replace strlen() with strlen_c()

include/common/mir/constexpr_utils.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright © Canonical Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 or 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#ifndef MIR_CONSTEXPR_UTILS_H_
+#define MIR_CONSTEXPR_UTILS_H_
+
+#include <string_view>
+
+namespace mir
+{
+inline constexpr std::size_t strlen_c(std::string_view str)
+{
+  return str.size();
+}
+}
+
+#endif

src/common/CMakeLists.txt

@@ -49,6 +49,7 @@ add_library(mircommon SHARED
   ${PROJECT_SOURCE_DIR}/include/common/mir/input/mir_touchscreen_config.h
   ${PROJECT_SOURCE_DIR}/include/common/mir/input/mir_keyboard_config.h
   ${PROJECT_SOURCE_DIR}/include/common/mir/input/keyboard_leds.h
+  ${PROJECT_SOURCE_DIR}/include/common/mir/constexpr_utils.h
   ${MIR_COMMON_SOURCES}
 )
 

src/miral/display_configuration_option.cpp

@@ -17,6 +17,7 @@
 #include <miral/display_configuration_option.h>
 #include "static_display_config.h"
 
+#include <mir/constexpr_utils.h>
 #include <mir/graphics/default_display_configuration_policy.h>
 #include <mir/graphics/display_configuration.h>
 #include <mir/options/option.h>
@@ -226,13 +227,13 @@ void miral::display_configuration_options(mir::Server& server)
             {
                 layout_selector = std::make_shared<mg::SingleDisplayConfigurationPolicy>();
             }
-            else if (display_layout.compare(0, strlen(static_opt_val), static_opt_val) == 0)
+            else if (display_layout.compare(0, mir::strlen_c(static_opt_val), static_opt_val) == 0)
             {
                 if (scale != 1.0)
                 {
                     mir::fatal_error("Display scale option can't be used with static display configuration");
                 }
-                auto sdc = std::make_shared<StaticDisplayConfig>(display_layout.substr(strlen(static_opt_val)));
+                auto sdc = std::make_shared<StaticDisplayConfig>(display_layout.substr(mir::strlen_c(static_opt_val)));
                 server.add_init_callback([sdc, &server]{ sdc->init_auto_reload(server); });
                 layout_selector = std::move(sdc);
             }
@@ -249,7 +250,7 @@ void miral::display_configuration_options(mir::Server& server)
                     mir::fatal_error("Display scale option can't be used with autoscale");
                 }
 
-                if (display_layout.compare(0, strlen(static_opt_val), static_opt_val) == 0)
+                if (display_layout.compare(0, mir::strlen_c(static_opt_val), static_opt_val) == 0)
                 {
                     mir::fatal_error("Display autoscale option can't be used with static display configuration");
                 }

src/platform/options/default_configuration.cpp

@@ -16,12 +16,13 @@
 
 #include <mir/options/default_configuration.h>
 
+#include <mir/abnormal_exit.h>
+#include <mir/constexpr_utils.h>
+#include <mir/graphics/platform.h>
+#include <mir/logging/null_shared_library_prober_report.h>
 #include <mir/options/program_option.h>
 #include <mir/shared_library.h>
-#include <mir/graphics/platform.h>
-#include <mir/abnormal_exit.h>
 #include <mir/shared_library_prober.h>
-#include <mir/logging/null_shared_library_prober_report.h>
 
 #include <algorithm>
 #include <format>
@@ -573,7 +574,7 @@ void mo::DefaultConfiguration::parse_environment(
         [=, this](std::string const& from) -> std::string
         {
             auto const prefix = "MIR_SERVER_";
-            auto const sizeof_prefix = strlen(prefix);
+            auto const sizeof_prefix = strlen_c(prefix);
 
             if (!from.starts_with(prefix))
             {

src/platforms/evdev/platform.cpp

@@ -19,12 +19,13 @@
 #include "libinput_ptr.h"
 #include "fd_store.h"
 
