[IR] Require that global value initializers are sized (#137358)
While external globals can be unsized, I don't think an unsized
initializer makes sense.
It seems like the backend currently ends up treating this as a zero-size
global. If people want that behavior, they should declare it as such.
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index c8cc38c..568843a 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -700,7 +700,7 @@
Global variables define regions of memory allocated at compilation time
instead of run-time.
-Global variable definitions must be initialized.
+Global variable definitions must be initialized with a sized value.
Global variables in other translation units can also be declared, in which
case they don't have an initializer.
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 7d1918e..a798808 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -835,6 +835,8 @@
"Global variable initializer type does not match global "
"variable type!",
&GV);
+ Check(GV.getInitializer()->getType()->isSized(),
+ "Global variable initializer must be sized", &GV);
// If the global has common linkage, it must have a zero initializer and
// cannot be constant.
if (GV.hasCommonLinkage()) {
diff --git a/llvm/test/Verifier/global-initializer-sized.ll b/llvm/test/Verifier/global-initializer-sized.ll
new file mode 100644
index 0000000..84fee12
--- /dev/null
+++ b/llvm/test/Verifier/global-initializer-sized.ll
@@ -0,0 +1,5 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+@g = global target("opaque") undef
+
+; CHECK: Global variable initializer must be sized
diff --git a/llvm/test/Verifier/scalable-global-vars.ll b/llvm/test/Verifier/scalable-global-vars.ll
index fb9a306..9df644d 100644
--- a/llvm/test/Verifier/scalable-global-vars.ll
+++ b/llvm/test/Verifier/scalable-global-vars.ll
@@ -13,7 +13,7 @@
; CHECK-NEXT: Globals cannot contain scalable types
; CHECK-NEXT: ptr @ScalableVecStructGlobal
-@ScalableVecStructGlobal = global { i32, <vscale x 4 x i32> } zeroinitializer
+@ScalableVecStructGlobal = external global { i32, <vscale x 4 x i32> }
; CHECK-NEXT: Globals cannot contain scalable types
; CHECK-NEXT: ptr @StructTestGlobal
@@ -23,9 +23,9 @@
; CHECK-NEXT: Globals cannot contain scalable types
; CHECK-NEXT: ptr @StructArrayTestGlobal
%struct.array.test = type { [2 x <vscale x 1 x double>] }
-@StructArrayTestGlobal = global %struct.array.test zeroinitializer
+@StructArrayTestGlobal = external global %struct.array.test
; CHECK-NEXT: Globals cannot contain scalable types
; CHECK-NEXT: ptr @StructTargetTestGlobal
%struct.target.test = type { target("aarch64.svcount"), target("aarch64.svcount") }
-@StructTargetTestGlobal = global %struct.target.test zeroinitializer
+@StructTargetTestGlobal = external global %struct.target.test
