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From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Fangrui Song <maskray@google.com>
Subject: [PATCH v2 1/4] Add declare_object_symbol_alias for assembly codes (BZ #28128)
Date: Thu, 12 May 2022 09:59:28 -0300	[thread overview]
Message-ID: <20220512125931.523712-2-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20220512125931.523712-1-adhemerval.zanella@linaro.org>

From: "H.J. Lu" <hjl.tools@gmail.com>

There are 2 problems in:

 #define declare_symbol_alias(symbol, original, type, size) \
  declare_symbol_alias_1 (symbol, original, type, size)
 #ifdef __ASSEMBLER__
 # define declare_symbol_alias_1(symbol, original, type, size) \
   strong_alias (original, symbol); \
   .type C_SYMBOL_NAME (symbol), %##type; \
   .size C_SYMBOL_NAME (symbol), size

1. .type and .size are substituted by arguments.
2. %##type is expanded to "% type" due to the GCC bug:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101613

But assembler doesn't support "% type".

Workaround BZ #28128 by

1. Don't define declare_symbol_alias for assembly codes.
2. Define declare_object_symbol_alias for assembly codes.
---
 include/libc-symbols.h | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 662bd118b1..4bb3d8c7ba 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -324,14 +324,16 @@ for linking")
    This is only necessary when defining something in assembly, or playing
    funny alias games where the size should be other than what the compiler
    thinks it is.  */
-#define declare_symbol_alias(symbol, original, type, size) \
-  declare_symbol_alias_1 (symbol, original, type, size)
 #ifdef __ASSEMBLER__
-# define declare_symbol_alias_1(symbol, original, type, size) \
-   strong_alias (original, symbol); \
-   .type C_SYMBOL_NAME (symbol), %##type; \
-   .size C_SYMBOL_NAME (symbol), size
+# define declare_object_symbol_alias(symbol, original, size) \
+  declare_object_symbol_alias_1 (symbol, original, size)
+# define declare_object_symbol_alias_1(symbol, original, s_size) \
+   strong_alias (original, symbol) ASM_LINE_SEP \
+   .type C_SYMBOL_NAME (symbol), %object ASM_LINE_SEP \
+   .size C_SYMBOL_NAME (symbol), s_size ASM_LINE_SEP
 #else /* Not __ASSEMBLER__.  */
+# define declare_symbol_alias(symbol, original, type, size) \
+  declare_symbol_alias_1 (symbol, original, type, size)
 # define declare_symbol_alias_1(symbol, original, type, size) \
    asm (".globl " __SYMBOL_PREFIX #symbol \
 	"\n\t" declare_symbol_alias_1_alias (symbol, original) \
-- 
2.34.1


  reply	other threads:[~2022-05-12 12:59 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-12 12:59 [PATCH v2 0/4] Remove fno_unit_at_a_time configure check Adhemerval Zanella
2022-05-12 12:59 ` Adhemerval Zanella [this message]
2022-05-12 16:52   ` [PATCH v2 1/4] Add declare_object_symbol_alias for assembly codes (BZ #28128) Fangrui Song
2022-05-12 12:59 ` [PATCH v2 2/4] stdio: Remove the usage of $(fno-unit-at-a-time) for errlist.c Adhemerval Zanella
2022-05-12 17:03   ` Fangrui Song
2022-05-12 20:03     ` Adhemerval Zanella
2022-05-12 12:59 ` [PATCH v2 3/4] stdio: Remove the usage of $(fno-unit-at-a-time) for siglist.c Adhemerval Zanella
2022-05-12 17:06   ` Fangrui Song
2022-05-12 20:04     ` Adhemerval Zanella
2022-05-12 12:59 ` [PATCH v2 4/4] Remove configure fno_unit_at_a_time Adhemerval Zanella
2022-05-12 17:07   ` Fangrui Song

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