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

[Ben Shi via cfe-commits]

https://github.com/benshi001 created https://github.com/llvm/llvm-project/pull/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.

And the corresponding unit test also show `Ret >= 0` not `Ret > 0`.

https://github.com/llvm/llvm-project/blob/main/clang/test/Analysis/stream-errno.c#L194

>From e33d2bce007ac6009870a4dbd5227b62c3d6ba41 Mon Sep 17 00:00:00 2001
From: Ben Shi <bennshi at tencent.com>
Date: Wed, 10 Jan 2024 18:28:30 +0800
Subject: [PATCH] [clang][analyzer] Fix incorrect range of 'ftell' in the
 StdLibraryFunctionsChecker

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.
---
 .../lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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))));