[llvm] a76209c - [ORC] Fix handling of casts in llvm.global_ctors.

[Lang Hames via llvm-commits]

Author: Lang Hames
Date: 2022-04-07T17:06:38-07:00
New Revision: a76209c265bdaca09d46ca4744c2d6e3602c908a

URL: https://github.com/llvm/llvm-project/commit/a76209c265bdaca09d46ca4744c2d6e3602c908a
DIFF: https://github.com/llvm/llvm-project/commit/a76209c265bdaca09d46ca4744c2d6e3602c908a.diff

LOG: [ORC] Fix handling of casts in llvm.global_ctors.

Removes a bogus dyn_cast_or_null that was breaking cast-expression handling when
parsing llvm.global_ctors.

The intent of this code was to identify Functions nested within cast
expressions, but the offending dyn_cast_or_null was actually blocking that:
Since a function is not a cast expression, we would set FuncC to null and break
the loop without finding the Function. The cast was not necessary either:
Functions are already Constants, and we didn't need to do anything
ConstantExpr-specific with FuncC, so we could just drop the cast.

Thanks to Jonas Hahnfeld for tracking this down.

http://llvm.org/PR54797

Added: 
    llvm/test/ExecutionEngine/Orc/global-ctor-with-cast.ll

Modified: 
    llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
index ae2d47fb8c5eb..cbc27980f57a3 100644
--- a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
@@ -62,7 +62,7 @@ CtorDtorIterator::Element CtorDtorIterator::operator*() const {
       break;
     } else if (ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(FuncC)) {
       if (CE->isCast())
-        FuncC = dyn_cast_or_null<ConstantExpr>(CE->getOperand(0));
+        FuncC = CE->getOperand(0);
       else
         break;
     } else {

diff  --git a/llvm/test/ExecutionEngine/Orc/global-ctor-with-cast.ll b/llvm/test/ExecutionEngine/Orc/global-ctor-with-cast.ll
new file mode 100644
index 0000000000000..d8ef219c025f3
--- /dev/null
+++ b/llvm/test/ExecutionEngine/Orc/global-ctor-with-cast.ll
@@ -0,0 +1,19 @@
+; Test that global constructors behind casts are run
+;
+; RUN: lli -jit-kind=orc %s | FileCheck %s
+;
+; CHECK: constructor
+
+declare i32 @puts(i8*)
+
+ at .str = private constant [12 x i8] c"constructor\00"
+ at llvm.global_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 1, void ()* bitcast (i32 ()* @constructor to void ()*), i8* null }]
+
+define internal i32 @constructor() #0 {
+  %call = tail call i32 @puts(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str, i64 0, i64 0))
+  ret i32 0
+}
+
+define i32 @main()  {
+  ret i32 0
+}