[clang] Add DisableInlineOpt code generation option

Author: gmh5225

clang/include/clang/Basic/CodeGenOptions.def

@@ -246,6 +246,7 @@ CODEGENOPT(SanitizeMemoryUseAfterDtor, 1, 0) ///< Enable use-after-delete detect
                                              ///< in MemorySanitizer
 CODEGENOPT(SanitizeCfiCrossDso, 1, 0) ///< Enable cross-dso support in CFI.
 CODEGENOPT(Jumptablerdata, 1, 0) ///< Put switch case jump tables in .rdata
+CODEGENOPT(DisableInlineOpt, 1, 0) ///< Disables the optimization of inline functions.
 CODEGENOPT(DisableCFICheckFail, 1, 0) ///< Disables the failure checks in CFI.
 CODEGENOPT(DisableCFICheck, 1, 0) ///< Disables the checks in CFI.
 CODEGENOPT(DisableCFISlowPathCheck, 1, 0) ///< Disables the slow path checks in CFI.

clang/include/clang/Driver/Options.td

@@ -2435,6 +2435,10 @@ def fjumptable_rdata : Flag<["-"], "fjumptable-rdata">,
                                           Group<f_clang_Group>,
                                           HelpText<"Put switch case jump tables in .rdata">,
                                           MarshallingInfoFlag<CodeGenOpts<"Jumptablerdata">>;
+def fdisable_inline_opt : Flag<["-"], "fdisable-inline-opt">,
+                                          Group<f_clang_Group>,
+                                          HelpText<"Disables the optimization of inline functions">,
+                                          MarshallingInfoFlag<CodeGenOpts<"DisableInlineOpt">>;
 def fdisable_cfi_check : Flag<["-"], "fdisable-cfi-check">,
                                           Group<f_clang_Group>,
                                           HelpText<"Disables the checks in CFI">,

clang/lib/CodeGen/CodeGenModule.cpp

@@ -1042,6 +1042,11 @@ void CodeGenModule::Release() {
     getModule().addModuleFlag(llvm::Module::Override, "Cross-DSO CFI", 1);
   }
 
+  if (CodeGenOpts.DisableInlineOpt) {
+    // Indicate that we want to disable optimization of inlined functions.
+    getModule().addModuleFlag(llvm::Module::Override, "DisableInlineOpt", 1);
+  }
+  
   if (CodeGenOpts.Jumptablerdata) {
     // Indicate that we want to emit jump table to .rdata.
     getModule().addModuleFlag(llvm::Module::Override, "Jumptablerdata", 1);

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6792,6 +6792,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     CmdArgs.push_back("-mllvm");
     CmdArgs.push_back("-jumptable-in-function-section=false");
   }
+
+  // -fdisable-inline-opt(Disables the optimization of inline functions)
+  if (Args.hasArg(options::OPT_fdisable_inline_opt))
+    CmdArgs.push_back("-fdisable-inline-opt");
 
   // -fdisable-cfi-check(Disables the checks in CFI)
   if (Args.hasArg(options::OPT_fdisable_cfi_check))

llvm/lib/Transforms/Utils/InlineFunction.cpp

@@ -2018,6 +2018,14 @@ inlineRetainOrClaimRVCalls(CallBase &CB, objcarc::ARCInstKind RVCallKind,
 // Set volatile attribute for inlined basic block and instructions.
 // This is used to preserve the volatile attribute of the original call instruction.
 static void setVolatileForInlinedBB(BasicBlock *BB) {
+
+  // We need BBs belong to a function.
+  if (!BB->getParent()->getParent())
+    return;
+
+  // Set volatile attribute for the basic block if the module flag is set.
+  if (!BB->getParent()->getParent()->getModuleFlag("DisableInlineOpt"))
+    return;
 
   // Do not set volatile attribute for basic block with only one instruction.
   if (BB->size() <= 1)
@@ -2830,10 +2838,10 @@ llvm::InlineResult llvm::InlineFunction(CallBase &CB, InlineFunctionInfo &IFI,
 
     if (MergeAttributes)
       AttributeFuncs::mergeAttributesForInlining(*Caller, *CalledFunc);
-#ifdef _WIN32
+
     // Set 'volatile' to the new BB and instructions.
     setVolatileForInlinedBB(OrigBB);
-#endif
+
     // We are now done with the inlining.
     return InlineResult::success();
   }
@@ -2997,9 +3005,9 @@ llvm::InlineResult llvm::InlineFunction(CallBase &CB, InlineFunctionInfo &IFI,
 
   if (MergeAttributes)
     AttributeFuncs::mergeAttributesForInlining(*Caller, *CalledFunc);
-#ifdef _WIN32
+
   // Set 'volatile' to the new BB and instructions.
   setVolatileForInlinedBB(AfterCallBB);
-#endif
+
   return InlineResult::success();
 }