Reapply 131644 including the missing header changes:

Introduce -fatal-assembler-warnings for the obvious purpose


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131655 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCParser/MCAsmParser.h

@@ -71,7 +71,9 @@ public:
 
   /// Warning - Emit a warning at the location \arg L, with the message \arg
   /// Msg.
-  virtual void Warning(SMLoc L, const Twine &Msg) = 0;
+  ///
+  /// \return The return value is true, if warnings are fatal.
+  virtual bool Warning(SMLoc L, const Twine &Msg) = 0;
 
   /// Error - Emit an error at the location \arg L, with the message \arg
   /// Msg.

include/llvm/MC/MCParser/MCAsmParserExtension.h

@@ -56,7 +56,7 @@ public:
   MCAsmParser &getParser() { return *Parser; }
   SourceMgr &getSourceManager() { return getParser().getSourceManager(); }
   MCStreamer &getStreamer() { return getParser().getStreamer(); }
-  void Warning(SMLoc L, const Twine &Msg) {
+  bool Warning(SMLoc L, const Twine &Msg) {
     return getParser().Warning(L, Msg);
   }
   bool Error(SMLoc L, const Twine &Msg) {

lib/MC/MCParser/AsmParser.cpp

@@ -27,6 +27,7 @@
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCDwarf.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/raw_ostream.h"
@@ -36,6 +37,10 @@
 #include <vector>
 using namespace llvm;
 
+static cl::opt<bool>
+FatalAssemblerWarnings("fatal-assembler-warnings",
+                       cl::desc("Consider warnings as error"));
+
 namespace {
 
 /// \brief Helper class for tracking macro definitions.
@@ -128,7 +133,7 @@ public:
   virtual MCContext &getContext() { return Ctx; }
   virtual MCStreamer &getStreamer() { return Out; }
 
-  virtual void Warning(SMLoc L, const Twine &Meg);
+  virtual bool Warning(SMLoc L, const Twine &Meg);
   virtual bool Error(SMLoc L, const Twine &Msg);
 
   const AsmToken &Lex();
@@ -370,9 +375,12 @@ void AsmParser::PrintMacroInstantiations() {
                  "note");
 }
 
-void AsmParser::Warning(SMLoc L, const Twine &Msg) {
+bool AsmParser::Warning(SMLoc L, const Twine &Msg) {
+  if (FatalAssemblerWarnings)
+    return Error(L, Msg);
   PrintMessage(L, Msg, "warning");
   PrintMacroInstantiations();
+  return false;
 }
 
 bool AsmParser::Error(SMLoc L, const Twine &Msg) {
@@ -1129,9 +1137,9 @@ bool AsmParser::ParseStatement() {
     if (!getTargetParser().ParseDirective(ID))
       return false;
 
-    Warning(IDLoc, "ignoring directive for now");
+    bool retval = Warning(IDLoc, "ignoring directive for now");
     EatToEndOfStatement();
-    return false;
+    return retval;
   }
 
   CheckForValidSection();

lib/MC/MCParser/DarwinAsmParser.cpp

@@ -369,11 +369,9 @@ bool DarwinAsmParser::ParseDirectiveDumpOrLoad(StringRef Directive,
   // FIXME: If/when .dump and .load are implemented they will be done in the
   // the assembly parser and not have any need for an MCStreamer API.
   if (IsDump)
-    Warning(IDLoc, "ignoring directive .dump for now");
+    return Warning(IDLoc, "ignoring directive .dump for now");
   else
-    Warning(IDLoc, "ignoring directive .load for now");
+    return Warning(IDLoc, "ignoring directive .load for now");
-
-  return false;
 }
 
 /// ParseDirectiveLsym