Thanks for all the responses. I have a solution that seem to be working. Here’s the problem in detail with an example. In main.c we have: #include <stdio.h> extern int foo(); int bar() { printf(“bar in main.c called\n”); return 0; } int main() { printf(“result from foo is %d\n”, foo()); printf(“result from bar is %d\n”, … Read more
You do not have to use PIC code in shared objects (as you have discovered you can use the -mimpure-text option to allow that). That said, non-PIC code in shared objects are more heavyweight. With PIC code, the text pages in memory are just direct memory mappings of the text pages on disk. This means … Read more
The library requiring the symbols is included by -lLLVMSupport, so -ldl must come after -lLLVMSupport. I changed this: `llvm-config –ldflags –libs core` To this: `llvm-config –libs core` `llvm-config –ldflags` And the linker was successful.
There are two answers to this question, part of the answer lies in the compile-time linking (i.e gcc -lfoo -L/usr/lib … which in turn calls ld), and run-time linker lookups. When you compile your program, the compiler checks syntax, and then the linker ensures that the symbols required for execution exist (i.e variables / methods … Read more
As the GCC manual says, LIBRARY_PATH is the correct environment variable to add directories to the library search path. If you add -v to the g++ command you should see the LIBRARY_PATH that it uses, and you should see it includes the directory you have specified, and that it gets added to the collect2 command … Read more
When a system uses virtual memory, the kernel uses virtual memory as well. Windows will use the upper 2GB (or 1GB if you’ve specified the /3GB switch in the Windows bootloader) for its own use. This includes kernel code, data (or at least the data that is paged in — that’s right, Windows can page … Read more
Any idea about what I might be doing wrong? The t function is indeed local to the library. This could happen due to a number or reasons. The most likely ones are: You declared the function static, or You compiled the library with -fvisibility=hidden and did not have __attribute__((visibility(“default”))) on the function, or You linked … Read more
The answer lies in a new Android security feature: Package Visibility. This works similar to iOS’ LSApplicationQueriesSchemes. Targeting Android 11 (SDK 30) requires you to update your AndroidManifest.xml and include a list of applications you’re querying for. E.g. here’s the code I’m using to check for Google Maps navigation in my own app. It also … Read more