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Preprocessor: remove deprecated PackedIntArray
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@ehaas @Vexu
ehaas authored and Vexu committed Oct 14, 2024
1 parent a0d5cc3 commit 0ee9317
Showing 1 changed file with 90 additions and 67 deletions.
157 changes: 90 additions & 67 deletions src/aro/Preprocessor.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -25,6 +25,40 @@ const max_include_depth = 200;
/// it is handled there and doesn't escape that function
const MacroError = Error || error{StopPreprocessing};

const IfContext = struct {
const Backing = u2;
const Nesting = enum(Backing) {
until_else,
until_endif,
until_endif_seen_else,
};

const buf_size_bits = @bitSizeOf(Backing) * 256;
kind: [buf_size_bits / std.mem.byte_size_in_bits]u8,
level: u8,

fn get(self: *const IfContext) Nesting {
return @enumFromInt(std.mem.readPackedIntNative(Backing, &self.kind, @as(usize, self.level) * 2));
}

fn set(self: *IfContext, context: Nesting) void {
std.mem.writePackedIntNative(Backing, &self.kind, @as(usize, self.level) * 2, @intFromEnum(context));
}

fn increment(self: *IfContext) bool {
self.level, const overflowed = @addWithOverflow(self.level, 1);
return overflowed != 0;
}

fn decrement(self: *IfContext) void {
self.level -= 1;
}

/// Initialize `kind` to an invalid value since it is an error to read the kind before setting it.
/// Doing so will trigger safety-checked undefined behavior in `IfContext.get`
const default: IfContext = .{ .kind = @splat(0xFF), .level = 0 };
};

const Macro = struct {
/// Parameters of the function type macro
params: []const []const u8,
Expand Down Expand Up @@ -388,11 +422,7 @@ fn preprocessExtra(pp: *Preprocessor, source: Source) MacroError!TokenWithExpans
const estimated_token_count = source.buf.len / 8;
try pp.ensureTotalTokenCapacity(pp.tokens.len + estimated_token_count);

var if_level: u8 = 0;
var if_kind = std.PackedIntArray(u2, 256).init([1]u2{0} ** 256);
const until_else = 0;
const until_endif = 1;
const until_endif_seen_else = 2;
var if_context: IfContext = .default;

var start_of_line = true;
while (true) {
Expand Down Expand Up @@ -424,71 +454,68 @@ fn preprocessExtra(pp: *Preprocessor, source: Source) MacroError!TokenWithExpans
}, &.{});
},
.keyword_if => {
const sum, const overflowed = @addWithOverflow(if_level, 1);
if (overflowed != 0)
const overflowed = if_context.increment();
if (overflowed)
return pp.fatal(directive, "too many #if nestings", .{});
if_level = sum;

if (try pp.expr(&tokenizer)) {
if_kind.set(if_level, until_endif);
if_context.set(.until_endif);
if (pp.verbose) {
pp.verboseLog(directive, "entering then branch of #if", .{});
}
} else {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #if", .{});
}
}
},
.keyword_ifdef => {
const sum, const overflowed = @addWithOverflow(if_level, 1);
if (overflowed != 0)
const overflowed = if_context.increment();
if (overflowed)
return pp.fatal(directive, "too many #if nestings", .{});
if_level = sum;

const macro_name = (try pp.expectMacroName(&tokenizer)) orelse continue;
try pp.expectNl(&tokenizer);
if (pp.defines.get(macro_name) != null) {
if_kind.set(if_level, until_endif);
if_context.set(.until_endif);
if (pp.verbose) {
pp.verboseLog(directive, "entering then branch of #ifdef", .{});
}
} else {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #ifdef", .{});
}
}
},
.keyword_ifndef => {
const sum, const overflowed = @addWithOverflow(if_level, 1);
if (overflowed != 0)
const overflowed = if_context.increment();
if (overflowed)
return pp.fatal(directive, "too many #if nestings", .{});
if_level = sum;

