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Mon, Dec 9, 4:01 PM

D62507.diff

Index: cfe/trunk/include/clang/Analysis/Analyses/Dominators.h
===================================================================
--- cfe/trunk/include/clang/Analysis/Analyses/Dominators.h
+++ cfe/trunk/include/clang/Analysis/Analyses/Dominators.h
@@ -155,13 +155,51 @@
} // namespace clang
+namespace llvm {
+
+/// Clang's CFG contains nullpointers for unreachable succesors, e.g. when an
+/// if statement's condition is always false, it's 'then' branch is represented
+/// with a nullptr. This however will result in a nullpointer derefernece for
+/// dominator tree calculation.
+///
+/// To circumvent this, let's just crudely specialize the children getters
+/// used in LLVM's dominator tree builder.
+namespace DomTreeBuilder {
+
+using ClangCFGDomChildrenGetter =
+SemiNCAInfo<DomTreeBase<clang::CFGBlock>>::ChildrenGetter</*Inverse=*/false>;
+
+template <>
+template <>
+inline ClangCFGDomChildrenGetter::ResultTy ClangCFGDomChildrenGetter::Get(
+ clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/false>) {
+ auto RChildren = reverse(children<NodePtr>(N));
+ ResultTy Ret(RChildren.begin(), RChildren.end());
+ Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
+ return Ret;
+}
+
+using ClangCFGDomReverseChildrenGetter =
+SemiNCAInfo<DomTreeBase<clang::CFGBlock>>::ChildrenGetter</*Inverse=*/true>;
+
+template <>
+template <>
+inline ClangCFGDomReverseChildrenGetter::ResultTy
+ClangCFGDomReverseChildrenGetter::Get(
+ clang::CFGBlock *N, std::integral_constant<bool, /*Inverse=*/true>) {
+ auto IChildren = inverse_children<NodePtr>(N);
+ ResultTy Ret(IChildren.begin(), IChildren.end());
+ Ret.erase(std::remove(Ret.begin(), Ret.end(), nullptr), Ret.end());
+ return Ret;
+}
+
+} // end of namespace DomTreeBuilder
+
//===-------------------------------------
/// DominatorTree GraphTraits specialization so the DominatorTree can be
/// iterable by generic graph iterators.
///
-namespace llvm {
-
-template <> struct GraphTraits< ::clang::DomTreeNode* > {
+template <> struct GraphTraits<clang::DomTreeNode *> {
using NodeRef = ::clang::DomTreeNode *;
using ChildIteratorType = ::clang::DomTreeNode::iterator;
Index: cfe/trunk/test/Analysis/domtest.c
===================================================================
--- cfe/trunk/test/Analysis/domtest.c
+++ cfe/trunk/test/Analysis/domtest.c
@@ -1,6 +1,6 @@
-// RUN: rm -f %t
-// RUN: %clang_analyze_cc1 -analyzer-checker=debug.DumpDominators %s > %t 2>&1
-// RUN: FileCheck --input-file=%t %s
+// RUN: %clang_analyze_cc1 %s \
+// RUN: -analyzer-checker=debug.DumpDominators \
+// RUN: 2>&1 | FileCheck %s
// Test the DominatorsTree implementation with various control flows
int test1()
@@ -24,17 +24,24 @@
return 0;
}
-// CHECK: Immediate dominance tree (Node#,IDom#):
-// CHECK: (0,1)
-// CHECK: (1,7)
-// CHECK: (2,3)
-// CHECK: (3,6)
-// CHECK: (4,6)
-// CHECK: (5,6)
-// CHECK: (6,7)
-// CHECK: (7,8)
-// CHECK: (8,9)
-// CHECK: (9,9)
+// [B9 (ENTRY)] -> [B8] -> [B7] -> [B6] -> [B5] -> [B3] -> [B2]
+// |\ \ / /
+// | \ ---> [B4] ---> /
+// | <---------------------------
+// V
+// [B1] -> [B0 (EXIT)]
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,1)
+// CHECK-NEXT: (1,7)
+// CHECK-NEXT: (2,3)
+// CHECK-NEXT: (3,6)
+// CHECK-NEXT: (4,6)
+// CHECK-NEXT: (5,6)
+// CHECK-NEXT: (6,7)
+// CHECK-NEXT: (7,8)
+// CHECK-NEXT: (8,9)
+// CHECK-NEXT: (9,9)
int test2()
{
@@ -54,15 +61,22 @@
return 0;
}
-// CHECK: Immediate dominance tree (Node#,IDom#):
-// CHECK: (0,1)
-// CHECK: (1,6)
-// CHECK: (2,3)
-// CHECK: (3,4)
-// CHECK: (4,6)
-// CHECK: (5,6)
-// CHECK: (6,7)
-// CHECK: (7,7)
+// <-------------
+// / \
+// -----------> [B4] -> [B3] -> [B2]
+// / |
+// / V
+// [B7 (ENTRY)] -> [B6] -> [B5] -> [B1] -> [B0 (EXIT)]
