introduce a new recoverable error handling API to LLVMContext

and use it in one place in inline asm handling stuff.  Before
we'd generate this for an invalid modifier letter:

$ clang asm.c -c -o t.o
fatal error: error in backend: Invalid operand found in inline asm: 'abc incl    ${0:Z}'
INLINEASM <es:abc incl    ${0:Z}>, 10, %EAX<def>, 2147483657, %EAX, 14, %EFLAGS<earlyclobber,def,dead>, <!-1>


Now we generate this:

$ clang asm.c -c -o t.o
error: invalid operand in inline asm: 'incl    ${0:Z}'
asm.c:3:12: note: generated from here
  __asm__ ("incl    %Z0" : "+r" (X));
           ^
1 error generated.

This is much better but still admittedly not great ("why" is the operand 
invalid??), codegen should try harder with its diagnostics :)

llvm-svn: 100723

1 files changed, 38 insertions, 0 deletions

diff --git a/llvm/lib/VMCore/LLVMContext.cpp b/llvm/lib/VMCore/LLVMContext.cpp
index 3244f2842c4..4d61363b939 100644
--- a/llvm/lib/VMCore/LLVMContext.cpp
+++ b/llvm/lib/VMCore/LLVMContext.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Constants.h"
 #include "llvm/Instruction.h"
 #include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/SourceMgr.h"
 #include "LLVMContextImpl.h"
 using namespace llvm;
 
@@ -33,6 +34,10 @@ LLVMContext::LLVMContext() : pImpl(new LLVMContextImpl(*this)) {
 }
 LLVMContext::~LLVMContext() { delete pImpl; }
 
+//===----------------------------------------------------------------------===//
+// Recoverable Backend Errors
+//===----------------------------------------------------------------------===//
+
 void LLVMContext::setInlineAsmDiagnosticHandler(void *DiagHandler, 
                                                 void *DiagContext) {
   pImpl->InlineAsmDiagHandler = DiagHandler;
@@ -51,6 +56,39 @@ void *LLVMContext::getInlineAsmDiagnosticContext() const {
   return pImpl->InlineAsmDiagContext;
 }
 
+void LLVMContext::emitError(StringRef ErrorStr) {
+  emitError(0U, ErrorStr);
+}
+
+void LLVMContext::emitError(const Instruction *I, StringRef ErrorStr) {
+  unsigned LocCookie = 0;
+  if (const MDNode *SrcLoc = I->getMetadata("srcloc")) {
+    if (SrcLoc->getNumOperands() != 0)
+      if (const ConstantInt *CI = dyn_cast<ConstantInt>(SrcLoc->getOperand(0)))
+        LocCookie = CI->getZExtValue();
+  }
+  return emitError(LocCookie, ErrorStr);
+}
+
+void LLVMContext::emitError(unsigned LocCookie, StringRef ErrorStr) {
+  // If there is no error handler installed, just print the error and exit.
+  if (pImpl->InlineAsmDiagHandler == 0) {
+    errs() << "error: " << ErrorStr << "\n";
+    exit(1);
+  }
+  
+  // If we do have an error handler, we can report the error and keep going.
+  SMDiagnostic Diag("", "error: " + ErrorStr.str());
+  
+  ((SourceMgr::DiagHandlerTy)(intptr_t)pImpl->InlineAsmDiagHandler)
+      (Diag, pImpl->InlineAsmDiagContext, LocCookie);
+  
+}
+
+//===----------------------------------------------------------------------===//
+// Metadata Kind Uniquing
+//===----------------------------------------------------------------------===//
+
 #ifndef NDEBUG
 /// isValidName - Return true if Name is a valid custom metadata handler name.
 static bool isValidName(StringRef MDName) {