1 //===- ForceFunctionAttrs.cpp - Force function attrs for debugging --------===// 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 #include "llvm/Transforms/IPO/ForceFunctionAttrs.h" 10 #include "llvm/IR/Function.h" 11 #include "llvm/IR/Module.h" 12 #include "llvm/Support/CommandLine.h" 13 #include "llvm/Support/Debug.h" 14 #include "llvm/Support/raw_ostream.h" 15 using namespace llvm; 16 17 #define DEBUG_TYPE "forceattrs" 18 19 static cl::list<std::string> 20 ForceAttributes("force-attribute", cl::Hidden, 21 cl::desc("Add an attribute to a function. This should be a " 22 "pair of 'function-name:attribute-name', for " 23 "example -force-attribute=foo:noinline. This " 24 "option can be specified multiple times.")); 25 26 static cl::list<std::string> ForceRemoveAttributes( 27 "force-remove-attribute", cl::Hidden, 28 cl::desc("Remove an attribute from a function. This should be a " 29 "pair of 'function-name:attribute-name', for " 30 "example -force-remove-attribute=foo:noinline. This " 31 "option can be specified multiple times.")); 32 33 /// If F has any forced attributes given on the command line, add them. 34 /// If F has any forced remove attributes given on the command line, remove 35 /// them. When both force and force-remove are given to a function, the latter 36 /// takes precedence. 37 static void forceAttributes(Function &F) { 38 auto ParseFunctionAndAttr = [&](StringRef S) { 39 auto Kind = Attribute::None; 40 auto KV = StringRef(S).split(':'); 41 if (KV.first != F.getName()) 42 return Kind; 43 Kind = Attribute::getAttrKindFromName(KV.second); 44 if (Kind == Attribute::None || !Attribute::canUseAsFnAttr(Kind)) { 45 LLVM_DEBUG(dbgs() << "ForcedAttribute: " << KV.second 46 << " unknown or not a function attribute!\n"); 47 } 48 return Kind; 49 }; 50 51 for (const auto &S : ForceAttributes) { 52 auto Kind = ParseFunctionAndAttr(S); 53 if (Kind == Attribute::None || F.hasFnAttribute(Kind)) 54 continue; 55 F.addFnAttr(Kind); 56 } 57 58 for (const auto &S : ForceRemoveAttributes) { 59 auto Kind = ParseFunctionAndAttr(S); 60 if (Kind == Attribute::None || !F.hasFnAttribute(Kind)) 61 continue; 62 F.removeFnAttr(Kind); 63 } 64 } 65 66 static bool hasForceAttributes() { 67 return !ForceAttributes.empty() || !ForceRemoveAttributes.empty(); 68 } 69 70 PreservedAnalyses ForceFunctionAttrsPass::run(Module &M, 71 ModuleAnalysisManager &) { 72 if (!hasForceAttributes()) 73 return PreservedAnalyses::all(); 74 75 for (Function &F : M.functions()) 76 forceAttributes(F); 77 78 // Just conservatively invalidate analyses, this isn't likely to be important. 79 return PreservedAnalyses::none(); 80 } 81