refactor(ffi-linkage): Phase 9.1a — rename collision-free linkage identifiers

Mechanical src/ rename of the linkage-family identifiers whose extern_* target is
collision-free: callForeign→callExtern, marshalForeignArg→marshalExternArg,
dedupeForeignSymbol→dedupeExternSymbol, foreign_name_map→extern_name_map,
is_foreign_c_api→is_extern_c_api. Snapshot-neutral (internal only); suite green
(646 corpus / 444 unit, 0 failed).

Deferred (need per-site analysis — target name already exists): is_foreign↔is_extern
(38 existing), foreign_lib/foreign_name↔extern_lib/extern_name (15/16 existing),
foreign_expr (still built by c_import.zig auto-synthesis). Runtime-class family
(ForeignClassDecl etc. → Runtime*, Decision 5) is Phase 9.2.

src/backend/llvm/abi.zig

@@ -26,7 +26,7 @@ pub const AbiLowering = struct {
     }
 
     /// Same as `abiCoerceParamType` but with an explicit
-    /// `is_foreign_c_api` knob. When true, sx `string` / `[]T` slices
+    /// `is_extern_c_api` knob. When true, sx `string` / `[]T` slices
     /// collapse to `ptr` — the libc convention where the user writes
     /// `string` to mean `char *` and the length is dropped. When
     /// false (sx-internal `callconv(.c)` like block trampolines), the
@@ -37,8 +37,8 @@ pub const AbiLowering = struct {
     /// `(*Block, string) -> void callconv(.c)` fn-pointer mismatched
     /// the caller's `{ptr, i64}` value against the trampoline's
     /// collapsed `ptr` param.
-    pub fn abiCoerceParamTypeEx(self: AbiLowering, ir_ty: TypeId, llvm_ty: c.LLVMTypeRef, is_foreign_c_api: bool) c.LLVMTypeRef {
+    pub fn abiCoerceParamTypeEx(self: AbiLowering, ir_ty: TypeId, llvm_ty: c.LLVMTypeRef, is_extern_c_api: bool) c.LLVMTypeRef {
-        if (is_foreign_c_api) {
+        if (is_extern_c_api) {
             if (ir_ty == .string) return self.e.cached_ptr;
             if (!ir_ty.isBuiltin()) {
                 const info = self.e.ir_mod.types.get(ir_ty);

src/ir/emit_llvm.zig

@@ -2528,8 +2528,8 @@ pub const LLVMEmitter = struct {
         return self.abiLowering().abiCoerceParamType(ir_ty, llvm_ty);
     }
 
-    fn abiCoerceParamTypeEx(self: *LLVMEmitter, ir_ty: TypeId, llvm_ty: c.LLVMTypeRef, is_foreign_c_api: bool) c.LLVMTypeRef {
+    fn abiCoerceParamTypeEx(self: *LLVMEmitter, ir_ty: TypeId, llvm_ty: c.LLVMTypeRef, is_extern_c_api: bool) c.LLVMTypeRef {
-        return self.abiLowering().abiCoerceParamTypeEx(ir_ty, llvm_ty, is_foreign_c_api);
+        return self.abiLowering().abiCoerceParamTypeEx(ir_ty, llvm_ty, is_extern_c_api);
     }
 
     pub fn needsByval(self: *LLVMEmitter, ir_ty: TypeId, raw_llvm_ty: c.LLVMTypeRef) bool {

src/ir/interp.zig

@@ -405,7 +405,7 @@ pub const Interpreter = struct {
     /// underlying address. The returned `usize` is only valid for the
     /// duration of this call — caller-allocated buffers are tracked in
     /// `tmp` so they get freed once the call returns.
-    fn marshalForeignArg(self: *Interpreter, v: Value, tmp: *std.ArrayList([]u8)) !usize {
+    fn marshalExternArg(self: *Interpreter, v: Value, tmp: *std.ArrayList([]u8)) !usize {
         return switch (v) {
             .int => |i| @bitCast(i),
             .boolean => |b| @intFromBool(b),
@@ -488,7 +488,7 @@ pub const Interpreter = struct {
         }
     }
 
-    fn callForeign(self: *Interpreter, func: *const inst_mod.Function, args: []const Value) InterpError!Value {
+    fn callExtern(self: *Interpreter, func: *const inst_mod.Function, args: []const Value) InterpError!Value {
         const name = self.module.types.getString(func.name);
 
         // A foreign call may not return (e.g. `process.exit` → `_exit`), which
@@ -513,7 +513,7 @@ pub const Interpreter = struct {
             tmp.deinit(self.alloc);
         }
         for (args, 0..) |a, i| {
-            packed_args[i] = self.marshalForeignArg(a, &tmp) catch return error.TypeError;
+            packed_args[i] = self.marshalExternArg(a, &tmp) catch return error.TypeError;
         }
         const argv = packed_args[0..args.len];
 
