commit 3faa76bfab41067743d92dbf5648f02180d1fd1b
author Justin Bogner <mail@justinbogner.com> Mon Mar 16 23:52:03 2015 +0000
committer Justin Bogner <mail@justinbogner.com> Mon Mar 16 23:52:03 2015 +0000
tree c5e3b8d3c1d53923c07565319690cf3127b83b7f
parent 933f853030ea34f2c718afea260572de2c4c9a31

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.

llvm-svn: 232438

llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp

diff --git a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
index e50ef1e..a793e69 100644
--- a/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
+++ b/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
@@ -47,6 +47,8 @@
 static cl::opt<std::string>
 DefaultGCOVVersion("default-gcov-version", cl::init("402*"), cl::Hidden,
                    cl::ValueRequired);
+static cl::opt<bool> DefaultExitBlockBeforeBody("gcov-exit-block-before-body",
+                                                cl::init(false), cl::Hidden);
 
 GCOVOptions GCOVOptions::getDefault() {
   GCOVOptions Options;
@@ -55,6 +57,7 @@
   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 @@
   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 @@
 
       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 @@
       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 @@
       EntryBlock.splitBasicBlock(It);
 
       Funcs.push_back(make_unique<GCOVFunction>(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) {