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author | Joseph Myers <joseph@codesourcery.com> | 2019-11-25 13:45:42 +0000 |
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committer | Joseph Myers <jsm28@gcc.gnu.org> | 2019-11-25 13:45:42 +0000 |
commit | 5b8d9367684f266c30c280b4d3c98830a88c70ab (patch) | |
tree | f3d44301e44a62097c89ae2d9b87cb97780f5d94 /gcc/tree.c | |
parent | 1723e1bedb9545c45619c4023729755243524584 (diff) | |
download | gcc-5b8d9367684f266c30c280b4d3c98830a88c70ab.zip gcc-5b8d9367684f266c30c280b4d3c98830a88c70ab.tar.gz gcc-5b8d9367684f266c30c280b4d3c98830a88c70ab.tar.bz2 |
Prevent all uses of DFP when unsupported (PR c/91985).
Code that directly uses _Decimal* types on architectures not
supporting DFP is properly diagnosed ("error: decimal floating-point
not supported for this target"), via a call to
targetm.decimal_float_supported_p, if the _Decimal32, _Decimal64 or
_Decimal128 keywords are used to access it. Use via mode attributes
is also diagnosed ("unable to emulate 'SD'"); so is use of the
FLOAT_CONST_DECIMAL64 pragma. However, it is possible to access those
types via typeof applied to constants or built-in functions without
such an error. I expect that there are ways to get an ICE from this;
certainly it uses a completely undefined ABI.
This patch arranges for the types not to exist in the compiler at all
when DFP is not supported. As is done with unsupported _FloatN /
_FloatNx types, the global tree nodes are left as NULL_TREE, and the
built-in function machinery is made to use error_mark_node for them in
that case in builtin-types.def, so that the built-in functions are
unavailable. Code handling constants is adjusted to give an error,
and other code that might not work with the global tree nodes being
NULL_TREE is also updated.
Bootstrapped with no regressions for x86_64-pc-linux-gnu. Also tested
with no regressions for cross to aarch64-linux-gnu, as a configuration
without DFP support.
PR c/91985
gcc:
* builtin-types.def (BT_DFLOAT32, BT_DFLOAT64, BT_DFLOAT128)
(BT_DFLOAT32_PTR, BT_DFLOAT64_PTR, BT_DFLOAT128_PTR): Define to
error_mark_node if corresponding global tree node is NULL.
* tree.c (build_common_tree_nodes): Do not initialize
dfloat32_type_node, dfloat64_type_node or dfloat128_type_node if
decimal floating-point not supported.
gcc/c:
* c-decl.c (finish_declspecs): Use int instead of decimal
floating-point types if decimal floating-point not supported.
gcc/c-family:
* c-common.c (c_common_type_for_mode): Handle decimal
floating-point types being NULL_TREE.
* c-format.c (get_format_for_type_1): Handle specified types being
NULL_TREE.
* c-lex.c (interpret_float): Give an error for decimal
floating-point constants when decimal floating-point not
supported.
gcc/lto:
* lto-lang.c (lto_type_for_mode): Handle decimal floating-point
types being NULL_TREE.
gcc/testsuite:
* gcc.dg/c2x-no-dfp-1.c, gcc.dg/gnu2x-builtins-no-dfp-1.c: New
tests.
* gcc.dg/fltconst-pedantic-dfp.c: Expect errors when decimal
floating-point not supported.
From-SVN: r278684
Diffstat (limited to 'gcc/tree.c')
-rw-r--r-- | gcc/tree.c | 37 |
1 files changed, 20 insertions, 17 deletions
@@ -10334,23 +10334,26 @@ build_common_tree_nodes (bool signed_char) uint64_type_node = make_or_reuse_type (64, 1); /* Decimal float types. */ - dfloat32_type_node = make_node (REAL_TYPE); - TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE; - SET_TYPE_MODE (dfloat32_type_node, SDmode); - layout_type (dfloat32_type_node); - dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node); - - dfloat64_type_node = make_node (REAL_TYPE); - TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE; - SET_TYPE_MODE (dfloat64_type_node, DDmode); - layout_type (dfloat64_type_node); - dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node); - - dfloat128_type_node = make_node (REAL_TYPE); - TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE; - SET_TYPE_MODE (dfloat128_type_node, TDmode); - layout_type (dfloat128_type_node); - dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node); + if (targetm.decimal_float_supported_p ()) + { + dfloat32_type_node = make_node (REAL_TYPE); + TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE; + SET_TYPE_MODE (dfloat32_type_node, SDmode); + layout_type (dfloat32_type_node); + dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node); + + dfloat64_type_node = make_node (REAL_TYPE); + TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE; + SET_TYPE_MODE (dfloat64_type_node, DDmode); + layout_type (dfloat64_type_node); + dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node); + + dfloat128_type_node = make_node (REAL_TYPE); + TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE; + SET_TYPE_MODE (dfloat128_type_node, TDmode); + layout_type (dfloat128_type_node); + dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node); + } complex_integer_type_node = build_complex_type (integer_type_node, true); complex_float_type_node = build_complex_type (float_type_node, true); |