llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang @llvm/pr-subscribers-clang-static-analyzer-1 Author: Balázs Kéri (balazske) <details> <summary>Changes</summary> --- Full diff: https://github.com/llvm/llvm-project/pull/83858.diff 1 Files Affected: - (modified) clang/docs/analyzer/checkers.rst (+52-14) ``````````diff diff --git a/clang/docs/analyzer/checkers.rst b/clang/docs/analyzer/checkers.rst index fe211514914272..aa79792c64dc54 100644 --- a/clang/docs/analyzer/checkers.rst +++ b/clang/docs/analyzer/checkers.rst @@ -3020,44 +3020,82 @@ Check for misuses of stream APIs. Check for misuses of stream APIs: ``fopen, fcl alpha.unix.Stream (C) """"""""""""""""""""" -Check stream handling functions: ``fopen, tmpfile, fclose, fread, fwrite, fseek, ftell, rewind, fgetpos,`` -``fsetpos, clearerr, feof, ferror, fileno``. +Check C stream handling functions: +``fopen, fdopen, freopen, tmpfile, fclose, fread, fwrite, fgetc, fgets, fputc, fputs, fprintf, fscanf, ungetc, getdelim, getline, fseek, fseeko, ftell, ftello, fflush, rewind, fgetpos, fsetpos, clearerr, feof, ferror, fileno``. + +The checker maintains information about the C stream objects (``FILE *``) and +can detect error conditions related to use of streams. The following conditions +are detected: + +* The ``FILE *`` pointer passed to the function is NULL. (At ``fflush`` + NULL is allowed.) +* Use of stream after close. +* Opened stream is not closed. +* Read from a stream after end-of-file. (This is not a fatal error but reported + by the checker. Stream remains in EOF state and the read operation fails.) +* Use of stream when the file position is indeterminate after a previous failed + operation. Some functions are allowed in this state. +* Invalid 3rd ("``whence``") argument to ``fseek``. + +The checker is not capable of maintaining a relation between integer file +descriptors and ``FILE *`` pointers. Operations on standard streams like +``stdin`` are not treated specially and are therefore often not recognized +(because these streams are usually not opened explicitly by the program, and +are global variables). .. code-block:: c - void test() { + void test1() { FILE *p = fopen("foo", "r"); } // warn: opened file is never closed - void test() { + void test2() { FILE *p = fopen("foo", "r"); fseek(p, 1, SEEK_SET); // warn: stream pointer might be NULL fclose(p); } - void test() { + void test3() { FILE *p = fopen("foo", "r"); + if (p) { + fseek(p, 1, 3); // warn: third arg should be SEEK_SET, SEEK_END, or SEEK_CUR + fclose(p); + } + } - if (p) - fseek(p, 1, 3); - // warn: third arg should be SEEK_SET, SEEK_END, or SEEK_CUR + void test4() { + FILE *p = fopen("foo", "r"); + if (!p) + return; fclose(p); + fclose(p); // warn: stream already closed } - void test() { + void test5() { FILE *p = fopen("foo", "r"); + if (!p) + return; + + fgetc(p); + if (!ferror(p)) + fgetc(p); // warn: possible read after end-of-file + fclose(p); - fclose(p); // warn: already closed } - void test() { - FILE *p = tmpfile(); - ftell(p); // warn: stream pointer might be NULL + void test6() { + FILE *p = fopen("foo", "r"); + if (!p) + return; + + fgetc(p); + if (!feof(p)) + fgetc(p); // warn: file position may be indeterminate after I/O error + fclose(p); } - .. _alpha-unix-cstring-BufferOverlap: alpha.unix.cstring.BufferOverlap (C) `````````` </details> https://github.com/llvm/llvm-project/pull/83858 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
