[PATCH] D100511: [clang] Modify diagnostic level from err to warn: anyx86_interrupt_regsave

[Melanie Blower via Phabricator via cfe-commits]

mibintc created this revision.
mibintc added a reviewer: aaron.ballman.
Herald added a subscriber: pengfei.
mibintc requested review of this revision.
Herald added a project: clang.

I got a bug report that https://reviews.llvm.org/D97764 which introduced this diagnostic, was causing problems in interrupt service routines, complaining about functions like abort, exit, or the x86intrin routines (that are really just inlined asm). I think modifying the diagnostic level from error to warn is the safest way to deal with the problem.  Checking "always inline" attribute on the called function isn't itself enough without knowing that the called function is leaf.  (Separately, perhaps x86intrin functions should be decorated with attribute 'no_caller_saved_registers' in their declarations.)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D100511

Files:
  clang/include/clang/Basic/DiagnosticSemaKinds.td
  clang/lib/Sema/SemaExpr.cpp
  clang/test/Sema/attr-x86-interrupt.c


Index: clang/test/Sema/attr-x86-interrupt.c
===================================================================
--- clang/test/Sema/attr-x86-interrupt.c
+++ clang/test/Sema/attr-x86-interrupt.c
@@ -51,7 +51,7 @@
 __attribute__((no_caller_saved_registers))
 #else
 // expected-note at +3 {{'foo9' declared here}}
-// expected-error at +4 {{interrupt service routine may only call a function with attribute 'no_caller_saved_registers'}}
+// expected-warning at +4 {{interrupt service routine should only call a function with attribute 'no_caller_saved_registers'}}
 #endif
 void foo9(int *a, Arg2Type b) {}
 __attribute__((interrupt)) void fooA(int *a, Arg2Type b) {
Index: clang/lib/Sema/SemaExpr.cpp
===================================================================
--- clang/lib/Sema/SemaExpr.cpp
+++ clang/lib/Sema/SemaExpr.cpp
@@ -6607,7 +6607,7 @@
     }
     if (Caller->hasAttr<AnyX86InterruptAttr>() &&
         ((!FDecl || !FDecl->hasAttr<AnyX86NoCallerSavedRegistersAttr>()))) {
-      Diag(Fn->getExprLoc(), diag::err_anyx86_interrupt_regsave);
+      Diag(Fn->getExprLoc(), diag::warn_anyx86_interrupt_regsave);
       if (FDecl)
         Diag(FDecl->getLocation(), diag::note_callee_decl) << FDecl;
     }
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -293,9 +293,10 @@
   "a pointer as the first parameter|a %2 type as the second parameter}1">;
 def err_anyx86_interrupt_called : Error<
   "interrupt service routine cannot be called directly">;
-def err_anyx86_interrupt_regsave : Error<
-  "interrupt service routine may only call a function"
-  " with attribute 'no_caller_saved_registers'">;
+def warn_anyx86_interrupt_regsave : Warning<
+  "interrupt service routine should only call a function"
+  " with attribute 'no_caller_saved_registers'">,
+   InGroup<Extra>;
 def warn_arm_interrupt_calling_convention : Warning<
    "call to function without interrupt attribute could clobber interruptee's VFP registers">,
    InGroup<Extra>;


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