commit f476463cd2552d384d0ef6f43f250b3abd45e4cd (tree)
parent eb010ce65ddddb23ceddae86d377432cf1b2b01c
Author: Veikka Tuominen <git@vexu.eu>
Date: Wed, 28 Jul 2021 21:37:46 +0300
Merge pull request #9468 from ehaas/translate-c-inf-nan
translate-c: handle NAN and INFINITY macros
Diffstat:
7 files changed, 115 insertions(+), 5 deletions(-)
diff --git a/lib/std/zig/c_builtins.zig b/lib/std/zig/c_builtins.zig
@@ -191,6 +191,49 @@ pub inline fn __builtin_expect(expr: c_long, c: c_long) c_long {
return expr;
}
+/// returns a quiet NaN. Quiet NaNs have many representations; tagp is used to select one in an
+/// implementation-defined way.
+/// This implementation is based on the description for __builtin_nan provided in the GCC docs at
+/// https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fnan
+/// Comment is reproduced below:
+/// Since ISO C99 defines this function in terms of strtod, which we do not implement, a description
+/// of the parsing is in order.
+/// The string is parsed as by strtol; that is, the base is recognized by leading ‘0’ or ‘0x’ prefixes.
+/// The number parsed is placed in the significand such that the least significant bit of the number is
+/// at the least significant bit of the significand.
+/// The number is truncated to fit the significand field provided.
+/// The significand is forced to be a quiet NaN.
+///
+/// If tagp contains any non-numeric characters, the function returns a NaN whose significand is zero.
+/// If tagp is empty, the function returns a NaN whose significand is zero.
+pub inline fn __builtin_nanf(tagp: []const u8) f32 {
+ const parsed = std.fmt.parseUnsigned(c_ulong, tagp, 0) catch 0;
+ const bits = @truncate(u23, parsed); // single-precision float trailing significand is 23 bits
+ return @bitCast(f32, @as(u32, bits) | std.math.qnan_u32);
+}
+
+pub inline fn __builtin_huge_valf() f32 {
+ return std.math.inf(f32);
+}
+
+pub inline fn __builtin_inff() f32 {
+ return std.math.inf(f32);
+}
+
+pub inline fn __builtin_isnan(x: anytype) c_int {
+ return @boolToInt(std.math.isNan(x));
+}
+
+pub inline fn __builtin_isinf(x: anytype) c_int {
+ return @boolToInt(std.math.isInf(x));
+}
+
+/// Similar to isinf, except the return value is -1 for an argument of -Inf and 1 for an argument of +Inf.
+pub inline fn __builtin_isinf_sign(x: anytype) c_int {
+ if (!std.math.isInf(x)) return 0;
+ return if (std.math.isPositiveInf(x)) 1 else -1;
+}
+
// __builtin_alloca_with_align is not currently implemented.
// It is used in a run-translated-c test and a test-translate-c test to ensure that non-implemented
// builtins are correctly demoted. If you implement __builtin_alloca_with_align, please update the
diff --git a/src/clang.zig b/src/clang.zig
@@ -269,6 +269,11 @@ pub const CharacterLiteral = opaque {
extern fn ZigClangCharacterLiteral_getValue(*const CharacterLiteral) c_uint;
};
+pub const ChooseExpr = opaque {
+ pub const getChosenSubExpr = ZigClangChooseExpr_getChosenSubExpr;
+ extern fn ZigClangChooseExpr_getChosenSubExpr(*const ChooseExpr) *const Expr;
+};
+
pub const CompoundAssignOperator = opaque {
pub const getType = ZigClangCompoundAssignOperator_getType;
extern fn ZigClangCompoundAssignOperator_getType(*const CompoundAssignOperator) QualType;
