Add passes for applying SFI sandboxing at the LLVM IR level

test/Transforms/NaCl/sandbox-memory-accesses.ll

+; RUN: opt %s -sandbox-memory-accesses -S | FileCheck %s
+
+
+; CHECK: @__sfi_memory_base = external global i64
+
+define void @func(i32* %ptr) {
+  %val = load i32* %ptr
+  ret void
+}
+; CHECK: define void @func(i32* %ptr) {
+; CHECK-NEXT: %mem_base = load i64* @__sfi_memory_base
+; CHECK-NEXT: %1 = ptrtoint i32* %ptr to i32
+; CHECK-NEXT: %2 = zext i32 %1 to i64
+; CHECK-NEXT: %3 = add i64 %mem_base, %2
+; CHECK-NEXT: %4 = inttoptr i64 %3 to i32*
+; CHECK-NEXT: %val = load i32* %4
+
+define void @func2(i32* %ptr) {
+  %val = load i32* %ptr
+  store i32 %val, i32* %ptr
+  ret void
+}
+; TODO...
+
+define void @ptr_with_addend(i32 %ptr) {
+  %add = add i32 %ptr, 1234
+  %add.p = inttoptr i32 %add to i32*
+  %val = load i32* %add.p
+  ret void
+}
+; CHECK: define void @ptr_with_addend(i32 %ptr) {
+; CHECK-NEXT: %mem_base = load i64* @__sfi_memory_base
+; CHECK-NEXT: %add = add i32 %ptr, 1234
+; CHECK-NEXT: %add.p = inttoptr i32 %add to i32*
+; CHECK-NEXT: %1 = zext i32 %ptr to i64
+; CHECK-NEXT: %2 = add i64 %mem_base, %1
+; CHECK-NEXT: %3 = add i64 %2, 1234
+; CHECK-NEXT: %4 = inttoptr i64 %3 to i32*
+; CHECK-NEXT: %val = load i32* %4