[clang] 66d022f - [clang][analyzer] Fix incorrect range of 'ftell' in the StdLibraryFunctionsChecker (#77576)

[via cfe-commits]

Author: Ben Shi
Date: 2024-01-11T09:10:34+08:00
New Revision: 66d022f326779c8abe80b272751fab1a10992222

URL: https://github.com/llvm/llvm-project/commit/66d022f326779c8abe80b272751fab1a10992222
DIFF: https://github.com/llvm/llvm-project/commit/66d022f326779c8abe80b272751fab1a10992222.diff

LOG: [clang][analyzer] Fix incorrect range of 'ftell' in the StdLibraryFunctionsChecker (#77576)

According to https://pubs.opengroup.org/onlinepubs/9699919799/, the
return value of `ftell` is not restricted to `> 0`, and may return `0`
in real world.

Added: 
    

Modified: 
    clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp

Removed: 
    


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diff  --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
index 32a2deab871c79..3b36565681a7f3 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -2274,7 +2274,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
     addToFunctionSummaryMap(
         "ftell", Signature(ArgTypes{FilePtrTy}, RetType{LongTy}),
         Summary(NoEvalCall)
-            .Case({ReturnValueCondition(WithinRange, Range(1, LongMax))},
+            .Case({ReturnValueCondition(WithinRange, Range(0, LongMax))},
                   ErrnoUnchanged, GenericSuccessMsg)
             .Case(ReturnsMinusOne, ErrnoNEZeroIrrelevant, GenericFailureMsg)
             .ArgConstraint(NotNull(ArgNo(0))));