Ensure that the line table for functions with cleanups is sequential.

If there is cleanup code, the cleanup code gets the debug location of
the closing '}'. The subsequent ret IR-instruction does not get a
debug location. The return _expression_ will get the debug location
of the return statement.

If the function contains only a single, simple return statement,
the cleanup code may become the first breakpoint in the function.
In this case we set the debug location for the cleanup code
to the location of the return statement.

rdar://problem/13442648

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@180932 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGCall.cpp b/lib/CodeGen/CGCall.cpp
index 47f3c648409e0883fbe5a03f7be7e143bc8092cf..4b6fe42fccf516c2a6e0a762b7bcc2bfd171cd34 100644 (file)
--- a/lib/CodeGen/CGCall.cpp
+++ b/lib/CodeGen/CGCall.cpp
@@ -1625,7 +1625,8 @@ static bool checkThisPointer(llvm::Value *ThisArg, llvm::Value *This) {
   return false;
 }
 
-void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI) {
+void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
+                                         bool EmitRetDbgLoc) {
   // Functions with no result always return void.
   if (ReturnValue == 0) {
     Builder.CreateRetVoid();
@@ -1670,8 +1671,10 @@ void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI) {
       // If there is a dominating store to ReturnValue, we can elide
       // the load, zap the store, and usually zap the alloca.
       if (llvm::StoreInst *SI = findDominatingStoreToReturnValue(*this)) {
+        // Reuse the debug location from the store unless we're told not to.
+        if (EmitRetDbgLoc)
+          RetDbgLoc = SI->getDebugLoc();
         // Get the stored value and nuke the now-dead store.
-        RetDbgLoc = SI->getDebugLoc();
         RV = SI->getValueOperand();
         SI->eraseFromParent();
 

diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index dcc423dbdc0158fa238a459ebea11891fa2ab14f..28bbc46c689c4efac4316b57453a228b58be985f 100644 (file)
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -37,6 +37,9 @@ void CodeGenFunction::EmitStopPoint(const Stmt *S) {
     else
       Loc = S->getLocStart();
     DI->EmitLocation(Builder, Loc);
+
+    if (++NumStopPoints == 1)
+      FirstStopPoint = Loc;
   }
 }
 
@@ -839,6 +842,9 @@ void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) {
     }
   }
 
+  if (RV == 0 || RV->isEvaluatable(getContext()))
+    ++NumSimpleReturnExprs;
+
   cleanupScope.ForceCleanup();
   EmitBranchThroughCleanup(ReturnBlock);
 }

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 0daae58bdc7c6389e2fe14f4ab90303d34029d7e..122e95b2663256ec8a4be6e1a4d1495d5359f60f 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -44,6 +44,7 @@ CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext)
     DebugInfo(0), DisableDebugInfo(false), CalleeWithThisReturn(0),
     DidCallStackSave(false),
     IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0),
+    NumStopPoints(0), NumSimpleReturnExprs(0),
     CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0),
     CXXDefaultInitExprThis(0),
     CXXStructorImplicitParamDecl(0), CXXStructorImplicitParamValue(0),
@@ -187,16 +188,35 @@ void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
   assert(BreakContinueStack.empty() &&
          "mismatched push/pop in break/continue stack!");
 
-  if (CGDebugInfo *DI = getDebugInfo())
-    DI->EmitLocation(Builder, EndLoc);
+  // If the function contains only a single, simple return statement,
+  // the cleanup code may become the first breakpoint in the
+  // function. To be safe set the debug location for it to the
+  // location of the return statement.  Otherwise point it to end of
+  // the function's lexical scope.
+  if (CGDebugInfo *DI = getDebugInfo()) {
+    if (NumSimpleReturnExprs == 1 && NumStopPoints == 1)
+      DI->EmitLocation(Builder, FirstStopPoint);
+    else
+      DI->EmitLocation(Builder, EndLoc);
+  }
 
   // Pop any cleanups that might have been associated with the
   // parameters.  Do this in whatever block we're currently in; it's
   // important to do this before we enter the return block or return
   // edges will be *really* confused.
-  if (EHStack.stable_begin() != PrologueCleanupDepth)
+  bool EmitRetDbgLoc = true;
+  if (EHStack.stable_begin() != PrologueCleanupDepth) {
     PopCleanupBlocks(PrologueCleanupDepth);
 
