compiler: Implement @disableIntrinsics() builtin function.

Closes #21833.
Closes #22110.

Author: alexrp

lib/std/zig/AstGen.zig

@@ -2907,6 +2907,7 @@ fn addEnsureResult(gz: *GenZir, maybe_unused_result: Zir.Inst.Ref, statement: As
             .extended => switch (gz.astgen.instructions.items(.data)[@intFromEnum(inst)].extended.opcode) {
                 .breakpoint,
                 .disable_instrumentation,
+                .disable_intrinsics,
                 .set_float_mode,
                 .branch_hint,
                 => break :b true,
@@ -9447,6 +9448,7 @@ fn builtinCall(
         .frame_address           => return rvalue(gz, ri, try gz.addNodeExtended(.frame_address,           node), node),
         .breakpoint              => return rvalue(gz, ri, try gz.addNodeExtended(.breakpoint,              node), node),
         .disable_instrumentation => return rvalue(gz, ri, try gz.addNodeExtended(.disable_instrumentation, node), node),
+        .disable_intrinsics      => return rvalue(gz, ri, try gz.addNodeExtended(.disable_intrinsics,      node), node),
 
         .type_info   => return simpleUnOpType(gz, scope, ri, node, params[0], .type_info),
         .size_of     => return simpleUnOpType(gz, scope, ri, node, params[0], .size_of),

lib/std/zig/AstRlAnnotate.zig

@@ -882,6 +882,7 @@ fn builtinCall(astrl: *AstRlAnnotate, block: ?*Block, ri: ResultInfo, node: Ast.
         .frame,
         .breakpoint,
         .disable_instrumentation,
+        .disable_intrinsics,
         .in_comptime,
         .panic,
         .trap,

lib/std/zig/BuiltinFn.zig

@@ -15,6 +15,7 @@ pub const Tag = enum {
     branch_hint,
     breakpoint,
     disable_instrumentation,
+    disable_intrinsics,
     mul_add,
     byte_swap,
     bit_reverse,
@@ -262,6 +263,14 @@ pub const list = list: {
                 .illegal_outside_function = true,
             },
         },
+        .{
+            "@disableIntrinsics",
+            .{
+                .tag = .disable_intrinsics,
+                .param_count = 0,
+                .illegal_outside_function = true,
+            },
+        },
         .{
             "@mulAdd",
             .{

lib/std/zig/Zir.zig

@@ -1575,7 +1575,11 @@ pub const Inst = struct {
                 => false,
 
                 .extended => switch (data.extended.opcode) {
-                    .branch_hint, .breakpoint, .disable_instrumentation => true,
+                    .branch_hint,
+                    .breakpoint,
+                    .disable_instrumentation,
+                    .disable_intrinsics,
+                    => true,
                     else => false,
                 },
             };
@@ -1996,6 +2000,8 @@ pub const Inst = struct {
         breakpoint,
         /// Implement builtin `@disableInstrumentation`. `operand` is `src_node: i32`.
         disable_instrumentation,
+        /// Implement builtin `@disableIntrinsics`. `operand` is `src_node: i32`.
+        disable_intrinsics,
         /// Implements the `@select` builtin.
         /// `operand` is payload index to `Select`.
         select,
@@ -4042,6 +4048,7 @@ fn findDeclsInner(
                 .await_nosuspend,
                 .breakpoint,
                 .disable_instrumentation,
+                .disable_intrinsics,
                 .select,
                 .int_from_error,
                 .error_from_int,

src/InternPool.zig

@@ -5562,8 +5562,9 @@ pub const FuncAnalysis = packed struct(u32) {
     /// True if this function has an inferred error set.
     inferred_error_set: bool,
     disable_instrumentation: bool,
+    disable_intrinsics: bool,
 
-    _: u23 = 0,
+    _: u22 = 0,
 
     pub const State = enum(u2) {
         /// The runtime function has never been referenced.
@@ -8597,6 +8598,7 @@ pub fn getFuncDecl(
             .calls_or_awaits_errorable_fn = false,
             .inferred_error_set = false,
             .disable_instrumentation = false,
+            .disable_intrinsics = false,
         },
         .owner_nav = key.owner_nav,
         .ty = key.ty,
@@ -8700,6 +8702,7 @@ pub fn getFuncDeclIes(
             .calls_or_awaits_errorable_fn = false,
             .inferred_error_set = true,
             .disable_instrumentation = false,
+            .disable_intrinsics = false,
         },
         .owner_nav = key.owner_nav,
         .ty = func_ty,
@@ -8891,6 +8894,7 @@ pub fn getFuncInstance(
             .calls_or_awaits_errorable_fn = false,
             .inferred_error_set = false,
             .disable_instrumentation = false,
+            .disable_intrinsics = false,
         },
         // This is populated after we create the Nav below. It is not read
         // by equality or hashing functions.
@@ -8990,6 +8994,7 @@ pub fn getFuncInstanceIes(
             .calls_or_awaits_errorable_fn = false,
             .inferred_error_set = true,
             .disable_instrumentation = false,
+            .disable_intrinsics = false,
         },
         // This is populated after we create the Nav below. It is not read
         // by equality or hashing functions.
@@ -11780,6 +11785,18 @@ pub fn funcSetDisableInstrumentation(ip: *InternPool, func: Index) void {
     @atomicStore(FuncAnalysis, analysis_ptr, analysis, .release);
 }
 
