[clang][analyzer] Improve modeling of 'execv' and 'execvp' in StdLibraryFunctionsChecker

[benshi001]

These functions always return -1 and set 'errno'.

[llvmbot]

@llvm/pr-subscribers-clang-static-analyzer-1

@llvm/pr-subscribers-clang

Author: Ben Shi (benshi001)

Changes

These functions always return -1 and set 'errno'.

---

Full diff: https://github.com/llvm/llvm-project/pull/78930.diff

1 Files Affected:

• (modified) clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp (+2-2)

diff --git a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
index fcd907a9bb0da0..61bf3c8528be2b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StdLibraryFunctionsChecker.cpp
@@ -3002,7 +3002,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
         "execv",
         Signature(ArgTypes{ConstCharPtrTy, CharPtrConstPtr}, RetType{IntTy}),
         Summary(NoEvalCall)
-            .Case(ReturnsMinusOne, ErrnoIrrelevant)
+            .Case(ReturnsMinusOne, ErrnoNEZeroIrrelevant)
             .ArgConstraint(NotNull(ArgNo(0))));
 
     // int execvp(const char *file, char *const argv[]);
@@ -3010,7 +3010,7 @@ void StdLibraryFunctionsChecker::initFunctionSummaries(
         "execvp",
         Signature(ArgTypes{ConstCharPtrTy, CharPtrConstPtr}, RetType{IntTy}),
         Summary(NoEvalCall)
-            .Case(ReturnsMinusOne, ErrnoIrrelevant)
+            .Case(ReturnsMinusOne, ErrnoNEZeroIrrelevant)
             .ArgConstraint(NotNull(ArgNo(0))));
 
     // int getopt(int argc, char * const argv[], const char *optstring);

[balazske]

Test for these functions can be added to file std-c-library-functions-POSIX.c (with check of return value and errno).

[benshi001]

Test for these functions can be added to file std-c-library-functions-POSIX.c (with check of return value and errno).

I will put them into errno-stdlibraryfunctions.c, which seems better.

[steakhal]

LGTM