| Message ID | orwmlshwy4.fsf@lxoliva.fsfla.org |
|---|---|
| State | New |
| Headers | show |
| Series | [analyzer,testsuite] avoid unexpected null dereference warning | expand |
On Thu, 2024-07-11 at 10:36 -0300, Alexandre Oliva wrote: > > The analyzer testsuite, on a customer's own operating system, reports > a potential NULL pointer dereference in flex-without-call- > summaries.c. > I'm not sure why it shows up on that system, but not on others, but > the test is not meant to test for that warning, so I'm silencing it. Hi Alex I intended that particular test as an integration test, to try to make sure that -fanalyzer is silent on the result of a minimal "flex" script. So if we're actually getting warnings, that's undesirable, and I'm not sure the approach in your patch is the right one. Given that the testcase includes various C headers, there's going to be some variability with different configurations. Are you able to share the preprocessed sources with me? Maybe we should eliminate those #includes from that test and convert it to something that's more config-independent? Thanks Dave > > Regstrapped on x86_64-linux-gnu, also tested with gcc-13 targeting > aarch64. Ok to install? > > > for gcc/testsuite/ChangeLog > > * c-c++-common/analyzer/flex-without-call-summaries.c: > Disable > null dereference analyzer warnings. > --- > .../analyzer/flex-without-call-summaries.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/gcc/testsuite/c-c++-common/analyzer/flex-without-call- > summaries.c b/gcc/testsuite/c-c++-common/analyzer/flex-without-call- > summaries.c > index c6ecb25d25d59..1aad2bc896b7e 100644 > --- a/gcc/testsuite/c-c++-common/analyzer/flex-without-call- > summaries.c > +++ b/gcc/testsuite/c-c++-common/analyzer/flex-without-call- > summaries.c > @@ -3,6 +3,7 @@ > > /* { dg-additional-options "-fno-analyzer-call-summaries" } */ > > +/* { dg-additional-options "-Wno-analyzer-null-dereference" } */ > /* { dg-additional-options "-Wno-analyzer-too-complex" } */ > /* { dg-additional-options "-D_POSIX_SOURCE" } */ > >
On Jul 11, 2024, David Malcolm <dmalcolm@redhat.com> wrote: > I intended that particular test as an integration test, to try to make > sure that -fanalyzer is silent on the result of a minimal "flex" > script. So if we're actually getting warnings, that's undesirable, and > I'm not sure the approach in your patch is the right one. Understood, thanks, patch withdrawn. > Given that the testcase includes various C headers, there's going to be > some variability with different configurations. Are you able to share > the preprocessed sources with me? I'm not sure, but I don't think that will be needed. Just replacing the includes with standard declarations and definitions used in the program was enough to trigger the warning. > Maybe we should eliminate those #includes from that test and convert > it to something that's more config-independent? Here's what I got. I tried some __builtin_-prefixing, particularly on exit, hoping that it would bring some noreturn into effect, but that didn't get rid of the warning, so I left it at that. diff --git a/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c b/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c index c6ecb25d25d59..41ad3359370ee 100644 --- a/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c +++ b/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c @@ -14,10 +14,31 @@ /* First, we deal with platform-specific or compiler-specific issues. */ /* begin standard C headers. */ -#include <stdio.h> -#include <string.h> -#include <errno.h> -#include <stdlib.h> +/* #include <stdio.h> */ +#define EOF -1 +typedef __SIZE_TYPE__ size_t; +typedef struct FILE FILE; +extern FILE *stdin, *stdout, *stderr; +int getc(FILE *); +int ferror(FILE *); +size_t fread (void *, size_t, size_t, FILE *); +size_t fwrite (void *, size_t, size_t, FILE *); +void clearerr(FILE *); +int fileno(FILE *); +int fprintf(FILE *, const char *, ...); +/* #include <string.h> */ +void *memset(void *, int, size_t); +size_t strlen(const char *); +/* #include <errno.h> */ +extern int *__get_errno (void); +#define errno (*__get_errno ()) +#define EINTR 42 +/* #include <stdlib.h> */ +#define NULL 0 +void exit(int); +void *malloc(size_t); +void *realloc(void *, size_t); +void free(void *); /* end standard C headers. */
diff --git a/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c b/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c index c6ecb25d25d59..1aad2bc896b7e 100644 --- a/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c +++ b/gcc/testsuite/c-c++-common/analyzer/flex-without-call-summaries.c @@ -3,6 +3,7 @@ /* { dg-additional-options "-fno-analyzer-call-summaries" } */ +/* { dg-additional-options "-Wno-analyzer-null-dereference" } */ /* { dg-additional-options "-Wno-analyzer-too-complex" } */ /* { dg-additional-options "-D_POSIX_SOURCE" } */