From bddd8d86e3036e480158ba9219ee3f290ba652ce Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Tue, 9 Aug 2022 19:58:54 -0400 Subject: [PATCH] analyzer: fix missing -Wanalyzer-use-of-uninitialized-value on special-cased functions [PR106573] We were missing checks for uninitialized params on calls to functions that the analyzer has hardcoded knowledge of - both for those that are handled just by state machines, and for those that are handled in region-model-impl-calls.cc (for those arguments for which the svalue wasn't accessed in handling the call). Fixed thusly. gcc/analyzer/ChangeLog: PR analyzer/106573 * region-model.cc (region_model::on_call_pre): Ensure that we call get_arg_svalue on all arguments. gcc/testsuite/ChangeLog: PR analyzer/106573 * gcc.dg/analyzer/error-uninit.c: New test. * gcc.dg/analyzer/fd-uninit-1.c: New test. * gcc.dg/analyzer/file-uninit-1.c: New test. Signed-off-by: David Malcolm --- gcc/analyzer/region-model.cc | 8 +++ gcc/testsuite/gcc.dg/analyzer/error-uninit.c | 29 +++++++++++ gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c | 21 ++++++++ gcc/testsuite/gcc.dg/analyzer/file-uninit-1.c | 52 +++++++++++++++++++ 4 files changed, 110 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/analyzer/error-uninit.c create mode 100644 gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c create mode 100644 gcc/testsuite/gcc.dg/analyzer/file-uninit-1.c diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc index a140f4d5088..8393c7ddbf7 100644 --- a/gcc/analyzer/region-model.cc +++ b/gcc/analyzer/region-model.cc @@ -1355,6 +1355,14 @@ region_model::on_call_pre (const gcall *call, region_model_context *ctxt, && gimple_call_internal_fn (call) == IFN_DEFERRED_INIT) return false; + /* Get svalues for all of the arguments at the callsite, to ensure that we + complain about any uninitialized arguments. This might lead to + duplicates if any of the handling below also looks up the svalues, + but the deduplication code should deal with that. */ + if (ctxt) + for (unsigned arg_idx = 0; arg_idx < cd.num_args (); arg_idx++) + cd.get_arg_svalue (arg_idx); + /* Some of the cases below update the lhs of the call based on the return value, but not all. Provide a default value, which may get overwritten below. */ diff --git a/gcc/testsuite/gcc.dg/analyzer/error-uninit.c b/gcc/testsuite/gcc.dg/analyzer/error-uninit.c new file mode 100644 index 00000000000..8d52a177b11 --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/error-uninit.c @@ -0,0 +1,29 @@ +/* Verify that we check for uninitialized values passed to functions + that we have special-cased region-model handling for. */ + +extern void error (int __status, int __errnum, const char *__format, ...) + __attribute__ ((__format__ (__printf__, 3, 4))); + +void test_uninit_status (int arg) +{ + int st; + error (st, 42, "test: %s", arg); /* { dg-warning "use of uninitialized value 'st'" } */ +} + +void test_uninit_errnum (int st) +{ + int num; + error (st, num, "test"); /* { dg-warning "use of uninitialized value 'num'" } */ +} + +void test_uninit_fmt (int st) +{ + const char *fmt; + error (st, 42, fmt); /* { dg-warning "use of uninitialized value 'fmt'" } */ +} + +void test_uninit_vargs (int st) +{ + int arg; + error (st, 42, "test: %s", arg); /* { dg-warning "use of uninitialized value 'arg'" } */ +} diff --git a/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c b/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c new file mode 100644 index 00000000000..b5b189ece98 --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/fd-uninit-1.c @@ -0,0 +1,21 @@ +/* Verify that we check for uninitialized values passed to functions + that we have special-cased state-machine handling for. */ + +int dup (int old_fd); +int not_dup (int old_fd); + +int +test_1 () +{ + int m; + return dup (m); /* { dg-warning "use of uninitialized value 'm'" "uninit" } */ + /* { dg-bogus "'dup' on possibly invalid file descriptor 'm'" "invalid fd false +ve" { xfail *-*-* } .-1 } */ + /* XFAIL: probably covered by fix for PR analyzer/106551. */ +} + +int +test_2 () +{ + int m; + return not_dup (m); /* { dg-warning "use of uninitialized value 'm'" } */ +} diff --git a/gcc/testsuite/gcc.dg/analyzer/file-uninit-1.c b/gcc/testsuite/gcc.dg/analyzer/file-uninit-1.c new file mode 100644 index 00000000000..0f8ac5442b1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/file-uninit-1.c @@ -0,0 +1,52 @@ +/* Verify that we check for uninitialized values passed to functions + that we have special-cased state-machine handling for. */ + +typedef struct FILE FILE; + +FILE* fopen (const char*, const char*); +int fclose (FILE*); +int fseek (FILE *, long, int); + +FILE * +test_fopen_uninit_path (void) +{ + const char *path; + FILE *f = fopen (path, "r"); /* { dg-warning "use of uninitialized value 'path'" } */ + return f; +} + +FILE * +test_fopen_uninit_mode (const char *path) +{ + const char *mode; + FILE *f = fopen (path, mode); /* { dg-warning "use of uninitialized value 'mode'" } */ + return f; +} + +void +test_fclose_uninit (void) +{ + FILE *f; + fclose (f); /* { dg-warning "use of uninitialized value 'f'" } */ +} + +int +test_fseek_uninit_stream (void) +{ + FILE *stream; + return fseek (stream, 0, 0); /* { dg-warning "use of uninitialized value 'stream'" } */ +} + +int +test_fseek_uninit_offset (FILE *stream, int whence) +{ + long offset; + return fseek (stream, offset, whence); /* { dg-warning "use of uninitialized value 'offset'" } */ +} + +int +test_fseek_uninit_whence (FILE *stream, long offset) +{ + int whence; + return fseek (stream, offset, whence); /* { dg-warning "use of uninitialized value 'whence'" } */ +}