[Assembler] Allow non-fatal errors after parsing

[olista01]

Summary

This adds reportError to MCContext, which can be used as an alternative to reportFatalError when the assembler wants to try to continue processing the rest of the file after the error is reported, so that all of the errors ina file can be reported. It records the fact that an error was encountered, so we can avoid emitting an object file if any errors occurred.

This patch doesn't add any uses of this function (a later patch will convert most uses of reportFatalError to use it), but there is a small functional change: we use the SourceManager to print the error message, even if we have a null SMLoc. This means that we get a SourceManager-style message, with the file and line information shown as <unknown>, rather than the "LLVM ERROR" style used by report_fatal_error.

[t.p.northover]

This seems fine to me.

Tim.

[olista01]

Committed revision 253327.

include/llvm/MC/MCContext.h

private:
     std::map<COFFSectionKey, MCSectionCOFF *> COFFUniquingMap;
     StringMap<bool> ELFRelSecNames;
 
     SpecificBumpPtrAllocator<MCSubtargetInfo> MCSubtargetAllocator;
 
     /// Do automatic reset in destructor
     bool AutoReset;
 
+    bool HadError;
+
     MCSymbol *createSymbolImpl(const StringMapEntry<bool> *Name,
                                bool CanBeUnnamed);
     MCSymbol *createSymbol(StringRef Name, bool AlwaysAddSuffix,
                            bool IsTemporary);
 
     MCSymbol *getOrCreateDirectionalLocalSymbol(unsigned LocalLabelVal,
                                                 unsigned Instance);
 
public:
     void setSecureLog(raw_ostream *Value) { SecureLog = Value; }
     void setSecureLogUsed(bool Value) { SecureLogUsed = Value; }
 
     void *allocate(unsigned Size, unsigned Align = 8) {
       return Allocator.Allocate(Size, Align);
     }
     void deallocate(void *Ptr) {}
 
+    bool hadError() { return HadError; }
+    void reportError(SMLoc L, const Twine &Msg);
     // Unrecoverable error has occurred. Display the best diagnostic we can
     // and bail via exit(1). For now, most MC backend errors are unrecoverable.
     // FIXME: We should really do something about that.
     LLVM_ATTRIBUTE_NORETURN void reportFatalError(SMLoc L,
-                                                  const Twine &Msg) const;
+                                                  const Twine &Msg);
   };
 
 } // end namespace llvm
 
 // operator new and delete aren't allowed inside namespaces.
 // The throw specifications are mandated by the standard.
 /// \brief Placement new for using the MCContext's allocator.
 ///

lib/MC/MCContext.cpp

 MCContext::MCContext(const MCAsmInfo *mai, const MCRegisterInfo *mri,
                      const MCObjectFileInfo *mofi, const SourceMgr *mgr,
                      bool DoAutoReset)
     : SrcMgr(mgr), MAI(mai), MRI(mri), MOFI(mofi), Allocator(),
       Symbols(Allocator), UsedNames(Allocator),
       CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0), DwarfLocSeen(false),
       GenDwarfForAssembly(false), GenDwarfFileNumber(0), DwarfVersion(4),
       AllowTemporaryLabels(true), DwarfCompileUnitID(0),
-      AutoReset(DoAutoReset) {
+      AutoReset(DoAutoReset), HadError(false) {
 
   std::error_code EC = llvm::sys::fs::current_path(CompilationDir);
   if (EC)
     CompilationDir.clear();
 
   SecureLogFile = getenv("AS_SECURE_LOG_FILE");
   SecureLog = nullptr;
   SecureLogUsed = false;
void MCContext::reset() {
   ELFUniquingMap.clear();
   COFFUniquingMap.clear();
 
   NextID.clear();
   AllowTemporaryLabels = true;
   DwarfLocSeen = false;
   GenDwarfForAssembly = false;
   GenDwarfFileNumber = 0;
+
+  HadError = false;
 }
 
 //===----------------------------------------------------------------------===//
 // Symbol Manipulation
 //===----------------------------------------------------------------------===//
 
 MCSymbol *MCContext::getOrCreateSymbol(const Twine &Name) {
   SmallString<128> NameSV;

 
 /// Remove empty sections from SectionStartEndSyms, to avoid generating
 /// useless debug info for them.
 void MCContext::finalizeDwarfSections(MCStreamer &MCOS) {
   SectionsForRanges.remove_if(
       [&](MCSection *Sec) { return !MCOS.mayHaveInstructions(*Sec); });
 }
 
-void MCContext::reportFatalError(SMLoc Loc, const Twine &Msg) const {
-  // If we have a source manager and a location, use it. Otherwise just
-  // use the generic report_fatal_error().
-  if (!SrcMgr || Loc == SMLoc())
+//===----------------------------------------------------------------------===//
+// Error Reporting
+//===----------------------------------------------------------------------===//
+
+void MCContext::reportError(SMLoc Loc, const Twine &Msg) {
+  HadError = true;
+
+  // If we have a source manager use it. Otherwise just use the generic
+  // report_fatal_error().
+  if (!SrcMgr)
     report_fatal_error(Msg, false);
 
   // Use the source manager to print the message.
   SrcMgr->PrintMessage(Loc, SourceMgr::DK_Error, Msg);
+}
+
+void MCContext::reportFatalError(SMLoc Loc, const Twine &Msg) {
+  reportError(Loc, Msg);
 
   // If we reached here, we are failing ungracefully. Run the interrupt handlers
   // to make sure any special cleanups get done, in particular that we remove
   // files registered with RemoveFileOnSignal.
   sys::RunInterruptHandlers();
   exit(1);
 }

lib/MC/MCParser/AsmParser.cpp

if (!NoFinalize && MAI.hasSubsectionsViaSymbols()) {
     }
   }
 
   // Finalize the output stream if there are no errors and if the client wants
   // us to.
   if (!HadError && !NoFinalize)
     Out.Finish();
 
-  return HadError;
+  return HadError || getContext().hadError();
 }
 
 void AsmParser::checkForValidSection() {
   if (!ParsingInlineAsm && !getStreamer().getCurrentSection().first) {
     TokError("expected section directive before assembly directive");
     Out.InitSections(false);
   }
 }

test/MC/Mips/micromips-diagnostic-fixup.s

 # RUN: not llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 -arch=mips -mattr=+micromips 2>&1 -filetype=obj | FileCheck %s
 #
-# CHECK: LLVM ERROR: out of range PC16 fixup
+# CHECK: error: out of range PC16 fixup
 
 .text
   b foo
   .space 65536 - 6, 1   # -6 = size of b instr plus size of automatically inserted nop
   nop                   # This instr makes the branch too long to fit into a 17-bit offset
 foo:
   add $0,$0,$0

test/MC/Mips/mips-diagnostic-fixup.s

 # RUN: not llvm-mc %s -triple=mipsel-unknown-linux -mcpu=mips32r2 -arch=mips 2>&1 -filetype=obj | FileCheck %s
 #
-# CHECK: LLVM ERROR: out of range PC16 fixup
+# CHECK: error: out of range PC16 fixup
 
 .text
   b foo
   .space 131072 - 8, 1  # -8 = size of b instr plus size of automatically inserted nop
   nop                   # This instr makes the branch too long to fit into a 18-bit offset
 foo:
   add $0,$0,$0