+pub fn funcSetDisableIntrinsics(ip: *InternPool, func: Index) void {
+    const unwrapped_func = func.unwrap(ip);
+    const extra_mutex = &ip.getLocal(unwrapped_func.tid).mutate.extra.mutex;
+    extra_mutex.lock();
+    defer extra_mutex.unlock();
+
+    const analysis_ptr = ip.funcAnalysisPtr(func);
+    var analysis = analysis_ptr.*;
+    analysis.disable_intrinsics = true;
+    @atomicStore(FuncAnalysis, analysis_ptr, analysis, .release);
+}
+
 pub fn funcZirBodyInst(ip: *const InternPool, func: Index) TrackedInst.Index {
     const unwrapped_func = func.unwrap(ip);
     const item = unwrapped_func.getItem(ip);

src/Sema.zig

@@ -1341,6 +1341,11 @@ fn analyzeBodyInner(
                         i += 1;
                         continue;
                     },
+                    .disable_intrinsics => {
+                        try sema.zirDisableIntrinsics();
+                        i += 1;
+                        continue;
+                    },
                     .restore_err_ret_index => {
                         try sema.zirRestoreErrRetIndex(block, extended);
                         i += 1;
@@ -6551,6 +6556,18 @@ fn zirDisableInstrumentation(sema: *Sema) CompileError!void {
     sema.allow_memoize = false;
 }
 
+fn zirDisableIntrinsics(sema: *Sema) CompileError!void {
+    const pt = sema.pt;
+    const zcu = pt.zcu;
+    const ip = &zcu.intern_pool;
+    const func = switch (sema.owner.unwrap()) {
+        .func => |func| func,
+        .cau => return, // does nothing outside a function
+    };
+    ip.funcSetDisableIntrinsics(func);
+    sema.allow_memoize = false;
+}
+
 fn zirSetFloatMode(sema: *Sema, block: *Block, extended: Zir.Inst.Extended.InstData) CompileError!void {
     const extra = sema.code.extraData(Zir.Inst.UnNode, extended.operand).data;
     const src = block.builtinCallArgSrc(extra.node, 0);

src/codegen/llvm.zig

@@ -1552,6 +1552,19 @@ pub const Object = struct {
             try attributes.addFnAttr(.nosanitize_coverage, &o.builder);
         }
 
+        const disable_intrinsics = func_analysis.disable_intrinsics or owner_mod.no_builtin;
+        if (disable_intrinsics) {
+            // The intent here is for compiler-rt and libc functions to not generate
+            // infinite recursion. For example, if we are compiling the memcpy function,
+            // and llvm detects that the body is equivalent to memcpy, it may replace the
+            // body of memcpy with a call to memcpy, which would then cause a stack
+            // overflow instead of performing memcpy.
+            try attributes.addFnAttr(.{ .string = .{
+                .kind = try o.builder.string("no-builtins"),
+                .value = .empty,
+            } }, &o.builder);
+        }
+
         // TODO: disable this if safety is off for the function scope
         const ssp_buf_size = owner_mod.stack_protector;
         if (ssp_buf_size != 0) {
@@ -1856,6 +1869,7 @@ pub const Object = struct {
             .prev_dbg_line = 0,
             .prev_dbg_column = 0,
             .err_ret_trace = err_ret_trace,
+            .disable_intrinsics = disable_intrinsics,
         };
         defer fg.deinit();
         deinit_wip = false;
@@ -3243,17 +3257,6 @@ pub const Object = struct {
         if (owner_mod.unwind_tables) {
             try attributes.addFnAttr(.{ .uwtable = Builder.Attribute.UwTable.default }, &o.builder);
         }
-        if (owner_mod.no_builtin) {
-            // The intent here is for compiler-rt and libc functions to not generate
-            // infinite recursion. For example, if we are compiling the memcpy function,
-            // and llvm detects that the body is equivalent to memcpy, it may replace the
-            // body of memcpy with a call to memcpy, which would then cause a stack
-            // overflow instead of performing memcpy.
-            try attributes.addFnAttr(.{ .string = .{
-                .kind = try o.builder.string("no-builtins"),
-                .value = .empty,
-            } }, &o.builder);
-        }
         if (owner_mod.optimize_mode == .ReleaseSmall) {
             try attributes.addFnAttr(.minsize, &o.builder);
             try attributes.addFnAttr(.optsize, &o.builder);
@@ -5042,6 +5045,8 @@ pub const FuncGen = struct {
 
     sync_scope: Builder.SyncScope,
 
+    disable_intrinsics: bool,
+
     const Fuzz = struct {
         counters_variable: Builder.Variable.Index,
         pcs: std.ArrayListUnmanaged(Builder.Constant),
@@ -5580,7 +5585,7 @@ pub const FuncGen = struct {
         var attributes: Builder.FunctionAttributes.Wip = .{};
         defer attributes.deinit(&o.builder);
 
-        if (self.ng.ownerModule().no_builtin) {
+        if (self.disable_intrinsics) {
             try attributes.addFnAttr(.nobuiltin, &o.builder);
         }
 

src/print_zir.zig

@@ -529,6 +529,7 @@ const Writer = struct {
             .frame_address,
             .breakpoint,
             .disable_instrumentation,
+            .disable_intrinsics,
             .c_va_start,
             .in_comptime,
             .value_placeholder,