[Verifier] add invariant check for callbr

Summary:
The list of indirect labels should ALWAYS have their blockaddresses as
argument operands to the callbr (but not necessarily the other way
around).  Add an invariant that checks this.

The verifier catches a bad test case that was added recently in r368478.
I think that was a simple mistake, and the test was made less strict in
regards to the precise addresses (as those weren't specifically the
point of the test).

This invariant will be used to find a reported bug.

Link: https://www.spinics.net/lists/arm-kernel/msg753473.html
Link: https://github.com/ClangBuiltLinux/linux/issues/649

Reviewers: craig.topper, void, chandlerc

Reviewed By: void

Subscribers: ychen, lebedev.ri, javed.absar, kristof.beyls, hiraditya, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67196

llvm-svn: 372923

1 files changed, 50 insertions, 0 deletions

diff --git a/llvm/test/Verifier/callbr.ll b/llvm/test/Verifier/callbr.ll
new file mode 100644
index 00000000000..403cc573d0d
--- /dev/null
+++ b/llvm/test/Verifier/callbr.ll
@@ -0,0 +1,50 @@
+; RUN: not opt -S %s -verify 2>&1 | FileCheck %s
+
+; CHECK: Indirect label missing from arglist.
+define void @foo() {
+  ; The %4 in the indirect label list is not found in the blockaddresses in the
+  ; arg list (bad).
+  callbr void asm sideeffect "${0:l} {1:l}", "X,X"(i8* blockaddress(@foo, %3), i8* blockaddress(@foo, %2))
+  to label %1 [label %4, label %2]
+1:
+  ret void
+2:
+  ret void
+3:
+  ret void
+4:
+  ret void
+}
+
+; CHECK-NOT: Indirect label missing from arglist.
+define void @bar() {
+  ; %4 and %2 are both in the indirect label list and the arg list (good).
+  callbr void asm sideeffect "${0:l} ${1:l}", "X,X"(i8* blockaddress(@bar, %4), i8* blockaddress(@bar, %2))
+  to label %1 [label %4, label %2]
+1:
+  ret void
+2:
+  ret void
+3:
+  ret void
+4:
+  ret void
+}
+
+; CHECK-NOT: Indirect label missing from arglist.
+define void @baz() {
+  ; note %2 blockaddress. Such a case is possible when passing the address of
+  ; a label as an input to the inline asm (both address of label and asm goto
+  ; use blockaddress constants; we're testing that the indirect label list from
+  ; the asm goto is in the arg list to the asm).
+  callbr void asm sideeffect "${0:l} ${1:l} ${2:l}", "X,X,X"(i8* blockaddress(@baz, %4), i8* blockaddress(@baz, %2), i8* blockaddress(@baz, %3))
+  to label %1 [label %3, label %4]
+1:
+  ret void
+2:
+  ret void
+3:
+  ret void
+4:
+  ret void
+}