Implement support for brackets in filter expressions

Extends the bytecode with new instructions.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/lib/lttng-ctl/filter/filter-ast.h b/src/lib/lttng-ctl/filter/filter-ast.h
index 73d8d44e6a189bfc72550af99776d84d5711a1dd..067624906d7ad5cd1fa8cc382c095dcd7e1f5387 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-ast.h
+++ b/src/lib/lttng-ctl/filter/filter-ast.h
@@ -95,6 +95,7 @@ enum ast_link_type {
        AST_LINK_UNKNOWN = 0,
        AST_LINK_DOT,
        AST_LINK_RARROW,
+       AST_LINK_BRACKET,
 };
 
 struct filter_node {
@@ -133,8 +134,9 @@ struct filter_node {
                                 */
                                struct filter_node *child;
                        } u;
-                       /* linked dot/arrow chain */
+                       /* prev: linked dot/arrow chain (postfix expression) */
                        struct filter_node *prev;
+                       /* next: linked bracket chain (prefix expression) */
                        struct filter_node *next;
                } expression;
                struct {

diff --git a/src/lib/lttng-ctl/filter/filter-bytecode.h b/src/lib/lttng-ctl/filter/filter-bytecode.h
index 627d0d6f0b6f58943b7326b8c59ba019f8682f11..b7b71ad538ad7de884bddf284b2532e09670851a 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-bytecode.h
+++ b/src/lib/lttng-ctl/filter/filter-bytecode.h
@@ -35,6 +35,12 @@ struct field_ref {
        uint16_t offset;
 } LTTNG_PACKED;
 
+struct field_ref_index {
+       /* Initially, symbol offset. After link, field offset. */
+       uint16_t offset;
+       uint64_t index;         /* array index */
+} LTTNG_PACKED;
+
 struct literal_numeric {
        int64_t v;
 } LTTNG_PACKED;
@@ -163,6 +169,14 @@ enum filter_op {
        FILTER_OP_EQ_STAR_GLOB_STRING           = 77,
        FILTER_OP_NE_STAR_GLOB_STRING           = 78,
 
+       /* load field ref with index */
+       FILTER_OP_LOAD_FIELD_REF_INDEX                  = 79,
+       FILTER_OP_LOAD_FIELD_REF_INDEX_S64              = 80,
+
+       /* get context ref with index */
+       FILTER_OP_GET_CONTEXT_REF_INDEX                 = 81,
+       FILTER_OP_GET_CONTEXT_REF_INDEX_S64             = 82,
+
        NR_FILTER_OPS,
 };
 

diff --git a/src/lib/lttng-ctl/filter/filter-ir.h b/src/lib/lttng-ctl/filter/filter-ir.h
index 10f339e6be931f6af0ca9d24683b10fad42490e6..c07050df58d666e9736e9095b1a74c847aa81c96 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-ir.h
+++ b/src/lib/lttng-ctl/filter/filter-ir.h
@@ -38,6 +38,8 @@ enum ir_data_type {
        IR_DATA_FLOAT,
        IR_DATA_FIELD_REF,
        IR_DATA_GET_CONTEXT_REF,
+       IR_DATA_FIELD_REF_INDEX,
+       IR_DATA_GET_CONTEXT_REF_INDEX,
 };
 
 enum ir_op_type {
@@ -80,6 +82,10 @@ struct ir_op_load {
                int64_t num;
                double flt;
                char *ref;
+               struct {
+                       char *symbol;
+                       uint64_t index;
+               } ref_index;
        } u;
 };
 

diff --git a/src/lib/lttng-ctl/filter/filter-parser.y b/src/lib/lttng-ctl/filter/filter-parser.y
index 92499e075c9a9bc0c53c3a19ea1cc5b9662a30c3..12605cd382b8af4d65c3d59b7076b3d982870af5 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-parser.y
+++ b/src/lib/lttng-ctl/filter/filter-parser.y
@@ -471,6 +471,12 @@ primary_expression
 postfix_expression
        : primary_expression
                {       $$ = $1;                                        }
+       | postfix_expression LSBRAC unary_expression RSBRAC
+               {
+                       $$ = $1;
+                       $$->u.expression.pre_op = AST_LINK_BRACKET;
+                       $$->u.expression.next = $3;
+               }
        | postfix_expression DOT IDENTIFIER
                {
                        $$ = make_node(parser_ctx, NODE_EXPRESSION);