@@ -569,7 +569,7 @@ pub const Interpreter = struct {
             // Dispatch to host libc via dlsym. Lets `#run` (and the
             // post-link bundler) call ordinary foreign symbols like
             // `puts`, `getenv`, `posix_spawn`, etc.
-            return self.callForeign(func, args);
+            return self.callExtern(func, args);
         }
 
         // Track the sx call chain for `trace.print_interpreter_frames()`.

src/ir/lower.zig

@@ -364,7 +364,7 @@ pub const Lowering = struct {
     /// Null / absent for the comptime `..$args` pack (no constraint).
     pack_constraint: ?std.StringHashMap([]const u8) = null,
     struct_const_map: std.StringHashMap(StructConstInfo), // "Struct.CONST" → value info
-    foreign_name_map: std.StringHashMap([]const u8), // sx name → C name for #foreign renames
+    extern_name_map: std.StringHashMap([]const u8), // sx name → C name for #foreign renames
     target_config: ?@import("../target.zig").TargetConfig = null, // compilation target (for inline if)
     comptime_constants: std.StringHashMap(ComptimeValue), // compile-time known constants (e.g. OS, ARCH)
     diagnostics: ?*errors.DiagnosticList = null, // error reporting with source locations
@@ -524,7 +524,7 @@ pub const Lowering = struct {
             .param_impl_map = std.StringHashMap(std.ArrayList(ParamImplEntry)).init(module.alloc),
             .param_impl_pack_map = std.StringHashMap(std.ArrayList(PackParamImplEntry)).init(module.alloc),
             .struct_const_map = std.StringHashMap(StructConstInfo).init(module.alloc),
-            .foreign_name_map = std.StringHashMap([]const u8).init(module.alloc),
+            .extern_name_map = std.StringHashMap([]const u8).init(module.alloc),
             .comptime_constants = std.StringHashMap(ComptimeValue).init(module.alloc),
             .xx_reentrancy = std.AutoHashMap(u64, void).init(module.alloc),
             .inferred_error_sets = std.StringHashMap([]const u32).init(module.alloc),
@@ -1820,7 +1820,7 @@ pub const Lowering = struct {
     pub const lowerCall = lower_call.lowerCall;
     pub const diagnoseMissingContext = lower_call.diagnoseMissingContext;
     pub const allocViaContext = lower_call.allocViaContext;
-    pub const callForeign = lower_call.callForeign;
+    pub const callExtern = lower_call.callExtern;
     pub const prependCtxIfNeeded = lower_call.prependCtxIfNeeded;
     pub const resolveFuncByName = lower_call.resolveFuncByName;
     pub const resolveBuiltin = lower_call.resolveBuiltin;
@@ -1920,7 +1920,7 @@ pub const Lowering = struct {
     pub const findTaggedVariant = lower_expr.findTaggedVariant;
     pub const emitBadVariant = lower_expr.emitBadVariant;
     pub const emitBadEnumVariant = lower_expr.emitBadEnumVariant;
-    pub const dedupeForeignSymbol = lower_decl.dedupeForeignSymbol;
+    pub const dedupeExternSymbol = lower_decl.dedupeExternSymbol;
     pub const resolveVariantValue = lower_expr.resolveVariantValue;
     pub const resolveVariantIndex = lower_expr.resolveVariantIndex;
     pub const lowerArrayLiteral = lower_expr.lowerArrayLiteral;

src/ir/lower/call.zig

@@ -1255,7 +1255,7 @@ pub fn allocViaContext(self: *Lowering, size_ref: Ref, void_ptr_ty: TypeId) Ref
 /// Used for the compiler-internal byte-copy in the protocol-erasure
 /// heap path and the closure env-copy path, both of which need
 /// libc `memcpy` after the `#builtin` form was dropped.
-pub fn callForeign(self: *Lowering, name: []const u8, args: []const Ref, ret_ty: TypeId) Ref {
+pub fn callExtern(self: *Lowering, name: []const u8, args: []const Ref, ret_ty: TypeId) Ref {
     const fid = self.resolveFuncByName(name) orelse @panic("foreign symbol missing — std.sx not imported?");
     return self.builder.call(fid, args, ret_ty);
 }
@@ -1286,7 +1286,7 @@ fn protocolHasMethod(proto_info: anytype, name: []const u8) bool {
 
 pub fn resolveFuncByName(self: *Lowering, name: []const u8) ?FuncId {
     // Check foreign name map first (e.g., "c_abs" → "abs")
-    const effective_name = self.foreign_name_map.get(name) orelse name;
+    const effective_name = self.extern_name_map.get(name) orelse name;
     const name_id = self.module.types.internString(effective_name);
     for (self.module.functions.items, 0..) |func, i| {
         if (func.name == name_id) return FuncId.fromIndex(@intCast(i));

src/ir/lower/closure.zig

@@ -216,7 +216,7 @@ pub fn lowerLambda(self: *Lowering, lam: *const ast.Lambda) Ref {
         const env_byte_size_inner = self.computeEnvSize(capture_list);
         const env_size_val = self.builder.constInt(@intCast(env_byte_size_inner), .i64);
         // memcpy(local_alloca, env_param, size)
-        _ = self.callForeign("memcpy", &.{ env_local, env_param_ref, env_size_val }, self.module.types.ptrTo(.void));
+        _ = self.callExtern("memcpy", &.{ env_local, env_param_ref, env_size_val }, self.module.types.ptrTo(.void));
 
