Provide a hook to set the code generation debug options to investigate lto failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53119 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm-c/lto.h

@@ -227,6 +227,11 @@ extern const void*
 lto_codegen_compile(lto_code_gen_t cg, size_t* length);
 
 
+/**
+ * Sets options to help debug codegen bugs.
+ */
+extern void
+lto_codegen_debug_options(lto_code_gen_t cg, const char *);
 #ifdef __cplusplus
 }
 #endif

tools/lto/LTOCodeGenerator.cpp

@@ -40,6 +40,7 @@
 #include "llvm/Target/TargetAsmInfo.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/Scalar.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/Config/config.h"
 
 
@@ -116,7 +117,6 @@ bool LTOCodeGenerator::setCodePICModel(lto_codegen_model model,
     return true;
 }
 
-
 void LTOCodeGenerator::addMustPreserveSymbol(const char* sym)
 {
     _mustPreserveSymbols[sym] = 1;
@@ -334,6 +334,18 @@ bool LTOCodeGenerator::generateAssemblyCode(std::ostream& out, std::string& errM
             break;
     }
 
+    for (unsigned opt_index = 0, opt_size = _codegenOptions.size();
+         opt_index < opt_size; ++opt_index) {
+      std::vector<const char *> cgOpts;
+      std::string &optString = _codegenOptions[opt_index];
+      for (std::string Opt = getToken(optString);
+           !Opt.empty(); Opt = getToken(optString))
+        cgOpts.push_back(Opt.c_str());
+     
+      int pseudo_argc = cgOpts.size()-1;
+      cl::ParseCommandLineOptions(pseudo_argc, (char**)&cgOpts[0]);
+     }
+
     // Instantiate the pass manager to organize the passes.
     PassManager passes;
 

tools/lto/LTOCodeGenerator.h

@@ -17,6 +17,7 @@
 
 #include "llvm/Linker.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/SmallVector.h"
 
 #include <string>
 
@@ -38,7 +39,9 @@ public:
     bool                writeMergedModules(const char* path, 
                                                            std::string& errMsg);
     const void*         compile(size_t* length, std::string& errMsg);
-    
+    void                setCodeGenDebugOptions(const char *opts) {
+                          _codegenOptions.push_back(std::string(opts)); 
+                        }
 private:
     bool                generateAssemblyCode(std::ostream& out, 
                                                         std::string& errMsg);
@@ -56,6 +59,7 @@ private:
     lto_codegen_model           _codeModel;
     StringSet                   _mustPreserveSymbols;
     llvm::MemoryBuffer*         _nativeObjectFile;
+    llvm::SmallVector<std::string, 4> _codegenOptions;
 };
 
 #endif // LTO_CODE_GENERATOR_H

tools/lto/lto.cpp

@@ -237,5 +237,11 @@ lto_codegen_compile(lto_code_gen_t cg, size_t* length)
     return cg->compile(length, sLastErrorString);
 }
 
+extern void
+lto_codegen_debug_options(lto_code_gen_t cg, const char * opt)
+{
+  cg->setCodeGenDebugOptions(opt);
+}
+