| author |  Veikka Tuominen <git@vexu.eu> 2020-08-20 10:08:27+03:00 |
| committer | Veikka Tuominen <git@vexu.eu> 2020-08-20 10:08:27+03:00 |
| log | adc5bce5e8487cf9507ab5dd2b1b60dd7f54cc3d |
| tree | 542edd9771b0a550642497108ab75fbc779f71db |
| parent | 91de5c212fe847a309f047e3097491bba6f86ae1 |
| signature | Commit is signed but in an unrecognized format. |
translate-c: correct translation of global variables
* externs with intializers are translated as exports
* non extern without explicit initialization are zero initalized3 files changed, 46 insertions(+), 7 deletions(-)
lib
std
src-self-hosted
test
lib/std/mem.zig+19-1
| ... | ... | @@ -221,9 +221,19 @@ pub fn zeroes(comptime T: type) T { |
| 221 | 221 | .Vector => |info| { |
| 222 | 222 | return @splat(info.len, zeroes(info.child)); |
| 223 | 223 | }, |
| 224 | .Union => |info| { | |
| 225 | if (comptime meta.containerLayout(T) == .Extern) { | |
| 226 | // The C language specification states that (global) unions | |
| 227 | // should be zero initialized to the first named member. | |
| 228 | var item: T = undefined; | |
| 229 | @field(item, info.fields[0].name) = zeroes(@TypeOf(@field(item, info.fields[0].name))); | |
| 230 | return item; | |
| 231 | } | |
| 232 | ||
| 233 | @compileError("Can't set a " ++ @typeName(T) ++ " to zero."); | |
| 234 | }, | |
| 224 | 235 | .ErrorUnion, |
| 225 | 236 | .ErrorSet, |
| 226 | .Union, | |
| 227 | 237 | .Fn, |
| 228 | 238 | .BoundFn, |
| 229 | 239 | .Type, |
| ... | ... | @@ -312,6 +322,14 @@ test "mem.zeroes" { |
| 312 | 322 | for (b.sentinel) |e| { |
| 313 | 323 | testing.expectEqual(@as(u8, 0), e); |
| 314 | 324 | } |
| 325 | ||
| 326 | const C_union = extern union { | |
| 327 | a: u8, | |
| 328 | b: u32, | |
| 329 | }; | |
| 330 | ||
| 331 | var c = zeroes(C_union); | |
| 332 | testing.expectEqual(@as(u8, 0), c.a); | |
| 315 | 333 | } |
| 316 | 334 | |
| 317 | 335 | /// Sets a slice to zeroes. |
src-self-hosted/translate_c.zig+25-4
| ... | ... | @@ -701,8 +701,14 @@ fn visitVarDecl(c: *Context, var_decl: *const ZigClangVarDecl) Error!void { |
| 701 | 701 | const qual_type = ZigClangVarDecl_getTypeSourceInfo_getType(var_decl); |
| 702 | 702 | const storage_class = ZigClangVarDecl_getStorageClass(var_decl); |
| 703 | 703 | const is_const = ZigClangQualType_isConstQualified(qual_type); |
| 704 | ||
| 705 | const extern_tok = if (storage_class == .Extern) | |
| 704 | const has_init = ZigClangVarDecl_hasInit(var_decl); | |
| 705 | ||
| 706 | // In C extern variables with initializers behave like Zig exports. | |
| 707 | // extern int foo = 2; | |
| 708 | // does the same as: | |
| 709 | // extern int foo; | |
| 710 | // int foo = 2; | |
| 711 | const extern_tok = if (storage_class == .Extern and !has_init) | |
| 706 | 712 | try appendToken(c, .Keyword_extern, "extern") |
| 707 | 713 | else if (storage_class != .Static) |
| 708 | 714 | try appendToken(c, .Keyword_export, "export") |
| ... | ... | @@ -730,7 +736,7 @@ fn visitVarDecl(c: *Context, var_decl: *const ZigClangVarDecl) Error!void { |
| 730 | 736 | // If the initialization expression is not present, initialize with undefined. |
| 731 | 737 | // If it is an integer literal, we can skip the @as since it will be redundant |
| 732 | 738 | // with the variable type. |
| 733 | if (ZigClangVarDecl_hasInit(var_decl)) { | |
| 739 | if (has_init) { | |
| 734 | 740 | eq_tok = try appendToken(c, .Equal, "="); |
| 735 | 741 | init_node = if (ZigClangVarDecl_getInit(var_decl)) |expr| |
| 736 | 742 | transExprCoercing(rp, &c.global_scope.base, expr, .used, .r_value) catch |err| switch (err) { |
| ... | ... | @@ -745,7 +751,22 @@ fn visitVarDecl(c: *Context, var_decl: *const ZigClangVarDecl) Error!void { |
| 745 | 751 | try transCreateNodeUndefinedLiteral(c); |
| 746 | 752 | } else if (storage_class != .Extern) { |
| 747 | 753 | eq_tok = try appendToken(c, .Equal, "="); |
| 748 | init_node = try transCreateNodeIdentifierUnchecked(c, "undefined"); | |
| 754 | // The C language specification states that variables with static or threadlocal | |
| 755 | // storage without an initializer are initialized to a zero value. | |
| 756 | ||
| 757 | // @import("std").mem.zeroes(T) | |
| 758 | const import_fn_call = try c.createBuiltinCall("@import", 1); | |
| 759 | const std_node = try transCreateNodeStringLiteral(c, "\"std\""); | |
| 760 | import_fn_call.params()[0] = std_node; | |
| 761 | import_fn_call.rparen_token = try appendToken(c, .RParen, ")"); | |
| 762 | const inner_field_access = try transCreateNodeFieldAccess(c, &import_fn_call.base, "mem"); | |
| 763 | const outer_field_access = try transCreateNodeFieldAccess(c, inner_field_access, "zeroes"); | |
| 764 | ||
| 765 | const zero_init_call = try c.createCall(outer_field_access, 1); | |
| 766 | zero_init_call.params()[0] = type_node; | |
| 767 | zero_init_call.rtoken = try appendToken(c, .RParen, ")"); | |
| 768 | ||
| 769 | init_node = &zero_init_call.base; | |
| 749 | 770 | } |
| 750 | 771 | |
| 751 | 772 | const linksection_expr = blk: { |
test/translate_c.zig+2-2
| ... | ... | @@ -466,7 +466,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void { |
| 466 | 466 | , &[_][]const u8{ |
| 467 | 467 | \\pub extern var extern_var: c_int; |
| 468 | 468 | \\pub const int_var: c_int = 13; |
| 469 | \\pub export var foo: c_int = undefined; | |
| 469 | \\pub export var foo: c_int = @import("std").mem.zeroes(c_int); | |
| 470 | 470 | }); |
| 471 | 471 | |
| 472 | 472 | cases.add("const ptr initializer", |
| ... | ... | @@ -1327,7 +1327,7 @@ pub fn addCases(cases: *tests.TranslateCContext) void { |
| 1327 | 1327 | \\static char arr1[] = "hello"; |
| 1328 | 1328 | \\char arr2[] = "hello"; |
| 1329 | 1329 | , &[_][]const u8{ |
| 1330 | \\pub extern var arr0: [*c]u8 = "hello"; | |
| 1330 | \\pub export var arr0: [*c]u8 = "hello"; | |
| 1331 | 1331 | \\pub var arr1: [*c]u8 = "hello"; |
| 1332 | 1332 | \\pub export var arr2: [*c]u8 = "hello"; |
| 1333 | 1333 | }); |