将ARMv7库链接到ARMv7s应用

Question

根据文献，A6处理器将执行ARMv7代码。我的项目在link上失败了，因为一个库是为ARMv7构建的，但应用程序是为ARMv7s构建的。

一个典型的信息是(当我连接我的iPad 4(视网膜)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体系结构(VALID_ARCHS)中删除ARMv7s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对象代码。或者，我可以为ARMv7s架构执行一个额外的库构建，但这需要更多的工作，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神奇之处吗？

Answer 1

Jim Grosbach在Xcode mailing list上说，链接器开关-allow_sub_type_mismatches应该允许ld继续进行链接。来自苹果的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.

还有一个名为LD_ALLOW_CPU_SUBTYPE_MISMATCHES的详细环境变量的Changelog entry。

然而，我发现-allow_sub_type_mismatches根本不能在Xcode4.5.2上工作。在互联网上，我们可以看到一些苹果公司为-allow_sub_type_mismatches设计的雷达。例如，请参阅雷达://6134468。

希望它现在已经解决了，但当谈到苹果和他们有缺陷的软件时，没有什么让我惊讶的。