diff --git a/src/translate_c.zig b/src/translate_c.zig
@@ -1308,6 +1308,10 @@ fn transStmt(
const shuffle_vec_node = try transShuffleVectorExpr(c, scope, shuffle_vec_expr);
return maybeSuppressResult(c, scope, result_used, shuffle_vec_node);
},
+ .ChooseExprClass => {
+ const choose_expr = @ptrCast(*const clang.ChooseExpr, stmt);
+ return transExpr(c, scope, choose_expr.getChosenSubExpr(), result_used);
+ },
// When adding new cases here, see comment for maybeBlockify()
.GCCAsmStmtClass,
.GotoStmtClass,
@@ -1969,7 +1973,7 @@ fn transBuiltinFnExpr(c: *Context, scope: *Scope, expr: *const clang.Expr, used:
const node = try transExpr(c, scope, expr, used);
if (node.castTag(.identifier)) |ident| {
const name = ident.data;
- if (!isBuiltinDefined(name)) return fail(c, error.UnsupportedTranslation, expr.getBeginLoc(), "TODO implement function '{s}' in std.c.builtins", .{name});
+ if (!isBuiltinDefined(name)) return fail(c, error.UnsupportedTranslation, expr.getBeginLoc(), "TODO implement function '{s}' in std.zig.c_builtins", .{name});
}
return node;
}
@@ -5574,7 +5578,7 @@ fn parseCPrimaryExprInner(c: *Context, m: *MacroCtx, scope: *Scope) ParseError!N
.Identifier => {
const mangled_name = scope.getAlias(slice);
if (mem.startsWith(u8, mangled_name, "__builtin_") and !isBuiltinDefined(mangled_name)) {
- try m.fail(c, "TODO implement function '{s}' in std.c.builtins", .{mangled_name});
+ try m.fail(c, "TODO implement function '{s}' in std.zig.c_builtins", .{mangled_name});
return error.ParseError;
}
const identifier = try Tag.identifier.create(c.arena, builtin_typedef_map.get(mangled_name) orelse mangled_name);
diff --git a/src/zig_clang.cpp b/src/zig_clang.cpp
@@ -2832,6 +2832,11 @@ unsigned ZigClangCharacterLiteral_getValue(const struct ZigClangCharacterLiteral
return casted->getValue();
}
+const struct ZigClangExpr *ZigClangChooseExpr_getChosenSubExpr(const struct ZigClangChooseExpr *self) {
+ auto casted = reinterpret_cast<const clang::ChooseExpr *>(self);
+ return reinterpret_cast<const ZigClangExpr *>(casted->getChosenSubExpr());
+}
+
const struct ZigClangExpr *ZigClangAbstractConditionalOperator_getCond(const struct ZigClangAbstractConditionalOperator *self) {
auto casted = reinterpret_cast<const clang::AbstractConditionalOperator *>(self);
return reinterpret_cast<const struct ZigClangExpr *>(casted->getCond());
diff --git a/src/zig_clang.h b/src/zig_clang.h
@@ -104,6 +104,7 @@ struct ZigClangCStyleCastExpr;
struct ZigClangCallExpr;
struct ZigClangCaseStmt;
struct ZigClangCharacterLiteral;
+struct ZigClangChooseExpr;
struct ZigClangCompoundAssignOperator;
struct ZigClangCompoundStmt;
struct ZigClangConditionalOperator;
@@ -1242,6 +1243,8 @@ ZIG_EXTERN_C struct ZigClangSourceLocation ZigClangCharacterLiteral_getBeginLoc(
ZIG_EXTERN_C enum ZigClangCharacterLiteral_CharacterKind ZigClangCharacterLiteral_getKind(const struct ZigClangCharacterLiteral *);
ZIG_EXTERN_C unsigned ZigClangCharacterLiteral_getValue(const struct ZigClangCharacterLiteral *);
+ZIG_EXTERN_C const struct ZigClangExpr *ZigClangChooseExpr_getChosenSubExpr(const struct ZigClangChooseExpr *);
+
ZIG_EXTERN_C const struct ZigClangExpr *ZigClangAbstractConditionalOperator_getCond(const struct ZigClangAbstractConditionalOperator *);
