From fd50696359ec86abd238993930e979433a31db9a Mon Sep 17 00:00:00 2001 From: antlilja Date: Tue, 23 Jun 2020 15:18:28 +0200 Subject: [PATCH 1/3] Store else node in IrInstSrcCheckSwitchProngs * Remove have_else_prong (bool) * Add else_prong (AstNode*) --- src/all_types.hpp | 2 +- src/ir.cpp | 16 ++++++++-------- src/ir_print.cpp | 2 +- 3 files changed, 10 insertions(+), 10 deletions(-) diff --git a/src/all_types.hpp b/src/all_types.hpp index 88c7e96943..ef60a05fab 100644 --- a/src/all_types.hpp +++ b/src/all_types.hpp @@ -4095,7 +4095,7 @@ struct IrInstSrcCheckSwitchProngs { IrInstSrc *target_value; IrInstSrcCheckSwitchProngsRange *ranges; size_t range_count; - bool have_else_prong; + AstNode* else_prong; bool have_underscore_prong; }; diff --git a/src/ir.cpp b/src/ir.cpp index 635af397c4..44df69aeed 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -4274,14 +4274,14 @@ static IrInstGen *ir_build_err_to_int_gen(IrAnalyze *ira, Scope *scope, AstNode static IrInstSrc *ir_build_check_switch_prongs(IrBuilderSrc *irb, Scope *scope, AstNode *source_node, IrInstSrc *target_value, IrInstSrcCheckSwitchProngsRange *ranges, size_t range_count, - bool have_else_prong, bool have_underscore_prong) + AstNode* else_prong, bool have_underscore_prong) { IrInstSrcCheckSwitchProngs *instruction = ir_build_instruction( irb, scope, source_node); instruction->target_value = target_value; instruction->ranges = ranges; instruction->range_count = range_count; - instruction->have_else_prong = have_else_prong; + instruction->else_prong = else_prong; instruction->have_underscore_prong = have_underscore_prong; ir_ref_instruction(target_value, irb->current_basic_block); @@ -9305,7 +9305,7 @@ static IrInstSrc *ir_gen_switch_expr(IrBuilderSrc *irb, Scope *scope, AstNode *n } IrInstSrc *switch_prongs_void = ir_build_check_switch_prongs(irb, scope, node, target_value, - check_ranges.items, check_ranges.length, else_prong != nullptr, underscore_prong != nullptr); + check_ranges.items, check_ranges.length, else_prong, underscore_prong != nullptr); IrInstSrc *br_instruction; if (cases.length == 0) { @@ -28685,7 +28685,7 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, buf_ptr(enum_field->name))); } } - } else if (!instruction->have_else_prong) { + } else if (instruction->else_prong == nullptr) { if (switch_type->data.enumeration.non_exhaustive) { ir_add_error(ira, &instruction->base.base, buf_sprintf("switch on non-exhaustive enum must include `else` or `_` prong")); @@ -28746,7 +28746,7 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, } field_prev_uses[start_index] = start_value->base.source_node; } - if (!instruction->have_else_prong) { + if (instruction->else_prong == nullptr) { if (type_is_global_error_set(switch_type)) { ir_add_error(ira, &instruction->base.base, buf_sprintf("else prong required when switching on type 'anyerror'")); @@ -28808,7 +28808,7 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, return ira->codegen->invalid_inst_gen; } } - if (!instruction->have_else_prong) { + if (instruction->else_prong == nullptr) { BigInt min_val; eval_min_max_value_int(ira->codegen, switch_type, &min_val, false); BigInt max_val; @@ -28847,11 +28847,11 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, return ira->codegen->invalid_inst_gen; } } - if (((seenTrue < 1) || (seenFalse < 1)) && !instruction->have_else_prong) { + if (((seenTrue < 1) || (seenFalse < 1)) && instruction->else_prong == nullptr) { ir_add_error(ira, &instruction->base.base, buf_sprintf("switch must handle all possibilities")); return ira->codegen->invalid_inst_gen; } - } else if (!instruction->have_else_prong) { + } else if (instruction->else_prong == nullptr) { ir_add_error(ira, &instruction->base.base, buf_sprintf("else prong required when switching on type '%s'", buf_ptr(&switch_type->name))); return ira->codegen->invalid_inst_gen; diff --git a/src/ir_print.cpp b/src/ir_print.cpp index 27bedff47f..e9f029c930 100644 --- a/src/ir_print.cpp +++ b/src/ir_print.cpp @@ -2177,7 +2177,7 @@ static void ir_print_check_switch_prongs(IrPrintSrc *irp, IrInstSrcCheckSwitchPr fprintf(irp->f, "..."); ir_print_other_inst_src(irp, instruction->ranges[i].end); } - const char *have_else_str = instruction->have_else_prong ? "yes" : "no"; + const char *have_else_str = instruction->else_prong != nullptr ? "yes" : "no"; fprintf(irp->f, ")else:%s", have_else_str); } From e60be3082499ff19078699675044b993f6921ad0 Mon Sep 17 00:00:00 2001 From: antlilja Date: Wed, 24 Jun 2020 19:02:31 +0200 Subject: [PATCH 2/3] Remove unreachable else prongs --- lib/std/zig/string_literal.zig | 1 - src-self-hosted/translate_c.zig | 1 - test/stage1/behavior/bugs/1111.zig | 1 - 3 files changed, 3 deletions(-) diff --git a/lib/std/zig/string_literal.zig b/lib/std/zig/string_literal.zig index cc6030ad15..9def0bdefc 100644 --- a/lib/std/zig/string_literal.zig +++ b/lib/std/zig/string_literal.zig @@ -104,7 +104,6 @@ pub fn parse( return error.InvalidCharacter; }, }, - else => unreachable, } } unreachable; diff --git a/src-self-hosted/translate_c.zig b/src-self-hosted/translate_c.zig index 3b1a91b28c..dad3b14a29 100644 --- a/src-self-hosted/translate_c.zig +++ b/src-self-hosted/translate_c.zig @@ -2791,7 +2791,6 @@ fn transCharLiteral( "TODO: support character literal kind {}", .{kind}, ), - else => unreachable, }; if (suppress_as == .no_as) { return maybeSuppressResult(rp, scope, result_used, int_lit_node); diff --git a/test/stage1/behavior/bugs/1111.zig b/test/stage1/behavior/bugs/1111.zig index f62107f9a3..607bc33666 100644 --- a/test/stage1/behavior/bugs/1111.zig +++ b/test/stage1/behavior/bugs/1111.zig @@ -7,6 +7,5 @@ test "issue 1111 fixed" { switch (v) { Foo.Bar => return, - else => return, } } From dcc406deff0fb4ee3c2cd1f4ff8614e972a8ea7a Mon Sep 17 00:00:00 2001 From: antlilja Date: Wed, 24 Jun 2020 19:12:42 +0200 Subject: [PATCH 3/3] Add new error message for unreachable else prongs * Adds error message for types: enum, int and bool * Adds compile error tests --- src/ir.cpp | 20 +++++++-- test/compile_errors.zig | 96 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 113 insertions(+), 3 deletions(-) diff --git a/src/ir.cpp b/src/ir.cpp index 44df69aeed..8395cf0a3e 100644 --- a/src/ir.cpp +++ b/src/ir.cpp @@ -28700,6 +28700,10 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, buf_ptr(enum_field->name))); } } + } else if(!switch_type->data.enumeration.non_exhaustive && switch_type->data.enumeration.src_field_count == instruction->range_count) { + ir_add_error_node(ira, instruction->else_prong, + buf_sprintf("unreachable else prong, all cases already handled")); + return ira->codegen->invalid_inst_gen; } } else if (switch_type->id == ZigTypeIdErrorSet) { if (!resolve_inferred_error_set(ira->codegen, switch_type, target_value->base.source_node)) { @@ -28808,16 +28812,20 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, return ira->codegen->invalid_inst_gen; } } - if (instruction->else_prong == nullptr) { + BigInt min_val; eval_min_max_value_int(ira->codegen, switch_type, &min_val, false); BigInt max_val; eval_min_max_value_int(ira->codegen, switch_type, &max_val, true); - if (!rangeset_spans(&rs, &min_val, &max_val)) { + bool handles_all_cases = rangeset_spans(&rs, &min_val, &max_val); + if (!handles_all_cases && instruction->else_prong == nullptr) { ir_add_error(ira, &instruction->base.base, buf_sprintf("switch must handle all possibilities")); return ira->codegen->invalid_inst_gen; + } else if(handles_all_cases && instruction->else_prong != nullptr) { + ir_add_error_node(ira, instruction->else_prong, + buf_sprintf("unreachable else prong, all cases already handled")); + return ira->codegen->invalid_inst_gen; } - } } else if (switch_type->id == ZigTypeIdBool) { int seenTrue = 0; int seenFalse = 0; @@ -28851,6 +28859,12 @@ static IrInstGen *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira, ir_add_error(ira, &instruction->base.base, buf_sprintf("switch must handle all possibilities")); return ira->codegen->invalid_inst_gen; } + + if(seenTrue == 1 && seenFalse == 1 && instruction->else_prong != nullptr) { + ir_add_error_node(ira, instruction->else_prong, + buf_sprintf("unreachable else prong, all cases already handled")); + return ira->codegen->invalid_inst_gen; + } } else if (instruction->else_prong == nullptr) { ir_add_error(ira, &instruction->base.base, buf_sprintf("else prong required when switching on type '%s'", buf_ptr(&switch_type->name))); diff --git a/test/compile_errors.zig b/test/compile_errors.zig index 3f898cc337..29ff994cd3 100644 --- a/test/compile_errors.zig +++ b/test/compile_errors.zig @@ -468,6 +468,102 @@ pub fn addCases(cases: *tests.CompileErrorContext) void { "tmp.zig:12:5: error: switch on non-exhaustive enum must include `else` or `_` prong", }); + cases.add("switch expression - unreachable else prong (bool)", + \\fn foo(x: bool) void { + \\ switch (x) { + \\ true => {}, + \\ false => {}, + \\ else => {}, + \\ } + \\} + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:5:9: error: unreachable else prong, all cases already handled", + }); + + cases.add("switch expression - unreachable else prong (u1)", + \\fn foo(x: u1) void { + \\ switch (x) { + \\ 0 => {}, + \\ 1 => {}, + \\ else => {}, + \\ } + \\} + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:5:9: error: unreachable else prong, all cases already handled", + }); + + cases.add("switch expression - unreachable else prong (u2)", + \\fn foo(x: u2) void { + \\ switch (x) { + \\ 0 => {}, + \\ 1 => {}, + \\ 2 => {}, + \\ 3 => {}, + \\ else => {}, + \\ } + \\} + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:7:9: error: unreachable else prong, all cases already handled", + }); + + cases.add("switch expression - unreachable else prong (range u8)", + \\fn foo(x: u8) void { + \\ switch (x) { + \\ 0 => {}, + \\ 1 => {}, + \\ 2 => {}, + \\ 3 => {}, + \\ 4...255 => {}, + \\ else => {}, + \\ } + \\} + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:8:9: error: unreachable else prong, all cases already handled", + }); + + cases.add("switch expression - unreachable else prong (range i8)", + \\fn foo(x: i8) void { + \\ switch (x) { + \\ -128...0 => {}, + \\ 1 => {}, + \\ 2 => {}, + \\ 3 => {}, + \\ 4...127 => {}, + \\ else => {}, + \\ } + \\} + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:8:9: error: unreachable else prong, all cases already handled", + }); + + cases.add("switch expression - unreachable else prong (enum)", + \\const TestEnum = enum{ T1, T2 }; + \\ + \\fn err(x: u8) TestEnum { + \\ switch (x) { + \\ 0 => return TestEnum.T1, + \\ else => return TestEnum.T2, + \\ } + \\} + \\ + \\fn foo(x: u8) void { + \\ switch (err(x)) { + \\ TestEnum.T1 => {}, + \\ TestEnum.T2 => {}, + \\ else => {}, + \\ } + \\} + \\ + \\export fn entry() usize { return @sizeOf(@TypeOf(foo)); } + , &[_][]const u8{ + "tmp.zig:14:9: error: unreachable else prong, all cases already handled", + }); + cases.addTest("@export with empty name string", \\pub export fn entry() void { } \\comptime {