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llvm-project/llvm/test/CodeGen/X86/win-catchpad-nested-cxx.ll

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[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
; RUN: llc -verify-machineinstrs -mtriple=i686-pc-windows-msvc < %s \
; RUN: | FileCheck --check-prefix=CHECK --check-prefix=X86 %s
; RUN: llc -verify-machineinstrs -mtriple=x86_64-pc-windows-msvc < %s \
; RUN: | FileCheck --check-prefix=CHECK --check-prefix=X64 %s
; Loosely based on IR for this C++ source code:
; void f(int p);
; void try_in_catch() {
; try {
; f(1);
; } catch (...) {
; try {
; f(2);
; } catch (...) {
; f(3);
; }
; }
; }
declare void @f(i32 %p)
declare i32 @__CxxFrameHandler3(...)
define i32 @try_in_catch() personality i32 (...)* @__CxxFrameHandler3 {
entry:
invoke void @f(i32 1)
to label %try.cont unwind label %catch.dispatch.1
try.cont:
ret i32 0
catch.dispatch.1:
%cs1 = catchswitch within none [label %handler1] unwind to caller
handler1:
%h1 = catchpad within %cs1 [i8* null, i32 64, i8* null]
[WinEH] Use operand bundles to describe call sites SimplifyCFG allows tail merging with code which terminates in unreachable which, in turn, makes it possible for an invoke to end up in a funclet which it was not originally part of. Using operand bundles on invokes allows us to determine whether or not an invoke was part of a funclet in the source program. Furthermore, it allows us to unambiguously answer questions about the legality of inlining into call sites which the personality may have trouble with. Differential Revision: http://reviews.llvm.org/D15517 llvm-svn: 255674
2015-12-16 05:27:27 +08:00
invoke void @f(i32 2) [ "funclet"(token %h1) ]
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
to label %catchret1 unwind label %catch.dispatch.2
catchret1:
catchret from %h1 to label %try.cont
catch.dispatch.2:
%cs2 = catchswitch within %h1 [label %handler2] unwind to caller
handler2:
%h2 = catchpad within %cs2 [i8* null, i32 64, i8* null]
call void @f(i32 3)
catchret from %h2 to label %catchret1
}
; X86-LABEL: L__ehtable$try_in_catch:
; X64-LABEL: $cppxdata$try_in_catch:
; CHECK-NEXT: .long 429065506
; CHECK-NEXT: .long 4
; CHECK-NEXT: .long ($stateUnwindMap$try_in_catch)
; CHECK-NEXT: .long 2
; CHECK-NEXT: .long ($tryMap$try_in_catch)
; ip2state num + ptr
; X86-NEXT: .long 0
; X86-NEXT: .long 0
; X64-NEXT: .long 7
; X64-NEXT: .long ($ip2state$try_in_catch)
; unwindhelp offset
; X64-NEXT: .long 40
; CHECK-NEXT: .long 0
; EHFlags
; CHECK-NEXT: .long 1
[Windows EH] Fix the order of Nested try-catches in $tryMap$ table This bug is exposed by Test7 of ehthrow.cxx in MSVC EH suite where a rethrow occurs in a try-catch inside a catch (i.e., a nested Catch handlers). See the test code in https://github.com/microsoft/compiler-tests/blob/master/eh/ehthrow.cxx#L346 When an object is rethrown in a Catch handler, the copy-ctor of this object must be executed after the destructions of live objects, but BEFORE the dtors of live objects in parent handlers. Today Windows 64-bit runtime (__CxxFrameHandler3 & 4) expects nested Catch handers are stored in pre-order (outer first, inner next) in $tryMap$ table, so that given a State, its Catch's beginning State can be properly retrieved. The Catch beginning state (which is also the ending State) is the State where rethrown object's copy-ctor must take place. LLVM currently stores nested catch handlers in post-ordering because it's the natural way to compute the highest State in Catch. The fix is to simply store TryCatch handler in pre-order, but update Catch's highest State after child Catches are all processed. Differential Revision: https://reviews.llvm.org/D79474?id=263919
