r8-3988-g356fcc67fba52b added code to turn return statements into __builtin_unreachable calls inside noreturn functions but only while optimizing. Since -funreachable-traps was added (r13-1204-gd68d3664253696), it is a good idea to move over to using __builtin_unreachable (and the trap version with this option which defaults at -O0 and -0g) instead of just a follow through even at -O0.
This also fixes a regression when inlining a noreturn function that returns at -O0 (due to always_inline) as we would get an empty bb which has no successor edge instead of one with a call to __builtin_unreachable. I also noticed there was no testcase testing the warning about __builtin_return inside a noreturn function so I added a testcase there. Bootstrapped and tested on x86_64-linux-gnu. PR ipa/119599 gcc/ChangeLog: * tree-cfg.cc (pass_warn_function_return::execute): Turn return statements always into __builtin_unreachable calls. gcc/testsuite/ChangeLog: * gcc.dg/torture/pr119599-1.c: New test. * gcc.dg/builtin-apply5.c: New test. Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com> --- gcc/testsuite/gcc.dg/builtin-apply5.c | 23 +++++++++++++++++++ gcc/testsuite/gcc.dg/torture/pr119599-1.c | 27 +++++++++++++++++++++++ gcc/tree-cfg.cc | 20 +++++++++-------- 3 files changed, 61 insertions(+), 9 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/builtin-apply5.c create mode 100644 gcc/testsuite/gcc.dg/torture/pr119599-1.c diff --git a/gcc/testsuite/gcc.dg/builtin-apply5.c b/gcc/testsuite/gcc.dg/builtin-apply5.c new file mode 100644 index 00000000000..16892f76a8a --- /dev/null +++ b/gcc/testsuite/gcc.dg/builtin-apply5.c @@ -0,0 +1,23 @@ +/* { dg-options "-O2 -Wmissing-noreturn -fgnu89-inline" } */ +/* { dg-additional-options "-mno-mmx" { target { { i?86-*-* x86_64-*-* } && ia32 } } } */ +/* { dg-do compile } */ + +extern void abort (void); + +double +foo (int arg) +{ + if (arg != 116) + abort(); + return arg + 1; +} + +__attribute__((noreturn)) +double +bar (int arg) +{ + foo (arg); + __builtin_return (__builtin_apply ((void (*) ()) foo, /* { dg-warning "'noreturn' function does return" } */ + __builtin_apply_args (), 16)); +} + diff --git a/gcc/testsuite/gcc.dg/torture/pr119599-1.c b/gcc/testsuite/gcc.dg/torture/pr119599-1.c new file mode 100644 index 00000000000..4fbd228a359 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr119599-1.c @@ -0,0 +1,27 @@ +/* { dg-do compile } */ +/* { dg-options "-fdump-tree-einline" } */ + +/* PR ipa/119599 */ +/* inlining a noreturn function which returns + can cause an ICE when dealing finding an unreachable block. + We should get a __builtin_unreachable after the inliing. */ + + +void baz (void); + +static inline __attribute__((always_inline, noreturn)) void +bar (void) +{ + static volatile int t = 0; + if (t == 0) + baz (); +} /* { dg-warning "function does return" } */ + +void +foo (void) +{ + bar (); +} + +/* After inlining, we should have call to __builtin_unreachable now. */ +/* { dg-final { scan-tree-dump "__builtin_unreachable " "einline" } } */ diff --git a/gcc/tree-cfg.cc b/gcc/tree-cfg.cc index f25480cf6fc..6a29a56ca9a 100644 --- a/gcc/tree-cfg.cc +++ b/gcc/tree-cfg.cc @@ -9808,18 +9808,20 @@ pass_warn_function_return::execute (function *fun) (e = ei_safe_edge (ei)); ) { last = *gsi_last_bb (e->src); - if ((gimple_code (last) == GIMPLE_RETURN - || gimple_call_builtin_p (last, BUILT_IN_RETURN)) - && location == UNKNOWN_LOCATION - && ((location = LOCATION_LOCUS (gimple_location (last))) - != UNKNOWN_LOCATION) - && !optimize) - break; - /* When optimizing, replace return stmts in noreturn functions + /* Warn about __builtin_return .*/ + if (gimple_call_builtin_p (last, BUILT_IN_RETURN) + && location == UNKNOWN_LOCATION) + { + location = LOCATION_LOCUS (gimple_location (last)); + ei_next (&ei); + } + /* Replace return stmts in noreturn functions with __builtin_unreachable () call. */ - if (optimize && gimple_code (last) == GIMPLE_RETURN) + else if (gimple_code (last) == GIMPLE_RETURN) { location_t loc = gimple_location (last); + if (location == UNKNOWN_LOCATION) + location = LOCATION_LOCUS (loc); gimple *new_stmt = gimple_build_builtin_unreachable (loc); gimple_stmt_iterator gsi = gsi_for_stmt (last); gsi_replace (&gsi, new_stmt, true); -- 2.43.0