4eabd00612
Summary: Per Windows SEH Spec, except _leave, all other early exits of a _try (goto/return/continue/break) are considered abnormal exits. In those cases, the first parameter passes to its _finally funclet should be TRUE to indicate an abnormal-termination. One way to implement abnormal exits in _try is to invoke Windows runtime _local_unwind() (MSVC approach) that will invoke _dtor funclet where abnormal-termination flag is always TRUE when calling _finally. Obviously this approach is less optimal and is complicated to implement in Clang. Clang today has a NormalCleanupDestSlot mechanism to dispatch multiple exits at the end of _try. Since _leave (or try-end fall-through) is always Indexed with 0 in that NormalCleanupDestSlot, this fix takes the advantage of that mechanism and just passes NormalCleanupDest ID as 1st Arg to _finally. Reviewers: rnk, eli.friedman, JosephTremoulet, asmith, efriedma Reviewed By: efriedma Subscribers: efriedma, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D77936
31 lines
948 B
C
31 lines
948 B
C
// RUN: %clang_cc1 -triple x86_64-windows -fms-extensions -Wno-implicit-function-declaration -S -emit-llvm %s -o - | FileCheck %s
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// CHECK: %[[src:[0-9-]+]] = call i8* @llvm.localaddress()
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// CHECK-NEXT: %cleanup.dest = load i32, i32* %cleanup.dest.slot, align 4
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// CHECK-NEXT: %[[src2:[0-9-]+]] = icmp ne i32 %cleanup.dest, 0
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// CHECK-NEXT: %[[src3:[0-9-]+]] = zext i1 %[[src2]] to i8
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// CHECK-NEXT: call void @"?fin$0@0@seh_abnormal_exits@@"(i8 %[[src3]], i8* %[[src]])
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void seh_abnormal_exits(int *Counter) {
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for (int i = 0; i < 5; i++) {
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__try {
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if (i == 0)
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continue; // abnormal termination
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else if (i == 1)
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goto t10; // abnormal termination
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else if (i == 2)
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__leave; // normal execution
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else if (i == 4)
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return; // abnormal termination
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}
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__finally {
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if (AbnormalTermination()) {
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*Counter += 1;
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}
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}
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t10:;
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}
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return; // *Counter == 3
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}
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