1 //===--- WebAssemblyExceptionInfo.cpp - Exception Infomation --------------===//
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
29 #define DEBUG_TYPE "wasm-exception-info"
34                       "WebAssembly Exception Information", true, true)
38                     "WebAssembly Exception Information", true, true)  in INITIALIZE_PASS_DEPENDENCY()
41   LLVM_DEBUG(dbgs() << "********** Exception Info Calculation **********\n"  in INITIALIZE_PASS_DEPENDENCY()
94   // which means, if an exception is not caught by the catchpad, it should end  in recalculate()
101   //      ...          // this catch (int) { ... } is grouped as an exception  in recalculate()
107   // unwind destination is in the outside of the catchpad's exception.  in recalculate()
111   // children outside of the exception, that unwind destination ends up also  in recalculate()
112   // being dominated by the EH pad and included in the exception, which is not  in recalculate()
116   // exception. Note that the unwind destinations may not be an immediate  in recalculate()
117   // children of the parent exception, so we have to traverse the parent chain.  in recalculate()
142                         << "'s exception is taken out of "  in recalculate()
144                         << SrcWE->getEHPad()->getName() << "'s exception\n");  in recalculate()
152   // For example, suppose Exception A is dominated by EHPad A and Exception B is  in recalculate()
154   // EHPad B is dominated by EHPad A, the initial grouping makes Exception B a  in recalculate()
155   // subexception of Exception A, and we fix it by taking Exception B out of  in recalculate()
156   // Exception A above. But there can still be remaining BBs within Exception A  in recalculate()
157   // that are reachable from Exception B. These BBs semantically don't belong  in recalculate()
158   // to Exception A and were not a part of this 'catch' clause or cleanup code  in recalculate()
159   // in the original code, but they just happened to be grouped within Exception  in recalculate()
161   // BBs out of the incorrect exception and all its subexceptions that it  in recalculate()
166   // change parent exception pointer.  in recalculate()
177       // If WE (the current EH pad's exception) is still contained in SrcWE but  in recalculate()
186                           << "'s exception is taken out of "  in recalculate()
188                           << SrcWE->getEHPad()->getName() << "'s exception\n");  in recalculate()
196   // for each exception.  in recalculate()
205   // exceptions' BlockSet, when we take a BB out of an exception, we need to fix  in recalculate()
227                      << "'s exception\n");  in recalculate()
233                           << "'s exception\n");  in recalculate()
296     // Find its outermost discovered exception. If this is a discovered block,  in discoverAndMapException()
297     // check if it is already discovered to be a subexception of this exception.  in discoverAndMapException()
301         // Discover a subexception of this exception.  in discoverAndMapException()
315     // This is an undiscovered block. Map it to the current exception.  in discoverAndMapException()
340   OS.indent(Depth * 2) << "Exception at depth " << getExceptionDepth()  in print()