-#include <mir/udev/wrapper.h>
+#include <mir/console_services.h>
+#include <mir/constexpr_utils.h>
 #include <mir/dispatch/dispatchable.h>
 #include <mir/dispatch/readable_fd.h>
 #include <mir/dispatch/multiplexing_dispatchable.h>
 #include <mir/dispatch/action_queue.h>
-#include <mir/console_services.h>
+#include <mir/udev/wrapper.h>
 
 #include <mir/input/input_device_registry.h>
 #include <mir/input/input_report.h>
@@ -310,7 +311,7 @@ void mie::Platform::start()
 
                         std::string devnode{workaround_device->devnode()};
                         // Libinput filters out anything without “event” as its name
-                        if (strncmp(workaround_device->sysname(), "event", strlen("event")) != 0)
+                        if (strncmp(workaround_device->sysname(), "event", strlen_c("event")) != 0)
                         {
                             return;
                         }

src/platforms/gbm-kms/server/kms/platform_symbols.cpp

@@ -30,6 +30,7 @@
 #include <mir/assert_module_entry_point.h>
 #include <mir/libname.h>
 #include <mir/console_services.h>
+#include <mir/constexpr_utils.h>
 #include "one_shot_device_observer.h"
 #include <mir/graphics/egl_error.h>
 #include <mir/graphics/gl_config.h>
@@ -452,7 +453,7 @@ auto probe_rendering_platform(
                 if (strncmp(
                     "llvmpipe",
                     renderer_string,
-                    strlen("llvmpipe")) == 0)
+                    mir::strlen_c("llvmpipe")) == 0)
                 {
                     mir::log_info("Detected software renderer: %s", renderer_string);
                     // Leave the priority at ::unsupported; if we've got a software renderer then

src/server/console/linux_virtual_terminal.cpp

@@ -15,11 +15,13 @@
  */
 
 #include "linux_virtual_terminal.h"
+#include "ioctl_vt_switcher.h"
+
+#include <mir/constexpr_utils.h>
+#include <mir/emergency_cleanup_registry.h>
+#include <mir/fd.h>
 #include <mir/graphics/display_report.h>
 #include <mir/graphics/event_handler_register.h>
-#include <mir/fd.h>
-#include <mir/emergency_cleanup_registry.h>
-#include "ioctl_vt_switcher.h"
 #include <mir/raii.h>
 #include <mir/synchronised.h>
 
@@ -658,9 +660,9 @@ std::future<std::unique_ptr<mir::Device>> mir::LinuxVirtualTerminal::acquire_dev
 
             while (uevent.getline(line_buffer, sizeof(line_buffer)))
             {
-                if (strncmp(line_buffer, "DEVNAME=", strlen("DEVNAME=")) == 0)
+                if (strncmp(line_buffer, "DEVNAME=", strlen_c("DEVNAME=")) == 0)
                 {
-                    return std::string{"/dev/"} + std::string{line_buffer + strlen("DEVNAME=")};
+                    return std::string{"/dev/"} + std::string{line_buffer + strlen_c("DEVNAME=")};
                 }
             }
             BOOST_THROW_EXCEPTION((std::runtime_error{"Failed to read DEVNAME"}));

src/server/console/logind_console_services.cpp

@@ -27,9 +27,10 @@
 
 #include "logind-session.h"
 
+#include <mir/constexpr_utils.h>
 #include <mir/fd.h>
-#include <mir/main_loop.h>
 #include <mir/glib_main_loop.h>
+#include <mir/main_loop.h>
 
 #define MIR_LOG_COMPONTENT "logind"
 #include <mir/log.h>
@@ -265,7 +266,7 @@ mir::LogindConsoleServices::LogindConsoleServices(
             session_path.c_str())},
       switch_away{[](){ return true; }},
       switch_to{[](){ return true; }},
-      active{strncmp("active", logind_session_get_state(session_proxy.get()), strlen("active")) == 0}
+      active{strncmp("active", logind_session_get_state(session_proxy.get()), strlen_c("active")) == 0}
 {
     GErrorPtr error;
 
@@ -789,7 +790,7 @@ GDBusMessage* mir::LogindConsoleServices::resume_device_dbus_filter(
         return message;
 
