[Bug c/35198] New: missed evaluation of VM array type

[Bug c/35198] New: missed evaluation of VM array type

[mrs at apple dot com]

void* a(void* x) {return (int (*)[10][printf("hi\n")])x;}
  int main() { int i; a(&i); }

should print hi.  This was still broken in 4.3 in July, 2007.


-- 
           Summary: missed evaluation of VM array type
           Product: gcc
           Version: 4.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mrs at apple dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2008-02-14 21:42 -------
Confirmed.

This used to work with gcc 2.95 at least.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
      Known to fail|                            |3.3.6 4.1.3 4.3.0
      Known to work|                            |2.95.4
   Last reconfirmed|0000-00-00 00:00:00         |2008-02-14 21:42:39
               date|                            |
            Summary|missed evaluation of VM     |[4.1/4.2/4.3 Regression]
                   |array type when used as a   |missed evaluation of VM
                   |cast                        |array type when used as a
                   |                            |cast
   Target Milestone|---                         |4.2.4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2008-02-17 16:19 -------
There are a few different cases.  For

int foo(void);
void *a(void *p)
{
  return (int (*)[foo()])p;
}

the frontend already got rid of the intermediate casts (and side-effects).  For

int foo(void);
void a(void *p)
{
  (int (*)[foo()])p;
}

the frontend retains the cast and the side-effects, but the gimplifier removes
them.

One error is certainly:

Breakpoint 3, fold_unary (code=NOP_EXPR, type=0xb7cee2d8, op0=0xb7d46140)
    at /home/richard/src/trunk/gcc/fold-const.c:7932
7932      enum tree_code_class kind = TREE_CODE_CLASS (code);
(int[0:(unsigned int) (SAVE_EXPR <foo ()> + -1)] *) p
(gdb) call debug_generic_expr (type)
void *
(gdb) print op0->base.side_effects_flag
$1 = 0

that is, the conversion is not marked as producing side-effects (possibly
because the side-effect is wrapped in a SAVE_EXPR).

It is also not clear to me whether we should do so (wrap the call inside
a SAVE_EXPR).  What is supposed to happen for

int foo(void);
void a(void *p)
{
  (int (*)[foo()])p;
  (int (*)[foo()])p;
}

?  Is foo supposed to be called twice?

I think the burden should be on the side of the frontend to instead emit
a COMPOUND_EXPR like

  ( SAVE_EXPR<foo()>, (int (*)[SAVE_EXPR<foo()>])p )

here.  At least marking the whole conversion as having no side-effects
doesn't tell the truth really, likewise if SAVE_EXPRs have no side-effects,
as that wouldn't guarantee it is evaluated at least once.

But maybe I am missing parts of GCC history here.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast

[ebotcazou at gcc dot gnu dot org]

------- Comment #3 from ebotcazou at gcc dot gnu dot org  2008-02-17 16:33 -------
> At least marking the whole conversion as having no side-effects doesn't tell
> the truth really, likewise if SAVE_EXPRs have no side-effects, as that
> wouldn't guarantee it is evaluated at least once.

SAVE_EXPRs can have side-effects like every other expression, and save_expr
automatically sets the flag.


-- 

ebotcazou at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast

[joseph at codesourcery dot com]

------- Comment #4 from joseph at codesourcery dot com  2008-02-17 23:12 -------
Subject: Re:  [4.1/4.2/4.3 Regression] missed evaluation of VM
 array type when used as a cast

My view remains as I said in 
<http://gcc.gnu.org/ml/gcc-patches/2006-09/msg00039.html>: front ends 
should make the internal variable for VLA sizes explicit.  This is not 
however suitable for implementing in development stage 3, let alone in 
regression-only mode or on release branches.  There may of course be a 
simpler fix for this particular bug.

