From 86e5cb0e0bc938c9cf44d91eeffdce31ab5cb3ee Mon Sep 17 00:00:00 2001
From: Shuai Wang <shuaiwang@google.com>
Date: Wed, 19 Sep 2018 18:00:55 +0000
Subject: [PATCH] [analyzer] Fix nullptr access when processing instantiated
 function in ExprMutationAnalyzer.

llvm-svn: 342562
---
 clang/lib/Analysis/ExprMutationAnalyzer.cpp        |  2 +-
 .../Analysis/ExprMutationAnalyzerTest.cpp          | 30 ++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Analysis/ExprMutationAnalyzer.cpp b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
index db8c259..8414cb5 100644
--- a/clang/lib/Analysis/ExprMutationAnalyzer.cpp
+++ b/clang/lib/Analysis/ExprMutationAnalyzer.cpp
@@ -379,7 +379,7 @@ const Stmt *ExprMutationAnalyzer::findFunctionArgMutation(const Expr *Exp) {
   for (const auto &Nodes : Matches) {
     const auto *Exp = Nodes.getNodeAs<Expr>(NodeID<Expr>::value);
     const auto *Func = Nodes.getNodeAs<FunctionDecl>("func");
-    if (!Func->getBody())
+    if (!Func->getBody() || !Func->getPrimaryTemplate())
       return Exp;
 
     const auto *Parm = Nodes.getNodeAs<ParmVarDecl>("parm");
diff --git a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
index 30950e0..8823ac8 100644
--- a/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
+++ b/clang/unittests/Analysis/ExprMutationAnalyzerTest.cpp
@@ -215,6 +215,12 @@ TEST(ExprMutationAnalyzerTest, ByValueArgument) {
                          "void f() { A x, y; y = x; }");
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = buildASTFromCode(
+      "template <int> struct A { A(); A(const A&); static void mf(A) {} };"
+      "void f() { A<0> x; A<0>::mf(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
 }
 
 TEST(ExprMutationAnalyzerTest, ByConstValueArgument) {
@@ -241,6 +247,12 @@ TEST(ExprMutationAnalyzerTest, ByConstValueArgument) {
       "void f() { struct A { A(const int); }; int x; A y(x); }");
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
+
+  AST = buildASTFromCode("template <int> struct A { A(); A(const A&);"
+                         "static void mf(const A&) {} };"
+                         "void f() { A<0> x; A<0>::mf(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
 }
 
 TEST(ExprMutationAnalyzerTest, ByNonConstRefArgument) {
@@ -288,6 +300,12 @@ TEST(ExprMutationAnalyzerTest, ByNonConstRefArgument) {
   AST = buildASTFromCode("void f() { struct A { A(); A(A&); }; A x; A y(x); }");
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("x"));
+
+  AST = buildASTFromCode(
+      "template <int> struct A { A(); A(const A&); static void mf(A&) {} };"
+      "void f() { A<0> x; A<0>::mf(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("A<0>::mf(x)"));
 }
 
 TEST(ExprMutationAnalyzerTest, ByConstRefArgument) {
@@ -686,6 +704,12 @@ TEST(ExprMutationAnalyzerTest, FollowFuncArgModified) {
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("x"));
 
+  AST = buildASTFromCode("template <class U> struct S {"
+                         "template <class T> S(T&& t) : m(++t) { } U m; };"
+                         "void f() { int x; S<int> s(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_THAT(mutatedBy(Results, AST.get()), ElementsAre("x"));
+
   AST = buildASTFromCode(StdRemoveReference + StdForward +
                          "template <class... Args> void u(Args&...);"
                          "template <class... Args> void h(Args&&... args)"
@@ -737,6 +761,12 @@ TEST(ExprMutationAnalyzerTest, FollowFuncArgNotModified) {
   Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
   EXPECT_FALSE(isMutated(Results, AST.get()));
 
+  AST = buildASTFromCode("template <class U> struct S {"
+                         "template <class T> S(T&& t) : m(t) { } U m; };"
+                         "void f() { int x; S<int> s(x); }");
+  Results = match(withEnclosingCompound(declRefTo("x")), AST->getASTContext());
+  EXPECT_FALSE(isMutated(Results, AST.get()));
+
   AST = buildASTFromCode(StdRemoveReference + StdForward +
                          "template <class... Args> void u(Args...);"
                          "template <class... Args> void h(Args&&... args)"
-- 
2.7.4