Do not make bitcode when in assemble-only mode (-S)

If we let the second compilation stage make bitcode, the driver will
dump the result into an assembly file (overwriting the real assembly
output from the first stage).  The result will be LLVM assembly, which
will make the rest of the compilation fail.

Author: Tristan Ravitch

driver/utils.py

@@ -34,6 +34,7 @@ def __init__(self, inputList, exactMatches={}, patternMatches={}):
             '-o' : (1, ArgumentListFilter.outputFileCallback),
             '-c' : (0, ArgumentListFilter.compileOnlyCallback),
             '-E' : (0, ArgumentListFilter.preprocessOnlyCallback),
+            '-S' : (0, ArgumentListFilter.assembleOnlyCallback),
             '--verbose' : (0, ArgumentListFilter.verboseFlagCallback),
             '--param' : (1, ArgumentListFilter.defaultOneArgument),
             '-aux-info' : (1, ArgumentListFilter.defaultOneArgument),
@@ -83,6 +84,7 @@ def __init__(self, inputList, exactMatches={}, patternMatches={}):
         self.outputFilename = None
         self.isVerbose = False
         self.isPreprocessOnly = False
+        self.isAssembleOnly = False
         self.isAssembly = False
         self.isCompileOnly = False
 
@@ -135,6 +137,10 @@ def preprocessOnlyCallback(self, flag):
         self.isPreprocessOnly = True
         self.keepArgument(flag)
 
+    def assembleOnlyCallback(self, flag):
+        self.isAssembleOnly = True
+        self.keepArgument(flag)
+
     def verboseFlagCallback(self, flag):
         self.isVerbose = True
 
@@ -307,7 +313,7 @@ def isLinkOption(arg):
 # This command does not have the executable with it
 def buildAndAttachBitcode(builder):
     af = builder.getBitcodeArglistFilter()
-    if len(af.inputFiles) == 0 or af.isAssembly:
+    if len(af.inputFiles) == 0 or af.isAssembly or af.isAssembleOnly:
         return
     bcc = builder.getBitcodeCompiler()
     bcc.extend(af.filteredArgs)