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,1)
+// CHECK-NEXT: (1,6)
+// CHECK-NEXT: (2,3)
+// CHECK-NEXT: (3,4)
+// CHECK-NEXT: (4,6)
+// CHECK-NEXT: (5,6)
+// CHECK-NEXT: (6,7)
+// CHECK-NEXT: (7,7)
int test3()
{
@@ -82,16 +96,26 @@
return 0;
}
-// CHECK: Immediate dominance tree (Node#,IDom#):
-// CHECK: (0,1)
-// CHECK: (1,7)
-// CHECK: (2,5)
-// CHECK: (3,4)
-// CHECK: (4,5)
-// CHECK: (5,6)
-// CHECK: (6,7)
-// CHECK: (7,8)
-// CHECK: (8,8)
+// <-------------
+// / \
+// | ---> [B2]
+// | /
+// [B8 (ENTRY)] -> [B7] -> [B6] -> [B5] -> [B4] -> [B3]
+// \ | \ /
+// \ | <-------------
+// \ \
+// --------> [B1] -> [B0 (EXIT)]
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,1)
+// CHECK-NEXT: (1,7)
+// CHECK-NEXT: (2,5)
+// CHECK-NEXT: (3,4)
+// CHECK-NEXT: (4,5)
+// CHECK-NEXT: (5,6)
+// CHECK-NEXT: (6,7)
+// CHECK-NEXT: (7,8)
+// CHECK-NEXT: (8,8)
int test4()
{
@@ -108,20 +132,33 @@
return 0;
}
-// CHECK: Immediate dominance tree (Node#,IDom#):
-// CHECK: (0,1)
-// CHECK: (1,10)
-// CHECK: (2,9)
-// CHECK: (3,4)
-// CHECK: (4,5)
-// CHECK: (5,9)
-// CHECK: (6,7)
-// CHECK: (7,8)
-// CHECK: (8,9)
-// CHECK: (9,10)
-// CHECK: (10,11)
-// CHECK: (11,12)
-// CHECK: (12,12)
+// <----------------------------------
+// / <----------------- \
+// / / \ \
+// [B12 (ENTRY)] -> [B11] -> [B10]-> [B9] -> [B8] ---> [B7] -> [B6] |
+// | \ \ /
+// | \ -----> [B2] --------/
+// | \ /
+// | -> [B5] -> [B4] -> [B3]
+// | \ /
+// | <------------
+// \
+// -> [B1] -> [B0 (EXIT)]
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,1)
+// CHECK-NEXT: (1,10)
+// CHECK-NEXT: (2,9)
+// CHECK-NEXT: (3,4)
+// CHECK-NEXT: (4,5)
+// CHECK-NEXT: (5,9)
+// CHECK-NEXT: (6,7)
+// CHECK-NEXT: (7,8)
+// CHECK-NEXT: (8,9)
+// CHECK-NEXT: (9,10)
+// CHECK-NEXT: (10,11)
+// CHECK-NEXT: (11,12)
+// CHECK-NEXT: (12,12)
int test5()
{
@@ -151,18 +188,25 @@
return 0;
}
-// CHECK: Immediate dominance tree (Node#,IDom#):
-// CHECK: (0,1)
-// CHECK: (1,10)
-// CHECK: (2,10)
-// CHECK: (3,9)
-// CHECK: (4,9)
-// CHECK: (5,8)
-// CHECK: (6,8)
-// CHECK: (7,8)
-// CHECK: (8,9)
-// CHECK: (9,10)
-// CHECK: (10,11)
-// CHECK: (11,11)
-
-
+// [B0 (EXIT)] <--
+// \
+// [B11 (ENTY)] -> [B10] -> [B9] -> [B8] -> [B7] -> [B5] -> [B3] -> [B1]
+// | | | / / /
+// | | V / / /
+// | V [B6] --> / /
+// V [B4] -----------------> /
+// [B2]--------------------------------->
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,1)
+// CHECK-NEXT: (1,10)
+// CHECK-NEXT: (2,10)
+// CHECK-NEXT: (3,9)
+// CHECK-NEXT: (4,9)
+// CHECK-NEXT: (5,8)
+// CHECK-NEXT: (6,8)
+// CHECK-NEXT: (7,8)
+// CHECK-NEXT: (8,9)
+// CHECK-NEXT: (9,10)
+// CHECK-NEXT: (10,11)
+// CHECK-NEXT: (11,11)
Index: cfe/trunk/test/Analysis/domtest.cpp
===================================================================
--- cfe/trunk/test/Analysis/domtest.cpp
+++ cfe/trunk/test/Analysis/domtest.cpp
@@ -0,0 +1,51 @@
+// RUN: %clang_analyze_cc1 %s \
+// RUN: -analyzer-checker=debug.DumpDominators \
+// RUN: 2>&1 | FileCheck %s
+
+bool coin();
+
+namespace pr42041_unreachable_cfg_successor {
+enum Kind {
+ A
+};
+
+void f() {
+ switch(Kind{}) {
+ case A:
+ break;
+ }
+}
+} // end of namespace pr42041_unreachable_cfg_successor
+
+// [B3 (ENTRY)] -> [B1] -> [B2] -> [B0 (EXIT)]
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,2)
+// CHECK-NEXT: (1,3)
+// CHECK-NEXT: (2,1)
+// CHECK-NEXT: (3,3)
+
+void funcWithBranch() {
+ int x = 0;
+ if (coin()) {
+ if (coin()) {
+ x = 5;
+ }
+ int j = 10 / x;
+ (void)j;
+ }
+}
+
+// ----> [B2] ---->
+// / \
+// [B5 (ENTRY)] -> [B4] -> [B3] -----------> [B1]
+// \ /
+// ----> [B0 (EXIT)] <----
+
+// CHECK: Immediate dominance tree (Node#,IDom#):
+// CHECK-NEXT: (0,4)
+// CHECK-NEXT: (1,3)
+// CHECK-NEXT: (2,3)
+// CHECK-NEXT: (3,4)
+// CHECK-NEXT: (4,5)
+// CHECK-NEXT: (5,5)

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