r227356 - DebugInfo: Attribute implicit boolean tests to the expression being tested, not to the outer use of that expression.

[David Blaikie]

Author: dblaikie
Date: Wed Jan 28 13:50:09 2015
New Revision: 227356

URL: http://llvm.org/viewvc/llvm-project?rev=227356&view=rev
Log:
DebugInfo: Attribute implicit boolean tests to the expression being tested, not to the outer use of that expression.

This is half a fix for a GDB test suite failure that expects to start at
'a' in the following code:

  void func(int a)
    if (a
        &&
	b)
	...

But instead, without this change, the comparison was assigned to '&&'
(well, worse actually - because there was a chained 'a && b && c' and it
was assigned to the second '&&' because of a recursive application of
this bug) and then the load folded into the comparison so breaking on
the function started at '&&' instead of 'a'.

The other part of this needs to be fixed in LLVM where it's ignoring the
location of the icmp and instead using the location of the branch
instruction.

The fix to the conditional operator is actually a no-op currently,
because the conditional operator's location coincides with 'a' (the
start of the conditional expression) but should probably be '?' instead.
See the FIXME in the test case that mentions the ARCMigration tool
failures when I tried to make that change.

Modified:
    cfe/trunk/lib/CodeGen/CGDebugInfo.h
    cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
    cfe/trunk/test/CodeGenCXX/debug-info-line.cpp

Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=227356&r1=227355&r2=227356&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Wed Jan 28 13:50:09 2015
@@ -443,6 +443,8 @@ private:
   }
 };
 
+/// A scoped helper to set the current debug location to the specified location
+/// or preferred location of the specified Expr.
 class ApplyDebugLocation {
 private:
   void init(SourceLocation TemporaryLocation);

Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=227356&r1=227355&r2=227356&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Wed Jan 28 13:50:09 2015
@@ -1058,8 +1058,11 @@ void CodeGenFunction::EmitBranchOnBoolEx
       uint64_t RHSCount = Cnt.getCount();
 
       ConditionalEvaluation eval(*this);
-      EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock, RHSCount);
-      EmitBlock(LHSTrue);
+      {
+        ApplyDebugLocation DL(*this, Cond);
+        EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock, RHSCount);
+        EmitBlock(LHSTrue);
+      }
 
       // Any temporaries created here are conditional.
       Cnt.beginRegion(Builder);
@@ -1103,8 +1106,11 @@ void CodeGenFunction::EmitBranchOnBoolEx
       uint64_t RHSCount = TrueCount - LHSCount;
 
       ConditionalEvaluation eval(*this);
-      EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse, LHSCount);
-      EmitBlock(LHSFalse);
+      {
+        ApplyDebugLocation DL(*this, Cond);
+        EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse, LHSCount);
+        EmitBlock(LHSFalse);
+      }
 
       // Any temporaries created here are conditional.
       Cnt.beginRegion(Builder);
@@ -1151,8 +1157,11 @@ void CodeGenFunction::EmitBranchOnBoolEx
     cond.begin(*this);
     EmitBlock(LHSBlock);
     Cnt.beginRegion(Builder);
-    EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock,
-                         LHSScaledTrueCount);
+    {
+      ApplyDebugLocation DL(*this, Cond);
+      EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock,
+                           LHSScaledTrueCount);
+    }
     cond.end(*this);
 
     cond.begin(*this);

Modified: cfe/trunk/test/CodeGenCXX/debug-info-line.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/debug-info-line.cpp?rev=227356&r1=227355&r2=227356&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/debug-info-line.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/debug-info-line.cpp Wed Jan 28 13:50:09 2015
@@ -213,6 +213,43 @@ void f17(int *x) {
       x[1];
 }
 
+// CHECK-LABEL: define
+void f18(int a, int b) {
+// CHECK: icmp {{.*}}, !dbg [[DBG_F18_1:![0-9]*]]
+// CHECK: br {{.*}}, !dbg [[DBG_F18_2:![0-9]*]]
+#line 2000
+  if (a  //
+      && //
+      b)
+    ;
+}
+
+// CHECK-LABEL: define
+void f19(int a, int b) {
+// CHECK: icmp {{.*}}, !dbg [[DBG_F19_1:![0-9]*]]
+// CHECK: br {{.*}}, !dbg [[DBG_F19_2:![0-9]*]]
+#line 2100
+  if (a  //
+      || //
+      b)
+    ;
+}
+
+// CHECK-LABEL: define
+void f20(int a, int b, int c) {
+// CHECK: icmp {{.*}}, !dbg [[DBG_F20_1:![0-9]*]]
+// FIXME: Conditional operator's exprloc should be the '?' not the start of the
+// expression, then this would go in the right place. (but adding getExprLoc to
+// the ConditionalOperator breaks the ARC migration tool - need to investigate
+// further).
+// CHECK: br {{.*}}, !dbg [[DBG_F20_1]]
+#line 2200
+  if (a  //
+      ? //
+      b : c)
+    ;
+}
+
 // CHECK: [[DBG_F1]] = !MDLocation(line: 100,
 // CHECK: [[DBG_FOO_VALUE]] = !MDLocation(line: 200,
 // CHECK: [[DBG_FOO_REF]] = !MDLocation(line: 202,
@@ -236,3 +273,8 @@ void f17(int *x) {
 // CHECK: [[DBG_F15]] = !MDLocation(line: 1700,
 // CHECK: [[DBG_F16]] = !MDLocation(line: 1800,
 // CHECK: [[DBG_F17]] = !MDLocation(line: 1900,
+// CHECK: [[DBG_F18_1]] = !MDLocation(line: 2000,
+// CHECK: [[DBG_F18_2]] = !MDLocation(line: 2001,
+// CHECK: [[DBG_F19_1]] = !MDLocation(line: 2100,
+// CHECK: [[DBG_F19_2]] = !MDLocation(line: 2101,
+// CHECK: [[DBG_F20_1]] = !MDLocation(line: 2200,