         for (capture_list, 0..) |cap, i| {
             // GEP into env struct to get field pointer
@@ -359,7 +359,7 @@ pub fn lowerLambda(self: *Lowering, lam: *const ast.Lambda) Ref {
         const ptr_void = self.module.types.ptrTo(.void);
         const env_heap = self.allocViaContext(env_size, ptr_void);
         // memcpy(heap, stack_alloca, size)
-        _ = self.callForeign("memcpy", &.{ env_heap, env_local, env_size }, ptr_void);
+        _ = self.callExtern("memcpy", &.{ env_heap, env_local, env_size }, ptr_void);
 
         return self.builder.closureCreate(func_id, env_heap, closure_ty);
     } else {

src/ir/lower/decl.zig

@@ -2035,7 +2035,7 @@ fn returnGenericLeaf(node: *const Node) ?[]const u8 {
 /// the later declaration (a `-> string` view of a symbol registered `-> *u8`
 /// reads the wrong shape; issue 0128). True = handled (shared or diagnosed),
 /// caller must not declare again.
-pub fn dedupeForeignSymbol(self: *Lowering, fd: *const ast.FnDecl, sym_name: StringId, params: []const Function.Param, ret_ty: TypeId) bool {
+pub fn dedupeExternSymbol(self: *Lowering, fd: *const ast.FnDecl, sym_name: StringId, params: []const Function.Param, ret_ty: TypeId) bool {
     for (self.module.functions.items, 0..) |*func, i| {
         if (func.name != sym_name or !func.is_extern) continue;
         var same = func.ret == ret_ty and func.params.len == params.len;
@@ -2142,8 +2142,8 @@ pub fn declareFunction(self: *Lowering, fd: *const ast.FnDecl, name: []const u8)
         null;
     if (rename_c_name) |c_name| {
         const c_name_id = self.module.types.internString(c_name);
-        if (self.dedupeForeignSymbol(fd, c_name_id, params.items, ret_ty)) {
+        if (self.dedupeExternSymbol(fd, c_name_id, params.items, ret_ty)) {
-            self.foreign_name_map.put(name, c_name) catch {};
+            self.extern_name_map.put(name, c_name) catch {};
             return;
         }
         const fid = self.builder.declareExtern(c_name_id, params.items, ret_ty);
@@ -2152,13 +2152,13 @@ pub fn declareFunction(self: *Lowering, fd: *const ast.FnDecl, name: []const u8)
         func.source_file = self.current_source_file;
         func.is_variadic = is_variadic;
         func.has_implicit_ctx = wants_ctx;
-        self.foreign_name_map.put(name, c_name) catch {};
+        self.extern_name_map.put(name, c_name) catch {};
         self.fn_decl_fids.put(fd, fid) catch {};
         return;
     }
 
     const name_id = self.module.types.internString(name);
-    if ((is_foreign or is_extern_decl) and self.dedupeForeignSymbol(fd, name_id, params.items, ret_ty)) return;
+    if ((is_foreign or is_extern_decl) and self.dedupeExternSymbol(fd, name_id, params.items, ret_ty)) return;
     const fid = self.builder.declareExtern(name_id, params.items, ret_ty);
     const func = self.module.getFunctionMut(fid);
     func.call_conv = cc;
@@ -2355,10 +2355,10 @@ pub fn lazyLowerFunction(self: *Lowering, name: []const u8) void {
     // its OWN FuncId by `lowerRetainedSameNameAuthors`.
     // A renamed `export … "csym"` fn was declared under its C symbol name
     // (declareFunction's rename path), so search for the stub under that name
-    // and promote the body into it. `foreign_name_map` only carries an entry
+    // and promote the body into it. `extern_name_map` only carries an entry
     // when a rename was registered; a bare export / normal define keeps its sx
     // name (Phase 2.2).
-    const search_name = self.foreign_name_map.get(name) orelse name;
+    const search_name = self.extern_name_map.get(name) orelse name;
     const name_id = self.module.types.internString(search_name);
     var func_id: ?FuncId = null;
     for (self.module.functions.items, 0..) |func, i| {

src/ir/lower/protocol.zig

@@ -443,7 +443,7 @@ pub fn buildProtocolValue(self: *Lowering, concrete_ptr: Ref, proto_name: []cons
         const concrete_size = self.module.types.typeSizeBytes(concrete_ty);
         const size_ref = self.builder.constInt(@intCast(concrete_size), .i64);
         const heap_ptr = self.allocViaContext(size_ref, void_ptr_ty);
-        _ = self.callForeign("memcpy", &.{ heap_ptr, concrete_ptr, size_ref }, void_ptr_ty);
+        _ = self.callExtern("memcpy", &.{ heap_ptr, concrete_ptr, size_ref }, void_ptr_ty);
         ctx_ptr = heap_ptr;
     }