add a new TGError class and use it to propagate location info with
errors when thrown.  This gets us nice errors like this from tblgen:

CMOVL32rr: 	(set GR32:i32:$dst, (X86cmov GR32:$src1, GR32:$src2))
/Users/sabre/llvm/Debug/bin/tblgen: error:
Included from X86.td:116:
Parsing X86InstrInfo.td:922: In CMOVL32rr: X86cmov node requires exactly 4 operands!
def CMOVL32rr : I<0x4C, MRMSrcReg,       // if <s, GR32 = GR32
^

instead of just:

CMOVL32rr: 	(set GR32:i32:$dst, (X86cmov GR32:$src1, GR32:$src2))
/Users/sabre/llvm/Debug/bin/tblgen: In CMOVL32rr: X86cmov node requires exactly 4 operands!

This is all I plan to do with this, but it should be easy enough to improve if anyone 
cares (e.g. keeping more loc info in "dag" expr records in tblgen.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66898 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/TableGen/TableGen.cpp b/utils/TableGen/TableGen.cpp
index 1beddf0..36ad999 100644
--- a/utils/TableGen/TableGen.cpp
+++ b/utils/TableGen/TableGen.cpp
@@ -114,7 +114,7 @@
 
 static TGSourceMgr SrcMgr;
 
-void PrintError(TGLoc ErrorLoc, const std::string &Msg) {
+void llvm::PrintError(TGLoc ErrorLoc, const std::string &Msg) {
   SrcMgr.PrintError(ErrorLoc, Msg);
 }
 
@@ -229,31 +229,26 @@
       assert(1 && "Invalid Action");
       return 1;
     }
+    
+    if (Out != cout.stream()) 
+      delete Out;                               // Close the file
+    return 0;
+    
+  } catch (const TGError &Error) {
+    cerr << argv[0] << ": error:\n";
+    PrintError(Error.getLoc(), Error.getMessage());
+    
   } catch (const std::string &Error) {
     cerr << argv[0] << ": " << Error << "\n";
-    if (Out != cout.stream()) {
-      delete Out;                             // Close the file
-      std::remove(OutputFilename.c_str());    // Remove the file, it's broken
-    }
-    return 1;
   } catch (const char *Error) {
     cerr << argv[0] << ": " << Error << "\n";
-    if (Out != cout.stream()) {
-      delete Out;                             // Close the file
-      std::remove(OutputFilename.c_str());    // Remove the file, it's broken
-    }
-    return 1;
   } catch (...) {
     cerr << argv[0] << ": Unknown unexpected exception occurred.\n";
-    if (Out != cout.stream()) {
-      delete Out;                             // Close the file
-      std::remove(OutputFilename.c_str());    // Remove the file, it's broken
-    }
-    return 2;
   }
-
+  
   if (Out != cout.stream()) {
-    delete Out;                               // Close the file
+    delete Out;                             // Close the file
+    std::remove(OutputFilename.c_str());    // Remove the file, it's broken
   }
-  return 0;
+  return 1;
 }