rustc: Fix passing errors from LLVM to rustc

Many of the instances of setting a global error variable ended up leaving a
dangling pointer into free'd memory. This changes the method of error
transmission to strdup any error and "relinquish ownership" to rustc when it
gets an error. The corresponding Rust code will then free the error as
necessary.

Closes #12865

1 files changed, 2 insertions, 2 deletions

diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp
index 32bac73debf..021dda49765 100644
--- a/src/rustllvm/PassWrapper.cpp
+++ b/src/rustllvm/PassWrapper.cpp
@@ -75,7 +75,7 @@ LLVMRustCreateTargetMachine(const char *triple,
     const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Trip.getTriple(),
                                                                  Error);
     if (TheTarget == NULL) {
-        LLVMRustError = Error.c_str();
+        LLVMRustSetLastError(Error.c_str());
         return NULL;
     }
 
@@ -178,7 +178,7 @@ LLVMRustWriteOutputFile(LLVMTargetMachineRef Target,
   raw_fd_ostream OS(path, ErrorInfo, raw_fd_ostream::F_Binary);
 #endif
   if (ErrorInfo != "") {
-    LLVMRustError = ErrorInfo.c_str();
+    LLVMRustSetLastError(ErrorInfo.c_str());
     return false;
   }
   formatted_raw_ostream FOS(OS);