p4lang · jafingerhut · May 20, 2026 · May 22, 2026 · May 23, 2026 · May 23, 2026
diff --git a/backends/graphs/README.md b/backends/graphs/README.md
@@ -1,3 +1,9 @@
+<!--
+SPDX-FileCopyrightText: 2017 Barefoot Networks, Inc.
+
+SPDX-License-Identifier: Apache-2.0
+-->
+
 <!--!
 \page graphs_backend Graphs Backend                                                                  
 -->

diff --git a/test/gtest/remove_dontcare_args_test.cpp b/test/gtest/remove_dontcare_args_test.cpp
@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+//
+// SPDX-License-Identifier: Apache-2.0
+
 #include <gtest/gtest.h>
 
 #include "frontends/common/parseInput.h"

diff --git a/testdata/p4_16_errors/issue1803_same_table_name.p4 b/testdata/p4_16_errors/issue1803_same_table_name.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2019 Barefoot Networks, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 #include <v1model.p4>
 

diff --git a/testdata/p4_16_errors/issue4365_no_demote_error_to_info.p4 b/testdata/p4_16_errors/issue4365_no_demote_error_to_info.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 // Ensure that errors cannot be demoted to info messages.
 @command_line("--Winfo=type-error")
 parser p() {

diff --git a/testdata/p4_16_errors/issue4365_no_demote_error_to_warning.p4 b/testdata/p4_16_errors/issue4365_no_demote_error_to_warning.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 // Ensure that errors cannot be demoted to warnings.
 @command_line("--Wwarn=type-error")
 parser p() {

diff --git a/testdata/p4_16_errors/issue4365_no_disable_error.p4 b/testdata/p4_16_errors/issue4365_no_disable_error.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 // Ensure that errors cannot be disabled.
 @command_line("--Wdisable=type-error")
 parser p() {

diff --git a/testdata/p4_16_errors/issue5254_dup_switch_case_label_error.p4 b/testdata/p4_16_errors/issue5254_dup_switch_case_label_error.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 control C();

diff --git a/testdata/p4_16_errors_outputs/issue1803_same_table_name.p4-stderr b/testdata/p4_16_errors_outputs/issue1803_same_table_name.p4-stderr
@@ -1,4 +1,4 @@
-issue1803_same_table_name.p4(13): [--Wwarn=unused] warning: 'empty' is unused
+issue1803_same_table_name.p4(19): [--Wwarn=unused] warning: 'empty' is unused
 action empty() { }
        ^^^^^
 [--Werror=duplicate] error: Name 't0' is used for multiple table objects in the P4Info message

