1 files changed, 128 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
new file mode 100644
index 000000000000..b38cb6d0ed3f
--- /dev/null
+++ b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
@@ -0,0 +1,128 @@
+//===- ForceFunctionAttrs.cpp - Force function attrs for debugging --------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO/ForceFunctionAttrs.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#define DEBUG_TYPE "forceattrs"
+
+static cl::list<std::string>
+    ForceAttributes("force-attribute", cl::Hidden,
+                    cl::desc("Add an attribute to a function. This should be a "
+                             "pair of 'function-name:attribute-name', for "
+                             "example -force-attribute=foo:noinline. This "
+                             "option can be specified multiple times."));
+
+static Attribute::AttrKind parseAttrKind(StringRef Kind) {
+  return StringSwitch<Attribute::AttrKind>(Kind)
+      .Case("alwaysinline", Attribute::AlwaysInline)
+      .Case("builtin", Attribute::Builtin)
+      .Case("cold", Attribute::Cold)
+      .Case("convergent", Attribute::Convergent)
+      .Case("inlinehint", Attribute::InlineHint)
+      .Case("jumptable", Attribute::JumpTable)
+      .Case("minsize", Attribute::MinSize)
+      .Case("naked", Attribute::Naked)
+      .Case("nobuiltin", Attribute::NoBuiltin)
+      .Case("noduplicate", Attribute::NoDuplicate)
+      .Case("noimplicitfloat", Attribute::NoImplicitFloat)
+      .Case("noinline", Attribute::NoInline)
+      .Case("nonlazybind", Attribute::NonLazyBind)
+      .Case("noredzone", Attribute::NoRedZone)
+      .Case("noreturn", Attribute::NoReturn)
+      .Case("nocf_check", Attribute::NoCfCheck)
+      .Case("norecurse", Attribute::NoRecurse)
+      .Case("nounwind", Attribute::NoUnwind)
+      .Case("optforfuzzing", Attribute::OptForFuzzing)
+      .Case("optnone", Attribute::OptimizeNone)
+      .Case("optsize", Attribute::OptimizeForSize)
+      .Case("readnone", Attribute::ReadNone)
+      .Case("readonly", Attribute::ReadOnly)
+      .Case("argmemonly", Attribute::ArgMemOnly)
+      .Case("returns_twice", Attribute::ReturnsTwice)
+      .Case("safestack", Attribute::SafeStack)
+      .Case("shadowcallstack", Attribute::ShadowCallStack)
+      .Case("sanitize_address", Attribute::SanitizeAddress)
+      .Case("sanitize_hwaddress", Attribute::SanitizeHWAddress)
+      .Case("sanitize_memory", Attribute::SanitizeMemory)
+      .Case("sanitize_thread", Attribute::SanitizeThread)
+      .Case("sanitize_memtag", Attribute::SanitizeMemTag)
+      .Case("speculative_load_hardening", Attribute::SpeculativeLoadHardening)
+      .Case("ssp", Attribute::StackProtect)
+      .Case("sspreq", Attribute::StackProtectReq)
+      .Case("sspstrong", Attribute::StackProtectStrong)
+      .Case("strictfp", Attribute::StrictFP)
+      .Case("uwtable", Attribute::UWTable)
+      .Default(Attribute::None);
+}
+
+/// If F has any forced attributes given on the command line, add them.
+static void addForcedAttributes(Function &F) {
+  for (auto &S : ForceAttributes) {
+    auto KV = StringRef(S).split(':');
+    if (KV.first != F.getName())
+      continue;
+
+    auto Kind = parseAttrKind(KV.second);
+    if (Kind == Attribute::None) {
+      LLVM_DEBUG(dbgs() << "ForcedAttribute: " << KV.second
+                        << " unknown or not handled!\n");
+      continue;
+    }
+    if (F.hasFnAttribute(Kind))
+      continue;
+    F.addFnAttr(Kind);
+  }
+}
+
+PreservedAnalyses ForceFunctionAttrsPass::run(Module &M,
+                                              ModuleAnalysisManager &) {
+  if (ForceAttributes.empty())
+    return PreservedAnalyses::all();
+
+  for (Function &F : M.functions())
+    addForcedAttributes(F);
+
+  // Just conservatively invalidate analyses, this isn't likely to be important.
+  return PreservedAnalyses::none();
+}
+
+namespace {
+struct ForceFunctionAttrsLegacyPass : public ModulePass {
+  static char ID; // Pass identification, replacement for typeid
+  ForceFunctionAttrsLegacyPass() : ModulePass(ID) {
+    initializeForceFunctionAttrsLegacyPassPass(
+        *PassRegistry::getPassRegistry());
+  }
+
+  bool runOnModule(Module &M) override {
+    if (ForceAttributes.empty())
+      return false;
+
+    for (Function &F : M.functions())
+      addForcedAttributes(F);
+
+    // Conservatively assume we changed something.
+    return true;
+  }
+};
+}
+
+char ForceFunctionAttrsLegacyPass::ID = 0;
+INITIALIZE_PASS(ForceFunctionAttrsLegacyPass, "forceattrs",
+                "Force set function attributes", false, false)
+
+Pass *llvm::createForceFunctionAttrsLegacyPass() {
+  return new ForceFunctionAttrsLegacyPass();
+}