I don't think side effects in VLA size expressions (let alone in VLA size 
expressions in casts) are that likely to be used in real code outside of 
conformance testsuites, so I wouldn't consider this regression (worked 
with 2.95.3, failed with 3.0.4) of great importance.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3 Regression] missed evaluation of VM array type when used as a cast

[rguenth at gcc dot gnu dot org]

------- Comment #5 from rguenth at gcc dot gnu dot org  2008-02-17 23:21 -------
The variables get made explicit by the gimplifier.  The problem here seems to
be that we lose the cast before we can do so and that the gimplifier only makes
the variables explicit if they are used (which they are not for casts - apart
from side-effects).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.1/4.2/4.3/4.4 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #6 from jsm28 at gcc dot gnu dot org  2008-05-19 20:24 -------
4.2.4 is being released, changing milestones to 4.2.5.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.2.4                       |4.2.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #7 from jsm28 at gcc dot gnu dot org  2008-07-04 22:59 -------
Closing 4.1 branch.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.1/4.2/4.3/4.4 Regression]|[4.2/4.3/4.4 Regression]
                   |missed evaluation of VM     |missed evaluation of VM
                   |array type when used as a   |array type when used as a
                   |cast                        |cast


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #8 from jsm28 at gcc dot gnu dot org  2008-10-24 00:09 -------
Testing a patch for 4.5.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jsm28 at gcc dot gnu dot org
                   |dot org                     |
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2008-02-14 21:42:39         |2008-10-24 00:09:23
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #9 from jsm28 at gcc dot gnu dot org  2008-10-24 19:36 -------
Subject: Bug 35198

Author: jsm28
Date: Fri Oct 24 19:34:52 2008
New Revision: 141349

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=141349
Log:
        PR c/456
        PR c/5675
        PR c/19976
        PR c/29116
        PR c/31871
        PR c/35198

fixincludes:
        * inclhack.def (glibc_tgmath): New fix.
        * fixincl.x: Regenerate.
        * tests/base/tgmath.h: New.