     // …if it's a signal, but it's not ResumeDevice, we don't need to process it.
-    if (strncmp(g_dbus_message_get_member(message), "ResumeDevice", strlen("ResumeDevice")) != 0)
+    if (strncmp(g_dbus_message_get_member(message), "ResumeDevice", strlen_c("ResumeDevice")) != 0)
         return message;
 
     // We've definitely got a ResumeDevice signal! Now to extract the parameters, and

src/server/console/minimal_console_services.cpp

@@ -16,6 +16,7 @@
 
 #include "minimal_console_services.h"
 
+#include <mir/constexpr_utils.h>
 #include <mir/log.h>
 
 #include <boost/exception/errinfo_errno.hpp>
@@ -104,9 +105,9 @@ std::future<std::unique_ptr<mir::Device>> mir::MinimalConsoleServices::acquire_d
 
         while (uevent.getline(line_buffer, sizeof(line_buffer)))
         {
-            if (strncmp(line_buffer, "DEVNAME=", strlen("DEVNAME=")) == 0)
+            if (strncmp(line_buffer, "DEVNAME=", strlen_c("DEVNAME=")) == 0)
             {
-                return std::string{"/dev/"} + std::string{line_buffer + strlen("DEVNAME=")};
+                return std::string{"/dev/"} + std::string{line_buffer + strlen_c("DEVNAME=")};
             }
         }
         BOOST_THROW_EXCEPTION((std::runtime_error{"Failed to read DEVNAME"}));

src/server/frontend_wayland/foreign_toplevel_manager_v1.cpp

@@ -18,17 +18,19 @@
 
 #include "wayland_utils.h"
 #include "desktop_file_manager.h"
-#include <mir/wayland/weak.h>
+
+#include <mir/constexpr_utils.h>
+#include <mir/executor.h>
 #include <mir/frontend/surface_stack.h>
-#include <mir/shell/shell.h>
-#include <mir/shell/surface_specification.h>
+#include <mir/log.h>
+#include <mir/main_loop.h>
 #include <mir/scene/null_observer.h>
 #include <mir/scene/null_surface_observer.h>
 #include <mir/scene/surface.h>
 #include <mir/scene/session.h>
-#include <mir/log.h>
-#include <mir/executor.h>
-#include <mir/main_loop.h>
+#include <mir/shell/surface_specification.h>
+#include <mir/shell/shell.h>
+#include <mir/wayland/weak.h>
 
 #include <algorithm>
 #include <mutex>
@@ -579,9 +581,10 @@ void mf::GDesktopFileCache::refresh_app_cache()
 
         // It is likely that [id] ends in a .desktop suffix. If that's the case, we will strip
         // it out since that isn't useful in this context.
+
         const char* const desktop_suffix = ".desktop";
         if (id.ends_with(desktop_suffix))
-            id.erase(id.length() - strlen(desktop_suffix));
+            id.erase(id.length() - strlen_c(desktop_suffix));
 
         std::shared_ptr<DesktopFile> file = std::make_shared<DesktopFile>(id.c_str(), wm_class, exec);
         if (g_app_info_should_show(app_info))

tests/mir_test_doubles/mock_drm.cpp

@@ -17,6 +17,7 @@
 #include <mir/test/doubles/mock_drm.h>
 #include <mir_test_framework/mmap_wrapper.h>
 #include <mir_test_framework/open_wrapper.h>
+#include <mir/constexpr_utils.h>
 #include <mir/geometry/size.h>
 #include <gtest/gtest.h>
 
@@ -235,7 +236,7 @@ mtd::MockDRM::MockDRM()
         [this](char const* path, int flags, std::optional<mode_t>) -> std::optional<int>
         {
             char const* const drm_prefix = "/dev/dri/";
-            if (!strncmp(path, drm_prefix, strlen(drm_prefix)))
+            if (!strncmp(path, drm_prefix, strlen_c(drm_prefix)))
             {
                 // I don't think we need to be able to distinguish based on mode. ppc64el (at least) *does*
                 // call the 3-parameter open()
@@ -373,11 +374,11 @@ mtd::MockDRM::MockDRM()
         1,
         2,
         3,
-        static_cast<int>(strlen("mock_driver")),
+        static_cast<int>(strlen_c("mock_driver")),
         const_cast<char*>("mock_driver"),
-        static_cast<int>(strlen("1 Jan 1970")),
+        static_cast<int>(strlen_c("1 Jan 1970")),
         const_cast<char*>("1 Jan 1970"),
-        static_cast<int>(strlen("Not really a driver")),
+        static_cast<int>(strlen_c("Not really a driver")),
         const_cast<char*>("Not really a driver")
     };
     ON_CALL(*this, drmGetVersion(_))