+    // Make sure the line table doesn't jump back into the body for
+    // the ret after it's been at EndLoc.
+    EmitRetDbgLoc = false;
+
+    if (CGDebugInfo *DI = getDebugInfo())
+      if (NumSimpleReturnExprs == 1 && NumStopPoints == 1)
+        DI->EmitLocation(Builder, EndLoc);
+  }
+
   // Emit function epilog (to return).
   EmitReturnBlock();
 
@@ -208,7 +228,7 @@ void CodeGenFunction::FinishFunction(SourceLocation EndLoc) {
     DI->EmitFunctionEnd(Builder);
   }
 
-  EmitFunctionEpilog(*CurFnInfo);
+  EmitFunctionEpilog(*CurFnInfo, EmitRetDbgLoc);
   EmitEndEHSpec(CurCodeDecl);
 
   assert(EHStack.empty() &&

diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 727a3be54b023e478416195ad60f076fe97dae34..17df1dad3ef082b7c42324a337cfd0f2e828c85b 100644 (file)
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1206,6 +1206,15 @@ private:
   /// lazily by getUnreachableBlock().
   llvm::BasicBlock *UnreachableBlock;
 
+  /// Counts of the number of distinct breakpoint locations in this function.
+  unsigned NumStopPoints;
+
+  /// Count the number of simple (constant) return expressions in the function.
+  unsigned NumSimpleReturnExprs;
+
+  /// The first debug location (breakpoint) in the function.
+  SourceLocation FirstStopPoint;
+
 public:
   /// A scope within which we are constructing the fields of an object which
   /// might use a CXXDefaultInitExpr. This stashes away a 'this' value to use
@@ -1563,7 +1572,7 @@ public:
 
   /// EmitFunctionEpilog - Emit the target specific LLVM code to return the
   /// given temporary.
-  void EmitFunctionEpilog(const CGFunctionInfo &FI);
+  void EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc);
 
   /// EmitStartEHSpec - Emit the start of the exception spec.
   void EmitStartEHSpec(const Decl *D);

diff --git a/test/CodeGenObjC/arc-linetable.m b/test/CodeGenObjC/arc-linetable.m
new file mode 100644 (file)
index 0000000..eac91f1
--- /dev/null
+++ b/test/CodeGenObjC/arc-linetable.m
@@ -0,0 +1,101 @@
+// RUN: %clang_cc1 -emit-llvm -fblocks -fobjc-arc -g -triple x86_64-apple-darwin10 %s -o - | FileCheck %s
+
+// Legend: EXP = Return expression, RET = ret instruction
+
+// CHECK: define {{.*}}testNoSideEffect
+// CHECK: call void @objc_storeStrong{{.*}}
+// CHECK: call void @objc_storeStrong{{.*}} !dbg ![[ARC1:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET1:[0-9]+]]
+
+// CHECK: define {{.*}}testNoCleanup
+// CHECK: ret {{.*}} !dbg ![[RET2:[0-9]+]]
+
+// CHECK: define {{.*}}testSideEffect
+// CHECK: @objc_msgSend{{.*}} !dbg ![[MSG3:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET3:[0-9]+]]
+
+// CHECK: define {{.*}}testMultiline
+// CHECK: @objc_msgSend{{.*}} !dbg ![[MSG4:[0-9]+]]
+// CHECK: load{{.*}} !dbg ![[EXP4:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET4:[0-9]+]]
+
+// CHECK: define {{.*}}testVoid
+// CHECK: call void @objc_storeStrong{{.*}}
+// CHECK: call void @objc_storeStrong{{.*}} !dbg ![[ARC5:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET5:[0-9]+]]
+
+// CHECK: define {{.*}}testVoidNoReturn
+// CHECK: @objc_msgSend{{.*}} !dbg ![[MSG6:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET6:[0-9]+]]
+
+// CHECK: define {{.*}}testNoCleanupSideEffect
+// CHECK: @objc_msgSend{{.*}} !dbg ![[MSG7:[0-9]+]]
+// CHECK: ret {{.*}} !dbg ![[RET7:[0-9]+]]
+
+
+@interface NSObject
++ (id)alloc;
+- (id)init;
+- (id)retain;
+@end
+
+@class NSString;
+
+@interface AppDelegate : NSObject
+
+@end
+
+@implementation AppDelegate : NSObject
+
+- (int)testNoSideEffect:(NSString *)foo {
+  // CHECK: ![[ARC1]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return 1; // Return expression
+  // CHECK: ![[RET1]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+}           // Cleanup + Ret
+
+- (int)testNoCleanup {
+  // CHECK: ![[RET2]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return 1;
+}
+
+- (int)testSideEffect:(NSString *)foo {
+  // CHECK: ![[MSG3]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return [self testNoSideEffect :foo];
+  // CHECK: ![[RET3]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+}
+
+- (int)testMultiline:(NSString *)foo {
+  // CHECK: ![[MSG4]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  int r = [self testSideEffect :foo];
+  // CHECK: ![[EXP4]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return r;
+  // CHECK: ![[RET4]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+}
+
+- (void)testVoid:(NSString *)foo {
+  // CHECK: ![[ARC5]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return;
+  // CHECK: ![[RET5]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+}
+
+- (void)testVoidNoReturn:(NSString *)foo {
+  // CHECK: ![[MSG6]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  [self testVoid :foo];
+  // CHECK: ![[RET6]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+}
+
+- (int)testNoCleanupSideEffect {
+  // CHECK: ![[MSG7]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  [self testVoid :@"foo"];
+  // CHECK: ![[RET7]] = metadata !{i32 [[@LINE+1]], i32 0, metadata !{{.*}}, null}
+  return 1;
+}
+
+
+@end
+
+
+int main(int argc, const char** argv) {
+  AppDelegate *o = [[AppDelegate alloc] init];
+  return [o testMultiline :@"foo"];
+}

