From cdf5a07c75b47481da1e99ee91ee860c2a6bb5f6 Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manish@mozilla.com>
Date: Sat, 29 Oct 2016 05:55:58 -0700
Subject: [PATCH] Add support for the sizeof function in Rust

2016-10-29  Manish Goregaokar  <manish@mozilla.com>

gdb/ChangeLog:
    * rust-exp.y: Parse `sizeof(exp)` as `UNOP_SIZEOF`

gdb/testsuite/ChangeLog:
    * gdb.rust/simple.exp: Add tests for `sizeof(expr)`
---
 gdb/ChangeLog                     | 4 ++++
 gdb/rust-exp.y                    | 8 ++++++--
 gdb/testsuite/ChangeLog           | 4 ++++
 gdb/testsuite/gdb.rust/simple.exp | 4 +++-
 4 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9d88984ca3..8e173a7a94 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2016-10-29  Manish Goregaokar  <manish@mozilla.com>
+
+    * rust-exp.y: Parse `sizeof(exp)` as `UNOP_SIZEOF`
+
 2016-10-28  Manish Goregaokar  <manish@mozilla.com>
 
     * rust-lang.c (rust_union_is_untagged): Add function to
diff --git a/gdb/rust-exp.y b/gdb/rust-exp.y
index 6dc4704efe..dffccd0605 100644
--- a/gdb/rust-exp.y
+++ b/gdb/rust-exp.y
@@ -276,6 +276,7 @@ struct rust_op
 %token <voidval> KW_EXTERN
 %token <voidval> KW_CONST
 %token <voidval> KW_FN
+%token <voidval> KW_SIZEOF
 
 /* Operator tokens.  */
 %token <voidval> DOTDOT
@@ -371,7 +372,7 @@ expr:
 |	array_expr
 |	idx_expr
 |	range_expr
-|	unop_expr
+|	unop_expr /* Must precede call_expr because of ambiguity with sizeof.  */
 |	binop_expr
 |	paren_expr
 |	call_expr
@@ -577,7 +578,8 @@ unop_expr:
 
 |	'&' KW_MUT expr	%prec UNARY
 		{ $$ = ast_unary (UNOP_ADDR, $3); }
-
+|   KW_SIZEOF '(' expr ')' %prec UNARY
+        { $$ = ast_unary (UNOP_SIZEOF, $3); }
 ;
 
 binop_expr:
@@ -872,6 +874,7 @@ static const struct token_info identifier_tokens[] =
   { "true", KW_TRUE, OP_NULL },
   { "extern", KW_EXTERN, OP_NULL },
   { "fn", KW_FN, OP_NULL },
+  { "sizeof", KW_SIZEOF, OP_NULL },
 };
 
 /* Operator tokens, sorted longest first.  */
@@ -2194,6 +2197,7 @@ convert_ast_to_expression (struct parser_state *state,
     case UNOP_COMPLEMENT:
     case UNOP_IND:
     case UNOP_ADDR:
+    case UNOP_SIZEOF:
       convert_ast_to_expression (state, operation->left.op, top);
       write_exp_elt_opcode (state, operation->opcode);
       break;
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 19cb7dc82a..ebeecf99b4 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2016-10-29  Manish Goregaokar  <manish@mozilla.com>
+
+    * gdb.rust/simple.exp: Add tests for `sizeof(expr)`
+
 2016-10-27  Manish Goregaokar  <manish@mozilla.com>
 
     * gdb.rust/simple.rs: Add test for univariant enums without discriminants
diff --git a/gdb/testsuite/gdb.rust/simple.exp b/gdb/testsuite/gdb.rust/simple.exp
index 8e84daab3a..4b9a979968 100644
--- a/gdb/testsuite/gdb.rust/simple.exp
+++ b/gdb/testsuite/gdb.rust/simple.exp
@@ -33,6 +33,7 @@ if {![runto ${srcfile}:$line]} {
 
 gdb_test "print a" " = \\(\\)"
 gdb_test "ptype a" " = \\(\\)"
+gdb_test "print sizeof(a)" " = 0"
 
 gdb_test "print b" " = \\\[\\\]"
 gdb_test "ptype b" " = \\\[i32; 0\\\]"
@@ -41,6 +42,7 @@ gdb_test "print *(&b as *const \[i32; 0_0\])" " = \\\[\\\]"
 
 gdb_test "print c" " = 99"
 gdb_test "ptype c" " = i32"
+gdb_test "print sizeof(c)" " = 4"
 
 gdb_test "print c = 87" " = \\(\\)"
 gdb_test "print c" " = 87"
@@ -127,7 +129,7 @@ gdb_test "print nosuchsymbol" \
 gdb_test "print e" " = simple::MoreComplicated::Two\\(73\\)"
 gdb_test "print e2" \
     " = simple::MoreComplicated::Four\\{this: true, is: 8, a: 109 'm', struct_: 100, variant: 10\\}"
-
+gdb_test "print sizeof(e)" " = 24"
 gdb_test_sequence "ptype e" "" {
     " = enum simple::MoreComplicated \\{"
     "  One,"