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llvm-project/clang/test/CodeGenCXX/ubsan-bitfields.cpp

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Retry: [ubsan] Detect UB loads from bitfields It's possible to load out-of-range values from bitfields backed by a boolean or an enum. Check for UB loads from bitfields. This is the motivating example: struct S { BOOL b : 1; // Signed ObjC BOOL. }; S s; s.b = 1; // This is actually stored as -1. if (s.b == 1) // Evaluates to false, -1 != 1. ... Changes since the original commit: - Single-bit bools are a special case (see CGF::EmitFromMemory), and we can't avoid dealing with them when loading from a bitfield. Don't try to insert a check in this case. Differential Revision: https://reviews.llvm.org/D30423 llvm-svn: 297389
2017-03-10 00:06:27 +08:00
// RUN: %clang_cc1 -std=c++11 -triple x86_64-apple-darwin10 -emit-llvm -o - %s -fsanitize=bool,enum | FileCheck %s
enum E {
a = 1,
b = 2,
c = 3
};
struct S {
E e1 : 10;
};
[test] Add {{.*}} to make tests immune to dso_local/dso_preemptable/(none) differences For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie and COFF, but not for Mach-O. This nuance causes unneeded binary format differences. This patch replaces (function) `define ` with `define{{.*}} `, (variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} ` if there is an explicit linkage. * Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar. * Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
2020-12-31 12:45:56 +08:00
// CHECK-LABEL: define{{.*}} i32 @_Z4loadP1S
Retry: [ubsan] Detect UB loads from bitfields It's possible to load out-of-range values from bitfields backed by a boolean or an enum. Check for UB loads from bitfields. This is the motivating example: struct S { BOOL b : 1; // Signed ObjC BOOL. }; S s; s.b = 1; // This is actually stored as -1. if (s.b == 1) // Evaluates to false, -1 != 1. ... Changes since the original commit: - Single-bit bools are a special case (see CGF::EmitFromMemory), and we can't avoid dealing with them when loading from a bitfield. Don't try to insert a check in this case. Differential Revision: https://reviews.llvm.org/D30423 llvm-svn: 297389
2017-03-10 00:06:27 +08:00
E load(S *s) {
// CHECK: [[LOAD:%.*]] = load i16, i16* {{.*}}
// CHECK: [[CLEAR:%.*]] = and i16 [[LOAD]], 1023
// CHECK: [[CAST:%.*]] = zext i16 [[CLEAR]] to i32
// CHECK: icmp ule i32 [[CAST]], 3, !nosanitize
// CHECK: call void @__ubsan_handle_load_invalid_value
return s->e1;
}
struct Bool {
bool b1 : 1;
bool b2 : 7;
bool b3 : 16;
};
[test] Add {{.*}} to make tests immune to dso_local/dso_preemptable/(none) differences For a definition (of most linkage types), dso_local is set for ELF -fno-pic/-fpie and COFF, but not for Mach-O. This nuance causes unneeded binary format differences. This patch replaces (function) `define ` with `define{{.*}} `, (variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} ` if there is an explicit linkage. * Clang will set dso_local for Mach-O, which is currently implied by TargetMachine.cpp. This will make COFF/Mach-O and executable ELF similar. * Eventually I hope we can make dso_local the textual LLVM IR default (write explicit "dso_preemptable" when applicable) and -fpic ELF will be similar to everything else. This patch helps move toward that goal.
2020-12-31 12:45:56 +08:00
// CHECK-LABEL: define{{.*}} zeroext i1 @_Z13load_cpp_boolP4Bool
Retry: [ubsan] Detect UB loads from bitfields It's possible to load out-of-range values from bitfields backed by a boolean or an enum. Check for UB loads from bitfields. This is the motivating example: struct S { BOOL b : 1; // Signed ObjC BOOL. }; S s; s.b = 1; // This is actually stored as -1. if (s.b == 1) // Evaluates to false, -1 != 1. ... Changes since the original commit: - Single-bit bools are a special case (see CGF::EmitFromMemory), and we can't avoid dealing with them when loading from a bitfield. Don't try to insert a check in this case. Differential Revision: https://reviews.llvm.org/D30423 llvm-svn: 297389
2017-03-10 00:06:27 +08:00
bool load_cpp_bool(Bool *b) {
// CHECK-NOT: call void @__ubsan_handle_load_invalid_value
// CHECK-NOT: !nosanitize
return b->b1 || b->b2 || b->b3;
}