gcc:
        * builtins.c (fold_call_expr): Return a NOP_EXPR from folding
        rather than the contained expression.
        * c-common.c (c_save_expr): New.
        (c_common_truthvalue_conversion): Use c_save_expr.  Do not fold
        conditional expressions for C.
        * c-common.def (C_MAYBE_CONST_EXPR): New.
        * c-common.h (c_fully_fold, c_save_expr): New prototypes.
        (C_MAYBE_CONST_EXPR_PRE, C_MAYBE_CONST_EXPR_EXPR,
        C_MAYBE_CONST_EXPR_INT_OPERANDS, C_MAYBE_CONST_EXPR_NON_CONST,
        EXPR_INT_CONST_OPERANDS): Define.
        * c-convert.c (convert): Strip nops from expression.
        * c-decl.c (groktypename): Take extra parameters expr and
        expr_const_operands.  Update call to grokdeclarator.
        (start_decl): Update call to grokdeclarator.  Add statement for
        expressions used in type of decl.
        (grokparm): Update call to grokdeclarator.
        (push_parm_decl): Update call to grokdeclarator.
        (build_compound_literal): Add parameter non_const and build a
        C_MAYBE_COSNT_EXPR if applicable.
        (grokdeclarator): Take extra parameters expr and
        expr_const_operands.  Track expressions used in declaration
        specifiers and declarators.  Fold array sizes and track whether
        they are constant expressions and whether they are integer
        constant expressions.
        (parser_xref_tag): Set expr and expr_const_operands fields in
        return value.
        (grokfield): Update call to grokdeclarator.
        (start_function): Update call to grokdeclarator.
        (build_null_declspecs): Set expr and expr_const_operands fields in
        return value.
        (declspecs_add_type): Handle expressions in typeof specifiers.
        * c-parser.c (c_parser_declspecs): Set expr and
        expr_const_operands fields for declaration specifiers.
        (c_parser_enum_specifier): Likewise.
        (c_parser_struct_or_union_specifier): Likewise.
        (c_parser_typeof_specifier): Likewise.  Update call to
        groktypename.  Fold expression as needed.  Return expressions with
        type instead of adding statements.
        (c_parser_attributes): Update calls to c_parser_expr_list.
        (c_parser_statement_after_labels): Fold expression before passing
        to objc_build_throw_stmt.
        (c_parser_condition): Fold expression.
        (c_parser_asm_operands): Fold expression.
        (c_parser_conditional_expression): Use c_save_expr.  Update call
        to build_conditional_expr.
        (c_parser_alignof_expression): Update call to groktypename.
        (c_parser_postfix_expression): Preserve C_MAYBE_CONST_EXPR as
        original_code.  Fold expression argument of va_arg.  Create
        C_MAYBE_CONST_EXPR to preserve side effects of expressions in type
        argument to va_arg.  Update calls to groktypename.  Fold array
        index for offsetof.  Verify that first argument to
        __builtin_choose_expr has integer type.
        (c_parser_postfix_expression_after_paren_type): Update calls to
        groktypename and build_compound_literal.  Handle expressions with
        side effects in type name.
        (c_parser_postfix_expression_after_primary): Update call to
        c_parser_expr_list.  Set original_code for calls to
        __builtin_constant_p.
        (c_parser_expr_list): Take extra parameter fold_p.  Fold
        expressions if requested.
        (c_parser_objc_type_name): Update call to groktypename.
        (c_parser_objc_synchronized_statement): Fold expression.
        (c_parser_objc_receiver): Fold expression.
        (c_parser_objc_keywordexpr): Update call to c_parser_expr_list.
        (c_parser_omp_clause_num_threads, c_parser_omp_clause_schedule,
        c_parser_omp_atomic, c_parser_omp_for_loop): Fold expressions.
        * c-tree.h (CONSTRUCTOR_NON_CONST): Define.
        (struct c_typespec): Add elements expr and expr_const_operands.
        (struct c_declspecs): Add elements expr and expr_const_operands.
        (groktypename, build_conditional_expr, build_compound_literal):
        Update prototypes.
        * c-typeck.c (c_fully_fold, c_fully_fold_internal,
        note_integer_operands): New functions.
        (decl_constant_value_for_broken_optimization): Rename to
        decl_constant_value_for_optimization:  Check whether optimizing
        and that the expression is a VAR_DECL not of array type instead of
        doing such checks in the caller.  Do not check pedantic.
        (default_function_array_conversion): Do not strip nops.
        (default_conversion): Do not call
        decl_constant_value_for_broken_optimization.
        (build_array_ref): Do not fold result.
        (c_expr_sizeof_expr): Fold operand.  Use C_MAYBE_CONST_EXPR for
        result when operand is a VLA.
        (c_expr_sizeof_type): Update call to groktypename.  Handle
        expressions included in type name.  Use C_MAYBE_CONST_EXPR for
        result when operand names a VLA type.
        (build_function_call): Update call to build_compound_literal.
        Only fold result for calls to __builtin_* functions.  Strip
        NOP_EXPR from INTEGER_CST returned from such functions.
        (convert_arguments): Fold arguments.  Update call to
        convert_for_assignment.
        (build_unary_op): Handle increment and decrement of
        C_MAYBE_CONST_EXPR.  Move lvalue checks for increment and
        decrement earlier.  Fold operand of increment and decrement.
        Handle address of C_MAYBE_CONST_EXPR.  Only fold expression being
        built for integer operand.  Wrap returns that are INTEGER_CSTs
        without being integer constant expressions or that have integer
        constant operands without being INTEGER_CSTs.
        (lvalue_p): Handle C_MAYBE_CONST_EXPR.
        (build_conditional_expr): Add operand ifexp_bcp.  Track whether
        result is an integer constant expression or can be used in
        unevaluated parts of one and avoid folding and wrap as
        appropriate.
        (build_compound_expr): Wrap result for C99 if operands can be used
        in integer constant expressions.
        (build_c_cast): Update call to digest_init.  Do not ignore
        overflow from casting floating-point constants to integers.  Wrap
        results that could be confused with integer constant expressions,
        null pointer constants or floating-point constants.
        (c_cast_expr): Update call to groktypename.  Handle expressions
        included in type name.
        (build_modify_expr): Handle modifying a C_MAYBE_CONST_EXPR.  Fold
        lhs inside possible SAVE_EXPR.  Fold RHS before assignment.
        Update calls to convert_for_assignment.
        (convert_for_assignment): Take new parameter
        null_pointer_constant.  Do not strip nops or call
        decl_constant_value_for_broken_optimization.
        (store_init_value): Update call to digest_init.
        (digest_init): Take new parameter null_pointer_constant.  Do not
        call decl_constant_value_for_broken_optimization.  pedwarn for
        initializers not constant expressions.  Update calls to
        convert_for_assignment.
        (constructor_nonconst): New.
        (struct constructor_stack): Add nonconst element.
        (really_start_incremental_init, push_init_level, pop_init_level):
        Handle constructor_nonconst and nonconst element.
        (set_init_index): Call constant_expression_warning for array
        designators.
        (output_init_element): Fold value.  Set constructor_nonconst as
        applicable.  pedwarn for initializers not constant expressions.
        Update call to digest_init.  Call constant_expression_warning
        where constant initializers are required.
        (process_init_element): Use c_save_expr.
        (c_finish_goto_ptr): Fold expression.
        (c_finish_return): Fold return value.  Update call to
        convert_for_assignment.
        (c_start_case): Fold switch expression.
        (c_process_expr_stmt): Fold expression.
        (c_finish_stmt_expr): Create C_MAYBE_CONST_EXPR as needed to
        ensure statement expression is not evaluated in constant
        expression.
        (build_binary_op): Track whether results are integer constant
        expressions or may occur in such, disable folding and wrap results
        as applicable.
        (c_objc_common_truthvalue_conversion): Handle results folded to
        integer constants that are not integer constant expressions.
        * doc/extend.texi: Document when typeof operands are evaluated,
        that condition of __builtin_choose_expr is an integer constant
        expression, and more about use of __builtin_constant_p in
        initializers.