tests/unit-tests/console/test_linux_virtual_terminal.cpp

@@ -16,9 +16,10 @@
 
 #include "src/server/console/linux_virtual_terminal.h"
 #include "src/server/report/null_report_factory.h"
-#include <mir/graphics/event_handler_register.h>
 #include <mir/anonymous_shm_file.h>
+#include <mir/constexpr_utils.h>
 #include <mir/emergency_cleanup_registry.h>
+#include <mir/graphics/event_handler_register.h>
 
 #include <mir/test/fake_shared.h>
 #include <mir/test/doubles/mock_display_report.h>
@@ -791,15 +792,15 @@ std::string uevent_content_for_device(
 {
     std::stringstream content;
 
-    if (strncmp(device_name, "/dev/", strlen("/dev/")) != 0)
+    if (strncmp(device_name, "/dev/", mir::strlen_c("/dev/")) != 0)
     {
         throw std::logic_error{"device_name is expected to be the fully-qualified /dev/foo path"};
     }
 
     content
         << "MAJOR=" << major << "\n"
         << "MINOR=" << minor << "\n"
-        << "DEVNAME=" << device_name + strlen ("/dev/") << "\n";
+        << "DEVNAME=" << device_name + mir::strlen_c("/dev/") << "\n";
 
     return content.str();
 }
@@ -931,8 +932,8 @@ TEST_F(LinuxVirtualTerminalTest, throws_error_when_parsing_fails)
         "MINOR=61\n"
         "I_AINT_NO_DEVNAME=fb0";
 
-    mir::AnonymousShmFile uevent{strlen(uevent_content)};
-    ::memcpy(uevent.base_ptr(), uevent_content, strlen(uevent_content));
+    mir::AnonymousShmFile uevent{mir::strlen_c(uevent_content)};
+    ::memcpy(uevent.base_ptr(), uevent_content, mir::strlen_c(uevent_content));
 
     EXPECT_CALL(*fops, open(StrEq(expected_filename), FlagsSet(O_RDONLY, O_CLOEXEC)))
         .WillOnce(Return(uevent.fd()));

tests/unit-tests/console/test_minimal_console_services.cpp

@@ -18,6 +18,7 @@
 #include <mir_test_framework/open_wrapper.h>
 #include <mir/test/doubles/mock_drm.h>
 #include <mir/test/doubles/simple_device_observer.h>
+#include <mir/constexpr_utils.h>
 
 #include <mir/anonymous_shm_file.h>
 
@@ -42,15 +43,15 @@ std::string uevent_content_for_device(
 {
     std::stringstream content;
 
-    if (strncmp(device_name, "/dev/", strlen("/dev/")) != 0)
+    if (strncmp(device_name, "/dev/", mir::strlen_c("/dev/")) != 0)
     {
         throw std::logic_error{"device_name is expected to be the fully-qualified /dev/foo path"};
     }
 
     content
         << "MAJOR=" << major << "\n"
         << "MINOR=" << minor << "\n"
-        << "DEVNAME=" << device_name + strlen ("/dev/") << "\n";
+        << "DEVNAME=" << device_name + mir::strlen_c("/dev/") << "\n";
 
     return content.str();
 }
@@ -276,7 +277,7 @@ TEST_F(MinimalConsoleServicesTest, failure_to_open_sys_file_results_in_immediate
     auto error_on_device_open = mtf::add_open_handler(
         [](char const* path, int, std::optional<mode_t>) -> std::optional<int>
         {
-            if (!strncmp("/sys", path, strlen("/sys")))
+            if (!strncmp("/sys", path, mir::strlen_c("/sys")))
             {
                 errno = EINVAL;
                 return {-1};