[clang] [llvm] Fix Windows EH IP2State tables (remove +1 bias) (PR #144745)

[via cfe-commits]

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@@ -0,0 +1,182 @@
+// REQUIRES: x86-registered-target
+
+// RUN: %clang_cl -c --target=x86_64-windows-msvc /EHa -O2 /GS- \
+// RUN:   -Xclang=-import-call-optimization \
+// RUN:   /clang:-S /clang:-o- %s 2>&1 \
+// RUN:   | FileCheck %s
+
+#ifdef __clang__
+#define NO_TAIL __attribute((disable_tail_calls))
+#else
+#define NO_TAIL
+#endif
+
+void might_throw();
+void other_func(int x);
+
+void does_not_throw() noexcept(true);
+
+extern "C" void __declspec(dllimport) some_dll_import();
+
+class HasDtor {
+    int x;
+    char foo[40];
+
+public:
+    explicit HasDtor(int x);
+    ~HasDtor();
+};
+
+class BadError {
+public:
+    int errorCode;
+};
+
+void normal_has_regions() {
+    // CHECK-LABEL: .def "?normal_has_regions@@YAXXZ"
+    // CHECK: .seh_endprologue
+
+    // <-- state -1 (none)
+    {
+        HasDtor hd{42};
+
+        // <-- state goes from -1 to 0
+        // because state changes, we expect the HasDtor::HasDtor() call to have a NOP
+        // CHECK: call "??0HasDtor@@QEAA at H@Z"
+        // CHECK-NEXT: nop
+
+        might_throw();
+        // CHECK: call "?might_throw@@YAXXZ"
+        // CHECK-NEXT: nop
+
+        // <-- state goes from 0 to -1 because we're about to call HasDtor::~HasDtor()
+        // CHECK: call "??1HasDtor@@QEAA at XZ"
+        // <-- state -1
+    }
+
+    // <-- state -1
+    other_func(10);
+    // CHECK: call "?other_func@@YAXH at Z"
+    // CHECK-NEXT: nop
+    // CHECK: .seh_startepilogue
+
+    // <-- state -1
+}
+
+// This tests a tail call to a destructor.
+void case_dtor_arg_empty_body(HasDtor x)
+{
+    // CHECK-LABEL: .def "?case_dtor_arg_empty_body@@YAXVHasDtor@@@Z"
+    // CHECK: jmp "??1HasDtor@@QEAA at XZ"
+}
+
+int case_dtor_arg_empty_with_ret(HasDtor x)
+{
+    // CHECK-LABEL: .def "?case_dtor_arg_empty_with_ret@@YAHVHasDtor@@@Z"
+    // CHECK: .seh_endprologue
+
+    // CHECK: call "??1HasDtor@@QEAA at XZ"
+    // CHECK-NOT: nop
+
+    // The call to HasDtor::~HasDtor() should NOT have a NOP because the
+    // following "mov eax, 100" instruction is in the same EH state.
+
+    return 100;
+
+    // CHECK: mov eax, 100
+    // CHECK: .seh_startepilogue
+    // CHECK: .seh_endepilogue
+    // CHECK: .seh_endproc
+}
+
+int case_noexcept_dtor(HasDtor x) noexcept(true)
+{
+    // CHECK: .def "?case_noexcept_dtor@@YAHVHasDtor@@@Z"
+    // CHECK: call "??1HasDtor@@QEAA at XZ"
+    // CHECK-NEXT: mov eax, 100
+    // CHECK: .seh_startepilogue
+    return 100;
+}
+
+void case_except_simple_call() NO_TAIL
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sivadeilra wrote:

Added checks

https://github.com/llvm/llvm-project/pull/144745