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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - lld-macho unconditionally loads all contents of an archive (unlike ld64)"
href="https://bugs.llvm.org/show_bug.cgi?id=51475">51475</a>
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<th>Summary</th>
<td>lld-macho unconditionally loads all contents of an archive (unlike ld64)
</td>
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<th>Product</th>
<td>lld
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
</tr>
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<th>OS</th>
<td>All
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>MachO
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>vyng@google.com
</td>
</tr>
<tr>
<th>CC</th>
<td>gkm@fb.com, jezreel@gmail.com, llvm-bugs@lists.llvm.org, smeenai@fb.com
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<pre>NOTE: I don't think ld64 is being reasonable here but can anyone please
double-check for me in case I've missed something obvious? :)
Repro:
- Make the following files:
```
echo '#import <Foundation/Foundation.h> \n extern NSString *const
SuperImportantSymbol;' > Constants.h && \
echo '#import "Constants.h" \n NSString *const SuperImportantSymbol =
@"SuperImportant";' > Constants.m && \
echo '#import <Foundation/Foundation.h> \n @interface FooUser : NSObject \n +
(NSString *)fooMeth; \n@end' > FooUser.h && \
echo '#import "FooUser.h" \n #import "Constants.h" \n @implementation FooUser
\n +(NSString *)fooMeth { return SuperImportantSymbol; }\n @end' > FooUser.m
&& \
echo '#import <Foundation/Foundation.h> \n @interface DYNFakeImpl : NSObject \n
+(NSString *)fakeMeth; \n @end' > DYNFakeImpl.h && \
echo '#import "DYNFakeImpl.h" \n NSString *const SuperImportantSymbol = @"FAKE
important"; \n @implementation DYNFakeImpl \n +(NSString *)fakeMeth { return
SuperImportantSymbol; } \n @end' > DYNFakeImpl.m
```
- Compile them
clang -c Constants.m && clang -c FooUser.m && clang -c DYNFakeImpl.m
- Pack them into an archive
llvm-ar r libAll.a Constants.o FooUser.o DYNFakeImpl.o
- Link with l64:
ld -demangle -dynamic -bundle -arch "x86_64" -platform_version macos 10.15
11.0 -syslibroot
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk"
-ObjC -lc++ -lobjc -lSystem -framework Foundation -o ld64_out libAll.a
This happily produces ld64_out.
Repeat the link step, but with lld, it'd complain about duplicate symbol:
ld64.lld.darwinnew -demangle -dynamic -bundle -arch "x86_64"
-platform_version macos 10.15 11.0 -syslibroot
"/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk"
-ObjC -lc++ -lobjc -lSystem -framework Foundation -o ld64_out Constants.o
FooUser.o DYNFakeImpl.o
ld64.lld.darwinnew: error: duplicate symbol: _SuperImportantSymbol
<span class="quote">>>> defined in Constants.o
>>> defined in DYNFakeImpl.o</span >
It's worth noting that even with ld64, if you replace the archive with the
three .o files, then it'd also complain about duplicate symbols.
Is this something lld-macho wants to imitate?</pre>
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