Add PNaClSjLjEH pass to implement C++ exception handling using setjmp()+longjmp()

test/Transforms/NaCl/pnacl-sjlj-eh.ll

+; RUN: opt %s -pnacl-sjlj-eh -S | FileCheck %s
+
+; This must be declared for expanding "invoke" and "landingpad" instructions.
+@__pnacl_eh_stack = external thread_local global i8*
+
+; This must be declared for expanding "resume" instructions.
+declare void @__pnacl_eh_resume(i32* %exception)
+
+declare i32 @external_func(i64 %arg)
+
+
+; CHECK: %ExceptionFrame = type { [1024 x i8], %ExceptionFrame*, i32 }
+
+define i32 @invoke_test(i64 %arg) {
+  %result = invoke i32 @external_func(i64 %arg)
+      to label %cont unwind label %lpad
+cont:
+  ret i32 %result
+lpad:
+  %lp = landingpad { i8*, i32 } personality i8* null cleanup
+  ret i32 999
+}
+; CHECK: define i32 @invoke_test
+; CHECK-NEXT: %invoke_frame = alloca %ExceptionFrame, align 8
+; CHECK-NEXT: %exc_info_ptr = getelementptr %ExceptionFrame* %invoke_frame, i32 0, i32 2
+; CHECK-NEXT: %invoke_next = getelementptr %ExceptionFrame* %invoke_frame, i32 0, i32 1
+; CHECK-NEXT: %invoke_jmp_buf = getelementptr %ExceptionFrame* %invoke_frame, i32 0, i32 0, i32 0
+; CHECK-NEXT: %pnacl_eh_stack = bitcast i8** @__pnacl_eh_stack to %ExceptionFrame**
+; CHECK-NEXT: %invoke_sj = call i32 @llvm.nacl.setjmp(i8* %invoke_jmp_buf)
+; CHECK-NEXT: %invoke_sj_is_zero = icmp eq i32 %invoke_sj, 0
+; CHECK-NEXT: br i1 %invoke_sj_is_zero, label %invoke_do_call, label %lpad
+; CHECK: invoke_do_call:
+; CHECK-NEXT: %old_eh_stack = load %ExceptionFrame** %pnacl_eh_stack
+; CHECK-NEXT: store %ExceptionFrame* %old_eh_stack, %ExceptionFrame** %invoke_next
+; CHECK-NEXT: store i32 {{[0-9]+}}, i32* %exc_info_ptr
+; CHECK-NEXT: store %ExceptionFrame* %invoke_frame, %ExceptionFrame** %pnacl_eh_stack
+; CHECK-NEXT: %result = call i32 @external_func(i64 %arg)
+; CHECK-NEXT: store %ExceptionFrame* %old_eh_stack, %ExceptionFrame** %pnacl_eh_stack
+; CHECK-NEXT: br label %cont
+; CHECK: cont:
+; CHECK-NEXT: ret i32 %result
+; CHECK: lpad:
+; CHECK-NEXT: %landingpad_ptr = bitcast i8* %invoke_jmp_buf to { i8*, i32 }*
+; CHECK-NEXT: %lp = load { i8*, i32 }* %landingpad_ptr
+; CHECK-NEXT: ret i32 999
+
+
+; A landingpad block may be used by multiple "invoke" instructions.
+define i32 @shared_landingpad(i64 %arg) {
+  %result1 = invoke i32 @external_func(i64 %arg)
+      to label %cont1 unwind label %lpad
+cont1:
+  %result2 = invoke i32 @external_func(i64 %arg)
+      to label %cont2 unwind label %lpad
+cont2:
+  ret i32 %result2
+lpad:
+  %lp = landingpad { i8*, i32 } personality i8* null cleanup
+  ret i32 999
+}
+; CHECK: define i32 @shared_landingpad
+; CHECK: br i1 %invoke_sj_is_zero, label %invoke_do_call, label %lpad
+; CHECK: br i1 %invoke_sj_is_zero2, label %invoke_do_call3, label %lpad
+
+
+; Check that the pass can handle a landingpad appearing before an invoke.
+define i32 @landingpad_before_invoke() {
+  ret i32 123
+
+dead_block:
+  %lp = landingpad i32 personality i8* null cleanup
+  ret i32 %lp
+}
+; CHECK: define i32 @landingpad_before_invoke
+; CHECK: %lp = load i32* %landingpad_ptr
+
+
+; Test the expansion of the "resume" instruction.
+define void @test_resume({ i8*, i32 } %arg) {
+  resume { i8*, i32 } %arg
+}
+; CHECK: define void @test_resume
+; CHECK-NEXT: %resume_exc = extractvalue { i8*, i32 } %arg, 0
+; CHECK-NEXT: %resume_cast = bitcast i8* %resume_exc to i32*
+; CHECK-NEXT: call void @__pnacl_eh_resume(i32* %resume_cast)
+; CHECK-NEXT: unreachable
+
+
+; Check that call attributes are preserved.
+define i32 @call_attrs(i64 %arg) {
+  %result = invoke fastcc i32 @external_func(i64 inreg %arg) noreturn
+      to label %cont unwind label %lpad
+cont:
+  ret i32 %result
+lpad:
+  %lp = landingpad { i8*, i32 } personality i8* null cleanup
+  ret i32 999
+}
+; CHECK: define i32 @call_attrs
+; CHECK: %result = call fastcc i32 @external_func(i64 inreg %arg) [[NORETURN:#[0-9]+]]
+
+
+; Check that any PHI nodes referring to the result of an "invoke" are
+; updated to refer to the correct basic block.
+define i32 @invoke_with_phi_nodes(i64 %arg) {
+entry:
+  %result = invoke i32 @external_func(i64 %arg)
+      to label %cont unwind label %lpad
+cont:
+  %cont_phi = phi i32 [ 100, %entry ]
+  ret i32 %cont_phi
+lpad:
+  %lpad_phi = phi i32 [ 200, %entry ]
+  %lp = landingpad { i8*, i32 } personality i8* null cleanup
+  ret i32 %lpad_phi
+}
+; CHECK: define i32 @invoke_with_phi_nodes
+; CHECK: %result = call i32 @external_func(i64 %arg)
+; CHECK: cont:
+; CHECK-NEXT: %cont_phi = phi i32 [ 100, %invoke_do_call ]
+; CHECK-NEXT: ret i32 %cont_phi
+; CHECK: lpad:
+; CHECK-NEXT: %lpad_phi = phi i32 [ 200, %entry ]
+; CHECK: ret i32 %lpad_phi
+
+
+; CHECK: attributes [[NORETURN]] = { noreturn }