diff --git a/include/llvm/Transforms/Instrumentation.h b/include/llvm/Transforms/Instrumentation.h index 8fac6ca83ac..a1477930ed6 100644 --- a/include/llvm/Transforms/Instrumentation.h +++ b/include/llvm/Transforms/Instrumentation.h @@ -60,6 +60,10 @@ struct GCOVOptions { // Emit the name of the function in the .gcda files. This is redundant, as // the function identifier can be used to find the name from the .gcno file. bool FunctionNamesInData; + + // Emit the exit block immediately after the start block, rather than after + // all of the function body's blocks. + bool ExitBlockBeforeBody; }; ModulePass *createGCOVProfilerPass(const GCOVOptions &Options = GCOVOptions::getDefault()); diff --git a/lib/Transforms/Instrumentation/GCOVProfiling.cpp b/lib/Transforms/Instrumentation/GCOVProfiling.cpp index e50ef1e0cd2..a793e69ce3d 100644 --- a/lib/Transforms/Instrumentation/GCOVProfiling.cpp +++ b/lib/Transforms/Instrumentation/GCOVProfiling.cpp @@ -47,6 +47,8 @@ using namespace llvm; static cl::opt DefaultGCOVVersion("default-gcov-version", cl::init("402*"), cl::Hidden, cl::ValueRequired); +static cl::opt DefaultExitBlockBeforeBody("gcov-exit-block-before-body", + cl::init(false), cl::Hidden); GCOVOptions GCOVOptions::getDefault() { GCOVOptions Options; @@ -55,6 +57,7 @@ GCOVOptions GCOVOptions::getDefault() { Options.UseCfgChecksum = false; Options.NoRedZone = false; Options.FunctionNamesInData = true; + Options.ExitBlockBeforeBody = DefaultExitBlockBeforeBody; if (DefaultGCOVVersion.size() != 4) { llvm::report_fatal_error(std::string("Invalid -default-gcov-version: ") + @@ -307,7 +310,7 @@ namespace { class GCOVFunction : public GCOVRecord { public: GCOVFunction(DISubprogram SP, raw_ostream *os, uint32_t Ident, - bool UseCfgChecksum) + bool UseCfgChecksum, bool ExitBlockBeforeBody) : SP(SP), Ident(Ident), UseCfgChecksum(UseCfgChecksum), CfgChecksum(0), ReturnBlock(1, os) { this->os = os; @@ -317,11 +320,13 @@ namespace { uint32_t i = 0; for (auto &BB : *F) { - // Skip index 1 (0, 2, 3, 4, ...) because that's assigned to the - // ReturnBlock. - bool first = i == 0; - Blocks.insert(std::make_pair(&BB, GCOVBlock(i++ + !first, os))); + // Skip index 1 if it's assigned to the ReturnBlock. + if (i == 1 && ExitBlockBeforeBody) + ++i; + Blocks.insert(std::make_pair(&BB, GCOVBlock(i++, os))); } + if (!ExitBlockBeforeBody) + ReturnBlock.Number = i; std::string FunctionNameAndLine; raw_string_ostream FNLOS(FunctionNameAndLine); @@ -464,7 +469,7 @@ static bool functionHasLines(Function *F) { if (Loc.isUnknown()) continue; // Artificial lines such as calls to the global constructors. - if (Loc.getLine() == 0) continue; + if (Loc.getLine() == 0) continue; return true; } @@ -508,7 +513,8 @@ void GCOVProfiler::emitProfileNotes() { EntryBlock.splitBasicBlock(It); Funcs.push_back(make_unique(SP, &out, FunctionIdent++, - Options.UseCfgChecksum)); + Options.UseCfgChecksum, + Options.ExitBlockBeforeBody)); GCOVFunction &Func = *Funcs.back(); for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) { diff --git a/test/Transforms/GCOVProfiling/return-block.ll b/test/Transforms/GCOVProfiling/return-block.ll index 8954157f548..0fafc559f5d 100644 --- a/test/Transforms/GCOVProfiling/return-block.ll +++ b/test/Transforms/GCOVProfiling/return-block.ll @@ -1,8 +1,14 @@ ; Inject metadata to set the .gcno file location ; RUN: echo '!19 = !{!"%/T/return-block.ll", !0}' > %t1 ; RUN: cat %s %t1 > %t2 + +; By default, the return block is last. ; RUN: opt -insert-gcov-profiling -disable-output %t2 -; RUN: llvm-cov gcov -n -dump %T/return-block.gcno 2>&1 | FileCheck %s +; RUN: llvm-cov gcov -n -dump %T/return-block.gcno 2>&1 | FileCheck -check-prefix=CHECK -check-prefix=RETURN-LAST %s + +; But we can optionally emit it second, to match newer gcc versions. +; RUN: opt -insert-gcov-profiling -gcov-exit-block-before-body -disable-output %t2 +; RUN: llvm-cov gcov -n -dump %T/return-block.gcno 2>&1 | FileCheck -check-prefix=CHECK -check-prefix=RETURN-SECOND %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target triple = "x86_64-unknown-linux-gnu" @@ -58,9 +64,12 @@ attributes #2 = { nounwind } !17 = distinct !MDLexicalBlock(line: 7, column: 7, file: !1, scope: !4) !18 = !MDLocation(line: 9, column: 1, scope: !4) -; There should be no destination edges for block 1. -; CHECK: Block : 0 Counter : 0 -; CHECK-NEXT: Destination Edges : 2 (0), -; CHECK-NEXT: Block : 1 Counter : 0 -; CHECK-NEXT: Source Edges : 4 (0), -; CHECK-NEXT: Block : 2 Counter : 0 +; There should be no destination edges for the exit block. +; CHECK: Block : 1 Counter : 0 +; RETURN-LAST: Destination Edges +; RETURN-SECOND-NOT: Destination Edges +; CHECK: Block : 2 Counter : 0 +; CHECK: Block : 4 Counter : 0 +; RETURN-LAST-NOT: Destination Edges +; RETURN-SECOND: Destination Edges +; CHECK-NOT: Block :