be undefined in a subtraction expression");
+      return;
+    }
 
     // Select the appropriate difference relocation type.
     Type = MachO::ARM_RELOC_HALF_SECTDIFF;
@@ -251,10 +255,12 @@ void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
   // See <reloc.h>.
   const MCSymbol *A = &Target.getSymA()->getSymbol();
 
-  if (!A->getFragment())
-    Asm.getContext().reportFatalError(Fixup.getLoc(),
+  if (!A->getFragment()) {
+    Asm.getContext().reportError(Fixup.getLoc(),
                        "symbol '" + A->getName() +
                        "' can not be undefined in a subtraction expression");
+    return;
+  }
 
   uint32_t Value = Writer->getSymbolAddress(*A, Layout);
   uint64_t SecAddr = Writer->getSectionAddress(A->getFragment()->getParent());
@@ -265,10 +271,12 @@ void ARMMachObjectWriter::RecordARMScatteredRelocation(MachObjectWriter *Writer,
     assert(Type == MachO::ARM_RELOC_VANILLA && "invalid reloc for 2 symbols");
     const MCSymbol *SB = &B->getSymbol();
 
-    if (!SB->getFragment())
-      Asm.getContext().reportFatalError(Fixup.getLoc(),
+    if (!SB->getFragment()) {
+      Asm.getContext().reportError(Fixup.getLoc(),
                          "symbol '" + B->getSymbol().getName() +
                          "' can not be undefined in a subtraction expression");
+      return;
+    }
 
     // Select the appropriate difference relocation type.
     Type = MachO::ARM_RELOC_SECTDIFF;
@@ -346,13 +354,15 @@ void ARMMachObjectWriter::recordRelocation(MachObjectWriter *Writer,
   unsigned IsPCRel = Writer->isFixupKindPCRel(Asm, Fixup.getKind());
   unsigned Log2Size;
   unsigned RelocType = MachO::ARM_RELOC_VANILLA;
-  if (!getARMFixupKindMachOInfo(Fixup.getKind(), RelocType, Log2Size))
+  if (!getARMFixupKindMachOInfo(Fixup.getKind(), RelocType, Log2Size)) {
     // If we failed to get fixup kind info, it's because there's no legal
     // relocation type for the fixup kind. This happens when it's a fixup that's
     // expected to always be resolvable at assembly time and not have any
     // relocations needed.
-    Asm.getContext().reportFatalError(Fixup.getLoc(),
-                                "unsupported relocation on symbol");
+    Asm.getContext().reportError(Fixup.getLoc(),
+                                 "unsupported relocation on symbol");
+    return;
+  }
 
   // If this is a difference or a defined symbol plus an offset, then we need a
   // scattered relocation entry.  Differences always require scattered