From 9186293fd6bd4c3a4855c7aa62ad2ab1734077e6 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Mon, 8 Mar 2021 07:27:57 -0700 Subject: [PATCH] Introduce ternop_cond_operation This adds class ternop_cond_operation, which implements TERNOP_COND. gdb/ChangeLog 2021-03-08 Tom Tromey * expop.h (class ternop_cond_operation): New. * ax-gdb.c (ternop_cond_operation::do_generate_ax): New method. --- gdb/ChangeLog | 5 +++++ gdb/ax-gdb.c | 29 +++++++++++++++++++++++++++++ gdb/expop.h | 31 +++++++++++++++++++++++++++++++ 3 files changed, 65 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c3fc9c8ad3d..5eb9dcac3e9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2021-03-08 Tom Tromey + + * expop.h (class ternop_cond_operation): New. + * ax-gdb.c (ternop_cond_operation::do_generate_ax): New method. + 2021-03-08 Tom Tromey * expop.h (class ternop_slice_operation): New. diff --git a/gdb/ax-gdb.c b/gdb/ax-gdb.c index e25e2942475..87aa2107872 100644 --- a/gdb/ax-gdb.c +++ b/gdb/ax-gdb.c @@ -2390,6 +2390,35 @@ internalvar_operation::do_generate_ax (struct expression *exp, "expressions cannot use convenience variables."), name); } +void +ternop_cond_operation::do_generate_ax (struct expression *exp, + struct agent_expr *ax, + struct axs_value *value, + struct type *cast_type) +{ + struct axs_value value1, value2, value3; + int if1, end; + + std::get<0> (m_storage)->generate_ax (exp, ax, &value1); + gen_usual_unary (ax, &value1); + /* For (A ? B : C), it's easiest to generate subexpression + bytecodes in order, but if_goto jumps on true, so we invert + the sense of A. Then we can do B by dropping through, and + jump to do C. */ + gen_logical_not (ax, &value1, builtin_type (ax->gdbarch)->builtin_int); + if1 = ax_goto (ax, aop_if_goto); + std::get<1> (m_storage)->generate_ax (exp, ax, &value2); + gen_usual_unary (ax, &value2); + end = ax_goto (ax, aop_goto); + ax_label (ax, if1, ax->len); + std::get<2> (m_storage)->generate_ax (exp, ax, &value3); + gen_usual_unary (ax, &value3); + ax_label (ax, end, ax->len); + /* This is arbitrary - what if B and C are incompatible types? */ + value->type = value2.type; + value->kind = value2.kind; +} + } /* This handles the middle-to-right-side of code generation for binary diff --git a/gdb/expop.h b/gdb/expop.h index 436a011e4d4..0f5b5042c10 100644 --- a/gdb/expop.h +++ b/gdb/expop.h @@ -734,6 +734,37 @@ public: { return TERNOP_SLICE; } }; +class ternop_cond_operation + : public maybe_constant_operation +{ +public: + + using maybe_constant_operation::maybe_constant_operation; + + value *evaluate (struct type *expect_type, + struct expression *exp, + enum noside noside) override + { + struct value *val + = std::get<0> (m_storage)->evaluate (nullptr, exp, noside); + + if (value_logical_not (val)) + return std::get<2> (m_storage)->evaluate (nullptr, exp, noside); + return std::get<1> (m_storage)->evaluate (nullptr, exp, noside); + } + + enum exp_opcode opcode () const override + { return TERNOP_COND; } + +protected: + + void do_generate_ax (struct expression *exp, + struct agent_expr *ax, + struct axs_value *value, + struct type *cast_type) + override; +}; + } /* namespace expr */ #endif /* EXPOP_H */ -- 2.30.2