diff --git a/testdata/p4_16_errors_outputs/issue4365_no_demote_error_to_info.p4-stderr b/testdata/p4_16_errors_outputs/issue4365_no_demote_error_to_info.p4-stderr
@@ -1,8 +1,8 @@
 [--Werror=invalid] error: Error type-error cannot be demoted.
 Use '--help' to see all available options.
-issue4365_no_demote_error_to_info.p4(4): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
+issue4365_no_demote_error_to_info.p4(10): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
     state accept {
           ^^^^^^
-issue4365_no_demote_error_to_info.p4(3): [--Werror=invalid] error: Parser p has no 'start' state
+issue4365_no_demote_error_to_info.p4(9): [--Werror=invalid] error: Parser p has no 'start' state
 parser p() {
        ^
diff --git a/testdata/p4_16_errors_outputs/issue4365_no_demote_error_to_warning.p4-stderr b/testdata/p4_16_errors_outputs/issue4365_no_demote_error_to_warning.p4-stderr
@@ -1,8 +1,8 @@
 [--Werror=invalid] error: Error type-error cannot be demoted.
 Use '--help' to see all available options.
-issue4365_no_demote_error_to_warning.p4(4): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
+issue4365_no_demote_error_to_warning.p4(10): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
     state accept {
           ^^^^^^
-issue4365_no_demote_error_to_warning.p4(3): [--Werror=invalid] error: Parser p has no 'start' state
+issue4365_no_demote_error_to_warning.p4(9): [--Werror=invalid] error: Parser p has no 'start' state
 parser p() {
        ^
diff --git a/testdata/p4_16_errors_outputs/issue4365_no_disable_error.p4-stderr b/testdata/p4_16_errors_outputs/issue4365_no_disable_error.p4-stderr
@@ -1,8 +1,8 @@
 [--Werror=invalid] error: Error type-error cannot be demoted.
 Use '--help' to see all available options.
-issue4365_no_disable_error.p4(4): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
+issue4365_no_disable_error.p4(10): [--Werror=invalid] error: Invalid parser state: accept should not be implemented, it is built-in
     state accept {
           ^^^^^^
-issue4365_no_disable_error.p4(3): [--Werror=invalid] error: Parser p has no 'start' state
+issue4365_no_disable_error.p4(9): [--Werror=invalid] error: Parser p has no 'start' state
 parser p() {
        ^
diff --git a/testdata/p4_16_errors_outputs/issue5254_dup_switch_case_label_error.p4-stderr b/testdata/p4_16_errors_outputs/issue5254_dup_switch_case_label_error.p4-stderr
@@ -1,36 +1,36 @@
-issue5254_dup_switch_case_label_error.p4(34): [--Werror=invalid] error: 8s1: duplicate case label 8s1
+issue5254_dup_switch_case_label_error.p4(40): [--Werror=invalid] error: 8s1: duplicate case label 8s1
       (int<8>)1: {}
               ^
-issue5254_dup_switch_case_label_error.p4(33)
+issue5254_dup_switch_case_label_error.p4(39)
       (int<8>)1: {}
               ^
-issue5254_dup_switch_case_label_error.p4(40): [--Werror=invalid] error: 8w1: duplicate case label 8w1
+issue5254_dup_switch_case_label_error.p4(46): [--Werror=invalid] error: 8w1: duplicate case label 8w1
       (bit<8>)1: {}
               ^
-issue5254_dup_switch_case_label_error.p4(39)
+issue5254_dup_switch_case_label_error.p4(45)
       (bit<8>)1: {}
               ^
-issue5254_dup_switch_case_label_error.p4(46): [--Werror=invalid] error: error.Error1: duplicate case label error.Error1
+issue5254_dup_switch_case_label_error.p4(52): [--Werror=invalid] error: error.Error1: duplicate case label error.Error1
       error.Error1: {}
       ^^^^^^^^^^^^
-issue5254_dup_switch_case_label_error.p4(45)
+issue5254_dup_switch_case_label_error.p4(51)
       error.Error1: {}
       ^^^^^^^^^^^^
-issue5254_dup_switch_case_label_error.p4(52): [--Werror=invalid] error: e.e1: duplicate case label e.e1
+issue5254_dup_switch_case_label_error.p4(58): [--Werror=invalid] error: e.e1: duplicate case label e.e1
       e.e1: {}
       ^^^^
-issue5254_dup_switch_case_label_error.p4(51)
+issue5254_dup_switch_case_label_error.p4(57)
       e.e1: {}
       ^^^^
-issue5254_dup_switch_case_label_error.p4(58): [--Werror=invalid] error: s.s1: duplicate case label s.s1
+issue5254_dup_switch_case_label_error.p4(64): [--Werror=invalid] error: s.s1: duplicate case label s.s1
       s.s1: {}
       ^^^^
-issue5254_dup_switch_case_label_error.p4(57)
+issue5254_dup_switch_case_label_error.p4(63)
       s.s1: {}
       ^^^^
-issue5254_dup_switch_case_label_error.p4(70): [--Werror=invalid] error: a: duplicate case label a
+issue5254_dup_switch_case_label_error.p4(76): [--Werror=invalid] error: a: duplicate case label a
       a: {}
       ^
-issue5254_dup_switch_case_label_error.p4(69)
+issue5254_dup_switch_case_label_error.p4(75)
       a: {}
       ^
diff --git a/testdata/p4_16_samples/action_selector_unused-bmv2.p4 b/testdata/p4_16_samples/action_selector_unused-bmv2.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2017 Barefoot Networks, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 #include <v1model.p4>
 

diff --git a/testdata/p4_16_samples/constant-in-calculation-bmv2.stf b/testdata/p4_16_samples/constant-in-calculation-bmv2.stf
@@ -1,3 +1,7 @@
+# SPDX-FileCopyrightText: 2017 Barefoot Networks, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # bit<16> A
 # In the output we need A = 1
 

diff --git a/testdata/p4_16_samples/invalid_header_default_action_arg.p4 b/testdata/p4_16_samples/invalid_header_default_action_arg.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 header h_t { bit<8> f; }
 header_union hu_t { h_t h1; h_t h2; }
 control C() {

diff --git a/testdata/p4_16_samples/issue3699.p4 b/testdata/p4_16_samples/issue3699.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 const bit<4> one = 1;
 const bit<4> max = 0xf;
 const bit<4> value = max |+| one;

diff --git a/testdata/p4_16_samples/issue4365_wdisable_precedence_over_werror.p4 b/testdata/p4_16_samples/issue4365_wdisable_precedence_over_werror.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 // Expect no errors, as --Wdisable should take precedence over --Werror for warnings.
 @command_line("--Werror", "--Wdisable=uninitialized-use", "--Wdisable=invalid-header")
 header h_t {

