The compiler now has fewer false alarms when warning about infinite
loops. For example, a loop of the form "for X of A ...", where A is an
array, cannot be infinite. The compiler no longer warns in this case.
Tested on x86_64-pc-linux-gnu, committed on trunk
2019-07-03 Bob Duff <d...@adacore.com>
gcc/ada/
* sem_warn.adb (Check_Infinite_Loop_Warning): Avoid the warning
if an Iterator_Specification is present.
gcc/testsuite/
* gnat.dg/warn20.adb, gnat.dg/warn20_pkg.adb,
gnat.dg/warn20_pkg.ads: New testcase.--- gcc/ada/sem_warn.adb
+++ gcc/ada/sem_warn.adb
@@ -632,9 +632,16 @@ package body Sem_Warn is
Expression := Condition (Iter);
- -- For iteration, do not process, since loop will always terminate
-
- elsif Present (Loop_Parameter_Specification (Iter)) then
+ -- For Loop_Parameter_Specification, do not process, since loop
+ -- will always terminate. For Iterator_Specification, also do not
+ -- process. Either it will always terminate (e.g. "for X of
+ -- Some_Array ..."), or we can't tell if it's going to terminate
+ -- without looking at the iterator, so any warning here would be
+ -- noise.
+
+ elsif Present (Loop_Parameter_Specification (Iter))
+ or else Present (Iterator_Specification (Iter))
+ then
return;
end if;
end if;
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/warn20.adb
@@ -0,0 +1,11 @@
+-- { dg-do compile }
+-- { dg-options "-gnatwa" }
+
+with Warn20_Pkg;
+
+procedure Warn20 is
+ package P is new Warn20_Pkg (Integer, 0);
+ pragma Unreferenced (P);
+begin
+ null;
+end Warn20;
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/warn20_pkg.adb
@@ -0,0 +1,10 @@
+package body Warn20_Pkg is
+ L : array (1 .. 10) of T := (1 .. 10 => None);
+ procedure Foo is
+ begin
+ for A of L loop
+ exit when A = None;
+ Dispatch (A);
+ end loop;
+ end;
+end;
--- /dev/null
new file mode 100644
+++ gcc/testsuite/gnat.dg/warn20_pkg.ads
@@ -0,0 +1,8 @@
+generic
+ type T is private;
+ None : T;
+package Warn20_Pkg is
+ generic
+ with procedure Dispatch (X : T) is null;
+ procedure Foo;
+end;
