| Message ID | 20141016172030.GM10501@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 10/16/14 11:20, Marek Polacek wrote: > On Wed, Oct 15, 2014 at 09:46:20PM +0000, Joseph S. Myers wrote: >> On Wed, 15 Oct 2014, Marek Polacek wrote: >> >>> We've got a complaint that the "dereferencing pointer to incomplete >>> type" error is printed for all occurrences of the incomplete type, >>> which is too verbose. Also it'd be nicer to print the type as well. >>> This patch fixes this; if we find an incomplete type, mark it with error >>> node, then we don't print the error message more than once. >> >> I don't like this approach of modifying the type; type nodes are shared >> objects and this could affect all sorts of other logic subsequently >> working with the type. I think there should be some sort of annotation of >> the type (either in the type itself, or on the side) that *only* means an >> error has been given for the type being incomplete, rather than inserting >> error_mark_node into the type. > > I'm sorry. Here is another version, which uses a lang flag to distinguish > whether a "dereferencing incomplete..." error message has been given. > > One could argue that I should've named the lang flag e.g. > C_TYPE_INCOMPLETE_ERROR_REPORTED, but I hope it can be reused in the > future for some similar purpose. > > Bootstrapped/regtested on x86_64-linux, ok for trunk? > > 2014-10-16 Marek Polacek <polacek@redhat.com> > > PR c/63543 > * c-tree.h (C_TYPE_ERROR_REPORTED): Define. > * c-typeck.c (build_indirect_ref): Don't print the "dereferencing..." > error multiple times. Print the type. > > * gcc.dg/pr63543.c: New test. > * gcc.dg/array-8.c: Remove dg-error. > * gcc.dg/pr48552-1.c: Remove and adjust dg-error. > * gcc.dg/pr48552-2.c: Likewise. OK. It's probably safe to assume we'll find more uses for that flag. jeff
diff --git gcc/c/c-tree.h gcc/c/c-tree.h index e6aca01..5ff9d9c 100644 --- gcc/c/c-tree.h +++ gcc/c/c-tree.h @@ -56,6 +56,9 @@ along with GCC; see the file COPYING3. If not see This is used for -Wc++-compat. */ #define C_TYPE_DEFINED_IN_STRUCT(TYPE) TYPE_LANG_FLAG_2 (TYPE) +/* Record whether an "incomplete type" error was given for the type. */ +#define C_TYPE_ERROR_REPORTED(TYPE) TYPE_LANG_FLAG_3 (TYPE) + /* Record whether a typedef for type `int' was actually `signed int'. */ #define C_TYPEDEF_EXPLICITLY_SIGNED(EXP) DECL_LANG_FLAG_1 (EXP) diff --git gcc/c/c-typeck.c gcc/c/c-typeck.c index 5c0697a..0f363f5 100644 --- gcc/c/c-typeck.c +++ gcc/c/c-typeck.c @@ -2378,7 +2378,12 @@ build_indirect_ref (location_t loc, tree ptr, ref_operator errstring) if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) { - error_at (loc, "dereferencing pointer to incomplete type"); + if (!C_TYPE_ERROR_REPORTED (TREE_TYPE (ptr))) + { + error_at (loc, "dereferencing pointer to incomplete type " + "%qT", t); + C_TYPE_ERROR_REPORTED (TREE_TYPE (ptr)) = 1; + } return error_mark_node; } if (VOID_TYPE_P (t) && c_inhibit_evaluation_warnings == 0) diff --git gcc/testsuite/gcc.dg/array-8.c gcc/testsuite/gcc.dg/array-8.c index d469a80..2872985 100644 --- gcc/testsuite/gcc.dg/array-8.c +++ gcc/testsuite/gcc.dg/array-8.c @@ -45,5 +45,4 @@ g (void) sip[0]; /* { dg-error "invalid use of undefined type 'struct si'" } */ /* { dg-error "dereferencing pointer to incomplete type" "incomplete" { target *-*-* } 45 } */ 0[sip]; /* { dg-error "invalid use of undefined type 'struct si'" } */ - /* { dg-error "dereferencing pointer to incomplete type" "incomplete" { target *-*-* } 47 } */ } diff --git gcc/testsuite/gcc.dg/pr48552-1.c gcc/testsuite/gcc.dg/pr48552-1.c index 877c4c2..4b833fb 100644 --- gcc/testsuite/gcc.dg/pr48552-1.c +++ gcc/testsuite/gcc.dg/pr48552-1.c @@ -49,5 +49,5 @@ f7 (struct S *x) void f8 (struct S *x) { - __asm volatile ("" : "=r" (*x)); /* { dg-error "dereferencing pointer to incomplete type" "incomplete" } */ -} /* { dg-error "invalid lvalue in asm output 0" "invalid lvalue" { target *-*-* } 52 } */ + __asm volatile ("" : "=r" (*x)); /* { dg-error "invalid lvalue in asm output 0" } */ +} diff --git gcc/testsuite/gcc.dg/pr48552-2.c gcc/testsuite/gcc.dg/pr48552-2.c index a796983..954c411 100644 --- gcc/testsuite/gcc.dg/pr48552-2.c +++ gcc/testsuite/gcc.dg/pr48552-2.c @@ -49,5 +49,5 @@ f7 (struct S *x) void f8 (struct S *x) { - __asm ("" : "=r" (*x)); /* { dg-error "dereferencing pointer to incomplete type" "incomplete" } */ -} /* { dg-error "invalid lvalue in asm output 0" "invalid lvalue" { target *-*-* } 52 } */ + __asm ("" : "=r" (*x)); /* { dg-error "invalid lvalue in asm output 0" } */ +} diff --git gcc/testsuite/gcc.dg/pr63543.c gcc/testsuite/gcc.dg/pr63543.c index e69de29..215b62e 100644 --- gcc/testsuite/gcc.dg/pr63543.c +++ gcc/testsuite/gcc.dg/pr63543.c @@ -0,0 +1,21 @@ +/* PR c/63543 */ +/* { dg-do compile } */ + +struct S; +union U; + +int +f1 (struct S *s) +{ + return s->a /* { dg-error "dereferencing pointer to incomplete type .struct S." } */ + + s->b + + s->c; +} + +int +f2 (union U *u) +{ + return u->a /* { dg-error "dereferencing pointer to incomplete type .union U." } */ + + u->a + + u->a; +}