[llvm] r349601 - [bugpoint][PR29027] Reduce function attributes
Brian Gesiak via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 18 19:42:19 PST 2018
Author: modocache
Date: Tue Dec 18 19:42:19 2018
New Revision: 349601
URL: http://llvm.org/viewvc/llvm-project?rev=349601&view=rev
Log:
[bugpoint][PR29027] Reduce function attributes
Summary:
In addition to reducing the functions in an LLVM module, bugpoint now
reduces the function attributes associated with each of the remaining
functions.
To test this, add a -bugpoint-crashfuncattr test pass, which crashes if
a function in the module has a "bugpoint-crash" attribute. A test case
demonstrates that the IR is reduced to just that one attribute.
Reviewers: MatzeB, silvas, davide, reames
Reviewed By: reames
Subscribers: reames, llvm-commits
Differential Revision: https://reviews.llvm.org/D55216
Added:
llvm/trunk/test/BugPoint/func-attrs-keyval.ll
llvm/trunk/test/BugPoint/func-attrs.ll
Modified:
llvm/trunk/tools/bugpoint-passes/TestPasses.cpp
llvm/trunk/tools/bugpoint/CrashDebugger.cpp
Added: llvm/trunk/test/BugPoint/func-attrs-keyval.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/BugPoint/func-attrs-keyval.ll?rev=349601&view=auto
==============================================================================
--- llvm/trunk/test/BugPoint/func-attrs-keyval.ll (added)
+++ llvm/trunk/test/BugPoint/func-attrs-keyval.ll Tue Dec 18 19:42:19 2018
@@ -0,0 +1,11 @@
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crashfuncattr -silence-passes
+; RUN: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s
+; REQUIRES: loadable_module
+
+; CHECK: f() #[[ATTRS:[0-9]+]]
+define void @f() #0 {
+ ret void
+}
+
+; CHECK: attributes #[[ATTRS]] = { "bugpoint-crash"="sure" }
+attributes #0 = { "bugpoint-crash"="sure" noreturn "no-frame-pointer-elim-non-leaf" }
Added: llvm/trunk/test/BugPoint/func-attrs.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/BugPoint/func-attrs.ll?rev=349601&view=auto
==============================================================================
--- llvm/trunk/test/BugPoint/func-attrs.ll (added)
+++ llvm/trunk/test/BugPoint/func-attrs.ll Tue Dec 18 19:42:19 2018
@@ -0,0 +1,11 @@
+; RUN: bugpoint -load %llvmshlibdir/BugpointPasses%shlibext %s -output-prefix %t -bugpoint-crashfuncattr -silence-passes
+; RUN: llvm-dis %t-reduced-simplified.bc -o - | FileCheck %s
+; REQUIRES: loadable_module
+
+; CHECK: f() #[[ATTRS:[0-9]+]]
+define void @f() #0 {
+ ret void
+}
+
+; CHECK: attributes #[[ATTRS]] = { "bugpoint-crash" }
+attributes #0 = { noinline "bugpoint-crash" "no-frame-pointer-elim-non-leaf" }
Modified: llvm/trunk/tools/bugpoint-passes/TestPasses.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/bugpoint-passes/TestPasses.cpp?rev=349601&r1=349600&r2=349601&view=diff
==============================================================================
--- llvm/trunk/tools/bugpoint-passes/TestPasses.cpp (original)
+++ llvm/trunk/tools/bugpoint-passes/TestPasses.cpp Tue Dec 18 19:42:19 2018
@@ -123,3 +123,28 @@ char CrashOnTooManyCUs::ID = 0;
static RegisterPass<CrashOnTooManyCUs>
A("bugpoint-crash-too-many-cus",
"BugPoint Test Pass - Intentionally crash on too many CUs");
+
+namespace {
+class CrashOnFunctionAttribute : public FunctionPass {
+public:
+ static char ID; // Pass ID, replacement for typeid
+ CrashOnFunctionAttribute() : FunctionPass(ID) {}
+
+private:
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.setPreservesAll();
+ }
+
+ bool runOnFunction(Function &F) override {
+ AttributeSet A = F.getAttributes().getFnAttributes();
+ if (A.hasAttribute("bugpoint-crash"))
+ abort();
+ return false;
+ }
+};
+} // namespace
+
+char CrashOnFunctionAttribute::ID = 0;
+static RegisterPass<CrashOnFunctionAttribute>
+ B("bugpoint-crashfuncattr", "BugPoint Test Pass - Intentionally crash on "
+ "function attribute 'bugpoint-crash'");
Modified: llvm/trunk/tools/bugpoint/CrashDebugger.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/bugpoint/CrashDebugger.cpp?rev=349601&r1=349600&r2=349601&view=diff
==============================================================================
--- llvm/trunk/tools/bugpoint/CrashDebugger.cpp (original)
+++ llvm/trunk/tools/bugpoint/CrashDebugger.cpp Tue Dec 18 19:42:19 2018
@@ -315,6 +315,66 @@ bool ReduceCrashingFunctions::TestFuncs(
}
namespace {
+/// ReduceCrashingFunctionAttributes reducer - This works by removing
+/// attributes on a particular function and seeing if the program still crashes.