gcc/cp:
        * typeck.c (c_fully_fold): New.

gcc/testsuite:
        * gcc.dg/bconstp-2.c, gcc.dg/c90-const-expr-6.c,
        gcc.dg/c90-const-expr-7.c, gcc.dg/c90-const-expr-8.c,
        gcc.dg/c90-const-expr-9.c, gcc.dg/c90-const-expr-10.c,
        gcc.dg/c90-const-expr-11.c, gcc.dg/c99-const-expr-6.c,
        gcc.dg/c99-const-expr-7.c, gcc.dg/c99-const-expr-8.c,
        gcc.dg/c99-const-expr-9.c, gcc.dg/c99-const-expr-10.c,
        gcc.dg/c99-const-expr-11.c, gcc.dg/c99-const-expr-12.c,
        gcc.dg/c99-const-expr-13.c, gcc.dg/gnu89-const-expr-1.c,
        gcc.dg/gnu89-const-expr-2.c, gcc.dg/gnu99-const-expr-1.c,
        gcc.dg/gnu99-const-expr-2.c, gcc.dg/gnu99-const-expr-3.c,
        gcc.dg/vla-11.c, gcc.dg/vla-12.c, gcc.dg/vla-13.c,
        gcc.dg/vla-14.c, gcc.dg/vla-15.c: New tests.
        * gcc.dg/c90-const-expr-1.c, gcc.dg/c90-const-expr-2.c,
        gcc.dg/c90-const-expr-3.c, gcc.dg/c99-const-expr-2.c,
        gcc.dg/c99-const-expr-3.c, gcc.dg/c99-static-1.c: Remove XFAILs.
        * gcc.dg/overflow-warn-1.c, gcc.dg/overflow-warn-2.c,
        gcc.dg/overflow-warn-3.c, gcc.dg/overflow-warn-4.c: Remove
        XFAILs.  Update expected messages.
        * gcc.dg/pr14649-1.c, gcc.dg/pr19984.c, gcc.dg/pr25682.c: Update
        expected messages.
        * gcc.dg/real-const-1.c: Replace with test from original PR.