ZIG_EXTERN_C const struct ZigClangExpr *ZigClangAbstractConditionalOperator_getTrueExpr(const struct ZigClangAbstractConditionalOperator *);
ZIG_EXTERN_C const struct ZigClangExpr *ZigClangAbstractConditionalOperator_getFalseExpr(const struct ZigClangAbstractConditionalOperator *);
diff --git a/test/run_translated_c.zig b/test/run_translated_c.zig
@@ -1243,7 +1243,7 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
\\}
, "");
- // See __builtin_alloca_with_align comment in std.c.builtins
+ // See __builtin_alloca_with_align comment in std.zig.c_builtins
cases.add("use of unimplemented builtin in unused function does not prevent compilation",
\\#include <stdlib.h>
\\void unused() {
@@ -1659,4 +1659,54 @@ pub fn addCases(cases: *tests.RunTranslatedCContext) void {
\\ return 0;
\\}
, "");
+
+ cases.add("__builtin_choose_expr (unchosen expression is not evaluated)",
+ \\#include <stdlib.h>
+ \\int main(void) {
+ \\ int x = 0.0;
+ \\ int y = 0.0;
+ \\ int res;
+ \\ res = __builtin_choose_expr(1, 1, x / y);
+ \\ if (res != 1) abort();
+ \\ res = __builtin_choose_expr(0, x / y, 2);
+ \\ if (res != 2) abort();
+ \\ return 0;
+ \\}
+ , "");
+
+ // TODO: add isnan check for long double once bitfield support is added
+ // (needed for x86_64-windows-gnu)
+ // TODO: add isinf check for long double once std.math.isInf supports c_longdouble
+ cases.add("NAN and INFINITY",
+ \\#include <math.h>
+ \\#include <stdint.h>
+ \\#include <stdlib.h>
+ \\union uf { uint32_t u; float f; };
+ \\#define CHECK_NAN(STR, VAL) { \
+ \\ union uf unpack = {.f = __builtin_nanf(STR)}; \
+ \\ if (!isnan(unpack.f)) abort(); \
+ \\ if (unpack.u != VAL) abort(); \
+ \\}
+ \\int main(void) {
+ \\ float f_nan = NAN;
+ \\ if (!isnan(f_nan)) abort();
+ \\ double d_nan = NAN;
+ \\ if (!isnan(d_nan)) abort();
+ \\ CHECK_NAN("0", 0x7FC00000);
+ \\ CHECK_NAN("", 0x7FC00000);
+ \\ CHECK_NAN("1", 0x7FC00001);
+ \\ CHECK_NAN("0x7FC00000", 0x7FC00000);
+ \\ CHECK_NAN("0x7FC0000F", 0x7FC0000F);
+ \\ CHECK_NAN("0x7FC000F0", 0x7FC000F0);
+ \\ CHECK_NAN("0x7FC00F00", 0x7FC00F00);
+ \\ CHECK_NAN("0x7FC0F000", 0x7FC0F000);
+ \\ CHECK_NAN("0x7FCF0000", 0x7FCF0000);
+ \\ CHECK_NAN("0xFFFFFFFF", 0x7FFFFFFF);
+ \\ float f_inf = INFINITY;
+ \\ if (!isinf(f_inf)) abort();
+ \\ double d_inf = INFINITY;
+ \\ if (!isinf(d_inf)) abort();
+ \\ return 0;
+ \\}
+ , "");
}
diff --git a/test/translate_c.zig b/test/translate_c.zig
@@ -3461,11 +3461,11 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
\\pub const MAY_NEED_PROMOTION_OCT = @import("std").zig.c_translation.promoteIntLiteral(c_int, 0o20000000000, .octal);
});
- // See __builtin_alloca_with_align comment in std.c.builtins
+ // See __builtin_alloca_with_align comment in std.zig.c_builtins
cases.add("demote un-implemented builtins",
\\#define FOO(X) __builtin_alloca_with_align((X), 8)
, &[_][]const u8{
- \\pub const FOO = @compileError("TODO implement function '__builtin_alloca_with_align' in std.c.builtins");
+ \\pub const FOO = @compileError("TODO implement function '__builtin_alloca_with_align' in std.zig.c_builtins");
});
cases.add("null sentinel arrays when initialized from string literal. Issue #8256",
