DebugInfo: Use the preferred location rather than the start location for expression...

This causes things like assignment to refer to the '=' rather than the
LHS when attributing the store instruction, for example.

There were essentially 3 options for this:

* The beginning of an expression (this was the behavior prior to this
  commit). This meant that stepping through subexpressions would bounce
  around from subexpressions back to the start of the outer expression,
  etc. (eg: x + y + z would go x, y, x, z, x (the repeated 'x's would be
  where the actual addition occurred)).

* The end of an expression. This seems to be what GCC does /mostly/, and
  certainly this for function calls. This has the advantage that
  progress is always 'forwards' (never jumping backwards - except for
  independent subexpressions if they're evaluated in interesting orders,
  etc). "x + y + z" would go "x y z" with the additions occurring at y
  and z after the respective loads.
  The problem with this is that the user would still have to think
  fairly hard about precedence to realize which subexpression is being
  evaluated or which operator overload is being called in, say, an asan
  backtrace.

* The preferred location or 'exprloc'. In this case you get sort of what
  you'd expect, though it's a bit confusing in its own way due to going
  'backwards'. In this case the locations would be: "x y + z +" in
  lovely postfix arithmetic order. But this does mean that if the op+
  were an operator overload, say, and in a backtrace, the backtrace will
  point to the exact '+' that's being called, not to the end of one of
  its operands.

(actually the operator overload case doesn't work yet for other reasons,
but that's being fixed - but this at least gets scalar/complex
assignments and other plain operators right)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@227027 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 17a8f063c5a066885a0d8dbcbde466e59054225c..38a1184bd725f73be6e907ea276871f4e71935a1 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -65,6 +65,10 @@ ArtificialLocation::ArtificialLocation(CodeGenFunction &CGF)
 ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF,
                                        SourceLocation TemporaryLocation)
     : CGF(CGF) {
+  init(TemporaryLocation);
+}
+
+void ApplyDebugLocation::init(SourceLocation TemporaryLocation) {
   if (auto *DI = CGF.getDebugInfo()) {
     OriginalLocation = CGF.Builder.getCurrentDebugLocation();
     if (TemporaryLocation.isInvalid())
@@ -74,6 +78,11 @@ ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF,
   }
 }
 
+ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E)
+    : CGF(CGF) {
+  init(E->getExprLoc());
+}
+
 ApplyDebugLocation::ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc)
     : CGF(CGF) {
   if (CGF.getDebugInfo()) {

diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index bcce90001835cfaa756016bec15c6b9a759dc3d1..8e00c1b048283e4fa677072fbbf1ef4712eaf2fd 100644 (file)
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -444,6 +444,9 @@ private:
 };
 
 class ApplyDebugLocation {
+private:
+  void init(SourceLocation TemporaryLocation);
+
 protected:
   llvm::DebugLoc OriginalLocation;
   CodeGenFunction &CGF;
@@ -451,6 +454,7 @@ protected:
 public:
   ApplyDebugLocation(CodeGenFunction &CGF,
                      SourceLocation TemporaryLocation = SourceLocation());
+  ApplyDebugLocation(CodeGenFunction &CGF, const Expr *E);
   ApplyDebugLocation(CodeGenFunction &CGF, llvm::DebugLoc Loc);
   ~ApplyDebugLocation();
 };

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 6fdd1104803b5632f91b3dadf0c3a8547b6e71f9..3a45d77e2c2e451d4e9530c67ba66c57e91f4f2b 100644 (file)
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -807,7 +807,7 @@ LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
 /// length type, this is not possible.
 ///
 LValue CodeGenFunction::EmitLValue(const Expr *E) {
-  ApplyDebugLocation DL(*this, E->getLocStart());
+  ApplyDebugLocation DL(*this, E);
   switch (E->getStmtClass()) {
   default: return EmitUnsupportedLValue(E, "l-value expression");
 
@@ -3060,7 +3060,7 @@ RValue CodeGenFunction::EmitRValueForField(LValue LV,
 
 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
                                      ReturnValueSlot ReturnValue) {
-  ApplyDebugLocation DL(*this, E->getLocStart());
+  ApplyDebugLocation DL(*this, E);
 
