From 23be8da7396ffc4d5492d976e244daaa543eaac9 Mon Sep 17 00:00:00 2001 From: Richard Bunt Date: Wed, 19 Sep 2018 10:43:56 +0100 Subject: Logical short circuiting with argument lists When evaluating Fortran expressions such as the following: print truth_table(1,1) .OR. truth_table(2,1) where truth_table(1,1) evaluates to true, the debugger would report that it could not perform substring operations on this type. This patch addresses this issue. Investigation revealed that EVAL_SKIP was not being handled correctly for all types serviced by the OP_F77_UNDETERMINED_ARGLIST case in evaluate_subexp_standard. While skipping an undetermined argument list the type is resolved to be an integer (as this is what evaluate_subexp returns when skipping) and so it was not possible to delegate to the appropriate case (e.g. array, function call). The solution implemented here updates OP_VAR_VALUE to return correct type information when skipping. This way OP_F77_UNDETERMINED_ARGLIST can delegate the skipping to the appropriate case or routine, which should know how to skip/evaluate the type in question. koenig.exp was updated to include a testcase which exercises the modified skip logic in OP_VAR_VALUE, as it falls through from OP_ADL_FUNC. This patch has been tested for regressions with GCC 7.3 on aarch64, ppc64le and x86_64. gdb/ChangeLog: * eval.c (skip_undetermined_arglist): Skip argument list helper. (evaluate_subexp_standard): Return a dummy type when honoring EVAL_SKIP in OP_VAR_VALUE and handle skipping in the OP_F77_UNDETERMINED_ARGLIST case. * expression.h (enum noside): Update comment. gdb/testsuite/ChangeLog: * gdb.cp/koenig.exp: Extend to test logical short circuiting. * gdb.fortran/short-circuit-argument-list.exp: New file. * gdb.fortran/short-circuit-argument-list.f90: New test. --- gdb/expression.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'gdb/expression.h') diff --git a/gdb/expression.h b/gdb/expression.h index 9f26bb8d60b..bc7625f9842 100644 --- a/gdb/expression.h +++ b/gdb/expression.h @@ -118,7 +118,9 @@ extern int parse_completion; enum noside { EVAL_NORMAL, - EVAL_SKIP, /* Only effect is to increment pos. */ + EVAL_SKIP, /* Only effect is to increment pos. + Return type information where + possible. */ EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or call any functions. The value returned will have the correct -- cgit v1.2.1