llvm-project/clang/test/CodeGenCXX/main-norecurse.cpp

// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s

// CHECK: define {{.*}} @main({{.*}}) #0
int main(int argc, char **argv) {
    return 1;
}

// CHECK: attributes #0 = { noinline norecurse{{.*}} }
[C++] Add the "norecurse" attribute to main() if in C++ mode The C++ spec (3.6.1.3) says "The function `main` shall not be used within a program". This implies that it cannot recurse, so add the norecurse attribute to help the midend out a bit. llvm-svn: 252902 2015-11-12 23:36:04 +08:00			`// RUN: %clang_cc1 -emit-llvm %s -o - \| FileCheck %s`

Slacken the norecurse test slightly It has been reported that this test currently fails on some Power buildbots due to them adding a "signext" function attribute. As that's not what we're checking here, slacken off the test a bit. llvm-svn: 253055 2015-11-14 01:29:18 +08:00			`// CHECK: define {{.}} @main({{.}}) #0`
[C++] Add the "norecurse" attribute to main() if in C++ mode The C++ spec (3.6.1.3) says "The function `main` shall not be used within a program". This implies that it cannot recurse, so add the norecurse attribute to help the midend out a bit. llvm-svn: 252902 2015-11-12 23:36:04 +08:00			`int main(int argc, char **argv) {`
			`return 1;`
			`}`

Cleanup the handling of noinline function attributes, -fno-inline, -fno-inline-functions, -O0, and optnone. These were really, really tangled together: - We used the noinline LLVM attribute for -fno-inline - But not for -fno-inline-functions (breaking LTO) - But we did use it for -finline-hint-functions (yay, LTO is happy!) - But we didn't for -O0 (LTO is sad yet again...) - We had weird structuring of CodeGenOpts with both an inlining enumeration and a boolean. They interacted in weird ways and needlessly. - A lot of set smashing went on with setting these, and then got worse when we considered optnone and other inlining-effecting attributes. - A bunch of inline affecting attributes were managed in a completely different place from -fno-inline. - Even with -fno-inline we failed to put the LLVM noinline attribute onto many generated function definitions because they didn't show up as AST-level functions. - If you passed -O0 but -finline-functions we would run the normal inliner pass in LLVM despite it being in the O0 pipeline, which really doesn't make much sense. - Lastly, we used things like '-fno-inline' to manipulate the pass pipeline which forced the pass pipeline to be much more parameterizable than it really needs to be. Instead we can just use the optimization level to select a pipeline and control the rest via attributes. Sadly, this causes a bunch of churn in tests because we don't run the optimizer in the tests and check the contents of attribute sets. It would be awesome if attribute sets were a bit more FileCheck friendly, but oh well. I think this is a significant improvement and should remove the semantic need to change what inliner pass we run in order to comply with the requested inlining semantics by relying completely on attributes. It also cleans up tho optnone and related handling a bit. One unfortunate aspect of this is that for generating alwaysinline routines like those in OpenMP we end up removing noinline and then adding alwaysinline. I tried a bunch of other approaches, but because we recompute function attributes from scratch and don't have a declaration here I couldn't find anything substantially cleaner than this. Differential Revision: https://reviews.llvm.org/D28053 llvm-svn: 290398 2016-12-23 09:24:49 +08:00			`// CHECK: attributes #0 = { noinline norecurse{{.*}} }`