diff --git a/testdata/p4_16_samples/issue4365_wdisable_precedence_over_werror_control.p4 b/testdata/p4_16_samples/issue4365_wdisable_precedence_over_werror_control.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 // Control testcase to ensure that this program actually emits warnings
 // that can be disabled with --Wdisable=uninitialized-use and --Wdisable=invalid-header.
 header h_t {

diff --git a/testdata/p4_16_samples/issue4507_1.p4 b/testdata/p4_16_samples/issue4507_1.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 extern void __e(in bit<28> arg);
 extern void __e2(in bit<28> arg);
 

diff --git a/testdata/p4_16_samples/issue4507_2.p4 b/testdata/p4_16_samples/issue4507_2.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 extern void __e(in bit<28> arg);
 extern void __e2(in bit<28> arg);
 

diff --git a/testdata/p4_16_samples/issue4625_remove_compile_time_bool_methodcall_of_mcs.p4 b/testdata/p4_16_samples/issue4625_remove_compile_time_bool_methodcall_of_mcs.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 header h_t {
     bit<8> f;
 }

diff --git a/testdata/p4_16_samples/issue4625_remove_compile_time_const_methodcall_of_mcs.p4 b/testdata/p4_16_samples/issue4625_remove_compile_time_const_methodcall_of_mcs.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 header h_t {
     bit<8> f;
 }

diff --git a/testdata/p4_16_samples/issue4656_const_fold_generic_switch_label_expr.p4 b/testdata/p4_16_samples/issue4656_const_fold_generic_switch_label_expr.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 extern void foo();

diff --git a/testdata/p4_16_samples/issue4656_fold_bit_width_const_mux_expr.p4 b/testdata/p4_16_samples/issue4656_fold_bit_width_const_mux_expr.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 header h_t {
     bit<((10 == 1 ? 1 : 10 + 1) * (8+1))> f;
 }

diff --git a/testdata/p4_16_samples/issue4661_non_pure_extern_function_const_args.p4 b/testdata/p4_16_samples/issue4661_non_pure_extern_function_const_args.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 extern void foo();

diff --git a/testdata/p4_16_samples/issue4661_pure_extern_function_const_args.p4 b/testdata/p4_16_samples/issue4661_pure_extern_function_const_args.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 extern void foo();

diff --git a/testdata/p4_16_samples/issue4760_dontcare_action_out_arg.p4 b/testdata/p4_16_samples/issue4760_dontcare_action_out_arg.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 struct S {
     bit<64> f;
 }

diff --git a/testdata/p4_16_samples/issue4883_dup_has_returned_decl.p4 b/testdata/p4_16_samples/issue4883_dup_has_returned_decl.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 struct S {

diff --git a/testdata/p4_16_samples/issue4883_dup_has_returned_decl2.p4 b/testdata/p4_16_samples/issue4883_dup_has_returned_decl2.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 struct S {

diff --git a/testdata/p4_16_samples/issue4901_new_start_with_no_start_loopback.p4 b/testdata/p4_16_samples/issue4901_new_start_with_no_start_loopback.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 parser Parser1() {
   bit<8> l = 0;
   state start {

diff --git a/testdata/p4_16_samples/issue4901_new_start_with_start_state_loopback.p4 b/testdata/p4_16_samples/issue4901_new_start_with_start_state_loopback.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 parser Parser1() {
   bit<8> l = 0;
   state start {

diff --git a/testdata/p4_16_samples/issue4901_new_start_with_start_state_loopback2.p4 b/testdata/p4_16_samples/issue4901_new_start_with_start_state_loopback2.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 parser Parser1() {
   bit<8> l = 0;
   state start {

diff --git a/testdata/p4_16_samples/issue5211_simplify_parsers_dup_state_local_var_decl.p4 b/testdata/p4_16_samples/issue5211_simplify_parsers_dup_state_local_var_decl.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 #include <core.p4>
 
 struct S {

diff --git a/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning.p4 b/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 control C(out bit<64> v64) {
     action a() {
         v64 = (bit<64>)(int<64>)(int<1>)1w1;

diff --git a/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning2.p4 b/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning2.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 control C(out bit<64> v64) {
     action a2(in bit<1> value) {
         v64 = (bit<64>)(int<64>)(int<1>)value;

diff --git a/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning3.p4 b/testdata/p4_16_samples/issue5331-explicit-cast-overflow-mismatch-warning3.p4
@@ -1,3 +1,9 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Advanced Micro Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 extern void __e(in bit<4> x);
 control C() {
     action a() {