From fe8b2236ef9cf873875135dcc41364911898698d Mon Sep 17 00:00:00 2001
From: Vince Bridgers <vince.a.bridgers@gmail.com>
Date: Fri, 25 Mar 2022 17:30:59 -0500
Subject: [PATCH] [analyzer] Fix "RhsLoc and LhsLoc bitwidth must be same"

clang: <root>/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp:727:
void assertEqualBitWidths(clang::ento::ProgramStateRef,
  clang::ento::Loc, clang::ento::Loc): Assertion `RhsBitwidth ==
  LhsBitwidth && "RhsLoc and LhsLoc bitwidth must be same!"'

This change adjusts the bitwidth of the smaller operand for an evalBinOp
as a result of a comparison operation. This can occur in the specific
case represented by the test cases for a target with different pointer
sizes.

Reviewed By: NoQ

Differential Revision: https://reviews.llvm.org/D122513
---
 clang/lib/StaticAnalyzer/Core/SValBuilder.cpp |  7 ++-
 clang/test/Analysis/addrspace-null.c          | 47 +++++++++++++++++++
 2 files changed, 52 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/Analysis/addrspace-null.c

diff --git a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
index e9a1ec3173a9..e045c9a91e60 100644
--- a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -682,8 +682,11 @@ SVal SValBuilder::evalCastSubKind(loc::ConcreteInt V, QualType CastTy,
   }
 
   // Pointer to any pointer.
-  if (Loc::isLocType(CastTy))
-    return V;
+  if (Loc::isLocType(CastTy)) {
+    llvm::APSInt Value = V.getValue();
+    BasicVals.getAPSIntType(CastTy).apply(Value);
+    return loc::ConcreteInt(BasicVals.getValue(Value));
+  }
 
   // Pointer to whatever else.
   return UnknownVal();
diff --git a/clang/test/Analysis/addrspace-null.c b/clang/test/Analysis/addrspace-null.c
new file mode 100644
index 000000000000..54d96b277db0
--- /dev/null
+++ b/clang/test/Analysis/addrspace-null.c
@@ -0,0 +1,47 @@
+// RUN: %clang_analyze_cc1 -triple amdgcn-unknown-unknown \
+// RUN: -analyze -analyzer-checker=core -DAMDGCN_TRIPLE \
+// RUN: -analyze -analyzer-checker=debug.ExprInspection \
+// RUN: -Wno-implicit-int -Wno-int-conversion -verify %s
+//
+// RUN: %clang_analyze_cc1 -triple amdgcn-unknown-unknown \
+// RUN: -analyze -analyzer-checker=core -DDEFAULT_TRIPLE \
+// RUN: -analyze -analyzer-checker=debug.ExprInspection \
+// RUN: -Wno-implicit-int -Wno-int-conversion -verify %s
+
+// From https://llvm.org/docs/AMDGPUUsage.html#address-spaces,
+// select address space 3 (local), since the pointer size is
+// different than Generic.
+
+// expected-no-diagnostics
+
+#define DEVICE __attribute__((address_space(3)))
+
+#if defined(AMDGCN_TRIPLE)
+// this crashes
+int fn1() {
+  int val = 0;
+  DEVICE int *dptr = val;
+  return dptr == (void *)0;
+}
+
+// does not crash
+int fn2() {
+  int val = 0;
+  DEVICE int *dptr = val;
+  return dptr == (DEVICE void *)0;
+}
+
+// this crashes
+int fn3() {
+  int val = 0;
+  int *dptr = val;
+  return dptr == (DEVICE void *)0;
+}
+#endif
+
+// does not crash
+int fn4() {
+  int val = 0;
+  int *dptr = val;
+  return dptr == (void *)0;
+}