Question

根据文献，A6处理器将执行ARMv7代码。我的项目在链接失败，因为为ARMv7构建了一个库，但该应用程序是为ARMv7s构建的。

典型的信息是（当我连接iPad 4（Retina）或iPhone 5时）：

ld: warning: ignoring file /usr/local/ssl/iphoneos/lib//fipscanister.o, file was built for armv7 which is not the architecture being linked (armv7s): /usr/local/ssl/iphoneos/lib//fipscanister.o
ld: warning: ignoring file /usr/local/ssl/iphoneos/lib//libcrypto.a, file was built for archive which is not the architecture being linked (armv7s): /usr/local/ssl/iphoneos/lib//libcrypto.a

Undefined symbols for architecture armv7s:
  "_FIPS_incore_fingerprint", referenced from:
      _FINGERPRINT_premain in fips_premain.o
  "_FIPS_signature", referenced from:
      _FINGERPRINT_premain in fips_premain.o
  "_FIPS_text_start", referenced from:
      _FINGERPRINT_premain in fips_premain.o
ld: symbol(s) not found for architecture armv7s

我知道我可以通过从有效架构（VALID_ARCHS）中删除ARMv7来解决这个问题，但我不确定为什么因为A6处理器可以执行A5目标代码。或者我可以为ARMv7s架构执行额外的库构建，但这需要更多工作，并且需要不同的磁盘目录结构。

将ARMv7库与ARMv7s应用程序链接起来有什么魔力吗？

Answer 1

来自Xcode mailing list的Jim Grosbach，链接器开关-allow_sub_type_mismatches应允许ld继续进行链接。来自Apple的ld man pages：

 -allow_sub_type_mismatches
             Normally the linker considers different cpu-subtype for ARM
             (e.g. armv4t and armv6) to be different different architec-
             tures that cannot be mixed at build time.  This option
             relaxes that requirement, allowing you to mix object files
             compiled for different ARM subtypes.

还有一个Changelog entry详细说明了名为LD_ALLOW_CPU_SUBTYPE_MISMATCHES的环境变量。

但是，我发现-allow_sub_type_mismatches根本无法在Xcode 4.5.2上运行。浏览网页会显示-allow_sub_type_mismatches的一些Apple RADAR。例如，参见radar：// 6134468。

希望它现在已经解决了，但是当谈到Apple及其有缺陷的软件时，没什么好惊讶的。

将ARMv7库链接到ARMv7s应用程序

1 个答案: