| Message ID | or1s7x49lc.fsf@lxoliva.fsfla.org |
|---|---|
| State | New |
| Headers | show |
| Series | [PR87793] reject non-toplevel unspecs in debug loc exprs on x86 | expand |
On 11/7/18 12:42 AM, Alexandre Oliva wrote: > Before revision 254025, we'd reject UNSPECs in debug loc exprs. > TARGET_CONST_NOT_OK_FOR_DEBUG_P still rejects that by default, on all > ports that override it, except for x86, that accepts @gotoff unspecs. > We can indeed accept them in top-level expressions, but not as > subexpressions: the assembler rejects the difference between two > @gotoff symbols, for example. > > We could simplify such a difference and drop the @gotoffs, provided > that the symbols are in the same section; we could also accept > @gotoffs plus literal constants. However, accepting those but > rejecting such combinations as subexpressions would be ugly, and most > likely not worth the trouble: sym@gotoff+litconst hardly makes sense > as a standalone expression, and the difference between @gotoffs should > be avoided to begin with, as follows. > > Ideally, the debug loc exprs would use the symbolic data in > REG_EQUIV/REG_EQUAL notes, or delegitimized addresses, instead of > simplifying the difference between two legitimized addresses so that > the occurrences of the GOT register cancel each other. That would > require some more elaborate surgery in var-tracking and cselib than > would be appropriate at this stage. > > Regstrapped on x86_64- and i686-linux-gnu. Ok to install? > > > for gcc/ChangeLog > > PR target/87793 > * config/i386/i386.c (ix86_const_not_ok_for_debug_p): Reject > non-toplevel UNSPEC. > > for gcc/testsuite/ChangeLog > > PR target/87793 > * gcc.dg/pr87793.c: New. OK. jeff
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index ae8971c82b0a..424a4b20631c 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -17172,6 +17172,18 @@ ix86_const_not_ok_for_debug_p (rtx x) if (SYMBOL_REF_P (x) && strcmp (XSTR (x, 0), GOT_SYMBOL_NAME) == 0) return true; + /* Reject UNSPECs within expressions. We could accept symbol@gotoff + + literal_constant, but that would hardly come up in practice, + and it's not worth the trouble of having to reject that as an + operand to pretty much anything else. */ + if (UNARY_P (x) + && GET_CODE (XEXP (x, 0)) == UNSPEC) + return true; + if (BINARY_P (x) + && (GET_CODE (XEXP (x, 0)) == UNSPEC + || GET_CODE (XEXP (x, 1)) == UNSPEC)) + return true; + return false; } diff --git a/gcc/testsuite/gcc.dg/pr87793.c b/gcc/testsuite/gcc.dg/pr87793.c new file mode 100644 index 000000000000..3194313a265d --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr87793.c @@ -0,0 +1,42 @@ +/* { dg-do compile } */ +/* { dg-options "-fpic -Os -g" } */ + +struct fit_loadable_tbl { + int type; + void (*handler)(int data, int size); +}; + +#define ll_entry_start(_type, _list) \ +({ \ + static char start[0] __attribute__((aligned(4))) \ + __attribute__((unused, section(".u_boot_list_2_"#_list"_1"))); \ + (_type *)&start; \ +}) + +#define ll_entry_end(_type, _list) \ +({ \ + static char end[0] __attribute__((aligned(4))) \ + __attribute__((unused, section(".u_boot_list_2_"#_list"_3"))); \ + (_type *)&end; \ +}) + +#define ll_entry_count(_type, _list) \ + ({ \ + _type *start = ll_entry_start(_type, _list); \ + _type *end = ll_entry_end(_type, _list); \ + unsigned int _ll_result = end - start; \ + _ll_result; \ + }) + +void test(int img_type, int img_data, int img_len) +{ + int i; + const unsigned int count = + ll_entry_count(struct fit_loadable_tbl, fit_loadable); + struct fit_loadable_tbl *fit_loadable_handler = + ll_entry_start(struct fit_loadable_tbl, fit_loadable); + + for (i = 0; i < count; i++, fit_loadable_handler++) + if (fit_loadable_handler->type == img_type) + fit_loadable_handler->handler(img_data, img_len); +}