Unverified Commit c12f30c7 authored by Ben Shi's avatar Ben Shi Committed by GitHub
Browse files

[clang][analyzer] Improve modeling of 'realpath' in StdLibraryFunctionsChecker (#79939)

parent 150ab995

clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp

+6 −2
Original line number Diff line number Diff line
@@ -2992,12 +2992,16 @@ void StdLibraryFunctionsChecker::initFunctionSummaries( 


    // char *realpath(const char *restrict file_name,

    //                char *restrict resolved_name);

    // FIXME: Improve for errno modeling.

    // FIXME: If the argument 'resolved_name' is not NULL, macro 'PATH_MAX'

    //        should be defined in "limits.h" to guarrantee a success.

    addToFunctionSummaryMap(

        "realpath",

        Signature(ArgTypes{ConstCharPtrRestrictTy, CharPtrRestrictTy},

                  RetType{CharPtrTy}),

        Summary(NoEvalCall).ArgConstraint(NotNull(ArgNo(0))));

        Summary(NoEvalCall)

            .Case({NotNull(Ret)}, ErrnoMustNotBeChecked, GenericSuccessMsg)

            .Case({IsNull(Ret)}, ErrnoNEZeroIrrelevant, GenericFailureMsg)

            .ArgConstraint(NotNull(ArgNo(0))));



    QualType CharPtrConstPtr = getPointerTy(getConstTy(CharPtrTy));

clang/test/Analysis/errno-stdlibraryfunctions.c

+10 −0
Original line number Diff line number Diff line
@@ -128,3 +128,13 @@ void errno_pclose(void) { 
    if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}

  }

}



void errno_realpath(char *Path, char *Buf) {

  char *Ret = realpath(Path, Buf);

  if (!Ret) {

    clang_analyzer_eval(errno != 0);  // expected-warning{{TRUE}}

    if (errno) {}                     // no-warning

  } else {

    if (errno) {} // expected-warning{{An undefined value may be read from 'errno'}}

  }

}