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s390: Add CC_HAS_ASM_IMMEDIATE_STRINGS

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Upcoming changes to s390 specific inline assemblies require the usage of
strings as immediate input operands. This works only with gcc-9 and newer
compilers. With gcc-8 this leads to a compile error:

void bar(void) { asm volatile("" :: "i" ("foo")); }

Results in:

In function 'bar':
 warning: asm operand 0 probably doesn't match constraints
  asm volatile("" :: "i" ("foo"));
  ^~~
 error: impossible constraint in 'asm'

Provide a CC_HAS_ASM_IMMEDIATE_STRINGS config option which allows to tell
if the compiler supports strings as immediate input operands.
Based on that conditional code can be provided.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Heiko Carstens
2026-01-09 16:31:36 +01:00
parent 88303fb68c
commit e5f3e67de5
1 changed files with 6 additions and 0 deletions
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6
arch/s390/Kconfig
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@@ -69,6 +69,12 @@ config CC_HAS_ASM_AOR_FORMAT_FLAGS
Clang versions before 19.1.0 do not support A,
O, and R inline assembly format flags.
config CC_HAS_ASM_IMMEDIATE_STRINGS
def_bool !(CC_IS_GCC && GCC_VERSION < 90000)
help
GCC versions before 9.0.0 cannot handle strings as immediate
input operands in inline assemblies.
config CC_HAS_STACKPROTECTOR_GLOBAL
def_bool $(cc-option, -mstack-protector-guard=global -mstack-protector-guard-record)