Add -fsanitize-address-use-after-return (#4334)

Author: JohanEngelen

driver/cl_options_sanitizers.cpp

@@ -25,6 +25,16 @@
 #include "llvm/Support/VirtualFileSystem.h"
 #endif
 
+#if LDC_LLVM_VER >= 1400
+#include "llvm/Transforms/Instrumentation/AddressSanitizerOptions.h"
+#else
+namespace llvm {
+// Declaring this simplifies code later, but the option is never used with LLVM
+// <= 13.
+enum class AsanDetectStackUseAfterReturnMode { Never, Runtime, Always };
+}
+#endif
+
 namespace {
 
 using namespace opts;
@@ -121,6 +131,25 @@ void parseFSanitizeCoverageCmdlineParameter(llvm::SanitizerCoverageOptions &opts
 
 namespace opts {
 
+cl::opt<llvm::AsanDetectStackUseAfterReturnMode> fSanitizeAddressUseAfterReturn(
+    "fsanitize-address-use-after-return", cl::ZeroOrMore,
+    cl::desc("Select the mode of detecting stack use-after-return (UAR) in "
+             "AddressSanitizer: never | runtime (default) | always"),
+    cl::init(llvm::AsanDetectStackUseAfterReturnMode::Runtime),
+    cl::values(
+        clEnumValN(
+            llvm::AsanDetectStackUseAfterReturnMode::Never, "never",
+            "Completely disables detection of UAR errors (reduces code size)."),
+        clEnumValN(llvm::AsanDetectStackUseAfterReturnMode::Runtime, "runtime",
+                   "Adds the code for detection, but it can be disabled via the "
+                   "runtime environment "
+                   "(ASAN_OPTIONS=detect_stack_use_after_return=0). Requires "
+                   "druntime support."),
+        clEnumValN(
+            llvm::AsanDetectStackUseAfterReturnMode::Always, "always",
+            "Enables detection of UAR errors in all cases. (reduces code size, "
+            "but not as much as never). Requires druntime support.")));
+
 SanitizerBits enabledSanitizers = 0;
 
 // Parse sanitizer name passed on commandline and return the corresponding

driver/cl_options_sanitizers.h

@@ -20,6 +20,7 @@ class FuncDeclaration;
 namespace llvm {
 class raw_ostream;
 class StringRef;
+enum class AsanDetectStackUseAfterReturnMode;
 }
 
 namespace opts {
@@ -37,6 +38,8 @@ enum SanitizerCheck : SanitizerBits {
 };
 extern SanitizerBits enabledSanitizers;
 
+extern cl::opt<llvm::AsanDetectStackUseAfterReturnMode> fSanitizeAddressUseAfterReturn;
+
 inline bool isAnySanitizerEnabled() { return enabledSanitizers; }
 inline bool isSanitizerEnabled(SanitizerBits san) {
   return enabledSanitizers & san;

gen/optimizer.cpp

@@ -454,7 +454,7 @@ static void addAddressSanitizerPasses(ModulePassManager &mpm,
   aso.CompileKernel = false;
   aso.Recover = false;
   aso.UseAfterScope = true;
-  aso.UseAfterReturn = AsanDetectStackUseAfterReturnMode::Runtime;
+  aso.UseAfterReturn = opts::fSanitizeAddressUseAfterReturn;
 
 #if LDC_LLVM_VER >= 1600
   mpm.addPass(AddressSanitizerPass(aso));

tests/sanitizers/fuzz_asan.d

@@ -3,7 +3,8 @@
 // REQUIRES: Fuzzer, ASan
 
 // See https://github.com/ldc-developers/ldc/issues/2222 for %disable_fp_elim
-// RUN: %ldc -g -fsanitize=address,fuzzer %disable_fp_elim %s -of=%t%exe
+// See https://github.com/ldc-developers/ldc/pull/4328 for -fsanitize-address-use-after-return=never
+// RUN: %ldc -g -fsanitize=address,fuzzer -fsanitize-address-use-after-return=never %disable_fp_elim %s -of=%t%exe
 // RUN: not %t%exe 2>&1 | FileCheck %s
 
 bool FuzzMe(ubyte* data, size_t dataSize)
@@ -12,7 +13,7 @@ bool FuzzMe(ubyte* data, size_t dataSize)
            data[0] == 'F' &&
            data[1] == 'U' &&
            data[2] == 'Z' &&
-    // CHECK: ERROR: AddressSanitizer: {{stack-buffer-overflow|stack-use-after-return}}
+    // CHECK: ERROR: AddressSanitizer: stack-buffer-overflow
     // CHECK-NEXT: READ of size 1
     // CHECK-NEXT: #0 {{.*}} in {{.*fuzz_asan6FuzzMe.*}} {{.*}}fuzz_asan.d:
     // FIXME, debug line info is wrong (Github issue #2090). Once fixed, add [[@LINE+1]]