diff --git a/test/CodeGenObjC/debug-info-block-line.m b/test/CodeGenObjC/debug-info-block-line.m
index c913a972e14fe6d41b0d3bcb305457917d104ef1..2192575bb78e1a4f95aa2881c3ce38aa6623399c 100644 (file)
--- a/test/CodeGenObjC/debug-info-block-line.m
+++ b/test/CodeGenObjC/debug-info-block-line.m
@@ -64,13 +64,16 @@ typedef enum : NSUInteger {
 // CHECK: define internal void @"__39-[TServer serverConnection:getCommand:]_block_invoke"
 // CHECK: call void @objc_storeStrong(i8** [[ZERO:%.*]], i8* [[ONE:%.*]]) [[NUW:#[0-9]+]]
 // CHECK: call void @objc_storeStrong(i8** [[TWO:%.*]], i8* [[THREE:%.*]]) [[NUW]]
+// CHECK: call {{.*}}@objc_msgSend{{.*}}, !dbg ![[LINE_ABOVE:[0-9]+]]
+// CHECK: getelementptr
+// CHECK-NOT: !dbg, ![[LINE_ABOVE]]
 // CHECK: bitcast %5** [[TMP:%.*]] to i8**
-// CHECK: call void @objc_storeStrong(i8** [[VAL1:%.*]], i8* null) [[NUW]], !dbg ![[MD1:.*]]
-// CHECK: bitcast %4** [[TMP:%.*]] to i8**
-// CHECK: call void @objc_storeStrong(i8** [[VAL2:%.*]], i8* null) [[NUW]], !dbg ![[MD1]]
+// CHECK-NOT: !dbg, ![[LINE_ABOVE]]
+// CHECK: call void @objc_storeStrong(i8** [[VAL1:%.*]], i8* null) [[NUW]]
+// CHECK-NEXT: bitcast %4** [[TMP:%.*]] to i8**
+// CHECK-NEXT: call void @objc_storeStrong(i8** [[VAL2:%.*]], i8* null) [[NUW]]
 // CHECK-NEXT: ret
 // CHECK: attributes [[NUW]] = { nounwind }
-// CHECK: ![[MD1]] = metadata !{i32 87
     [map dataWithCompletionBlock:^(NSData *data, NSError *error) {
         if (data) {
             NSString    *encoded = [[data compressedData] encodedString:18];