Added:
    branches/c-4_5-branch/fixincludes/ChangeLog.c45
    branches/c-4_5-branch/fixincludes/tests/base/tgmath.h
    branches/c-4_5-branch/gcc/ChangeLog.c45
    branches/c-4_5-branch/gcc/cp/ChangeLog.c45
    branches/c-4_5-branch/gcc/testsuite/ChangeLog.c45
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/bconstp-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-10.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-11.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-6.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-7.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-8.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-9.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-10.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-11.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-12.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-13.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-6.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-7.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-8.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-9.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu89-const-expr-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu89-const-expr-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-11.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-12.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-13.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-14.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/vla-15.c
Modified:
    branches/c-4_5-branch/fixincludes/fixincl.x
    branches/c-4_5-branch/fixincludes/inclhack.def
    branches/c-4_5-branch/gcc/builtins.c
    branches/c-4_5-branch/gcc/c-common.c
    branches/c-4_5-branch/gcc/c-common.def
    branches/c-4_5-branch/gcc/c-common.h
    branches/c-4_5-branch/gcc/c-convert.c
    branches/c-4_5-branch/gcc/c-decl.c
    branches/c-4_5-branch/gcc/c-parser.c
    branches/c-4_5-branch/gcc/c-tree.h
    branches/c-4_5-branch/gcc/c-typeck.c
    branches/c-4_5-branch/gcc/cp/typeck.c
    branches/c-4_5-branch/gcc/doc/extend.texi
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c90-const-expr-3.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-const-expr-3.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/c99-static-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-2.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-3.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/overflow-warn-4.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr14649-1.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr19984.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/pr25682.c
    branches/c-4_5-branch/gcc/testsuite/gcc.dg/real-const-1.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #10 from jsm28 at gcc dot gnu dot org  2008-11-12 23:15 -------
Although technically wrong-code, side effects in VLA size expressions are a
very dubious practice I don't expect to be used like this outside of
testsuites.
The fix is clearly unsuitable for any development stage other than Stage 1;
downgrading to P4 to reflect this.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4/4.5 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #11 from jsm28 at gcc dot gnu dot org  2009-03-29 18:14 -------
Subject: Bug 35198

Author: jsm28
Date: Sun Mar 29 18:13:43 2009
New Revision: 145254

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=145254
Log:
        PR c/456
        PR c/5675
        PR c/19976
        PR c/29116
        PR c/31871
        PR c/35198

fixincludes:
        * inclhack.def (glibc_tgmath): New fix.
        * fixincl.x: Regenerate.
        * tests/base/tgmath.h: New.

