[Qemu-devel] [RISU PATCH v3 05/18] risugen_x86_memory: add module

[Jan Bobek <jan.bobek@gmail.com>]

The module risugen_x86_memory.pm provides environment for evaluating
x86 "!memory" blocks. This is facilitated by the single exported
function eval_memory_block.

Signed-off-by: Jan Bobek <jan.bobek@gmail.com>
---
 risugen_x86_memory.pm | 87 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 risugen_x86_memory.pm

diff --git a/risugen_x86_memory.pm b/risugen_x86_memory.pm
new file mode 100644
index 0000000..6aa6877
--- /dev/null
+++ b/risugen_x86_memory.pm
@@ -0,0 +1,87 @@
+#!/usr/bin/perl -w
+###############################################################################
+# Copyright (c) 2019 Jan Bobek
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Eclipse Public License v1.0
+# which accompanies this distribution, and is available at
+# http://www.eclipse.org/legal/epl-v10.html
+#
+# Contributors:
+#     Jan Bobek - initial implementation
+###############################################################################
+
+# risugen_x86_memory -- risugen_x86's helper module for "!memory" blocks
+package risugen_x86_memory;
+
+use strict;
+use warnings;
+
+use risugen_common;
+use risugen_x86_asm;
+
+our @ISA    = qw(Exporter);
+our @EXPORT = qw(eval_memory_block);
+
+my %memory_opts;
+
+sub load(%)
+{
+    my (%args) = @_;
+
+    @memory_opts{keys %args} = values %args;
+    $memory_opts{is_write}   = 0;
+}
+
+sub store(%)
+{
+    my (%args) = @_;
+
+    @memory_opts{keys %args} = values %args;
+    $memory_opts{is_write}   = 1;
+}
+
+sub eval_memory_block(%)
+{
+    my (%args) = @_;
+    my $rec = $args{rec};
+    my $insn = $args{insn};
+    my $insnname = $rec->{name};
+    my $opcode = $insn->{opcode}{value};
+
+    # Setup reasonable defaults
+    %memory_opts           = ();
+    $memory_opts{size}     = 0;
+    $memory_opts{align}    = 1;
+    $memory_opts{disp}     = 0;
+    $memory_opts{ss}       = 0;
+    $memory_opts{value}    = 0;
+    $memory_opts{mask}     = 0;
+    $memory_opts{rollback} = 0;
+    $memory_opts{is_write} = 0;
+
+    if (defined $insn->{modrm}) {
+        my $modrm = $insn->{modrm};
+
+        $memory_opts{ss}     = $modrm->{ss}          if defined $modrm->{ss};
+        $memory_opts{index}  = $modrm->{index}       if defined $modrm->{index};
+        $memory_opts{vindex} = $modrm->{vindex}      if defined $modrm->{vindex};
+        $memory_opts{base}   = $modrm->{base}        if defined $modrm->{base};
+        $memory_opts{disp}   = $modrm->{disp}{value} if defined $modrm->{disp};
+
+        $memory_opts{rollback} = defined $modrm->{base};
+    }
+
+    my $memory = $rec->{blocks}{"memory"};
+    if (defined $memory) {
+        # Evaluate in an environment with variables set corresponding
+        # to the variable fields.
+        my %env = extract_fields($opcode, $rec);
+        # set the variable $_ to the instruction in question
+        $env{_} = $insn;
+
+        eval_block($insnname, "memory", $memory, \%env);
+    }
+    return %memory_opts;
+}
+
+1;
-- 
2.20.1