Re: [RFC PATCH 10/11] qemu: Introduce qemu_arch_name() helper

[BALATON Zoltan]

On Wed, 5 Mar 2025, Philippe Mathieu-Daudé wrote:
On 5/3/25 02:32, BALATON Zoltan wrote:
On Wed, 5 Mar 2025, Philippe Mathieu-Daudé wrote:
Introduce a generic helper to get the target name of a QemuArchBit.
(This will be used for single / heterogeneous binaries).
Use it in target_name(), removing the last use of the TARGET_NAME
definition.
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
include/qemu/arch_info.h |  2 ++
arch_info-target.c       | 34 +++++++++++++++++++++++++++++++++-
2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/include/qemu/arch_info.h b/include/qemu/arch_info.h
index 613dc2037db..7e3192f590f 100644
--- a/include/qemu/arch_info.h
+++ b/include/qemu/arch_info.h
@@ -46,6 +46,8 @@ typedef enum QemuArchBit {
#define QEMU_ARCH_LOONGARCH     BIT(QEMU_ARCH_BIT_LOONGARCH)
#define QEMU_ARCH_ALL           -1

+const char *qemu_arch_name(QemuArchBit qemu_arch_bit);
+
const char *target_name(void);

bool qemu_arch_available(unsigned qemu_arch_mask);
diff --git a/arch_info-target.c b/arch_info-target.c
index 61007415b30..9b19fe8d56d 100644
--- a/arch_info-target.c
+++ b/arch_info-target.c
@@ -24,9 +24,41 @@
#include "qemu/osdep.h"
#include "qemu/arch_info.h"

+const char *qemu_arch_name(QemuArchBit qemu_arch_bit)
+{
+    static const char *legacy_target_names[] = {
+        [QEMU_ARCH_ALPHA] = "alpha",
+        [QEMU_ARCH_BIT_ARM] = TARGET_LONG_BITS == 32 ? "arm" : "aarch64",
+        [QEMU_ARCH_BIT_AVR] = "avr",
+        [QEMU_ARCH_BIT_HEXAGON] = "hexagon",
+        [QEMU_ARCH_BIT_HPPA] = "hppa",
+        [QEMU_ARCH_BIT_I386] = TARGET_LONG_BITS == 32 ? "i386" : 
"x86_64",
+        [QEMU_ARCH_BIT_LOONGARCH] = "loongarch64",
+        [QEMU_ARCH_BIT_M68K] = "m68k",
+        [QEMU_ARCH_BIT_MICROBLAZE] = TARGET_BIG_ENDIAN ? "microblaze"
+                                                       : "microblazeel",
+        [QEMU_ARCH_BIT_MIPS] = TARGET_BIG_ENDIAN
+                             ? (TARGET_LONG_BITS == 32 ? "mips" : 
"mips64")
+                             : (TARGET_LONG_BITS == 32 ? "mipsel" : 
"mips64el"),
+        [QEMU_ARCH_BIT_OPENRISC] = "or1k",
+        [QEMU_ARCH_BIT_PPC] = TARGET_LONG_BITS == 32 ? "ppc" : "ppc64",
+        [QEMU_ARCH_BIT_RISCV] = TARGET_LONG_BITS == 32 ? "riscv32" : 
"riscv64",
+        [QEMU_ARCH_BIT_RX] = "rx",
+        [QEMU_ARCH_BIT_S390X] = "s390x",
+        [QEMU_ARCH_BIT_SH4] = TARGET_BIG_ENDIAN ? "sh4eb" : "sh4",
+        [QEMU_ARCH_BIT_SPARC] = TARGET_LONG_BITS == 32 ? "sparc" : 
"sparc64",
+        [QEMU_ARCH_BIT_TRICORE] = "tricore",
+        [QEMU_ARCH_BIT_XTENSA] = TARGET_BIG_ENDIAN ? "xtensaeb" : 
"xtensa",
+    };
+
+    assert(qemu_arch_bit < ARRAY_SIZE(legacy_target_names));
+    assert(legacy_target_names[qemu_arch_bit]);
+    return legacy_target_names[qemu_arch_bit];
+}
+
const char *target_name(void)
{
-    return TARGET_NAME;
+    return qemu_arch_name(QEMU_ARCH_BIT);
}

Why two functions that do the same? Do you plan to remove target_name later 
or it should just do what the new function does?

target_name() is a no-op for current binaries, where one binary include
a single target.

The "single binary" will include multiple targets. We plan to symlink it
to the previous binaries and use argv[0] to mimic previous behavior.

This didn't answer the question for me why this would need target_name() 
and qemu_arch_name() which are the same function with two names. If these 
do the same why not only have one of them?

Regards,
BALATON Zoltan