   // Builtins never have block type.
   if (E->getCallee()->getType()->isBlockPointerType())

diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 4cba4781afc3cadfc672f7cd0127ae79a3be541a..80b16dd5ba3c15570900e4f21067856f6e472a23 100644 (file)
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -99,7 +99,7 @@ public:
   //===--------------------------------------------------------------------===//
 
   void Visit(Expr *E) {
-    ApplyDebugLocation DL(CGF, E->getLocStart());
+    ApplyDebugLocation DL(CGF, E);
     StmtVisitor<AggExprEmitter>::Visit(E);
   }
 

diff --git a/lib/CodeGen/CGExprCXX.cpp b/lib/CodeGen/CGExprCXX.cpp
index 6d63b3ae9cf8dcf046bb97ad5526eec7101ff8ad..cead8a429df8ca5891b40c9d53549a909163b4ae 100644 (file)
--- a/lib/CodeGen/CGExprCXX.cpp
+++ b/lib/CodeGen/CGExprCXX.cpp
@@ -1016,7 +1016,7 @@ static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
                                llvm::Value *NewPtr,
                                llvm::Value *NumElements,
                                llvm::Value *AllocSizeWithoutCookie) {
-  ApplyDebugLocation DL(CGF, E->getStartLoc());
+  ApplyDebugLocation DL(CGF, E);
   if (E->isArray())
     CGF.EmitNewArrayInitializer(E, ElementType, NewPtr, NumElements,
                                 AllocSizeWithoutCookie);

diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 2cbd42b7ee5ba2f1d09676f048e0ffd7a1e52d0a..b6adbf64f82e79df023aef1371a8c9730ef4d026 100644 (file)
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -95,7 +95,7 @@ public:
   //===--------------------------------------------------------------------===//
 
   ComplexPairTy Visit(Expr *E) {
-    ApplyDebugLocation DL(CGF, E->getLocStart());
+    ApplyDebugLocation DL(CGF, E);
     return StmtVisitor<ComplexExprEmitter, ComplexPairTy>::Visit(E);
   }
 

diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index a9cbf05da10451c45d0b73f27cd7e98d6d7728bf..2e2821b62304360f2eb39c986478357163337623 100644 (file)
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -196,7 +196,7 @@ public:
   //===--------------------------------------------------------------------===//
 
   Value *Visit(Expr *E) {
-    ApplyDebugLocation DL(CGF, E->getLocStart());
+    ApplyDebugLocation DL(CGF, E);
     return StmtVisitor<ScalarExprEmitter, Value*>::Visit(E);
   }
 

diff --git a/test/CodeGenCXX/debug-info-line.cpp b/test/CodeGenCXX/debug-info-line.cpp
index 87ea576ccab791066a0a49cff77725d1e46b4798..340222eba5b7e32f33953b7d707cb7e04e062b6b 100644 (file)
--- a/test/CodeGenCXX/debug-info-line.cpp
+++ b/test/CodeGenCXX/debug-info-line.cpp
@@ -10,11 +10,11 @@ extern "C" __complex float *complex_sink();
 
 // CHECK-LABEL: define
 void f1() {
-#line 100
-  * // The store for the assignment should be attributed to the start of the
-      // assignment expression here, regardless of the location of subexpressions.
-      sink() = src();
+  *sink()
   // CHECK: store {{.*}}, !dbg [[DBG_F1:!.*]]
+#line 100
+      = //
+      src();
 }
 
 struct foo {
@@ -38,16 +38,20 @@ foo::foo()
 
 // CHECK-LABEL: define {{.*}}f2{{.*}}
 void f2() {
+  // CHECK: store float {{.*}} !dbg [[DBG_F2:!.*]]
+  *complex_sink()
 #line 300
-  * // CHECK: store float {{.*}} !dbg [[DBG_F2:!.*]]
-      complex_sink() = complex_src();
+      = //
+      complex_src();
 }
 
 // CHECK-LABEL: define
 void f3() {
+  // CHECK: store float {{.*}} !dbg [[DBG_F3:!.*]]
+  *complex_sink()
 #line 400
-  * // CHECK: store float {{.*}} !dbg [[DBG_F3:!.*]]
-      complex_sink() += complex_src();
+      += //
+      complex_src();
 }
 
 // CHECK-LABEL: define