Upgrade Rust support for LLVM 8

* Install the most recent Rust compiler to support LLVM 8
* Improve entry point detection
* Streamline Rust compiler installation. Closes #489

Author: keram88

bin/build.sh

@@ -387,8 +387,9 @@ if [ ${INSTALL_RUST} -eq 1 ] ; then
   ${WGET} https://static.rust-lang.org/dist/${RUST_VERSION}/rust-nightly-x86_64-unknown-linux-gnu.tar.gz -O rust.tar.gz
   tar xf rust.tar.gz
   cd rust-nightly-x86_64-unknown-linux-gnu
-  sudo ./install.sh
+  sudo ./install.sh --without=rust-docs
   cd ..
+  rm -r rust-nightly-x86_64-unknown-linux-gnu rust.tar.gz
 
   puts "Installed Rust"
 fi

lib/smack/SmackInstGenerator.cpp

@@ -646,10 +646,8 @@ void SmackInstGenerator::visitCallInst(llvm::CallInst &ci) {
   } else if (name.find(Naming::RUST_ENTRY) != std::string::npos) {
     // Set the entry point for Rust programs
     auto castExpr = ci.getArgOperand(0);
-    if (auto CE = dyn_cast<const Constant>(castExpr)) {
-      auto mainFunc = CE->getOperand(0);
-      emit(Stmt::call(mainFunc->getName(), {}, {}));
-    }
+    auto mainFunction = dyn_cast<const Function>(castExpr);
+    emit(Stmt::call(mainFunction->getName(), {}, {}));
 
   } else if (name.find(Naming::RUST_PANIC1) != std::string::npos ||
              name.find(Naming::RUST_PANIC2) != std::string::npos) {

share/smack/frontend.py

@@ -220,7 +220,7 @@ def rust_frontend(input_file, args):
   """Generate Boogie code from Rust programming language source(s)."""
   compile_command = ['rustc', '-A', 'unused-imports', '-C', 'opt-level=0',
                      '-C', 'no-prepopulate-passes', '-g', '--emit=llvm-bc',
-                     '--cfg', 'verifier="smack"']
+                     '--cfg', 'verifier="smack"', '-C', 'passes=name-anon-globals']
 
   # This links in the Rust SMACK library. This is needed due to the way rustc
   # finds a programs libraries.