From 6837ab53fb0d06460979e4e4a662b116fcbcca5b Mon Sep 17 00:00:00 2001 From: Justin Bogner Date: Mon, 16 Mar 2015 23:52:03 +0000 Subject: [PATCH] GCOV: Make the exit block placement from r223193 optional By default we want our gcov emission to stay 4.2 compatible, which means we need to continue emit the exit block last by default. We add an option to emit it before the body for users that need it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232438 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Instrumentation.h | 4 ++++ .../Instrumentation/GCOVProfiling.cpp | 20 ++++++++++------ test/Transforms/GCOVProfiling/return-block.ll | 23 +++++++++++++------ 3 files changed, 33 insertions(+), 14 deletions(-) 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 :