Add a statistic for counting {must,no}_preserve_cheri_tags attributes

CTSRD-CHERI · Aug 16, 2022 · c169ab1 · c169ab1
1 parent a5c94c8
commit c169ab1
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Showing 3 changed files with 44 additions and 21 deletions.
diff --git a/llvm/include/llvm/IR/IntrinsicInst.h b/llvm/include/llvm/IR/IntrinsicInst.h
@@ -681,6 +681,12 @@ static inline PreserveCheriTags shouldPreserveTags(const CallInst *CI) {
   return PreserveCheriTags::Unknown;
 }
 
+/// Out-of-line to allow counting statistics. This is only possible in source
+/// files and MemTransferBase is templated so moving it out-of-line is more
+/// awkward.
+void setPreserveCheriTags(IntrinsicInst *I, PreserveCheriTags NewValue,
+                          const DataLayout &DL);
+
 /// Common base class for all memory transfer intrinsics. Simply provides
 /// common methods.
 template <class BaseCL> class MemTransferBase : public BaseCL {
@@ -751,22 +757,8 @@ template <class BaseCL> class MemTransferBase : public BaseCL {
         .getValueAsString();
   }
 
-  void setPreserveCheriTags(PreserveCheriTags NewValue) {
-    if (NewValue == PreserveCheriTags::Required) {
-      assert(!BaseCL::hasFnAttr(Attribute::NoPreserveCheriTags) &&
-             "attempting to set conflicting attributes");
-      BaseCL::addAttribute(llvm::AttributeList::FunctionIndex,
-                           llvm::Attribute::MustPreserveCheriTags);
-    } else if (NewValue == PreserveCheriTags::Unnecessary) {
-      assert(!BaseCL::hasFnAttr(Attribute::MustPreserveCheriTags) &&
-             "attempting to set conflicting attributes");
-      BaseCL::addAttribute(llvm::AttributeList::FunctionIndex,
-                           llvm::Attribute::NoPreserveCheriTags);
-    } else {
-      assert(!BaseCL::hasFnAttr(Attribute::MustPreserveCheriTags) &&
-             !BaseCL::hasFnAttr(Attribute::NoPreserveCheriTags) &&
-             "Cannot set unknown on an already annotated instruction");
-    }
+  void setPreserveCheriTags(PreserveCheriTags NewValue, const DataLayout &DL) {
+    llvm::setPreserveCheriTags(this, NewValue, DL);
   }
 };
 

diff --git a/llvm/lib/IR/IRBuilder.cpp b/llvm/lib/IR/IRBuilder.cpp
@@ -206,7 +206,7 @@ CallInst *IRBuilderBase::CreateMemTransferInst(
 
   auto* MCI = cast<MemTransferInst>(CI);
   if (M->getDataLayout().hasCheriCapabilities())
-    MCI->setPreserveCheriTags(PreserveTags);
+    MCI->setPreserveCheriTags(PreserveTags, M->getDataLayout());
   if (DstAlign)
     MCI->setDestAlignment(*DstAlign);
   if (SrcAlign)
@@ -247,7 +247,7 @@ CallInst *IRBuilderBase::CreateMemCpyInline(
 
   auto *MCI = cast<MemCpyInlineInst>(CI);
   if (M->getDataLayout().hasCheriCapabilities())
-    MCI->setPreserveCheriTags(PreserveTags);
+    MCI->setPreserveCheriTags(PreserveTags, M->getDataLayout());
   if (DstAlign)
     MCI->setDestAlignment(*DstAlign);
   if (SrcAlign)
@@ -292,7 +292,7 @@ CallInst *IRBuilderBase::CreateElementUnorderedAtomicMemCpy(
   // Set the alignment of the pointer args.
   auto *AMCI = cast<AtomicMemCpyInst>(CI);
   if (M->getDataLayout().hasCheriCapabilities())
-    AMCI->setPreserveCheriTags(PreserveTags);
+    AMCI->setPreserveCheriTags(PreserveTags, M->getDataLayout());
   AMCI->setDestAlignment(DstAlign);
   AMCI->setSourceAlignment(SrcAlign);
 
@@ -335,7 +335,7 @@ CallInst *IRBuilderBase::CreateMemMove(Value *Dst, MaybeAlign DstAlign,
 
   auto *MMI = cast<MemMoveInst>(CI);
   if (M->getDataLayout().hasCheriCapabilities())
-    MMI->setPreserveCheriTags(PreserveTags);
+    MMI->setPreserveCheriTags(PreserveTags, M->getDataLayout());
   if (DstAlign)
     MMI->setDestAlignment(*DstAlign);
   if (SrcAlign)
@@ -373,7 +373,8 @@ CallInst *IRBuilderBase::CreateElementUnorderedAtomicMemMove(
 
   CallInst *CI = createCallHelper(TheFn, Ops, this);
   if (M->getDataLayout().hasCheriCapabilities())
-    cast<AtomicMemTransferInst>(CI)->setPreserveCheriTags(PreserveTags);
+    cast<AtomicMemTransferInst>(CI)->setPreserveCheriTags(PreserveTags,
+                                                          M->getDataLayout());
 
   // Set the alignment of the pointer args.
   CI->addParamAttr(0, Attribute::getWithAlignment(CI->getContext(), DstAlign));

diff --git a/llvm/lib/IR/IntrinsicInst.cpp b/llvm/lib/IR/IntrinsicInst.cpp
@@ -21,6 +21,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/IntrinsicInst.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfoMetadata.h"
@@ -34,6 +35,12 @@
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "intrinsics"
+STATISTIC(NumMustPreserveTagAttrs,
+          "Number of must_preserve_cheri_tags attributes specified");
+STATISTIC(NumNoPreserveTagAttrs,
+          "Number of no_preserve_cheri_tags attributes specified");
+
 //===----------------------------------------------------------------------===//
 /// DbgVariableIntrinsic - This is the common base class for debug info
 /// intrinsics for variables.
@@ -544,6 +551,29 @@ unsigned BinaryOpIntrinsic::getNoWrapKind() const {
     return OverflowingBinaryOperator::NoUnsignedWrap;
 }
 
+void llvm::setPreserveCheriTags(IntrinsicInst *I, PreserveCheriTags NewValue,
+                                const DataLayout &DL) {
+  if (NewValue == PreserveCheriTags::Required) {
+    assert(DL.hasCheriCapabilities());
+    assert(!I->hasFnAttr(Attribute::NoPreserveCheriTags) &&
+           "attempting to set conflicting attributes");
+    I->addAttribute(llvm::AttributeList::FunctionIndex,
+                    llvm::Attribute::MustPreserveCheriTags);
+    NumMustPreserveTagAttrs++;
+  } else if (NewValue == PreserveCheriTags::Unnecessary) {
+    assert(!I->hasFnAttr(Attribute::MustPreserveCheriTags) &&
+           "attempting to set conflicting attributes");
+    assert(DL.hasCheriCapabilities());
+    I->addAttribute(llvm::AttributeList::FunctionIndex,
+                    llvm::Attribute::NoPreserveCheriTags);
+    NumNoPreserveTagAttrs++;
+  } else {
+    assert(!I->hasFnAttr(Attribute::MustPreserveCheriTags) &&
+           !I->hasFnAttr(Attribute::NoPreserveCheriTags) &&
+           "Cannot set unknown on an already annotated instruction");
+  }
+}
+
 const GCStatepointInst *GCProjectionInst::getStatepoint() const {
   const Value *Token = getArgOperand(0);