Roland Scheidegger <[email protected]> writes: > Am 25.02.2018 um 03:35 schrieb Francisco Jerez: >> Roland Scheidegger <[email protected]> writes: >> >>> This seems to have broken compilation with some gcc versions (with scons >>> build): >>> >>> In file included from src/compiler/glsl/ast_array_index.cpp:24:0: >>> src/compiler/glsl/ast.h:648:16: error: member >>> ‘ast_type_qualifier::bitset_t ast_type_qualifier::flags::i’ with >>> constructor not allowed in union >>> bitset_t i; >>> ^ >> >> Oops... And the only reason bitset_t has a default constructor was... >> to avoid using another C++11 feature (defaulted member functions). >> Does the attached patch fix the build failure for you? The cleaner >> alternative would be to define the default constructor of the bitset >> object like 'T() = default', but that would imply dropping support for >> GCC 4.2-4.3 which don't implement the feature... > > FWIW the compile error was happening with gcc 4.8 - I didn't see it with > gcc 5.4. > (I don't think at vmware we'd care about anything older than gcc 4.4 at > least but last time someone wanted to bump gcc requirements there were > still people requiring gcc 4.2.) > > The patch compiles albeit there's about two dozen warnings like the > following: > glsl/ast_type.cpp: In member function 'bool > ast_fully_specified_type::has_qualifiers(_mesa_glsl_parse_state*) const': > glsl/ast_type.cpp:50:67: warning: ISO C++ says that these are ambiguous, > even though the worst conversion for the first is better than the worst > conversion for the second: [enabled by default] > return (this->qualifier.flags.i & ~subroutine_only.flags.i) != 0; > ^ > In file included from glsl/ast.h:31:0, > from glsl/ast_type.cpp:24: > ../../src/util/bitset.h:181:7: note: candidate 1: bool operator!=(const > ast_type_qualifier::bitset_t&, unsigned int) > operator!=(const T &b, BITSET_WORD x) \ > ^ > glsl/ast.h:477:4: note: in expansion of macro 'DECLARE_BITSET_T' > DECLARE_BITSET_T(bitset_t, 128); > ^ > glsl/ast_type.cpp:50:67: note: candidate 2: operator!=(int, int) <built-in> > return (this->qualifier.flags.i & ~subroutine_only.flags.i) != 0; > ^ > Roland >
Ah, yeah, that's because I didn't provide overloads for signed integer types, but it should be harmless since the two candidates have the same semantics, and should go away with a C++11-capable compiler. I think the attached patch should shut the warnings on older compilers. > > >> >>> src/compiler/glsl/ast.h:648:16: note: unrestricted unions only available >>> with -std=c++11 or -std=gnu++11 >>> scons: *** [build/linux-x86_64-checked/compiler/glsl/ast_array_index.os] >>> Error 1 >>> src/gallium/tests/unit/u_format_test.c: In function ‘main’: >>> src/gallium/tests/unit/u_format_test.c:649:44: warning: array subscript >>> is above array bounds [-Warray-bounds] >>> unpacked[i][j] = test->unpacked[i][j][1]; >>> ^ >>> In file included from src/compiler/glsl/ast_expr.cpp:24:0: >>> src/compiler/glsl/ast.h:648:16: error: member >>> ‘ast_type_qualifier::bitset_t ast_type_qualifier::flags::i’ with >>> constructor not allowed in union >>> bitset_t i; >>> ^ >>> src/compiler/glsl/ast.h:648:16: note: unrestricted unions only available >>> with -std=c++11 or -std=gnu++11 >>> >>> Roland >>> >>> [...] >>
From 14d35896450e6d5495c440a3b9440689a91724a1 Mon Sep 17 00:00:00 2001 From: Francisco Jerez <[email protected]> Date: Sat, 24 Feb 2018 18:37:34 -0800 Subject: [PATCH] util/bitset: Make C++ wrapper trivially constructible. v2: Provide signed integer comparison and assignment operators instead of BITSET_WORD ones to avoid spurious ambiguity warnings on comparisons with a signed integer literal. --- src/compiler/glsl/ast.h | 2 -- src/compiler/glsl/glsl_parser.yy | 1 - src/util/bitset.h | 37 ++++++++++++++++++++----------------- 3 files changed, 20 insertions(+), 20 deletions(-) diff --git a/src/compiler/glsl/ast.h b/src/compiler/glsl/ast.h index e5e4b572fff..a1ec0d566f4 100644 --- a/src/compiler/glsl/ast.h +++ b/src/compiler/glsl/ast.h @@ -477,8 +477,6 @@ struct ast_type_qualifier { DECLARE_BITSET_T(bitset_t, 128); union flags { - flags() : i(0) {} - struct { unsigned invariant:1; unsigned precise:1; diff --git a/src/compiler/glsl/glsl_parser.yy b/src/compiler/glsl/glsl_parser.yy index f1986ed0a8a..e5ea41d4dff 100644 --- a/src/compiler/glsl/glsl_parser.yy +++ b/src/compiler/glsl/glsl_parser.yy @@ -96,7 +96,6 @@ static bool match_layout_qualifier(const char *s1, const char *s2, %parse-param {struct _mesa_glsl_parse_state *state} %union { - YYSTYPE() {} int n; int64_t n64; float real; diff --git a/src/util/bitset.h b/src/util/bitset.h index 7bb5f3c83cf..b4c21520238 100644 --- a/src/util/bitset.h +++ b/src/util/bitset.h @@ -142,23 +142,6 @@ __bitset_next_set(unsigned i, BITSET_WORD *tmp, * it as, and N is the number of bits in the bitset. */ #define DECLARE_BITSET_T(T, N) struct T { \ - /* XXX - Replace this with an implicitly-defined \ - * constructor when support for C++11 defaulted \ - * constructors can be assumed (available on GCC 4.4 and \ - * later) in order to make the object trivially \ - * constructible like a fundamental integer type for \ - * convenience. \ - */ \ - T() \ - { \ - } \ - \ - T(BITSET_WORD x) \ - { \ - for (unsigned i = 0; i < BITSET_WORDS(N); i++, x = 0) \ - words[i] = x; \ - } \ - \ EXPLICIT_CONVERSION \ operator bool() const \ { \ @@ -168,6 +151,13 @@ __bitset_next_set(unsigned i, BITSET_WORD *tmp, return false; \ } \ \ + T & \ + operator=(int x) \ + { \ + const T c = {{ (BITSET_WORD)x }}; \ + return *this = c; \ + } \ + \ friend bool \ operator==(const T &b, const T &c) \ { \ @@ -180,6 +170,19 @@ __bitset_next_set(unsigned i, BITSET_WORD *tmp, return !(b == c); \ } \ \ + friend bool \ + operator==(const T &b, int x) \ + { \ + const T c = {{ (BITSET_WORD)x }}; \ + return b == c; \ + } \ + \ + friend bool \ + operator!=(const T &b, int x) \ + { \ + return !(b == x); \ + } \ + \ friend T \ operator~(const T &b) \ { \ -- 2.16.1
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