balazske added a comment.
> I'd like to test cases where the very same function call gets a different
> note message depending on the BugType:
These tests are doing this:
void check_indeterminate_notes_fseek_no_feof_no_ferror() {
FILE *F;
char Buf[10];
F = fopen("foo1.c", "r");
if (!F) // expected-note {{Taking false branch}} expected-note {{'F' is
non-null}}
return;
fseek(F, 1, SEEK_SET); // expected-note {{Assuming this stream
operation fails and leaves the file position indeterminate}}
if (!ferror(F) && !feof(F)) // expected-note {{The error flag is not set on
the stream}} expected-note {{The end-of-file flag is not set on the stream}}
// expected-note@-1 {{Taking true branch}}
expected-note@-1 {{Left side of '&&' is true}}
fread(Buf, 1, 1, F); // expected-warning{{File position of the
stream might be 'indeterminate' after a failed operation. Can cause undefined
behavior}}
// expected-note@-1{{File position of the stream might be 'indeterminate'
after a failed operation. Can cause undefined behavior}}
fclose(F);
}
void check_feof_notes_fseek() {
FILE *F;
char Buf[10];
F = fopen("foo1.c", "r");
if (!F) // expected-note {{Taking false branch}} expected-note {{'F' is
non-null}}
return;
fseek(F, 1, SEEK_SET); // expected-note {{Assuming stream reaches
end-of-file here}}
if (feof(F)) // expected-note{{The end-of-file flag is set on the
stream}} expected-note {{Taking true branch}}
fread(Buf, 1, 1, F); // expected-warning {{Read function called when
stream is in EOF state. Function has no effect}}
// expected-note@-1 {{Read function called when stream is in EOF state.
Function has no effect}}
fclose(F);
}
Why is the last test not sufficient and I should use instead this test?
void check_notes_fseek_caused_feof() {
FILE *F;
char Buf[10];
F = fopen("foo1.c", "r");
if (!F) // expected-note {{Taking false branch}} expected-note {{'F' is
non-null}}
return;
fseek(F, 1, SEEK_SET); // expected-note {{Assuming stream reaches
end-of-file here}}
if (ferror(F)) { // expected-note {{The error flag is not set on the
stream}}
// expected-note@-1 {{Taking false branch}}
fclose(F);
return;
}
StreamTesterChecker_clear_indeterminate_file_position(F);
fread(Buf, 1, 1, F); // expected-warning{{Read function called when stream
is in EOF state. Function has no effect}}
// expected-note@-1{{Read function called when stream is in EOF state.
Function has no effect}}
fclose(F);
}
In the first case before the `fread` the EOF bit is on. In the second there are
2 possibilities, one is when `fseek` did not fail at all, other when it failed
and then EOF is on. This are really 3 execution paths: `fseek` did not fail,
`fseek` failed with EOF, and `fseek` failed without FEOF or FERROR but leaves
indeterminate position (that is cleared, so we get the same state as after
success).
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D106262/new/
https://reviews.llvm.org/D106262
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