delete-null-pointer-checks.c
894 Bytes
// RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-linux-gnu -O2 -o - %s | FileCheck -check-prefix=NULL-POINTER-INVALID %s
// RUN: %clang_cc1 -emit-llvm -triple x86_64-unknown-linux-gnu -O2 -o - %s -fno-delete-null-pointer-checks | FileCheck -check-prefix=NULL-POINTER-VALID %s
// Test that clang does not remove the null pointer check with
// -fno-delete-null-pointer-checks.
int null_check(int *P) {
// NULL-POINTER-VALID: %[[TOBOOL:.*]] = icmp eq i32* %P, null
// NULL-POINTER-INVALID-NOT: icmp eq
// NULL-POINTER-VALID: %[[SEL:.*]] = select i1 %[[TOBOOL:.*]], i32* null, i32*
// NULL-POINTER-INVALID-NOT: select i1
// NULL-POINTER-VALID: load i32, i32* %[[SEL:.*]]
int *Q = P;
if (P) {
Q = P + 2;
}
return *Q;
}
// NULL-POINTER-INVALID-NOT: attributes #0 = {{.*}} "null-pointer-is-valid"="true"
// NULL-POINTER-VALID: attributes #0 = {{.*}} "null-pointer-is-valid"="true"