const macro_name = (try pp.expectMacroName(&tokenizer)) orelse continue;
try pp.expectNl(&tokenizer);
if (pp.defines.get(macro_name) == null) {
if_kind.set(if_level, until_endif);
if_context.set(.until_endif);
} else {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
}
},
.keyword_elif => {
if (if_level == 0) {
if (if_context.level == 0) {
try pp.err(directive, .elif_without_if);
if_level += 1;
if_kind.set(if_level, until_else);
} else if (if_level == 1) {
_ = if_context.increment();
if_context.set(.until_else);
} else if (if_context.level == 1) {
guard_name = null;
}
switch (if_kind.get(if_level)) {
until_else => if (try pp.expr(&tokenizer)) {
if_kind.set(if_level, until_endif);
switch (if_context.get()) {
.until_else => if (try pp.expr(&tokenizer)) {
if_context.set(.until_endif);
if (pp.verbose) {
pp.verboseLog(directive, "entering then branch of #elif", .{});
}
Expand All @@ -498,134 +525,130 @@ fn preprocessExtra(pp: *Preprocessor, source: Source) MacroError!TokenWithExpans
pp.verboseLog(directive, "entering else branch of #elif", .{});
}
},
until_endif => try pp.skip(&tokenizer, .until_endif),
until_endif_seen_else => {
.until_endif => try pp.skip(&tokenizer, .until_endif),
.until_endif_seen_else => {
try pp.err(directive, .elif_after_else);
skipToNl(&tokenizer);
},
else => unreachable,
}
},
.keyword_elifdef => {
if (if_level == 0) {
if (if_context.level == 0) {
try pp.err(directive, .elifdef_without_if);
if_level += 1;
if_kind.set(if_level, until_else);
} else if (if_level == 1) {
_ = if_context.increment();
if_context.set(.until_else);
} else if (if_context.level == 1) {
guard_name = null;
}
switch (if_kind.get(if_level)) {
until_else => {
switch (if_context.get()) {
.until_else => {
const macro_name = try pp.expectMacroName(&tokenizer);
if (macro_name == null) {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #elifdef", .{});
}
} else {
try pp.expectNl(&tokenizer);
if (pp.defines.get(macro_name.?) != null) {
if_kind.set(if_level, until_endif);
if_context.set(.until_endif);
if (pp.verbose) {
pp.verboseLog(directive, "entering then branch of #elifdef", .{});
}
} else {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #elifdef", .{});
}
}
}
},
until_endif => try pp.skip(&tokenizer, .until_endif),
until_endif_seen_else => {
.until_endif => try pp.skip(&tokenizer, .until_endif),
.until_endif_seen_else => {
try pp.err(directive, .elifdef_after_else);
skipToNl(&tokenizer);
},
else => unreachable,
}
},
.keyword_elifndef => {
if (if_level == 0) {
if (if_context.level == 0) {
try pp.err(directive, .elifdef_without_if);
if_level += 1;
if_kind.set(if_level, until_else);
} else if (if_level == 1) {
_ = if_context.increment();
if_context.set(.until_else);
} else if (if_context.level == 1) {
guard_name = null;
}
switch (if_kind.get(if_level)) {
until_else => {
switch (if_context.get()) {
.until_else => {
const macro_name = try pp.expectMacroName(&tokenizer);
if (macro_name == null) {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #elifndef", .{});
}
} else {
try pp.expectNl(&tokenizer);
if (pp.defines.get(macro_name.?) == null) {
if_kind.set(if_level, until_endif);
if_context.set(.until_endif);
if (pp.verbose) {
pp.verboseLog(directive, "entering then branch of #elifndef", .{});
}
} else {
if_kind.set(if_level, until_else);
if_context.set(.until_else);
try pp.skip(&tokenizer, .until_else);
if (pp.verbose) {
pp.verboseLog(directive, "entering else branch of #elifndef", .{});
}
}
}
},
until_endif => try pp.skip(&tokenizer, .until_endif),
until_endif_seen_else => {
.until_endif => try pp.skip(&tokenizer, .until_endif),
.until_endif_seen_else => {
try pp.err(directive, .elifdef_after_else);
skipToNl(&tokenizer);
},
else => unreachable,
}
},
.keyword_else => {
try pp.expectNl(&tokenizer);
if (if_level == 0) {
if (if_context.level == 0) {
try pp.err(directive, .else_without_if);
continue;
} else if (if_level == 1) {
} else if (if_context.level == 1) {
guard_name = null;
}
switch (if_kind.get(if_level)) {
until_else => {
if_kind.set(if_level, until_endif_seen_else);
switch (if_context.get()) {
.until_else => {
if_context.set(.until_endif_seen_else);
if (pp.verbose) {
pp.verboseLog(directive, "#else branch here", .{});
}
},
until_endif => try pp.skip(&tokenizer, .until_endif_seen_else),
until_endif_seen_else => {
.until_endif => try pp.skip(&tokenizer, .until_endif_seen_else),
.until_endif_seen_else => {
try pp.err(directive, .else_after_else);
skipToNl(&tokenizer);
},
else => unreachable,
}
},
.keyword_endif => {
try pp.expectNl(&tokenizer);
if (if_level == 0) {
if (if_context.level == 0) {
guard_name = null;
try pp.err(directive, .endif_without_if);
continue;
} else if (if_level == 1) {
} else if (if_context.level == 1) {
const saved_tokenizer = tokenizer;
defer tokenizer = saved_tokenizer;

var next = tokenizer.nextNoWS();
while (next.id == .nl) : (next = tokenizer.nextNoWS()) {}
if (next.id != .eof) guard_name = null;
}
if_level -= 1;
if_context.decrement();
},
.keyword_define => try pp.define(&tokenizer, directive),
.keyword_undef => {
Expand Down Expand Up @@ -693,7 +716,7 @@ fn preprocessExtra(pp: *Preprocessor, source: Source) MacroError!TokenWithExpans
},
.nl => {},
.eof => {
if (if_level != 0) try pp.err(tok, .unterminated_conditional_directive);
if (if_context.level != 0) try pp.err(tok, .unterminated_conditional_directive);
return tokFromRaw(directive);
},
else => {
Expand All @@ -712,7 +735,7 @@ fn preprocessExtra(pp: *Preprocessor, source: Source) MacroError!TokenWithExpans
if (pp.preserve_whitespace) try pp.addToken(tokFromRaw(tok));
},
.eof => {
if (if_level != 0) try pp.err(tok, .unterminated_conditional_directive);
if (if_context.level != 0) try pp.err(tok, .unterminated_conditional_directive);
// The following check needs to occur here and not at the top of the function
// because a pragma may change the level during preprocessing
if (source.buf.len > 0 and source.buf[source.buf.len - 1] != '\n') {
Expand Down

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