+/// If it does, then keep the newer, smaller program.
+///
+class ReduceCrashingFunctionAttributes : public ListReducer<Attribute> {
+ BugDriver &BD;
+ std::string FnName;
+ BugTester TestFn;
+
+public:
+ ReduceCrashingFunctionAttributes(BugDriver &bd, const std::string &FnName,
+ BugTester testFn)
+ : BD(bd), FnName(FnName), TestFn(testFn) {}
+
+ Expected<TestResult> doTest(std::vector<Attribute> &Prefix,
+ std::vector<Attribute> &Kept) override {
+ if (!Kept.empty() && TestFuncAttrs(Kept))
+ return KeepSuffix;
+ if (!Prefix.empty() && TestFuncAttrs(Prefix))
+ return KeepPrefix;
+ return NoFailure;
+ }
+
+ bool TestFuncAttrs(std::vector<Attribute> &Attrs);
+};
+}
+
+bool ReduceCrashingFunctionAttributes::TestFuncAttrs(
+ std::vector<Attribute> &Attrs) {
+ // Clone the program to try hacking it apart...
+ std::unique_ptr<Module> M = CloneModule(BD.getProgram());
+ Function *F = M->getFunction(FnName);
+
+ // Build up an AttributeList from the attributes we've been given by the
+ // reducer.
+ AttrBuilder AB;
+ for (auto A : Attrs)
+ AB.addAttribute(A);
+ AttributeList NewAttrs;
+ NewAttrs =
+ NewAttrs.addAttributes(BD.getContext(), AttributeList::FunctionIndex, AB);
+
+ // Set this new list of attributes on the function.
+ F->setAttributes(NewAttrs);
+
+ // Try running on the hacked up program...
+ if (TestFn(BD, M.get())) {
+ BD.setNewProgram(std::move(M)); // It crashed, keep the trimmed version...
+
+ // Pass along the set of attributes that caused the crash.
+ Attrs.clear();
+ for (Attribute A : NewAttrs.getFnAttributes()) {
+ Attrs.push_back(A);
+ }
+ return true;
+ }
+ return false;
+}
+
+namespace {
/// Simplify the CFG without completely destroying it.
/// This is not well defined, but basically comes down to "try to eliminate
/// unreachable blocks and constant fold terminators without deciding that
@@ -1056,6 +1116,38 @@ static Error DebugACrash(BugDriver &BD,
BD.EmitProgressBitcode(BD.getProgram(), "reduced-function");
}
+ // For each remaining function, try to reduce that function's attributes.
+ std::vector<std::string> FunctionNames;
+ for (Function &F : BD.getProgram())
+ FunctionNames.push_back(F.getName());
+
+ if (!FunctionNames.empty() && !BugpointIsInterrupted) {
+ outs() << "\n*** Attempting to reduce the number of function attributes in "
+ "the testcase\n";
+
+ unsigned OldSize = 0;
+ unsigned NewSize = 0;
+ for (std::string &Name : FunctionNames) {
+ Function *Fn = BD.getProgram().getFunction(Name);
+ assert(Fn && "Could not find funcion?");
+
+ std::vector<Attribute> Attrs;
+ for (Attribute A : Fn->getAttributes().getFnAttributes())
+ Attrs.push_back(A);
+
+ OldSize += Attrs.size();
+ Expected<bool> Result =
+ ReduceCrashingFunctionAttributes(BD, Name, TestFn).reduceList(Attrs);
+ if (Error E = Result.takeError())
+ return E;
+
+ NewSize += Attrs.size();
+ }
+
+ if (OldSize < NewSize)
+ BD.EmitProgressBitcode(BD.getProgram(), "reduced-function-attributes");
+ }
+
// Attempt to change conditional branches into unconditional branches to
// eliminate blocks.
if (!DisableSimplifyCFG && !BugpointIsInterrupted) {
More information about the llvm-commits
mailing list