{"id":1205,"date":"2022-08-30T15:14:08","date_gmt":"2022-08-30T15:14:08","guid":{"rendered":"https:\/\/unknownerror.org\/index.php\/2013\/11\/10\/problem-about-ar-collection-of-common-programming-errors\/"},"modified":"2022-08-30T15:14:08","modified_gmt":"2022-08-30T15:14:08","slug":"problem-about-ar-collection-of-common-programming-errors","status":"publish","type":"post","link":"https:\/\/unknownerror.org\/index.php\/2022\/08\/30\/problem-about-ar-collection-of-common-programming-errors\/","title":{"rendered":"problem about ar-Collection of common programming errors"},"content":{"rendered":"<ul>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/7dbcc45029a276d6f3d4018b29896319?s=32&amp;d=identicon&amp;r=PG&amp;f=1\" \/><br \/>\ngeekydel<br \/>\nc osx linker ld ar<br \/>\nI am having problems with the linker when porting a C library from Linux (Ubuntu) to OS X. The C code is auto-generated from Matlab, so ideally I don&#8217;t want to change the code itself.The problem seems to be in a C file which contains ONLY uninitialised variable declarations, which are then EXTERNed by other C files to implement the Matlab algorithms. The OS X linker is apparently unable to recognise symbols from this file. The same source code works fine on Linux, so I want to understand how the OS X linker is behaving<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/1265a28e28ac02df1fdfc345bd2567f2?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nKONSTANTIN MALOLIN<br \/>\ngcc osx-snow-leopard binutils ar<br \/>\nBelow is the description of the issue. I marked it all as a code to avoid the implicit formatting that StackOverflow does. That is pretty annoying to have to deal with the Wiki-like markup language when I know exactly myself how I want to format my question.I am dealing with a weird toolchain issue on Macos. Here is what is going on :$ cat<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/b38c03070e5322a669332fe98e608d52?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nEldila<br \/>\nc osx-leopard ar<br \/>\nI am attempting to link a thin archive that combines two archive libraries to a C program. I constructed two simple hello world functions and built an archive with the commands:ar rcs lib1.a lib1.o ar rcs lib2.a lib2.oThe two archives are then merged using a thin-archive:ar rcsT all_lib.a lib1.a lib2.aand then compiled with gcc:gcc main.o all_lib.a -o helloI end up with a e<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/2385676760fc16f76a43f3319faaa843?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nJohannes Schaub &#8211; litb<br \/>\nlinker static-libraries ar .a<br \/>\nIf one builds static libraries in one&#8217;s build scripts and one wants to use those static libraries in linking the final executable, the order one mentions the .a files is important:g++ main.o hw.a gui.a -o executableIf gui.a uses something defined in hw.a the link will fail, because at the time hw.a is processed, the linker doesn&#8217;t yet know that the definition is needed later, and doesn&#8217;t include it in the being.generated executable. Manually fiddling around with the linke<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/b30b3b4ab5550482532acfe52c81ad38?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nuser1986698<br \/>\nc linker make static-libraries ar<br \/>\nI&#8217;m working on a quite large and messy project that I haven&#8217;t really got time to clean up and I&#8217;ve been tasked with providing an API for it. What I&#8217;m trying to do is wrapping all the ugly stuff up in a single static library and then provide it with a single head<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/91aef7668303115d1faecbc3fb582253?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nBart<br \/>\nc++ c ar<br \/>\nFirst of all, I have all sources for my libraries. (The other topics on the matter I found on SO were not quite about the same thing) The only problem is that the c<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/b38376e8266417ab4576f2c68671b605?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\naneccodeal<br \/>\ngcc ld ar<br \/>\nLet&#8217;s say I&#8217;ve got a couple of .o files in a directory that get ar&#8217;ed into a static library:ar cr libstuff.a a.o b.oIn another directory there a<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/3e8242329ec2756662c818a9baba76f9?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nHonza<br \/>\ngcc linker static-libraries ar<br \/>\nI have a C project using several object files that needs to be linked in a specific order to find all needed symbols.For example this command works fine (lib2.o depends on lib1.o etc.)gcc -o my_app main.o lib1.o lib2.o lib3.o -lm<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/c630ef59937076af694a610237bff5eb?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\npatseb<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/142dbbce38e59d6b5e452ca6fcf725ef?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nAndrew<br \/>\ng++ ld ar<br \/>\nSo, I&#8217;m trying to incorporate the libpthread.a library into my own library. But its giving me linke<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/10832763f28e3dd9181ea447a1a44bfe?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nManan Shah<br \/>\nc++ linux g++ ar<br \/>\nI have written some code in Lib_file.h and Lib_file.cpp. I wish to convert this code to a static library. I am able to compile the code (using the command g++ -I -o Lib_file.o Lib_file.cpp)to get Lib_file.o. I am also able to add it to an archive using the ar rv<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/66d739684d639c77055885a029e0866d?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nchriskirk<\/li>\n<li><img decoding=\"async\" src=\"http:\/\/www.gravatar.com\/avatar\/5a5a092c2659f9d07d66fe4dbe459a8e?s=32&amp;d=identicon&amp;r=PG\" \/><br \/>\nAlex Kremer<br \/>\nc++ templates linker ar<br \/>\nConsider the following minimal example which reproduces a problem in a much bigger project:spec.h:#include class A { public:templateT test(const std::string&amp; a){std::cout<\/li>\n<\/ul>\n<p id=\"rop\"><small>Originally posted 2013-11-10 00:09:43. <\/small><\/p>","protected":false},"excerpt":{"rendered":"<p>geekydel c osx linker ld ar I am having problems with the linker when porting a C library from Linux (Ubuntu) to OS X. The C code is auto-generated from Matlab, so ideally I don&#8217;t want to change the code itself.The problem seems to be in a C file which contains ONLY uninitialised variable declarations, [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1205","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/1205","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/comments?post=1205"}],"version-history":[{"count":0,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/1205\/revisions"}],"wp:attachment":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/media?parent=1205"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/categories?post=1205"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/tags?post=1205"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}