[RFC PATCH v4 02/19] qemu: Convert target_name() to TargetInfo API

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Have target_name() be a target-agnostic method, dispatching
to a per-target TargetInfo singleton structure.
By default a stub singleton is used. No logical change
expected.

Inspired-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
---
 MAINTAINERS                     |  7 +++++++
 meson.build                     |  3 +++
 include/hw/core/cpu.h           |  2 --
 include/qemu/target-info-impl.h | 28 ++++++++++++++++++++++++++++
 include/qemu/target-info.h      | 19 +++++++++++++++++++
 cpu-target.c                    |  5 -----
 hw/core/machine-qmp-cmds.c      |  1 +
 plugins/loader.c                |  2 +-
 system/vl.c                     |  2 +-
 target-info-stub.c              | 19 +++++++++++++++++++
 target-info.c                   | 16 ++++++++++++++++
 11 files changed, 95 insertions(+), 9 deletions(-)
 create mode 100644 include/qemu/target-info-impl.h
 create mode 100644 include/qemu/target-info.h
 create mode 100644 target-info-stub.c
 create mode 100644 target-info.c

diff --git a/MAINTAINERS b/MAINTAINERS
index c7083ab1d93..a055f67b5fc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1913,6 +1913,13 @@ F: tests/functional/test_empty_cpu_model.py
 F: tests/unit/test-smp-parse.c
 T: git https://gitlab.com/ehabkost/qemu.git machine-next
 
+TargetInfo API
+M: Pierrick Bouvier <pierrick.bouvier@linaro.org>
+M: Philippe Mathieu-Daudé <philmd@linaro.org>
+S: Supported
+F: include/qemu/target-info*.h
+F: target-info*.c
+
 Xtensa Machines
 ---------------
 sim
diff --git a/meson.build b/meson.build
index bcb9d39a387..09b16e2f7ae 100644
--- a/meson.build
+++ b/meson.build
@@ -3807,6 +3807,9 @@ endif
 common_ss.add(pagevary)
 specific_ss.add(files('page-target.c', 'page-vary-target.c'))
 
+common_ss.add(files('target-info.c'))
+specific_ss.add(files('target-info-stub.c'))
+
 subdir('backends')
 subdir('disas')
 subdir('migration')
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 5b645df59f5..9d9448341d1 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -1115,8 +1115,6 @@ bool cpu_exec_realizefn(CPUState *cpu, Error **errp);
 void cpu_exec_unrealizefn(CPUState *cpu);
 void cpu_exec_reset_hold(CPUState *cpu);
 
-const char *target_name(void);
-
 #ifdef COMPILING_PER_TARGET
 
 extern const VMStateDescription vmstate_cpu_common;
diff --git a/include/qemu/target-info-impl.h b/include/qemu/target-info-impl.h
new file mode 100644
index 00000000000..c276b84ceca
--- /dev/null
+++ b/include/qemu/target-info-impl.h
@@ -0,0 +1,28 @@
+/*
+ * QEMU TargetInfo structure definition
+ *
+ *  Copyright (c) Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef QEMU_TARGET_INFO_IMPL_H
+#define QEMU_TARGET_INFO_IMPL_H
+
+#include "qemu/target-info.h"
+
+typedef struct TargetInfo {
+
+    /* runtime equivalent of TARGET_NAME definition */
+    const char *const target_name;
+
+} TargetInfo;
+
+/**
+ * target_info:
+ *
+ * Returns: The TargetInfo structure definition for this target binary.
+ */
+const TargetInfo *target_info(void);
+
+#endif
diff --git a/include/qemu/target-info.h b/include/qemu/target-info.h
new file mode 100644
index 00000000000..1007dc9a5e4
--- /dev/null
+++ b/include/qemu/target-info.h
@@ -0,0 +1,19 @@
+/*
+ * QEMU target info API
+ *
+ *  Copyright (c) Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef QEMU_TARGET_INFO_H
+#define QEMU_TARGET_INFO_H
+
+/**
+ * target_name:
+ *
+ * Returns: Canonical target name (i.e. "i386").
+ */
+const char *target_name(void);
+
+#endif
diff --git a/cpu-target.c b/cpu-target.c
index c99d208a7c4..3f82d3ea444 100644
--- a/cpu-target.c
+++ b/cpu-target.c
@@ -165,8 +165,3 @@ bool target_words_bigendian(void)
 {
     return TARGET_BIG_ENDIAN;
 }
-
-const char *target_name(void)
-{
-    return TARGET_NAME;
-}
diff --git a/hw/core/machine-qmp-cmds.c b/hw/core/machine-qmp-cmds.c
index 0e9ca1b90e2..529ce8dd9a0 100644
--- a/hw/core/machine-qmp-cmds.c
+++ b/hw/core/machine-qmp-cmds.c
@@ -19,6 +19,7 @@
 #include "qapi/qobject-input-visitor.h"
 #include "qapi/type-helpers.h"
 #include "qemu/uuid.h"
+#include "qemu/target-info.h"
 #include "qom/qom-qobject.h"
 #include "system/hostmem.h"
 #include "system/hw_accel.h"
diff --git a/plugins/loader.c b/plugins/loader.c
index 7523d554f03..ccde83414d6 100644
--- a/plugins/loader.c
+++ b/plugins/loader.c
@@ -29,7 +29,7 @@
 #include "qemu/xxhash.h"
 #include "qemu/plugin.h"
 #include "qemu/memalign.h"
-#include "hw/core/cpu.h"
+#include "qemu/target-info.h"
 #include "exec/tb-flush.h"
 
 #include "plugin.h"
diff --git a/system/vl.c b/system/vl.c
index c17945c4939..cdf6eb9ee49 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -40,6 +40,7 @@
 #include "qemu/help_option.h"
 #include "qemu/hw-version.h"
 #include "qemu/uuid.h"
+#include "qemu/target-info.h"
 #include "system/reset.h"
 #include "system/runstate.h"
 #include "system/runstate-action.h"
@@ -79,7 +80,6 @@
 #include "hw/block/block.h"
 #include "hw/i386/x86.h"
 #include "hw/i386/pc.h"
-#include "hw/core/cpu.h"
 #include "migration/cpr.h"
 #include "migration/misc.h"
 #include "migration/snapshot.h"
diff --git a/target-info-stub.c b/target-info-stub.c
new file mode 100644
index 00000000000..076b9254dd0
--- /dev/null
+++ b/target-info-stub.c
@@ -0,0 +1,19 @@
+/*
+ * QEMU target info stubs
+ *
+ *  Copyright (c) Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/target-info-impl.h"
+
+static const TargetInfo target_info_stub = {
+    .target_name = TARGET_NAME,
+};
+
+const TargetInfo *target_info(void)
+{
+    return &target_info_stub;
+}
diff --git a/target-info.c b/target-info.c
new file mode 100644
index 00000000000..84b18931e7e
--- /dev/null
+++ b/target-info.c
@@ -0,0 +1,16 @@
+/*
+ * QEMU target info helpers
+ *
+ *  Copyright (c) Linaro
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/target-info.h"
+#include "qemu/target-info-impl.h"
+
+const char *target_name(void)
+{
+    return target_info()->target_name;
+}
-- 
2.47.1