c95ffadb24
Summary: NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html Complemantary to the assumption outliner prototype in D71692, this patch shows how we could simplify the code emitted for an alignemnt assumption. The generated code is smaller, less fragile, and it makes it easier to recognize the additional use as a "assumption use". As mentioned in D71692 and on the mailing list, we could adopt this scheme, and similar schemes for other patterns, without adopting the assumption outlining. Reviewers: hfinkel, xbolva00, lebedev.ri, nikic, rjmccall, spatel, jdoerfert, sstefan1 Reviewed By: jdoerfert Subscribers: yamauchi, kuter, fhahn, merge_guards_bot, hiraditya, bollu, rkruppe, cfe-commits, llvm-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D71739
51 lines
4.3 KiB
C++
51 lines
4.3 KiB
C++
// RUN: %clang_cc1 -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s --check-prefixes=CHECK,CHECK-NOSANITIZE
|
|
// RUN: %clang_cc1 -fsanitize=alignment -fno-sanitize-recover=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-ANYRECOVER,CHECK-SANITIZE-NORECOVER,CHECK-SANITIZE-UNREACHABLE
|
|
// RUN: %clang_cc1 -fsanitize=alignment -fsanitize-recover=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-ANYRECOVER,CHECK-SANITIZE-RECOVER
|
|
// RUN: %clang_cc1 -fsanitize=alignment -fsanitize-trap=alignment -emit-llvm %s -o - -triple x86_64-linux-gnu | FileCheck %s -implicit-check-not="call void @__ubsan_handle_alignment_assumption" --check-prefixes=CHECK,CHECK-SANITIZE,CHECK-SANITIZE-TRAP,CHECK-SANITIZE-UNREACHABLE
|
|
|
|
// CHECK-SANITIZE-ANYRECOVER: @[[CHAR:.*]] = {{.*}} c"'char **'\00" }
|
|
// CHECK-SANITIZE-ANYRECOVER: @[[LINE_100_ALIGNMENT_ASSUMPTION:.*]] = {{.*}}, i32 100, i32 10 }, {{.*}}* @[[CHAR]] }
|
|
|
|
char **__attribute__((alloc_align(2)))
|
|
passthrough(char **x, unsigned long alignment) {
|
|
// CHECK: define i8** @[[PASSTHROUGH:.*]](i8** %[[X:.*]], i64 %[[ALIGNMENT:.*]])
|
|
// CHECK-NEXT: entry:
|
|
// CHECK-NEXT: %[[X_ADDR:.*]] = alloca i8**, align 8
|
|
// CHECK-NEXT: %[[ALIGNMENT_ADDR:.*]] = alloca i64, align 8
|
|
// CHECK-NEXT: store i8** %[[X]], i8*** %[[X_ADDR]], align 8
|
|
// CHECK-NEXT: store i64 %[[ALIGNMENT]], i64* %[[ALIGNMENT_ADDR]], align 8
|
|
// CHECK-NEXT: %[[X_RELOADED:.*]] = load i8**, i8*** %[[X_ADDR]], align 8
|
|
// CHECK-NEXT: ret i8** %[[X_RELOADED]]
|
|
// CHECK-NEXT: }
|
|
return x;
|
|
}
|
|
|
|
char **caller(char **x, unsigned long alignment) {
|
|
// CHECK: define i8** @{{.*}}(i8** %[[X:.*]], i64 %[[ALIGNMENT:.*]])
|
|
// CHECK-NEXT: entry:
|
|
// CHECK-NEXT: %[[X_ADDR:.*]] = alloca i8**, align 8
|
|
// CHECK-NEXT: %[[ALIGNMENT_ADDR:.*]] = alloca i64, align 8
|
|
// CHECK-NEXT: store i8** %[[X]], i8*** %[[X_ADDR]], align 8
|
|
// CHECK-NEXT: store i64 %[[ALIGNMENT]], i64* %[[ALIGNMENT_ADDR]], align 8
|
|
// CHECK-NEXT: %[[X_RELOADED:.*]] = load i8**, i8*** %[[X_ADDR]], align 8
|
|
// CHECK-NEXT: %[[ALIGNMENT_RELOADED:.*]] = load i64, i64* %[[ALIGNMENT_ADDR]], align 8
|
|
// CHECK-NEXT: %[[X_RETURNED:.*]] = call i8** @[[PASSTHROUGH]](i8** %[[X_RELOADED]], i64 %[[ALIGNMENT_RELOADED]])
|
|
// CHECK-SANITIZE-NEXT: %[[PTRINT:.*]] = ptrtoint i8** %[[X_RETURNED]] to i64
|
|
// CHECK-SANITIZE-NEXT: %[[MASK:.*]] = sub i64 %[[ALIGNMENT_RELOADED]], 1
|
|
// CHECK-SANITIZE-NEXT: %[[MASKEDPTR:.*]] = and i64 %[[PTRINT]], %[[MASK]]
|
|
// CHECK-SANITIZE-NEXT: %[[MASKCOND:.*]] = icmp eq i64 %[[MASKEDPTR]], 0
|
|
// CHECK-SANITIZE-NEXT: %[[PTRINT_DUP:.*]] = ptrtoint i8** %[[X_RETURNED]] to i64, !nosanitize
|
|
// CHECK-SANITIZE-NEXT: br i1 %[[MASKCOND]], label %[[CONT:.*]], label %[[HANDLER_ALIGNMENT_ASSUMPTION:[^,]+]],{{.*}} !nosanitize
|
|
// CHECK-SANITIZE: [[HANDLER_ALIGNMENT_ASSUMPTION]]:
|
|
// CHECK-SANITIZE-NORECOVER-NEXT: call void @__ubsan_handle_alignment_assumption_abort(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 %[[ALIGNMENT_RELOADED]], i64 0){{.*}}, !nosanitize
|
|
// CHECK-SANITIZE-RECOVER-NEXT: call void @__ubsan_handle_alignment_assumption(i8* bitcast ({ {{{.*}}}, {{{.*}}}, {{{.*}}}* }* @[[LINE_100_ALIGNMENT_ASSUMPTION]] to i8*), i64 %[[PTRINT_DUP]], i64 %[[ALIGNMENT_RELOADED]], i64 0){{.*}}, !nosanitize
|
|
// CHECK-SANITIZE-TRAP-NEXT: call void @llvm.trap(){{.*}}, !nosanitize
|
|
// CHECK-SANITIZE-UNREACHABLE-NEXT: unreachable, !nosanitize
|
|
// CHECK-SANITIZE: [[CONT]]:
|
|
// CHECK-NEXT: call void @llvm.assume(i1 true) [ "align"(i8** %[[X_RETURNED]], i64 %1) ]
|
|
// CHECK-NEXT: ret i8** %[[X_RETURNED]]
|
|
// CHECK-NEXT: }
|
|
#line 100
|
|
return passthrough(x, alignment);
|
|
}
|