[ExecutionEngine] Allow JIT clients to enable/disable module verification.

Previously module verification was always enabled, with no way to turn it off.
As of this commit, module verification is on by default in Debug builds, and off
by default in release builds. The default behaviour can be overridden by calling
setVerifyModules(bool) on the JIT instance (this works for both the old JIT, and
MCJIT).

<rdar://problem/16150008>

llvm-svn: 206561

llvm/include/llvm/ExecutionEngine/ExecutionEngine.h

@@ -123,6 +123,9 @@ class ExecutionEngine {
   /// using dlsym).
   bool SymbolSearchingDisabled;
 
+  /// Whether the JIT should verify IR modules during compilation.
+  bool VerifyModules;
+
   friend class EngineBuilder;  // To allow access to JITCtor and InterpCtor.
 
 protected:
@@ -525,6 +528,17 @@ public:
     return SymbolSearchingDisabled;
   }
 
+  /// Enable/Disable IR module verification.
+  ///
+  /// Note: Module verification is enabled by default in Debug builds, and
+  /// disabled by default in Release. Use this method to override the default.
+  void setVerifyModules(bool Verify) {
+    VerifyModules = Verify;
+  }
+  bool getVerifyModules() const {
+    return VerifyModules;
+  }
+
   /// InstallLazyFunctionCreator - If an unknown function is needed, the
   /// specified function pointer is invoked to create it.  If it returns null,
   /// the JIT will abort.
@@ -572,6 +586,7 @@ private:
   std::string MCPU;
   SmallVector<std::string, 4> MAttrs;
   bool UseMCJIT;
+  bool VerifyModules;
 
   /// InitEngine - Does the common initialization of default options.
   void InitEngine() {
@@ -585,6 +600,14 @@ private:
     RelocModel = Reloc::Default;
     CMModel = CodeModel::JITDefault;
     UseMCJIT = false;
+
+  // IR module verification is enabled by default in debug builds, and disabled
+  // by default in release builds.
+#ifndef NDEBUG
+  VerifyModules = true;
+#else
+  VerifyModules = false;
+#endif
   }
 
 public:
@@ -694,6 +717,13 @@ public:
     return *this;
   }
 
+  /// setVerifyModules - Set whether the JIT implementation should verify
+  /// IR modules during compilation.
+  EngineBuilder &setVerifyModules(bool Verify) {
+    VerifyModules = Verify;
+    return *this;
+  }
+
   /// setMAttrs - Set cpu-specific attributes.
   template<typename StringSequence>
   EngineBuilder &setMAttrs(const StringSequence &mattrs) {

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

@@ -66,6 +66,15 @@ ExecutionEngine::ExecutionEngine(Module *M)
   CompilingLazily         = false;
   GVCompilationDisabled   = false;
   SymbolSearchingDisabled = false;
+
+  // IR module verification is enabled by default in debug builds, and disabled
+  // by default in release builds.
+#ifndef NDEBUG
+  VerifyModules = true;
+#else
+  VerifyModules = false;
+#endif
+
   Modules.push_back(M);
   assert(M && "Module is null?");
 }
@@ -483,16 +492,17 @@ ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
              << " a different -march switch.\n";
     }
 
-    if (UseMCJIT && ExecutionEngine::MCJITCtor) {
-      ExecutionEngine *EE =
-        ExecutionEngine::MCJITCtor(M, ErrorStr, MCJMM ? MCJMM : JMM,
-                                   AllocateGVsWithCode, TheTM.release());
-      if (EE) return EE;
-    } else if (ExecutionEngine::JITCtor) {
-      ExecutionEngine *EE =
-        ExecutionEngine::JITCtor(M, ErrorStr, JMM,
-                                 AllocateGVsWithCode, TheTM.release());
-      if (EE) return EE;
+    ExecutionEngine *EE = nullptr;
+    if (UseMCJIT && ExecutionEngine::MCJITCtor)
+      EE = ExecutionEngine::MCJITCtor(M, ErrorStr, MCJMM ? MCJMM : JMM,
+                                      AllocateGVsWithCode, TheTM.release());
+    else if (ExecutionEngine::JITCtor)
+      EE = ExecutionEngine::JITCtor(M, ErrorStr, JMM,
+                                    AllocateGVsWithCode, TheTM.release());
+
+    if (EE) {
+      EE->setVerifyModules(VerifyModules);
+      return EE;
     }
   }
 

llvm/lib/ExecutionEngine/JIT/JIT.cpp

@@ -157,7 +157,7 @@ JIT::JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji,
 
   // Turn the machine code intermediate representation into bytes in memory that
   // may be executed.
-  if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
+  if (TM.addPassesToEmitMachineCode(PM, *JCE, !getVerifyModules())) {
     report_fatal_error("Target does not support machine code emission!");
   }
 
@@ -190,7 +190,7 @@ void JIT::addModule(Module *M) {
 
     // Turn the machine code intermediate representation into bytes in memory
     // that may be executed.
-    if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
+    if (TM.addPassesToEmitMachineCode(PM, *JCE, !getVerifyModules())) {
       report_fatal_error("Target does not support machine code emission!");
     }
 
@@ -222,7 +222,7 @@ bool JIT::removeModule(Module *M) {
 
     // Turn the machine code intermediate representation into bytes in memory
     // that may be executed.
-    if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
+    if (TM.addPassesToEmitMachineCode(PM, *JCE, !getVerifyModules())) {
       report_fatal_error("Target does not support machine code emission!");
     }
 

llvm/lib/ExecutionEngine/MCJIT/MCJIT.cpp

@@ -150,7 +150,8 @@ ObjectBufferStream* MCJIT::emitObject(Module *M) {
 
   // Turn the machine code intermediate representation into bytes in memory
   // that may be executed.
-  if (TM->addPassesToEmitMC(PM, Ctx, CompiledObject->getOStream(), false)) {
+  if (TM->addPassesToEmitMC(PM, Ctx, CompiledObject->getOStream(),
+                            !getVerifyModules())) {
     report_fatal_error("Target does not support MC emission!");
   }