gcc:
        * builtins.c (fold_builtin_sincos): Build COMPOUND_EXPR in
        void_type_node.
        (fold_call_expr): Return a NOP_EXPR from folding rather than the
        contained expression.
        * c-common.c (c_fully_fold, c_fully_fold_internal, c_save_expr):
        New.
        (c_common_truthvalue_conversion): Use c_save_expr.  Do not fold
        conditional expressions for C.
        (decl_constant_value_for_optimization): Move from
        decl_constant_value_for_broken_optimization in c-typeck.c.  Check
        whether optimizing and that the expression is a VAR_DECL not of
        array type instead of doing such checks in the caller.  Do not
        check pedantic.  Call gcc_unreachable for C++.
        * c-common.def (C_MAYBE_CONST_EXPR): New.
        * c-common.h (c_fully_fold, c_save_expr,
        decl_constant_value_for_optimization): New prototypes.
        (C_MAYBE_CONST_EXPR_PRE, C_MAYBE_CONST_EXPR_EXPR,
        C_MAYBE_CONST_EXPR_INT_OPERANDS, C_MAYBE_CONST_EXPR_NON_CONST,
        EXPR_INT_CONST_OPERANDS): Define.
        * c-convert.c (convert): Strip nops from expression.
        * c-decl.c (groktypename): Take extra parameters expr and
        expr_const_operands.  Update call to grokdeclarator.
        (start_decl): Update call to grokdeclarator.  Add statement for
        expressions used in type of decl.
        (grokparm): Update call to grokdeclarator.
        (push_parm_decl): Update call to grokdeclarator.
        (build_compound_literal): Add parameter non_const and build a
        C_MAYBE_COSNT_EXPR if applicable.
        (grokdeclarator): Take extra parameters expr and
        expr_const_operands.  Track expressions used in declaration
        specifiers and declarators.  Fold array sizes and track whether
        they are constant expressions and whether they are integer
        constant expressions.
        (parser_xref_tag): Set expr and expr_const_operands fields in
        return value.
        (grokfield): Update call to grokdeclarator.
        (start_function): Update call to grokdeclarator.
        (build_null_declspecs): Set expr and expr_const_operands fields in
        return value.
        (declspecs_add_type): Handle expressions in typeof specifiers.
        * c-parser.c (c_parser_declspecs): Set expr and
        expr_const_operands fields for declaration specifiers.
        (c_parser_enum_specifier): Likewise.
        (c_parser_struct_or_union_specifier): Likewise.
        (c_parser_typeof_specifier): Likewise.  Update call to
        groktypename.  Fold expression as needed.  Return expressions with
        type instead of adding statements.
        (c_parser_attributes): Update calls to c_parser_expr_list.
        (c_parser_statement_after_labels): Fold expression before passing
        to objc_build_throw_stmt.
        (c_parser_condition): Fold expression.
        (c_parser_asm_operands): Fold expression.
        (c_parser_conditional_expression): Use c_save_expr.  Update call
        to build_conditional_expr.
        (c_parser_alignof_expression): Update call to groktypename.
        (c_parser_postfix_expression): Preserve C_MAYBE_CONST_EXPR as
        original_code.  Fold expression argument of va_arg.  Create
        C_MAYBE_CONST_EXPR to preserve side effects of expressions in type
        argument to va_arg.  Update calls to groktypename.  Fold array
        index for offsetof.  Verify that first argument to
        __builtin_choose_expr has integer type.
        (c_parser_postfix_expression_after_paren_type): Update calls to
        groktypename and build_compound_literal.  Handle expressions with
        side effects in type name.
        (c_parser_postfix_expression_after_primary): Update call to
        c_parser_expr_list.  Set original_code for calls to
        __builtin_constant_p.
        (c_parser_expr_list): Take extra parameter fold_p.  Fold
        expressions if requested.
        (c_parser_objc_type_name): Update call to groktypename.
        (c_parser_objc_synchronized_statement): Fold expression.
        (c_parser_objc_receiver): Fold expression.
        (c_parser_objc_keywordexpr): Update call to c_parser_expr_list.
        (c_parser_omp_clause_num_threads, c_parser_omp_clause_schedule,
        c_parser_omp_atomic, c_parser_omp_for_loop): Fold expressions.
        * c-tree.h (CONSTRUCTOR_NON_CONST): Define.
        (struct c_typespec): Add elements expr and expr_const_operands.
        (struct c_declspecs): Add elements expr and expr_const_operands.
        (groktypename, build_conditional_expr, build_compound_literal):
        Update prototypes.
        (in_late_binary_op): Declare.
        * c-typeck.c (note_integer_operands): New function.
        (in_late_binary_op): New variable.
        (decl_constant_value_for_broken_optimization): Move to c-common.c
        and rename to decl_constant_value_for_optimization.
        (default_function_array_conversion): Do not strip nops.
        (default_conversion): Do not call
        decl_constant_value_for_broken_optimization.
        (build_array_ref): Do not fold result.
        (c_expr_sizeof_expr): Fold operand.  Use C_MAYBE_CONST_EXPR for
        result when operand is a VLA.
        (c_expr_sizeof_type): Update call to groktypename.  Handle
        expressions included in type name.  Use C_MAYBE_CONST_EXPR for
        result when operand names a VLA type.
        (build_function_call): Update call to build_compound_literal.
        Only fold result for calls to __builtin_* functions.  Strip
        NOP_EXPR from INTEGER_CST returned from such functions.  Fold
        the function designator.
        (convert_arguments): Fold arguments.  Update call to
        convert_for_assignment.
        (build_unary_op): Handle increment and decrement of
        C_MAYBE_CONST_EXPR.  Move lvalue checks for increment and
        decrement earlier.  Fold operand of increment and decrement.
        Handle address of C_MAYBE_CONST_EXPR.  Only fold expression being
        built for integer operand.  Wrap returns that are INTEGER_CSTs
        without being integer constant expressions or that have integer
        constant operands without being INTEGER_CSTs.
        (lvalue_p): Handle C_MAYBE_CONST_EXPR.
        (build_conditional_expr): Add operand ifexp_bcp.  Track whether
        result is an integer constant expression or can be used in
        unevaluated parts of one and avoid folding and wrap as
        appropriate.  Fold operands before possibly doing -Wsign-compare
        warnings.
        (build_compound_expr): Wrap result for C99 if operands can be used
        in integer constant expressions.
        (build_c_cast): Update call to digest_init.  Do not ignore
        overflow from casting floating-point constants to integers.  Wrap
        results that could be confused with integer constant expressions,
        null pointer constants or floating-point constants.
        (c_cast_expr): Update call to groktypename.  Handle expressions
        included in type name.
        (build_modify_expr): Handle modifying a C_MAYBE_CONST_EXPR.  Fold
        lhs inside possible SAVE_EXPR.  Fold RHS before assignment.
        Update calls to convert_for_assignment.
        (convert_for_assignment): Take new parameter
        null_pointer_constant.  Do not strip nops or call
        decl_constant_value_for_broken_optimization.  Set
        in_late_binary_op for conversions to boolean.
        (store_init_value): Update call to digest_init.
        (digest_init): Take new parameter null_pointer_constant.  Do not
        call decl_constant_value_for_broken_optimization.  pedwarn for
        initializers not constant expressions.  Update calls to
        convert_for_assignment.
        (constructor_nonconst): New.
        (struct constructor_stack): Add nonconst element.
        (really_start_incremental_init, push_init_level, pop_init_level):
        Handle constructor_nonconst and nonconst element.
        (set_init_index): Call constant_expression_warning for array
        designators.
        (output_init_element): Fold value.  Set constructor_nonconst as
        applicable.  pedwarn for initializers not constant expressions.
        Update call to digest_init.  Call constant_expression_warning
        where constant initializers are required.
        (process_init_element): Use c_save_expr.
        (c_finish_goto_ptr): Fold expression.
        (c_finish_return): Fold return value.  Update call to
        convert_for_assignment.
        (c_start_case): Fold switch expression.
        (c_process_expr_stmt): Fold expression.
        (c_finish_stmt_expr): Create C_MAYBE_CONST_EXPR as needed to
        ensure statement expression is not evaluated in constant
        expression.
        (build_binary_op): Track whether results are integer constant
        expressions or may occur in such, disable folding and wrap results
        as applicable.  Fold operands for -Wsign-compare warnings unless
        in_late_binary_op.
        (c_objc_common_truthvalue_conversion): Handle results folded to
        integer constants that are not integer constant expressions.
        * doc/extend.texi: Document when typeof operands are evaluated,
        that condition of __builtin_choose_expr is an integer constant
        expression, and more about use of __builtin_constant_p in
        initializers.

