add default "auto" as option to --check-bounds (#41551)

* add default "auto" as option to --check-bounds

* add to NEWS

(cherry picked from commit 7d0f769)

Author: IanButterworth

NEWS.md

@@ -30,6 +30,7 @@ New language features
   for example `a, b... = [1, 2, 3]`. This syntax is implemented using `Base.rest`,
   which can be overloaded to customize its behavior for different collection types
   ([#37410]).
+* The default behavior of observing `@inbounds` declarations is now an option via `auto` in `--check-bounds=yes|no|auto` ([#41551])
 
 Language changes
 ----------------

base/util.jl

@@ -154,7 +154,7 @@ function julia_cmd(julia=joinpath(Sys.BINDIR::String, julia_exename()))
                   elseif opts.check_bounds == 2
                       "no" # off
                   else
-                      "" # "default"
+                      "" # default = "auto"
                   end
         isempty(check_bounds) || push!(addflags, "--check-bounds=$check_bounds")
     end

doc/man/julia.1

@@ -158,8 +158,8 @@ Set the level of debug info generation to <n>
 Control whether inlining is permitted (overrides functions declared as @inline)
 
 .TP
---check-bounds={yes|no}
-Emit bounds checks always or never (ignoring declarations)
+--check-bounds={yes|no|auto}
+Emit bounds checks always, never, or respect @inbounds declarations
 
 .TP
 --math-mode={ieee|user}

doc/src/devdocs/boundscheck.md

@@ -89,3 +89,7 @@ Note this hierarchy has been designed to reduce the likelihood of method ambigui
 to make `checkbounds` the place to specialize on array type, and try to avoid specializations
 on index types; conversely, `checkindex` is intended to be specialized only on index type (especially,
 the last argument).
+
+## Emit bounds checks
+
+Julia can be launched with `--check-bounds={yes|no|auto}` to emit bounds checks always, never, or respect @inbounds declarations.

doc/src/manual/command-line-options.md

@@ -30,7 +30,7 @@ The following is a complete list of command-line switches available when launchi
 |`-O`, `--optimize={0,1,2,3}`           |Set the optimization level (default level is 2 if unspecified or 3 if used without a level)|
 |`-g`, `-g <level>`                     |Enable / Set the level of debug info generation (default level is 1 if unspecified or 2 if used without a level)|
 |`--inline={yes\|no}`                   |Control whether inlining is permitted, including overriding `@inline` declarations|
-|`--check-bounds={yes\|no}`             |Emit bounds checks always or never (ignoring declarations)|
+|`--check-bounds={yes\|no\|auto}`       |Emit bounds checks always, never, or respect @inbounds declarations|
 |`--math-mode={ieee,fast}`              |Disallow or enable unsafe floating point optimizations (overrides @fastmath declaration)|
 |`--code-coverage={none\|user\|all}`    |Count executions of source lines|
 |`--code-coverage`                      |equivalent to `--code-coverage=user`|

src/jloptions.c

@@ -129,7 +129,8 @@ static const char opts[]  =
         " (default level is 1 if unspecified or 2 if used without a level)\n"
 #endif
     " --inline={yes|no}         Control whether inlining is permitted, including overriding @inline declarations\n"
-    " --check-bounds={yes|no}   Emit bounds checks always or never (ignoring declarations)\n"
+    " --check-bounds={yes|no|auto}\n"
+    "                           Emit bounds checks always, never, or respect @inbounds declarations\n"
 #ifdef USE_POLLY
     " --polly={yes|no}          Enable or disable the polyhedral optimizer Polly (overrides @polly declaration)\n"
 #endif
@@ -544,8 +545,10 @@ JL_DLLEXPORT void jl_parse_opts(int *argcp, char ***argvp)
                 jl_options.check_bounds = JL_OPTIONS_CHECK_BOUNDS_ON;
             else if (!strcmp(optarg,"no"))
                 jl_options.check_bounds = JL_OPTIONS_CHECK_BOUNDS_OFF;
+            else if (!strcmp(optarg,"auto"))
+                jl_options.check_bounds = JL_OPTIONS_CHECK_BOUNDS_DEFAULT;
             else
-                jl_errorf("julia: invalid argument to --check-bounds={yes|no} (%s)", optarg);
+                jl_errorf("julia: invalid argument to --check-bounds={yes|no|auto} (%s)", optarg);
             break;
         case opt_output_bc:
             jl_options.outputbc = optarg;

test/cmdlineargs.jl

@@ -378,6 +378,8 @@ let exename = `$(Base.julia_cmd()) --startup-file=no`
         filter!(a -> !startswith(a, "--check-bounds="), exename_default_checkbounds.exec)
         @test parse(Int, readchomp(`$exename_default_checkbounds -E "Int(Base.JLOptions().check_bounds)"`)) ==
             JL_OPTIONS_CHECK_BOUNDS_DEFAULT
+        @test parse(Int, readchomp(`$exename -E "Int(Base.JLOptions().check_bounds)"
+            --check-bounds=auto`)) == JL_OPTIONS_CHECK_BOUNDS_DEFAULT
         @test parse(Int, readchomp(`$exename -E "Int(Base.JLOptions().check_bounds)"
             --check-bounds=yes`)) == JL_OPTIONS_CHECK_BOUNDS_ON
         @test parse(Int, readchomp(`$exename -E "Int(Base.JLOptions().check_bounds)"