compiler: use std.heap.smp_allocator

In main, now this allocator is chosen by default when compiling without
libc in ReleaseFast or ReleaseSmall, and not targeting WebAssembly.

Author: andrewrk

bootstrap.c

@@ -139,7 +139,7 @@ int main(int argc, char **argv) {
             "pub const enable_tracy = false;\n"
             "pub const value_tracing = false;\n"
             "pub const skip_non_native = false;\n"
-            "pub const force_gpa = false;\n"
+            "pub const debug_gpa = false;\n"
             "pub const dev = .core;\n"
             "pub const value_interpret_mode = .direct;\n"
         , zig_version);

build.zig

@@ -171,7 +171,7 @@ pub fn build(b: *std.Build) !void {
     const tracy_callstack = b.option(bool, "tracy-callstack", "Include callstack information with Tracy data. Does nothing if -Dtracy is not provided") orelse (tracy != null);
     const tracy_allocation = b.option(bool, "tracy-allocation", "Include allocation information with Tracy data. Does nothing if -Dtracy is not provided") orelse (tracy != null);
     const tracy_callstack_depth: u32 = b.option(u32, "tracy-callstack-depth", "Declare callstack depth for Tracy data. Does nothing if -Dtracy_callstack is not provided") orelse 10;
-    const force_gpa = b.option(bool, "force-gpa", "Force the compiler to use GeneralPurposeAllocator") orelse false;
+    const debug_gpa = b.option(bool, "debug-allocator", "Force the compiler to use DebugAllocator") orelse false;
     const link_libc = b.option(bool, "force-link-libc", "Force self-hosted compiler to link libc") orelse (enable_llvm or only_c);
     const sanitize_thread = b.option(bool, "sanitize-thread", "Enable thread-sanitization") orelse false;
     const strip = b.option(bool, "strip", "Omit debug information");
@@ -233,7 +233,7 @@ pub fn build(b: *std.Build) !void {
     exe_options.addOption(bool, "llvm_has_csky", llvm_has_csky);
     exe_options.addOption(bool, "llvm_has_arc", llvm_has_arc);
     exe_options.addOption(bool, "llvm_has_xtensa", llvm_has_xtensa);
-    exe_options.addOption(bool, "force_gpa", force_gpa);
+    exe_options.addOption(bool, "debug_gpa", debug_gpa);
     exe_options.addOption(DevEnv, "dev", b.option(DevEnv, "dev", "Build a compiler with a reduced feature set for development of specific features") orelse if (only_c) .bootstrap else .full);
     exe_options.addOption(ValueInterpretMode, "value_interpret_mode", value_interpret_mode);
 
@@ -608,7 +608,7 @@ fn addWasiUpdateStep(b: *std.Build, version: [:0]const u8) !void {
 
     exe_options.addOption(u32, "mem_leak_frames", 0);
     exe_options.addOption(bool, "have_llvm", false);
-    exe_options.addOption(bool, "force_gpa", false);
+    exe_options.addOption(bool, "debug_gpa", false);
     exe_options.addOption([:0]const u8, "version", version);
     exe_options.addOption(std.SemanticVersion, "semver", semver);
     exe_options.addOption(bool, "enable_debug_extensions", false);

src/main.zig

@@ -171,30 +171,31 @@ pub fn log(
     std.debug.print(prefix1 ++ prefix2 ++ format ++ "\n", args);
 }
 
-var general_purpose_allocator = std.heap.GeneralPurposeAllocator(.{
+var debug_allocator: std.heap.DebugAllocator(.{
     .stack_trace_frames = build_options.mem_leak_frames,
-}){};
+}) = .init;
 
 pub fn main() anyerror!void {
     crash_report.initialize();
 
-    const use_gpa = (build_options.force_gpa or !builtin.link_libc) and native_os != .wasi;
-    const gpa = gpa: {
-        if (native_os == .wasi) {
-            break :gpa std.heap.wasm_allocator;
-        }
-        if (use_gpa) {
-            break :gpa general_purpose_allocator.allocator();
-        }
-        // We would prefer to use raw libc allocator here, but cannot
-        // use it if it won't support the alignment we need.
-        if (@alignOf(std.c.max_align_t) < @max(@alignOf(i128), std.atomic.cache_line)) {
-            break :gpa std.heap.c_allocator;
+    const gpa, const is_debug = gpa: {
+        if (build_options.debug_gpa) break :gpa .{ debug_allocator.allocator(), true };
+        if (native_os == .wasi) break :gpa .{ std.heap.wasm_allocator, false };
+        if (builtin.link_libc) {
+            // We would prefer to use raw libc allocator here, but cannot use
+            // it if it won't support the alignment we need.
+            if (@alignOf(std.c.max_align_t) < @max(@alignOf(i128), std.atomic.cache_line)) {
+                break :gpa .{ std.heap.c_allocator, false };
+            }
+            break :gpa .{ std.heap.raw_c_allocator, false };
         }
-        break :gpa std.heap.raw_c_allocator;
+        break :gpa switch (builtin.mode) {
+            .Debug, .ReleaseSafe => .{ debug_allocator.allocator(), true },
+            .ReleaseFast, .ReleaseSmall => .{ std.heap.smp_allocator, false },
+        };
     };
-    defer if (use_gpa) {
-        _ = general_purpose_allocator.deinit();
+    defer if (is_debug) {
+        _ = debug_allocator.deinit();
     };
     var arena_instance = std.heap.ArenaAllocator.init(gpa);
     defer arena_instance.deinit();

stage1/config.zig.in

@@ -11,6 +11,6 @@ pub const enable_link_snapshots = false;
 pub const enable_tracy = false;
 pub const value_tracing = false;
 pub const skip_non_native = false;
-pub const force_gpa = false;
+pub const debug_gpa = false;
 pub const dev = .core;
 pub const value_interpret_mode = .direct;