[PATCH] [ipa]: Fix segfault ICE with fdump-tree-einline on TARGET_OPTION_MISMATCH

[SenthilKumar.Selvaraj]

Hello,

  If a target rejects inlining via the TARGET_CAN_INLINE_P hook for
  reasons other than optimization options, the compiler currently
  crashes with a segfault. The MIPS target
  (mips.cc:mips_can_inline_p), for e.g., rejects inlining on
  conflicting target attributes, and compiling
  gcc.target/mips/mips16-attributes-5.c with -fdump-tree-einline
  segfaults.

$ mips-unknown-elf-gcc -Os -mips32r2 -fdump-tree-einline 
/opt/developer/oss/src/gcc/gcc/testsuite/gcc.target/mips/mips16-
attributes-5.c  -DMIPS16='__attribute__((mips16))' 
-DNOMIPS16='__attribute__((nomips16))'
during GIMPLE pass: einline
dump file: a-mips16-attributes-5.c.035t.einline
/opt/developer/oss/src/gcc/gcc/testsuite/gcc.target/mips/mips16-attributes-5.c: 
In function 'f1':
/opt/developer/oss/src/gcc/gcc/testsuite/gcc.target/mips/mips16-attributes-5.c:13:1:
 internal compiler error: Segmentation fault
   13 | int NOMIPS16 f4 (void) { return i4 (); }
      | ^~~
0x33c5347 internal_error(char const*, ...)
        /opt/developer/oss/src/gcc/gcc/diagnostic-global-context.cc:787
0x1a2bc07 crash_signal
        /opt/developer/oss/src/gcc/gcc/toplev.cc:325
0x186608c cl_target_option_print_diff(_IO_FILE*, int, cl_target_option*, 
cl_target_option*)
        /opt/developer/build/gcc/gcc/options-save.cc:10136
0x3184fe0 report_inline_failed_reason
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:299
0x31855b4 can_inline_edge_p
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:462
0x31868cb can_early_inline_edge_p
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:717
0x318e098 early_inline_small_functions
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:3093
0x318e992 early_inliner(function*)
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:3291
0x318ec79 execute
        /opt/developer/oss/src/gcc/gcc/ipa-inline.cc:3397

The following patch adds NULL checks before calling
cl_target_option_print_diff to fix the crash.

Ok for master?

gcc/ChangeLog:

        * ipa-inline.cc (report_inline_failed_reason): Check for NULL
        before calling cl_target_option_print_diff.

diff --git gcc/ipa-inline.cc gcc/ipa-inline.cc
index 5a7615666cc..111593f45fd 100644
--- gcc/ipa-inline.cc
+++ gcc/ipa-inline.cc
@@ -294,10 +294,14 @@ report_inline_failed_reason (struct cgraph_edge *e)
                           e->callee->ultimate_alias_target 
()->lto_file_data->file_name);
        }
       if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH)
-       if (dump_file)
-         cl_target_option_print_diff
-           (dump_file, 2, target_opts_for_fn (e->caller->decl),
-            target_opts_for_fn (e->callee->ultimate_alias_target ()->decl));
+       {
+         struct cl_target_option *opt_caller
+           = target_opts_for_fn (e->caller->decl);
+         struct cl_target_option *opt_callee
+           = target_opts_for_fn (e->callee->ultimate_alias_target ()->decl);
+         if (dump_file && opt_caller != NULL && opt_callee != NULL)
+           cl_target_option_print_diff (dump_file, 2, opt_caller, opt_callee);
+       }
       if (e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
        if (dump_file)
          cl_optimization_print_diff