gcc/objc:
        * objc-act.c (objc_finish_try_stmt): Set in_late_binary_op.

gcc/testsuite:
        * gcc.c-torture/compile/20081108-1.c,
        gcc.c-torture/compile/20081108-2.c,
        gcc.c-torture/compile/20081108-3.c, gcc.dg/bconstp-2.c,
        gcc.dg/bconstp-3.c, gcc.dg/bconstp-4.c, gcc.dg/c90-const-expr-6.c,
        gcc.dg/c90-const-expr-7.c, gcc.dg/c90-const-expr-8.c,
        gcc.dg/c90-const-expr-9.c, gcc.dg/c90-const-expr-10.c,
        gcc.dg/c90-const-expr-11.c, gcc.dg/c99-const-expr-6.c,
        gcc.dg/c99-const-expr-7.c, gcc.dg/c99-const-expr-8.c,
        gcc.dg/c99-const-expr-9.c, gcc.dg/c99-const-expr-10.c,
        gcc.dg/c99-const-expr-11.c, gcc.dg/c99-const-expr-12.c,
        gcc.dg/c99-const-expr-13.c, gcc.dg/compare10.c,
        gcc.dg/gnu89-const-expr-1.c, gcc.dg/gnu89-const-expr-2.c,
        gcc.dg/gnu99-const-expr-1.c, gcc.dg/gnu99-const-expr-2.c,
        gcc.dg/gnu99-const-expr-3.c, gcc.dg/vla-12.c, gcc.dg/vla-13.c,
        gcc.dg/vla-14.c, gcc.dg/vla-15.c, gcc.dg/vla-16.c: New tests.
        * gcc.dg/c90-const-expr-1.c, gcc.dg/c90-const-expr-2.c,
        gcc.dg/c90-const-expr-3.c, gcc.dg/c99-const-expr-2.c,
        gcc.dg/c99-const-expr-3.c, gcc.dg/c99-static-1.c: Remove XFAILs.
        * gcc.dg/c90-const-expr-2.c: Use ZERO in place of 0 in another
        case.
        * gcc.dg/overflow-warn-1.c, gcc.dg/overflow-warn-2.c,
        gcc.dg/overflow-warn-3.c, gcc.dg/overflow-warn-4.c: Remove
        XFAILs.  Update expected messages.
        * gcc.dg/pr14649-1.c, gcc.dg/pr19984.c, gcc.dg/pr25682.c: Update
        expected messages.
        * gcc.dg/real-const-1.c: Replace with test from original PR.
        * gcc.dg/vect/pr32230.c: Use intermediate cast to __PTRDIFF_TYPE__
        when casting from non-constant integer to pointer.

