Sym.sym_scope and Sym.f (FuncAttr) share space, so blindly setting
one clobbers the other. Right now this only leads to missing errors
on incompatible typedefs (see testcase), which this commit fixes.
But it points to a larger problem:
Generally we can only manipulate Sym.f for anonymous and field symbols,
not for anything that has a top-level name (basically any proper decl),
because the latter use sym_scope. Luckily the functions type always
contains an anonymous symbol (in sym->type.ref), so we can use that.
But some of the functions attributes actually _do_ apply to the decl,
not the type (e.g. always_inline), so we still have a problem possibly,
when we update an pre-existing type that may already be shared with
another decl.
Would need untangling and perhaps using accessor functions that check
that Sym.f and Sym.sym_scope aren't used for the same symbol.
- also simplify parse(_line)_comment() and parse_pp_string()
- fixes a continuation problem in strings (see tcctest.c)
- no differences in performance could be observed
161 insertions(+), 246 deletions(-), less 85 lines
Modify function parameter parser such that symbols are
put into token-table temporarily. Benefits are:
- detects redefinitions, as with
int foo(int a, int a);
- detects reserved symbols, as with
int foo(int if);
- can parse expressions like
int main(int argc, char *argv[argc + 1]);
- doesn't fix this one
int main(int argc, char *argv[++argc]);
Also: fix unexpected "function might return no value"
with statement expression
int f() { ({ return 0; }); }
136 insertions(+), 226 deletions(-), less 90 lines (except tests)
only one set_flag() function required
* can now turn off specific errors: -Werror -Wno-error=option
* new interface: tcc_warning_c(warn_option)("format", args...);
* new warning: -Wdiscarded-qualifiers (on by default)
* new variable 'warn_all' for conditional warnings with -Wall
see also the tests
when used with string initialization the size of nested struct flex
array member was tested too late for < 0.
GCC accepts but discards such initializers (the flex array member will
become zero sized). TCC supports flex arrays members only in
top-level structs and gives an error in this case.
When defining an array with non-explicit size, one would get
"incompatible types for redefinition of 'array' if the array was already
declared with a different size.
For example:
extern int array[2];
int array[] = {1};
would fail to compile with tcc. Instead the above is now equivalent to:
int array[] = {1, 0};
Check duplicate struct/union member names
tcc.h: Add cnt field in TokenSym
tccgen.c: New function check_fields to find duplicate member names.
This avoids quadratic behavior and can be used for large structs.
- tcc.h: msvc doesn't grok __func__ (reverts previous commit)
- tccgen.c: fortify tcc against bogus code:
- n[sizeof({3;})]; // statement expression outside of function
- f(){"123"4}; // tokens with values following each other
(also, add "type defaults to int" warning for variables)
- tccpe.c: removed a check that caused BSS symbols not to be
exported. Whatever that check was meant to prevent.
- win32/build-tcc.bat: cmd.exe sometimes doesn't grok '-' in labels
- Revert "libtcc: no need to undef"
This reverts commit 2b7aa2a1e1.
- Revert "tcc.h libtcc.c: remove unused defines"
This reverts commit 985d963745.
The point of these "unused defines" is to be unused, that is
to remind people not to use malloc but please to "use_tcc_malloc",
instead.
Fixes potential writes past the allocated space with mostly
illegal flex array initializers. (60_errors_and_warnings.c
:test_var_array)
In exchange suspicious precautions such as section_reserve
or checks with sec->data_allocated were removed. (There is
an hard check 'init_assert()' for now but it's meant to be
just temporary)
Also, instead of filling holes, always memset(0) structures
& arrays on stack. Sometimes more efficient, sometimes isn't.
At least we can omit putting null initializers.
About array range inititializers: Reparsing tokens has a
small problem with sideeffects, for example
int c = 0, dd[] = { [0 ... 1] = ++c, [2 ... 3] = ++c };
Also, instead of 'squeeze_multi_relocs()', delete pre-existing
relocations in advance. This works even if secondary initializers
don't even have relocations, as with
[0 ... 7] = &stuff,
[4] = NULL
Also, in tcc.h: new macro "tcc_internal_error()"
It might have advantages in cases if tcc/libtcc does not
depend on extern files.
Also:
- apply "stray \\ ..." check to macros only. For files it
was already checked. Add positive test.
an enum must be compatible with one or more integer type,
so adjust the test accordingly. That means the following
redeclarations should work:
enum e6 { E1 = -1, E0 };
void f3(enum e6);
void f3(int); // should work as int and e6 are compatible
while the following should not:
void f4(enum e6 e);
void f4(unsigned e); // should error as unsigned and e6 are incompatible
they were emitted too early, in particular also in macro
substitution which might turn out to not be stray in case it's
further stringified. Check in next() instead. Add two testcases
that an error is still emitted for obvious top-level baskslashes,
and that stringifying such a thing works.
