[PATCH] D15208: Patch for inline abort code generation

[Dan Austin via cfe-commits]

danielaustin updated this revision to Diff 41957.
danielaustin added a comment.

Added a flag controlling whether or not the inlining occurs. Tested with ARM 32 bit (shamu) with AOSP. The patched compiler resulted in correct code generation and no stability issues. The flag is probably not ideally named, but treating it as a sanitizer did allow for easy integration into the Android build system.


Repository:
  rL LLVM

http://reviews.llvm.org/D15208

Files:
  include/clang/Basic/Sanitizers.def
  lib/CodeGen/CGExpr.cpp
  lib/Driver/ToolChain.cpp

Index: lib/Driver/ToolChain.cpp
===================================================================
--- lib/Driver/ToolChain.cpp
+++ lib/Driver/ToolChain.cpp
@@ -657,7 +657,8 @@
   // platform dependent.
   using namespace SanitizerKind;
   SanitizerMask Res = (Undefined & ~Vptr & ~Function) | (CFI & ~CFIICall) |
-                      CFICastStrict | UnsignedIntegerOverflow | LocalBounds;
+                      CFICastStrict | UnsignedIntegerOverflow | LocalBounds |
+                      DebugMode;
   if (getTriple().getArch() == llvm::Triple::x86 ||
       getTriple().getArch() == llvm::Triple::x86_64)
     Res |= CFIICall;
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -27,6 +27,7 @@
 #include "llvm/ADT/Hashing.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/MDBuilder.h"
@@ -2535,9 +2536,25 @@
 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
   llvm::BasicBlock *Cont = createBasicBlock("cont");
 
-  // If we're optimizing, collapse all calls to trap down to just one per
-  // function to save on code size.
-  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
+  // Collapsing all calls to trap down to one per function makes debugging
+  // these issues much more difficult. Eliminating this optimization 
+  // for debugging purposes.
+  // RE: Bug: 25682
+  if(SanOpts.has(SanitizerKind::DebugMode)) {
+      llvm::InlineAsm *EmptyAsm = llvm::InlineAsm::get(llvm::FunctionType::get(CGM.VoidTy, false), 
+						       StringRef(""), StringRef(""), true);
+      TrapBB = createBasicBlock("trap");
+      Builder.CreateCondBr(Checked, Cont, TrapBB);
+      EmitBlock(TrapBB);
+      llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
+      TrapCall->setDoesNotReturn();
+      TrapCall->setDoesNotThrow();
+      Builder.CreateUnreachable();
+      //this stops the trap calls from being merged at the end of the function
+      Builder.CreateCall(EmptyAsm, {});
+  } else if(!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
+    // If we're optimizing, collapse all calls to trap down to just one per
+    // function to save on code size.
     TrapBB = createBasicBlock("trap");
     Builder.CreateCondBr(Checked, Cont, TrapBB);
     EmitBlock(TrapBB);
@@ -2548,7 +2565,7 @@
   } else {
     Builder.CreateCondBr(Checked, Cont, TrapBB);
   }
-
+  
   EmitBlock(Cont);
 }
 
Index: include/clang/Basic/Sanitizers.def
===================================================================
--- include/clang/Basic/Sanitizers.def
+++ include/clang/Basic/Sanitizers.def
@@ -37,6 +37,8 @@
 #define SANITIZER_GROUP(NAME, ID, ALIAS)
 #endif
 
+// Debug mode for sanitizers
+SANITIZER("debug-mode", DebugMode)
 
 // AddressSanitizer
 SANITIZER("address", Address)


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