[PATCH] IR: Check inalloca call argument originating from parameter

[David Majnemer]

Address review comments.

http://reviews.llvm.org/D3593

Files:
  lib/Analysis/Lint.cpp
  lib/IR/Verifier.cpp
  test/Analysis/Lint/inalloca1.ll
  test/Analysis/Lint/inalloca2.ll
  test/Analysis/Lint/inalloca3.ll
  test/Verifier/inalloca3.ll

Index: lib/Analysis/Lint.cpp
===================================================================
--- lib/Analysis/Lint.cpp
+++ lib/Analysis/Lint.cpp
@@ -219,6 +219,29 @@
             "Undefined behavior: Call return type mismatches "
             "callee return type", &I);
 
+    // Conservatively check the inalloca argument.
+    if (CS.hasInAllocaArgument()) {
+      Value *InAllocaArg =
+          CS.getArgument(FT->getNumParams() - 1)->stripInBoundsOffsets();
+      // We have a bug if we can find that there is an underlying alloca without
+      // inalloca.
+      if (auto AI = dyn_cast<AllocaInst>(InAllocaArg))
+        Assert2(AI->isUsedWithInAlloca(),
+                "inalloca argument for call has mismatched alloca", AI, &I);
+
+      // If our inalloca argument came from one of our arguments, check it for
+      // inalloca as well.
+      if (auto A = dyn_cast<Argument>(InAllocaArg)) {
+        Assert2(A->hasInAllocaAttr(), "inalloca argument for call originated "
+                                      "from argument without inalloca",
+                A, &I);
+        Assert1(CS.isMustTailCall(), "inalloca argument comes from previous "
+                                     "caller, call site should be annotated "
+                                     "with musttail",
+                &I);
+      }
+    }
+
     // Check argument types (in case the callee was casted) and attributes.
     // TODO: Verify that caller and callee attributes are compatible.
     Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end();
Index: lib/IR/Verifier.cpp
===================================================================
--- lib/IR/Verifier.cpp
+++ lib/IR/Verifier.cpp
@@ -1490,16 +1490,6 @@
   // Verify call attributes.
   VerifyFunctionAttrs(FTy, Attrs, I);
 
-  // Conservatively check the inalloca argument.
-  // We have a bug if we can find that there is an underlying alloca without
-  // inalloca.
-  if (CS.hasInAllocaArgument()) {
-    Value *InAllocaArg = CS.getArgument(FTy->getNumParams() - 1);
-    if (auto AI = dyn_cast<AllocaInst>(InAllocaArg->stripInBoundsOffsets()))
-      Assert2(AI->isUsedWithInAlloca(),
-              "inalloca argument for call has mismatched alloca", AI, I);
-  }
-
   if (FTy->isVarArg()) {
     // FIXME? is 'nest' even legal here?
     bool SawNest = false;
Index: test/Analysis/Lint/inalloca1.ll
===================================================================
--- test/Analysis/Lint/inalloca1.ll
+++ test/Analysis/Lint/inalloca1.ll
@@ -1,4 +1,4 @@
-; RUN: not llvm-as %s -o /dev/null 2>&1 | FileCheck %s
+; RUN: opt -lint %s -o /dev/null 2>&1 | FileCheck %s
 
 
 declare void @doit(i64* inalloca %a)
Index: test/Analysis/Lint/inalloca2.ll
===================================================================
--- /dev/null
+++ test/Analysis/Lint/inalloca2.ll
@@ -0,0 +1,10 @@
+; RUN: opt -lint %s -o /dev/null 2>&1 | FileCheck %s
+
+declare void @doit(i64* inalloca %a)
+
+define void @a(i64* %a) {
+entry:
+  call void @doit(i64* inalloca %a)
+; CHECK: inalloca argument for call originated from argument without inalloca
+  ret void
+}
Index: test/Analysis/Lint/inalloca3.ll
===================================================================
--- /dev/null
+++ test/Analysis/Lint/inalloca3.ll
@@ -0,0 +1,10 @@
+; RUN: opt -lint %s -o /dev/null 2>&1 | FileCheck %s
+
+declare void @doit(i64* inalloca %a)
+
+define void @a(i64* inalloca %a) {
+entry:
+  call void @doit(i64* inalloca %a)
+; CHECK: inalloca argument comes from previous caller, call site should be annotated with musttail
+  ret void
+}
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