2020-05-16 13:03:43 +08:00
; X86-LABEL: $tryMap$try_in_catch:
; X86-NEXT: .long 2
; X86-NEXT: .long 2
; X86-NEXT: .long 3
; X86-NEXT: .long 1
; X86-NEXT: .long ($handlerMap$0$try_in_catch)
; X86-NEXT: .long 0
; X86-NEXT: .long 0
; X86-NEXT: .long 3
; X86-NEXT: .long 1
; X86-NEXT: .long ($handlerMap$1$try_in_catch)
; X64-LABEL: $tryMap$try_in_catch:
; X64-NEXT: .long 0
; X64-NEXT: .long 0
; X64-NEXT: .long 3
; X64-NEXT: .long 1
; X64-NEXT: .long ($handlerMap$0$try_in_catch)
; X64-NEXT: .long 2
; X64-NEXT: .long 2
; X64-NEXT: .long 3
; X64-NEXT: .long 1
; X64-NEXT: .long ($handlerMap$1$try_in_catch)
[IR] Reformulate LLVM's EH funclet IR While we have successfully implemented a funclet-oriented EH scheme on top of LLVM IR, our scheme has some notable deficiencies: - catchendpad and cleanupendpad are necessary in the current design but they are difficult to explain to others, even to seasoned LLVM experts. - catchendpad and cleanupendpad are optimization barriers. They cannot be split and force all potentially throwing call-sites to be invokes. This has a noticable effect on the quality of our code generation. - catchpad, while similar in some aspects to invoke, is fairly awkward. It is unsplittable, starts a funclet, and has control flow to other funclets. - The nesting relationship between funclets is currently a property of control flow edges. Because of this, we are forced to carefully analyze the flow graph to see if there might potentially exist illegal nesting among funclets. While we have logic to clone funclets when they are illegally nested, it would be nicer if we had a representation which forbade them upfront. Let's clean this up a bit by doing the following: - Instead, make catchpad more like cleanuppad and landingpad: no control flow, just a bunch of simple operands; catchpad would be splittable. - Introduce catchswitch, a control flow instruction designed to model the constraints of funclet oriented EH. - Make funclet scoping explicit by having funclet instructions consume the token produced by the funclet which contains them. - Remove catchendpad and cleanupendpad. Their presence can be inferred implicitly using coloring information. N.B. The state numbering code for the CLR has been updated but the veracity of it's output cannot be spoken for. An expert should take a look to make sure the results are reasonable. Reviewers: rnk, JosephTremoulet, andrew.w.kaylor Differential Revision: http://reviews.llvm.org/D15139 llvm-svn: 255422
2015-12-12 13:38:55 +08:00
; CHECK: $handlerMap$0$try_in_catch:
; CHECK-NEXT: .long 64
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long "?catch${{[0-9]+}}@?0?try_in_catch@4HA"
; X64-NEXT: .long 56
; CHECK: $handlerMap$1$try_in_catch:
; CHECK-NEXT: .long 64
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long "?catch${{[0-9]+}}@?0?try_in_catch@4HA"
; X64-NEXT: .long 56
; X64: $ip2state$try_in_catch:
; X64-NEXT: .long .Lfunc_begin0@IMGREL
; X64-NEXT: .long -1
; X64-NEXT: .long .Ltmp0@IMGREL+1
; X64-NEXT: .long 0
; X64-NEXT: .long .Ltmp1@IMGREL+1
; X64-NEXT: .long -1
; X64-NEXT: .long "?catch$2@?0?try_in_catch@4HA"@IMGREL
; X64-NEXT: .long 1
; X64-NEXT: .long .Ltmp2@IMGREL+1
; X64-NEXT: .long 2
; X64-NEXT: .long .Ltmp3@IMGREL+1
; X64-NEXT: .long 1
; X64-NEXT: .long "?catch$4@?0?try_in_catch@4HA"@IMGREL
; X64-NEXT: .long 3