summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorAlejandro Piñeiro <apinheiro@igalia.com>2016-02-25 11:11:54 +0100
committerAlejandro Piñeiro <apinheiro@igalia.com>2016-03-29 07:28:57 +0200
commit8568d02498d12ebde6a6245056eebfbfe18aaf8f (patch)
tree759937d780434c0309710b99354c6fa36786c1a0
parent35e2e96b307bcd6dd839a11e2bd98fa22bd4d50a (diff)
glsl: add is_lhs bool on ast_expression
Useful to know if a expression is the recipient of an assignment or not, that would be used to (for example) raise warnings of "use of uninitialized variable" without getting a false positive when assigning first a variable. By default the value is false, and it is assigned to true on the following cases: * The lhs assignments subexpression * At ast_array_index, on the array itself. * While handling the method on an array, to avoid the warning calling array.length * When computed the cached test expression at test_to_hir, to avoid a duplicate warning on the test expression of a switch. set_is_lhs setter is added, because in some cases (like ast_field_selection) the value need to be propagated on the expression tree. To avoid doing the propatagion if not needed, it skips if no primary_expression.identifier is available. v2: use a new bool on ast_expression, instead of a new parameter on ast_expression::hir (Timothy Arceri) v3: fix style and some typos on comments, initialize is_lhs default value on constructor, to avoid a c++11 feature (Ian Romanick) v4: some tweaks on comments (Timothy Arceri) Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94129 Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
-rw-r--r--src/compiler/glsl/ast.h6
-rw-r--r--src/compiler/glsl/ast_function.cpp4
-rw-r--r--src/compiler/glsl/ast_to_hir.cpp33
-rw-r--r--src/compiler/glsl/glsl_parser_extras.cpp1
4 files changed, 44 insertions, 0 deletions
diff --git a/src/compiler/glsl/ast.h b/src/compiler/glsl/ast.h
index 727aa432631..9f46340e6e2 100644
--- a/src/compiler/glsl/ast.h
+++ b/src/compiler/glsl/ast.h
@@ -214,6 +214,7 @@ public:
subexpressions[2] = NULL;
primary_expression.identifier = identifier;
this->non_lvalue_description = NULL;
+ this->is_lhs = false;
}
static const char *operator_string(enum ast_operators op);
@@ -263,6 +264,11 @@ public:
* This pointer may be \c NULL.
*/
const char *non_lvalue_description;
+
+ void set_is_lhs(bool new_value);
+
+private:
+ bool is_lhs;
};
class ast_expression_bin : public ast_expression {
diff --git a/src/compiler/glsl/ast_function.cpp b/src/compiler/glsl/ast_function.cpp
index 1a440203cfc..db68d5dfa48 100644
--- a/src/compiler/glsl/ast_function.cpp
+++ b/src/compiler/glsl/ast_function.cpp
@@ -1727,6 +1727,10 @@ ast_function_expression::handle_method(exec_list *instructions,
const char *method;
method = field->primary_expression.identifier;
+ /* This would prevent to raise "uninitialized variable" warnings when
+ * calling array.length.
+ */
+ field->subexpressions[0]->set_is_lhs(true);
op = field->subexpressions[0]->hir(instructions, state);
if (strcmp(method, "length") == 0) {
if (!this->expressions.is_empty()) {
diff --git a/src/compiler/glsl/ast_to_hir.cpp b/src/compiler/glsl/ast_to_hir.cpp
index 35def8e3ae0..e162203c1c8 100644
--- a/src/compiler/glsl/ast_to_hir.cpp
+++ b/src/compiler/glsl/ast_to_hir.cpp
@@ -1248,6 +1248,24 @@ ast_expression::hir_no_rvalue(exec_list *instructions,
do_hir(instructions, state, false);
}
+void
+ast_expression::set_is_lhs(bool new_value)
+{
+ /* is_lhs is tracked only to print "variable used uninitialized" warnings,
+ * if we lack a identifier we can just skip it.
+ */
+ if (this->primary_expression.identifier == NULL)
+ return;
+
+ this->is_lhs = new_value;
+
+ /* We need to go through the subexpressions tree to cover cases like
+ * ast_field_selection
+ */
+ if (this->subexpressions[0] != NULL)
+ this->subexpressions[0]->set_is_lhs(new_value);
+}
+
ir_rvalue *
ast_expression::do_hir(exec_list *instructions,
struct _mesa_glsl_parse_state *state,
@@ -1323,6 +1341,7 @@ ast_expression::do_hir(exec_list *instructions,
break;
case ast_assign: {
+ this->subexpressions[0]->set_is_lhs(true);
op[0] = this->subexpressions[0]->hir(instructions, state);
op[1] = this->subexpressions[1]->hir(instructions, state);
@@ -1592,6 +1611,7 @@ ast_expression::do_hir(exec_list *instructions,
case ast_div_assign:
case ast_add_assign:
case ast_sub_assign: {
+ this->subexpressions[0]->set_is_lhs(true);
op[0] = this->subexpressions[0]->hir(instructions, state);
op[1] = this->subexpressions[1]->hir(instructions, state);
@@ -1618,6 +1638,7 @@ ast_expression::do_hir(exec_list *instructions,
}
case ast_mod_assign: {
+ this->subexpressions[0]->set_is_lhs(true);
op[0] = this->subexpressions[0]->hir(instructions, state);
op[1] = this->subexpressions[1]->hir(instructions, state);
@@ -1640,6 +1661,7 @@ ast_expression::do_hir(exec_list *instructions,
case ast_ls_assign:
case ast_rs_assign: {
+ this->subexpressions[0]->set_is_lhs(true);
op[0] = this->subexpressions[0]->hir(instructions, state);
op[1] = this->subexpressions[1]->hir(instructions, state);
type = shift_result_type(op[0]->type, op[1]->type, this->oper, state,
@@ -1658,6 +1680,7 @@ ast_expression::do_hir(exec_list *instructions,
case ast_and_assign:
case ast_xor_assign:
case ast_or_assign: {
+ this->subexpressions[0]->set_is_lhs(true);
op[0] = this->subexpressions[0]->hir(instructions, state);
op[1] = this->subexpressions[1]->hir(instructions, state);
type = bit_logic_result_type(op[0], op[1], this->oper, state, &loc);
@@ -1839,6 +1862,11 @@ ast_expression::do_hir(exec_list *instructions,
case ast_array_index: {
YYLTYPE index_loc = subexpressions[1]->get_location();
+ /* Getting if an array is being used uninitialized is beyond what we get
+ * from ir_value.data.assigned. Setting is_lhs as true would force to
+ * not raise a uninitialized warning when using an array
+ */
+ subexpressions[0]->set_is_lhs(true);
op[0] = subexpressions[0]->hir(instructions, state);
op[1] = subexpressions[1]->hir(instructions, state);
@@ -5746,6 +5774,11 @@ ast_switch_statement::test_to_hir(exec_list *instructions,
{
void *ctx = state;
+ /* set to true to avoid a duplicate "use of uninitialized variable" warning
+ * on the switch test case. The first one would be already raised when
+ * getting the test_expression at ast_switch_statement::hir
+ */
+ test_expression->set_is_lhs(true);
/* Cache value of test expression. */
ir_rvalue *const test_val =
test_expression->hir(instructions,
diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index 1d9bfd6aaba..ea9639b728d 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -1206,6 +1206,7 @@ ast_expression::ast_expression(int oper,
this->subexpressions[1] = ex1;
this->subexpressions[2] = ex2;
this->non_lvalue_description = NULL;
+ this->is_lhs = false;
}