Use litsupport.shellcommand to set LLVM_PROFILE_FILE

[MatzeB]

Summary

• Fix bug in shellcommand.envvars handling set variables before the command.
• Use shellcommand in profilegen mutator to fix bug reported in D120406

[taolq]

Thanks for the fix.
This patch works well. All MicroBenchmarks passed at the profile generation run.

litsupport/modules/profilegen.py

 """Test module that runs llvm-profdata merge after executing the benchmark."""
 from litsupport import shellcommand
 from litsupport import testplan
 
 
 def _mutateCommandline(context, commandline):
     """Adjust runscript to set a different value to the LLVM_PROFILE_FILE
     environment variable for each execution."""
     profilefile = context.tmpBase + ".profraw"
-    prefix = "env LLVM_PROFILE_FILE=%s " % profilefile
     context.profilefiles.append(profilefile)
-    return prefix + commandline
+    cmd = shellcommand.parse(commandline)
+    cmd.envvars.update({"LLVM_PROFILE_FILE": profilefile})
+    return cmd.toCommandline()
 
 
 def _mutateScript(context, script):
     return testplan.mutateScript(context, script, _mutateCommandline)
 
 
 def mutatePlan(context, plan):
     context.profilefiles = []

litsupport/shellcommand.py

class ShellCommand:
 
     def toCommandline(self):
         """Transforms ShellCommand object to a posix shell commandline."""
         result = ""
 
         if self.workdir is not None:
             result += "cd %s && " % quote(self.workdir)
 
-        res_list = [self.executable] + self.arguments
-        result += " ".join(map(quote, res_list))
-
         for key, value in self.envvars.items():
             result += "%s=%s " % (key, quote(value))
 
+        res_list = [self.executable] + self.arguments
+        result += " ".join(map(quote, res_list))
+
         if self.stdin is not None:
             result += " < %s" % quote(self.stdin)
         if self.stdout is not None:
             result += " > %s" % quote(self.stdout)
         if self.stderr is not None:
             result += " 2> %s" % quote(self.stderr)
         return result