[clang-tools-extra] r303001 - [clang-tidy] TwineLocalCheck: add param # checking

[Yan Wang via cfe-commits]

Author: yawanng
Date: Sat May 13 23:14:59 2017
New Revision: 303001

URL: http://llvm.org/viewvc/llvm-project?rev=303001&view=rev
Log:
[clang-tidy] TwineLocalCheck: add param # checking

Summary:
The statement **getArg** tries to get the first one without checking, which may cause segmentation fault.

 

Reviewers: chh, bkramer

Reviewed By: bkramer

Subscribers: cfe-commits, xazax.hun

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D33103

Modified:
    clang-tools-extra/trunk/clang-tidy/llvm/TwineLocalCheck.cpp
    clang-tools-extra/trunk/test/clang-tidy/llvm-twine-local.cpp

Modified: clang-tools-extra/trunk/clang-tidy/llvm/TwineLocalCheck.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/clang-tidy/llvm/TwineLocalCheck.cpp?rev=303001&r1=303000&r2=303001&view=diff
==============================================================================
--- clang-tools-extra/trunk/clang-tidy/llvm/TwineLocalCheck.cpp (original)
+++ clang-tools-extra/trunk/clang-tidy/llvm/TwineLocalCheck.cpp Sat May 13 23:14:59 2017
@@ -35,8 +35,11 @@ void TwineLocalCheck::check(const MatchF
     // of the initializer.
     const Expr *C = VD->getInit()->IgnoreImplicit();
 
-    while (isa<CXXConstructExpr>(C))
+    while (isa<CXXConstructExpr>(C)) {
+      if (cast<CXXConstructExpr>(C)->getNumArgs() == 0)
+        break;
       C = cast<CXXConstructExpr>(C)->getArg(0)->IgnoreParenImpCasts();
+    }
 
     SourceRange TypeRange =
         VD->getTypeSourceInfo()->getTypeLoc().getSourceRange();

Modified: clang-tools-extra/trunk/test/clang-tidy/llvm-twine-local.cpp
URL: http://llvm.org/viewvc/llvm-project/clang-tools-extra/trunk/test/clang-tidy/llvm-twine-local.cpp?rev=303001&r1=303000&r2=303001&view=diff
==============================================================================
--- clang-tools-extra/trunk/test/clang-tidy/llvm-twine-local.cpp (original)
+++ clang-tools-extra/trunk/test/clang-tidy/llvm-twine-local.cpp Sat May 13 23:14:59 2017
@@ -5,6 +5,7 @@ class Twine {
 public:
   Twine(const char *);
   Twine(int);
+  Twine();
   Twine &operator+(const Twine &);
 };
 }
@@ -29,4 +30,35 @@ int main() {
 // CHECK-MESSAGES: :[[@LINE-1]]:9: warning: twine variables are prone to use-after-free bugs
 // CHECK-MESSAGES: note: FIX-IT applied suggested code changes
 // CHECK-FIXES: const char * Prefix = false ? "__INT_FAST" : "__UINT_FAST";
+
+  const Twine t2 = Twine();
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t2 = (Twine()).str();
+  foo(Twine() + "b");
+
+  const Twine t3 = Twine(42);
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t3 = (Twine(42)).str();
+
+  const Twine t4 = Twine(42) + "b";
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t4 = (Twine(42) + "b").str();
+
+  const Twine t5 = Twine() + "b";
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t5 = (Twine() + "b").str();
+
+  const Twine t6 = true ? Twine() : Twine(42);
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t6 = (true ? Twine() : Twine(42)).str();
+
+  const Twine t7 = false ? Twine() : Twine("b");
+// CHECK-MESSAGES: :[[@LINE-1]]:15: warning: twine variables are prone to use-after-free bugs
+// CHECK-MESSAGES: note: FIX-IT applied suggested code changes
+// CHECK-FIXES: std::string t7 = (false ? Twine() : Twine("b")).str();
 }