Allow users to choose identity used to sign tools.

Summary:
No change if the identity isn't defined by the makefile.

Reviewers: echristo

Differential Revision: http://llvm-reviews.chandlerc.com/D632

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180240 91177308-0d34-0410-b5e6-96231b3b80d8

Makefile.rules

@@ -1515,14 +1515,16 @@ $(ToolBuildPath): $(ToolDir)/.dir
 endif
 
 ifdef CODESIGN_TOOLS
+TOOL_CODESIGN_IDENTITY ?= -
+
 $(ToolBuildPath): $(ObjectsO) $(ProjLibsPaths) $(LLVMLibsPaths)
 	$(Echo) Linking $(BuildMode) executable $(TOOLNAME) $(StripWarnMsg)
 	$(Verb) $(Link) -o $@ $(TOOLLINKOPTS) $(ObjectsO) $(ProjLibsOptions) \
 	$(LLVMLibsOptions) $(ExtraLibs) $(TOOLLINKOPTSB) $(LIBS)
 	$(Echo) ======= Finished Linking $(BuildMode) Executable $(TOOLNAME) \
           $(StripWarnMsg)
 	$(Echo) ======= Code-Signing $(BuildMode) Executable $(TOOLNAME)
-	$(Verb) codesign -s - $@
+	$(Verb) codesign -s $(TOOL_CODESIGN_IDENTITY) $@
 else
 $(ToolBuildPath): $(ObjectsO) $(ProjLibsPaths) $(LLVMLibsPaths)
 	$(Echo) Linking $(BuildMode) executable $(TOOLNAME) $(StripWarnMsg)