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/ADT/StringSwitch.h"
11 #include "llvm/IR/Function.h"
12 #include "llvm/IR/LLVMContext.h"
13 #include "llvm/IR/Module.h"
14 #include "llvm/InitializePasses.h"
15 #include "llvm/Support/CommandLine.h"
16 #include "llvm/Support/Debug.h"
17 #include "llvm/Support/raw_ostream.h"
18 using namespace llvm;
19
20 #define DEBUG_TYPE "forceattrs"
21
22 static cl::list<std::string>
23 ForceAttributes("force-attribute", cl::Hidden,
24 cl::desc("Add an attribute to a function. This should be a "
25 "pair of 'function-name:attribute-name', for "
26 "example -force-attribute=foo:noinline. This "
27 "option can be specified multiple times."));
28
parseAttrKind(StringRef Kind)29 static Attribute::AttrKind parseAttrKind(StringRef Kind) {
30 return StringSwitch<Attribute::AttrKind>(Kind)
31 .Case("alwaysinline", Attribute::AlwaysInline)
32 .Case("builtin", Attribute::Builtin)
33 .Case("cold", Attribute::Cold)
34 .Case("convergent", Attribute::Convergent)
35 .Case("inlinehint", Attribute::InlineHint)
36 .Case("jumptable", Attribute::JumpTable)
37 .Case("minsize", Attribute::MinSize)
38 .Case("naked", Attribute::Naked)
39 .Case("nobuiltin", Attribute::NoBuiltin)
40 .Case("noduplicate", Attribute::NoDuplicate)
41 .Case("noimplicitfloat", Attribute::NoImplicitFloat)
42 .Case("noinline", Attribute::NoInline)
43 .Case("nonlazybind", Attribute::NonLazyBind)
44 .Case("noredzone", Attribute::NoRedZone)
45 .Case("noreturn", Attribute::NoReturn)
46 .Case("nocf_check", Attribute::NoCfCheck)
47 .Case("norecurse", Attribute::NoRecurse)
48 .Case("nounwind", Attribute::NoUnwind)
49 .Case("optforfuzzing", Attribute::OptForFuzzing)
50 .Case("optnone", Attribute::OptimizeNone)
51 .Case("optsize", Attribute::OptimizeForSize)
52 .Case("readnone", Attribute::ReadNone)
53 .Case("readonly", Attribute::ReadOnly)
54 .Case("argmemonly", Attribute::ArgMemOnly)
55 .Case("returns_twice", Attribute::ReturnsTwice)
56 .Case("safestack", Attribute::SafeStack)
57 .Case("shadowcallstack", Attribute::ShadowCallStack)
58 .Case("sanitize_address", Attribute::SanitizeAddress)
59 .Case("sanitize_hwaddress", Attribute::SanitizeHWAddress)
60 .Case("sanitize_memory", Attribute::SanitizeMemory)
61 .Case("sanitize_thread", Attribute::SanitizeThread)
62 .Case("sanitize_memtag", Attribute::SanitizeMemTag)
63 .Case("speculative_load_hardening", Attribute::SpeculativeLoadHardening)
64 .Case("ssp", Attribute::StackProtect)
65 .Case("sspreq", Attribute::StackProtectReq)
66 .Case("sspstrong", Attribute::StackProtectStrong)
67 .Case("strictfp", Attribute::StrictFP)
68 .Case("uwtable", Attribute::UWTable)
69 .Default(Attribute::None);
70 }
71
72 /// If F has any forced attributes given on the command line, add them.
addForcedAttributes(Function & F)73 static void addForcedAttributes(Function &F) {
74 for (auto &S : ForceAttributes) {
75 auto KV = StringRef(S).split(':');
76 if (KV.first != F.getName())
77 continue;
78
79 auto Kind = parseAttrKind(KV.second);
80 if (Kind == Attribute::None) {
81 LLVM_DEBUG(dbgs() << "ForcedAttribute: " << KV.second
82 << " unknown or not handled!\n");
83 continue;
84 }
85 if (F.hasFnAttribute(Kind))
86 continue;
87 F.addFnAttr(Kind);
88 }
89 }
90
run(Module & M,ModuleAnalysisManager &)91 PreservedAnalyses ForceFunctionAttrsPass::run(Module &M,
92 ModuleAnalysisManager &) {
93 if (ForceAttributes.empty())
94 return PreservedAnalyses::all();
95
96 for (Function &F : M.functions())
97 addForcedAttributes(F);
98
99 // Just conservatively invalidate analyses, this isn't likely to be important.
100 return PreservedAnalyses::none();
101 }
102
103 namespace {
104 struct ForceFunctionAttrsLegacyPass : public ModulePass {
105 static char ID; // Pass identification, replacement for typeid
ForceFunctionAttrsLegacyPass__anon34b82ace0111::ForceFunctionAttrsLegacyPass106 ForceFunctionAttrsLegacyPass() : ModulePass(ID) {
107 initializeForceFunctionAttrsLegacyPassPass(
108 *PassRegistry::getPassRegistry());
109 }
110
runOnModule__anon34b82ace0111::ForceFunctionAttrsLegacyPass111 bool runOnModule(Module &M) override {
112 if (ForceAttributes.empty())
113 return false;
114
115 for (Function &F : M.functions())
116 addForcedAttributes(F);
117
118 // Conservatively assume we changed something.
119 return true;
120 }
121 };
122 }
123
124 char ForceFunctionAttrsLegacyPass::ID = 0;
125 INITIALIZE_PASS(ForceFunctionAttrsLegacyPass, "forceattrs",
126 "Force set function attributes", false, false)
127
createForceFunctionAttrsLegacyPass()128 Pass *llvm::createForceFunctionAttrsLegacyPass() {
129 return new ForceFunctionAttrsLegacyPass();
130 }
131