[cfi] Support sanstats if binary is not available in the original location

[vitalybuka]

Summary

By default sanstats search binaries at the same location where the were when
stats was collected. Sometime you can print report immediately or need to move
post-processing to another workstation. To support this use-case if original binary is missing sanstats will fall-back to directory with sanstats file.

[vitalybuka]

ping

[pcc]

Test case?

[vitalybuka]

test

[vitalybuka]

done

[vitalybuka]

ping

[pcc]

LGTM

llvm/trunk/test/tools/sanstats/elf.test

 # RUN: printf "\x01\x00\x00\x00\x09\x00\x00\x40" >> %t.stats
 # RUN: printf "\x21\x00\x00\x00\x0b\x00\x00\x60" >> %t.stats
 # RUN: printf "\x11\x00\x00\x00\x0c\x00\x00\x80" >> %t.stats
 # RUN: printf "\x01\x00\x00\x00\x0e\x00\x00\xa0" >> %t.stats
 # RUN: printf "\x00\x00\x00\x00\x00\x00\x00\x00" >> %t.stats
 
 # RUN: sanstats %t.stats | FileCheck %s
 
+# Test that if binaries are not in the original location then sanstats
+# searches them next to the stats file.
+# RUN: mkdir -p %t.dir
+# RUN: mv -f %t1.o %t2.o %t.dir
+# RUN: sanstats %t.stats | FileCheck %s --check-prefix=INVALID
+# RUN: mv -f %t.stats %t.dir/copy.stats
+# RUN: cd %t.dir && sanstats copy.stats | FileCheck %s
+
+# INVALID: <invalid>
+# CHECK-NOT: <invalid>
 # CHECK: 0x0000000000000000 /tmp{{[/\\]}}f.c:1 f1 cfi-vcall 1
 # CHECK: 0x0000000000000010 /tmp{{[/\\]}}f.c:2 f2 cfi-nvcall 2
 # CHECK: 0x0000000000000020 /tmp{{[/\\]}}f.c:3 f3 cfi-derived-cast 3
 # CHECK: 0x0000000000000000 /tmp{{[/\\]}}f.c:1 f1 cfi-unrelated-cast 4
 # CHECK: 0x0000000000000010 /tmp{{[/\\]}}f.c:2 f2 cfi-icall 5
 # CHECK: 0x0000000000000020 /tmp{{[/\\]}}f.c:3 f3 <unknown> 6
 
 # CHECK: 0x0000000000000020 /tmp{{[/\\]}}f.c:3 f3 cfi-vcall 7

llvm/trunk/tools/sanstats/sanstats.cpp

 // This tool dumps statistics information from files in the format produced
 // by clang's -fsanitize-stats feature.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/DebugInfo/Symbolize/Symbolize.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Transforms/Utils/SanitizerStats.h"
 #include <stdint.h>
 
 using namespace llvm;
 
 static cl::opt<std::string> ClInputFile(cl::Positional, cl::Required,
                                         cl::desc("<filename>"));
 

 }
 
 const char *ReadModule(char SizeofPtr, const char *Begin, const char *End) {
   const char *FilenameBegin = Begin;
   while (Begin != End && *Begin)
     ++Begin;
   if (Begin == End)
     return nullptr;
-  StringRef Filename(FilenameBegin, Begin - FilenameBegin);
+  std::string Filename(FilenameBegin, Begin - FilenameBegin);
+
+  if (!llvm::sys::fs::exists(Filename))
+    Filename = std::string(llvm::sys::path::parent_path(ClInputFile)) +
+               std::string(llvm::sys::path::filename(Filename));
 
   ++Begin;
   if (Begin == End)
     return nullptr;
 
   symbolize::LLVMSymbolizer::Options SymbolizerOptions;
   SymbolizerOptions.Demangle = ClDemangle;
   SymbolizerOptions.UseSymbolTable = true;