[PATCH] D41384: [analyzer] Suppress false positive warnings form security.insecureAPI.strcpy

[Phabricator via Phabricator via cfe-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL322410: [analyzer] Don't flag strcpy of string literals into sufficiently large buffers. (authored by dergachev, committed by ).
Herald added a subscriber: llvm-commits.

Changed prior to commit:
  https://reviews.llvm.org/D41384?vs=129676&id=129706#toc

Repository:
  rL LLVM

https://reviews.llvm.org/D41384

Files:
  cfe/trunk/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
  cfe/trunk/test/Analysis/security-syntax-checks.m


Index: cfe/trunk/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
===================================================================
--- cfe/trunk/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
+++ cfe/trunk/lib/StaticAnalyzer/Checkers/CheckSecuritySyntaxOnly.cpp
@@ -510,6 +510,17 @@
   if (!checkCall_strCommon(CE, FD))
     return;
 
+  const auto *Target = CE->getArg(0)->IgnoreImpCasts(),
+             *Source = CE->getArg(1)->IgnoreImpCasts();
+  if (const auto *DeclRef = dyn_cast<DeclRefExpr>(Target))
+    if (const auto *Array = dyn_cast<ConstantArrayType>(DeclRef->getType())) {
+      uint64_t ArraySize = BR.getContext().getTypeSize(Array) / 8;
+      if (const auto *String = dyn_cast<StringLiteral>(Source)) {
+        if (ArraySize >= String->getLength() + 1)
+          return;
+      }
+    }
+
   // Issue a warning.
   PathDiagnosticLocation CELoc =
     PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
Index: cfe/trunk/test/Analysis/security-syntax-checks.m
===================================================================
--- cfe/trunk/test/Analysis/security-syntax-checks.m
+++ cfe/trunk/test/Analysis/security-syntax-checks.m
@@ -146,6 +146,16 @@
   strcpy(x, y); //expected-warning{{Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119}}
 }
 
+void test_strcpy_2() {
+  char x[4];
+  strcpy(x, "abcd"); //expected-warning{{Call to function 'strcpy' is insecure as it does not provide bounding of the memory buffer. Replace unbounded copy functions with analogous functions that support length arguments such as 'strlcpy'. CWE-119}}
+}
+
+void test_strcpy_safe() {
+  char x[5];
+  strcpy(x, "abcd");
+}
+
 //===----------------------------------------------------------------------===
 // strcat()
 //===----------------------------------------------------------------------===


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