Bug 19933 – MSVC: Undefined std{in,out,err} with -betterC

Not only stdout, (stderr too, maybe more) Window 10 DMD D Compiler v2.086.0 LLVM D compiler (1.16.0-beta2) import core.stdc.stdio; extern(C) void main() { fprintf(stdout , "testing\n"); } //dub run --compiler=dmd --arch=x86_64 /* Program exited with code -1073740777 */ //dub run --compiler=ldc2 --arch=x86_64 /* lld-link: error: undefined symbol: stdout (...) */

Quoting myself from https://github.com/ldc-developers/ldc/issues/3640#issuecomment-757464048: The MSVC runtime doesn't feature these symbols; MS defines them as macros, whereas druntime defines and sets them at startup for convenience. [And druntime of course isn't linked with -betterC.]

Just noticed that the OP hasn't used -betterC, but a C main, thus skipping the druntime initialization (incl. setting std{in,out,err}). With LDC v1.25, there's no linker error anymore, but the expected segfault as with DMD.

*** Issue 20532 has been marked as a duplicate of this issue. ***

I just got hit by this, using -betterC There are no errors, it just crash The solution is to init windows runtime, but how to do that? Shouldn't the solution be simpler? the experience as a result is very poor

I feel like the "Important" should be changed since it just crashes without any hints on how to solve the issue

Could https://github.com/dlang/druntime/blob/master/src/rt/msvc.d be moved to src/core? So everyone could just call: init_msvc()

@rainers created dlang/druntime pull request #3740 "fix issue 19933 and 18816: MSVC: Undefined std{in,out,err} with -betterC" fixing this issue: - fix issue 19933 and 18816: MSVC: Undefined std{in,out,err} with -betterC moved C runtime check into template function https://github.com/dlang/druntime/pull/3740

dlang/druntime pull request #3740 "fix issue 19933 and 18816: MSVC: Undefined std{in,out,err} with -betterC" was merged into master: - e7e6800babed4ff51b6c3b57dfa7e54cb76247f7 by Rainer Schuetze: fix issue 19933 and 18816: MSVC: Undefined std{in,out,err} with -betterC made stdin/out/err template function return value https://github.com/dlang/druntime/pull/3740