Added:
    trunk/fixincludes/tests/base/tgmath.h
    trunk/gcc/testsuite/gcc.c-torture/compile/20081108-1.c
    trunk/gcc/testsuite/gcc.c-torture/compile/20081108-2.c
    trunk/gcc/testsuite/gcc.c-torture/compile/20081108-3.c
    trunk/gcc/testsuite/gcc.dg/bconstp-2.c
    trunk/gcc/testsuite/gcc.dg/bconstp-3.c
    trunk/gcc/testsuite/gcc.dg/bconstp-4.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-10.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-11.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-6.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-7.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-8.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-9.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-10.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-11.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-12.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-13.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-6.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-7.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-8.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-9.c
    trunk/gcc/testsuite/gcc.dg/compare10.c
    trunk/gcc/testsuite/gcc.dg/gnu89-const-expr-1.c
    trunk/gcc/testsuite/gcc.dg/gnu89-const-expr-2.c
    trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-1.c
    trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-2.c
    trunk/gcc/testsuite/gcc.dg/gnu99-const-expr-3.c
    trunk/gcc/testsuite/gcc.dg/vla-12.c
    trunk/gcc/testsuite/gcc.dg/vla-13.c
    trunk/gcc/testsuite/gcc.dg/vla-14.c
    trunk/gcc/testsuite/gcc.dg/vla-15.c
    trunk/gcc/testsuite/gcc.dg/vla-16.c
Modified:
    trunk/fixincludes/ChangeLog
    trunk/fixincludes/fixincl.x
    trunk/fixincludes/inclhack.def
    trunk/gcc/ChangeLog
    trunk/gcc/builtins.c
    trunk/gcc/c-common.c
    trunk/gcc/c-common.def
    trunk/gcc/c-common.h
    trunk/gcc/c-convert.c
    trunk/gcc/c-decl.c
    trunk/gcc/c-parser.c
    trunk/gcc/c-tree.h
    trunk/gcc/c-typeck.c
    trunk/gcc/doc/extend.texi
    trunk/gcc/objc/ChangeLog
    trunk/gcc/objc/objc-act.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-1.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-2.c
    trunk/gcc/testsuite/gcc.dg/c90-const-expr-3.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-2.c
    trunk/gcc/testsuite/gcc.dg/c99-const-expr-3.c
    trunk/gcc/testsuite/gcc.dg/c99-static-1.c
    trunk/gcc/testsuite/gcc.dg/overflow-warn-1.c
    trunk/gcc/testsuite/gcc.dg/overflow-warn-2.c
    trunk/gcc/testsuite/gcc.dg/overflow-warn-3.c
    trunk/gcc/testsuite/gcc.dg/overflow-warn-4.c
    trunk/gcc/testsuite/gcc.dg/pr14649-1.c
    trunk/gcc/testsuite/gcc.dg/pr19984.c
    trunk/gcc/testsuite/gcc.dg/pr25682.c
    trunk/gcc/testsuite/gcc.dg/real-const-1.c
    trunk/gcc/testsuite/gcc.dg/vect/pr32230.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198

[Bug c/35198] [4.2/4.3/4.4/4.5 Regression] missed evaluation of VM array type when used as a cast

[jsm28 at gcc dot gnu dot org]

------- Comment #12 from jsm28 at gcc dot gnu dot org  2009-03-29 18:23 -------
Fixed for 4.5.  Fix not suitable for backporting.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|2.95.4                      |2.95.4 4.5.0
         Resolution|                            |FIXED
   Target Milestone|4.2.5                       |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35198