[clang] [clang][analyzer] MmapWriteExecChecker improvements (PR #97078)

[Balazs Benics via cfe-commits]

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@@ -21,30 +21,55 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"
 
 using namespace clang;
 using namespace ento;
 
 namespace {
-class MmapWriteExecChecker : public Checker<check::PreCall> {
+class MmapWriteExecChecker
+    : public Checker<check::BeginFunction, check::PreCall> {
   CallDescription MmapFn{CDM::CLibrary, {"mmap"}, 6};
   CallDescription MprotectFn{CDM::CLibrary, {"mprotect"}, 3};
-  static int ProtWrite;
-  static int ProtExec;
-  static int ProtRead;
   const BugType BT{this, "W^X check fails, Write Exec prot flags set",
                    "Security"};
 
+  mutable bool FlagsInitialized = false;
+  mutable int ProtRead = 0x01;
+  mutable int ProtWrite = 0x02;
+  mutable int ProtExec = 0x04;
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steakhal wrote:

Maybe leave here a comment explaining that the macro `PROT_READ` `PROT_WRITE` `PROT_EXEC` will be used if present, otherwise defaults to these initializer values.

https://github.com/llvm/llvm-project/pull/97078