1 //===-- WebAssemblyUtilities - WebAssembly Utility Functions ---*- C++ -*-====//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 ///
9 /// \file
10 /// This file contains the declaration of the WebAssembly-specific
11 /// utility functions.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_LIB_TARGET_WEBASSEMBLY_UTILS_WEBASSEMBLYUTILITIES_H
16 #define LLVM_LIB_TARGET_WEBASSEMBLY_UTILS_WEBASSEMBLYUTILITIES_H
17 
18 namespace llvm {
19 
20 class MachineBasicBlock;
21 class MachineInstr;
22 class MachineOperand;
23 class MCContext;
24 class MCSymbolWasm;
25 class StringRef;
26 class WebAssemblyFunctionInfo;
27 class WebAssemblySubtarget;
28 
29 namespace WebAssembly {
30 
31 enum WasmAddressSpace : unsigned {
32   // Default address space, for pointers to linear memory (stack, heap, data).
33   WASM_ADDRESS_SPACE_DEFAULT = 0,
34   // A non-integral address space for pointers to named objects outside of
35   // linear memory: WebAssembly globals or WebAssembly locals.  Loads and stores
36   // to these pointers are lowered to global.get / global.set or local.get /
37   // local.set, as appropriate.
38   WASM_ADDRESS_SPACE_WASM_VAR = 1
39 };
40 
41 inline bool isDefaultAddressSpace(unsigned AS) {
42   return AS == WASM_ADDRESS_SPACE_DEFAULT;
43 }
44 inline bool isWasmVarAddressSpace(unsigned AS) {
45   return AS == WASM_ADDRESS_SPACE_WASM_VAR;
46 }
47 inline bool isValidAddressSpace(unsigned AS) {
48   return isDefaultAddressSpace(AS) || isWasmVarAddressSpace(AS);
49 }
50 
51 bool isChild(const MachineInstr &MI, const WebAssemblyFunctionInfo &MFI);
52 bool mayThrow(const MachineInstr &MI);
53 
54 // Exception-related function names
55 extern const char *const ClangCallTerminateFn;
56 extern const char *const CxaBeginCatchFn;
57 extern const char *const CxaRethrowFn;
58 extern const char *const StdTerminateFn;
59 extern const char *const PersonalityWrapperFn;
60 
61 /// Returns the operand number of a callee, assuming the argument is a call
62 /// instruction.
63 const MachineOperand &getCalleeOp(const MachineInstr &MI);
64 
65 /// Returns the __indirect_function_table, for use in call_indirect and in
66 /// function bitcasts.
67 MCSymbolWasm *
68 getOrCreateFunctionTableSymbol(MCContext &Ctx,
69                                const WebAssemblySubtarget *Subtarget);
70 
71 /// Returns the __funcref_call_table, for use in funcref calls when lowered to
72 /// table.set + call_indirect.
73 MCSymbolWasm *
74 getOrCreateFuncrefCallTableSymbol(MCContext &Ctx,
75                                   const WebAssemblySubtarget *Subtarget);
76 
77 /// Find a catch instruction from an EH pad. Returns null if no catch
78 /// instruction found or the catch is in an invalid location.
79 MachineInstr *findCatch(MachineBasicBlock *EHPad);
80 
81 } // end namespace WebAssembly
82 
83 } // end namespace llvm
84 
85 #endif
86