Clarify lifetime of result of computeWorkingDirectory.

David Ungar · David Ungar · commit 77ec1e1c3603 · 2018-06-22T13:41:53.000-07:00
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
@@ -700,7 +700,9 @@ computeWorkingDirectory(const llvm::opt::InputArgList *ArgList) {
     SmallString<128> workingDirectory;
     workingDirectory = A->getValue();
     llvm::sys::fs::make_absolute(workingDirectory);
-    return workingDirectory.str();
+    //  Create a new string that can outlive ArgList.
+    std::string result = workingDirectory.str().str();
+    return result;
   }
   return std::string();
 }

Original file line number	Diff line number	Diff line change
`@@ -700,7 +700,9 @@ computeWorkingDirectory(const llvm::opt::InputArgList *ArgList) {`
`700`	`700`	`SmallString<128> workingDirectory;`
`701`	`701`	`workingDirectory = A->getValue();`
`702`	`702`	`llvm::sys::fs::make_absolute(workingDirectory);`
`703`		`- return workingDirectory.str();`
	`703`	`+ // Create a new string that can outlive ArgList.`
	`704`	`+ std::string result = workingDirectory.str().str();`
	`705`	`+ return result;`
`704`	`706`	`}`
`705`	`707`	`return std::string();`
`706`	`708`	`}`