Fix depfile name construction

[LukeCheeseman]

Summary

• When using -o, the provided filename is using for constructing the depfile name (when -MMD is passed).
• The logic looks for the rightmost '.' character and replaces what comes after with 'd'.
• This works incorrectly when the filename has no extension and the directories have '.' in them (e.g. out.dir/test)
• This replaces the funciton to just llvm::sys::path functionality

[chill]

clang/test/Driver/metadata-with-dots.c

2 ↗

(On Diff #220058)

Is this going to ruin on Windows ?

4–6 ↗

(On Diff #220058)

And these ?

[LukeCheeseman]

• Add a requires shell

[chill]

LGTM

[thakis]

cfe/trunk/lib/Driver/ToolChains/Clang.cpp

6076

Can you use llvm::Twine() instead of std::string() here?

cfe/trunk/lib/Driver/ToolChains/Clang.cpp

if (const char *End = strrchr(Str, '.'))
     return Args.MakeArgString(std::string(Str, End));
 
   return Str;
 }
 
 const char *Clang::getDependencyFileName(const ArgList &Args,
                                          const InputInfoList &Inputs) {
   // FIXME: Think about this more.
-  std::string Res;
 
   if (Arg *OutputOpt = Args.getLastArg(options::OPT_o)) {
-    std::string Str(OutputOpt->getValue());
-    Res = Str.substr(0, Str.rfind('.'));
-  } else {
-    Res = getBaseInputStem(Args, Inputs);
+    SmallString<128> OutputFilename(OutputOpt->getValue());
+    llvm::sys::path::replace_extension(OutputFilename, llvm::Twine('d'));
+    return Args.MakeArgString(OutputFilename);
   }
-  return Args.MakeArgString(Res + ".d");
+
+  return Args.MakeArgString(std::string(getBaseInputStem(Args, Inputs)) + ".d");
 }
 
 // Begin ClangAs
 
 void ClangAs::AddMIPSTargetArgs(const ArgList &Args,
                                 ArgStringList &CmdArgs) const {
   StringRef CPUName;
   StringRef ABIName;

cfe/trunk/test/Driver/metadata-with-dots.c

+// REQUIRES: shell
+// RUN: mkdir -p out.dir
+// RUN: cat %s > out.dir/test.c
+// RUN: %clang -E -MMD %s -o out.dir/test
+// RUN: test ! -f %out.d
+// RUN: test -f out.dir/test.d
+// RUN: rm -rf out.dir/test.d out.dir/ out.d
+int main (void)
+{
+    return 0;
+}