On windows. there is no long double really IOW it is the
same as double. However setting the VT_LONG flag in
combination with VT_DOUBLE allows to keep track of the
original type for the purpose of '_Generic() or more
accurate type warnings.
Fix static assert to support literal string instead of just printing
the sring of the current token as it use to be
so we can now use _Static_assert(0, "0" "1") which will print
__FILE__ __LINE__ error: 01
This makes it possible to get backtraces with executables
(including DLLs/SOs) like we had it already with -g -run.
Option -b includes -bt, and -bt includes -g.
- new file lib/bt-exe.c: used to link rt_printline and the
exception handler from tccrun.c into executables/DLLs.
- new file lib/bt-log.c: provides a function that may be
called from user code to print out a backtrace with a
message (currently for i386/x86_64 only):
int (*tcc_backtrace)(const char *fmt, ...);
As an extra hack, if 'fmt' is prefixed like "^file.c^..."
then the backtrace will skip calls from within 'file.c'.
- new file lib/bt-dll.c: used on win32 to link the backtrace
and bcheck functions with the main module at runtime
- bcheck.c: now uses the tcc_backtrace function from above
- tccgen.c: minor cleanups
- tccelf.c: stab sections get SHF_ALLOC for easy access.
Also in relocate_section(): 64bit relocations for stabs
in DLLs cannot work. To find DLL addresses, the DLL base
is added manually in tccrun.c via rc.prog_base instead.
- tccpe.c: there are some changes to allow merging sections,
used to merge .finit_array into .data in the first place.
- tccpp.c: tcc -run now #defines __TCC_RUN__
also: refactor a line in tal_realloc that was incompatible
with bcheck
- tcctest.c: fixed a problem with r12 which tcc cannot preserve
as well as gcc does.
- tests2/112_backtrace.c: test the feature and the bcheck test18
that previously was in boundtest.c
we were emitting error messages for something like
'static int i = 2 || 1/0', even though the exception would be in
the unevaluated part. This doesn't destroy const-ness, so we must
accept it. This requires splitting the nocode_wanted values a bit more,
so that nocode_wanted due to const_wanted can be differentiated from
nocode_wanted due to non-evaluation.
This fixes the issue
int main() { extern char *x; }
void main1() { extern char *x; }
t2.c:5: error: incompatible types for redefinition of 'x'
(reported by Giovanni Mascellani 2019/07/16)
Example:
int a = 1;
void f(void)
{
int a = 2;
{
extern int a; // = 1 !!
....
To get this (more) correctly there is a new function to copy
syms between local to global stacks.
Also, this patch changes the meaning of VT_EXTERN back
to the simpler and IMO more useful notion of
DECLARED but not (yet) DEFINED.
and that for both variables and functions. That is, VT_EXTERN
in tcc doesn't have to do with the keyword 'extern' necessarily.
Also this patch does allow
int x[];
as alias for
extern int x[];
(as do gcc and msvc)
see testcase, when the inner array dimension of multi-dimensional
VLAs isn't given TCC was generating invalid vstack accesses.
Those are actually invalid, so just diagnose them.
see testcases. A local 'extern int i' declaration needs to
refer to the global declaration, not to a local one it might
be shadowing. Doesn't seem to happen in the wild very often as
this was broken forever.
in presence of invalid source code we can't rely on the
next token to determine if we have or haven't already parsed
an initializer element, we really have to track it in some separate
state; it's a flag, so merge it with the other two we have (size_only
and first). Also add some syntax checks for situations which
formerly lead to vstack leaks, see the added testcases.
sometimes abstract decls in parameter lists left the returned name
uninitialized potentially leading to segfaults, like in
int f(int ()) {
return 0;
}
Deal with this.
like on 'enum myenum { L = -1 } L;'. It's a bit tedious as
there are two paths (for global vs local symbols), and because
the scope and enum_val share same storage.
* -dt now with lowercase t
* test snippets now separated by real preprocessor statements
which is valid C also for other compilers
#if defined test_xxx
< test snippet x >
#elif defined test_yyy
< test snippet y >
#elif ...
#endif
* simpler implementation, behaves like -run if no 'test_...' macros
are seen, works with -E too
* for demonstration I combined some of the small tests for errors
and warnings (56..63,74) in "60_errors_and_warnings.c"
Also:
* libtcc.c:
put tcc_preprocess() and tcc_assemble() under the setjmp clause
to let them return to caller after errors. This is for -dt -E.
* tccgen.c:
- get rid of save/restore_parse_state(), macro_ptr is saved
by begin_macro anyway, now line_num too.
- use expr_eq for parsing _Generic's controlling_type
- set nocode_wanted with const_wanted. too, This is to keep
VT_JMP on vtop when parsing preprocessor expressions.
* tccpp.c: tcc -E: suppress trailing whitespace from lines with
comments (that -E removes) such as
NO_GOTPLT_ENTRY,\t /* never generate ... */