diff --git a/src/lib/lttng-ctl/filter/filter-visitor-generate-bytecode.c b/src/lib/lttng-ctl/filter/filter-visitor-generate-bytecode.c
index d0cc49556fc11560b02a8aca54cb736d2ac4291f..74cef91dc3c0c35acb9ce7b167afc05b3a71286a 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-visitor-generate-bytecode.c
+++ b/src/lib/lttng-ctl/filter/filter-visitor-generate-bytecode.c
@@ -252,7 +252,7 @@ int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node)
                insn = calloc(insn_len, 1);
                if (!insn)
                        return -ENOMEM;
-               switch(node->data_type) {
+               switch (node->data_type) {
                case IR_DATA_FIELD_REF:
                        insn->op = FILTER_OP_LOAD_FIELD_REF;
                        break;
@@ -289,6 +289,57 @@ int visit_node_load(struct filter_parser_ctx *ctx, struct ir_op *node)
                free(insn);
                return ret;
        }
+       case IR_DATA_FIELD_REF_INDEX:   /* fall-through */
+       case IR_DATA_GET_CONTEXT_REF_INDEX:
+       {
+               struct load_op *insn;
+               uint32_t insn_len = sizeof(struct load_op)
+                       + sizeof(struct field_ref_index);
+               struct field_ref_index ref_index_offset;
+               uint32_t reloc_offset_u32;
+               uint16_t reloc_offset;
+
+               insn = calloc(insn_len, 1);
+               if (!insn)
+                       return -ENOMEM;
+               switch (node->data_type) {
+               case IR_DATA_FIELD_REF_INDEX:
+                       insn->op = FILTER_OP_LOAD_FIELD_REF_INDEX;
+                       break;
+               case IR_DATA_GET_CONTEXT_REF_INDEX:
+                       insn->op = FILTER_OP_GET_CONTEXT_REF_INDEX;
+                       break;
+               default:
+                       free(insn);
+                       return -EINVAL;
+               }
+               ref_index_offset.offset = (uint16_t) -1U;
+               ref_index_offset.index = node->u.load.u.ref_index.index;
+               memcpy(insn->data, &ref_index_offset, sizeof(ref_index_offset));
+               /* reloc_offset points to struct load_op */
+               reloc_offset_u32 = bytecode_get_len(&ctx->bytecode->b);
+               if (reloc_offset_u32 > LTTNG_FILTER_MAX_LEN - 1) {
+                       free(insn);
+                       return -EINVAL;
+               }
+               reloc_offset = (uint16_t) reloc_offset_u32;
+               ret = bytecode_push(&ctx->bytecode, insn, 1, insn_len);
+               if (ret) {
+                       free(insn);
+                       return ret;
+               }
+               /* append reloc */
+               ret = bytecode_push(&ctx->bytecode_reloc, &reloc_offset,
+                                       1, sizeof(reloc_offset));
+               if (ret) {
+                       free(insn);
+                       return ret;
+               }
+               ret = bytecode_push(&ctx->bytecode_reloc, node->u.load.u.ref_index.symbol,
+                                       1, strlen(node->u.load.u.ref_index.symbol) + 1);
+               free(insn);
+               return ret;
+       }
        }
 }
 
@@ -423,12 +474,16 @@ int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node)
                return ret;
        /* Cast to s64 if float or field ref */
        if ((node->u.binary.left->data_type == IR_DATA_FIELD_REF
-                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF)
+                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF
+                               || node->u.binary.left->data_type == IR_DATA_FIELD_REF_INDEX
+                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF_INDEX)
                        || node->u.binary.left->data_type == IR_DATA_FLOAT) {
                struct cast_op cast_insn;
 
                if (node->u.binary.left->data_type == IR_DATA_FIELD_REF
-                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF) {
+                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF
+                               || node->u.binary.left->data_type == IR_DATA_FIELD_REF_INDEX
+                               || node->u.binary.left->data_type == IR_DATA_GET_CONTEXT_REF_INDEX) {
                        cast_insn.op = FILTER_OP_CAST_TO_S64;
                } else {
                        cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;
@@ -462,12 +517,16 @@ int visit_node_logical(struct filter_parser_ctx *ctx, struct ir_op *node)
                return ret;
        /* Cast to s64 if float or field ref */
        if ((node->u.binary.right->data_type == IR_DATA_FIELD_REF
-                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF)
+                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF
+                               || node->u.binary.right->data_type == IR_DATA_FIELD_REF_INDEX
+                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF_INDEX)
                        || node->u.binary.right->data_type == IR_DATA_FLOAT) {
                struct cast_op cast_insn;
 
                if (node->u.binary.right->data_type == IR_DATA_FIELD_REF
-                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF) {
+                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF
+                               || node->u.binary.right->data_type == IR_DATA_FIELD_REF_INDEX
+                               || node->u.binary.right->data_type == IR_DATA_GET_CONTEXT_REF_INDEX) {
                        cast_insn.op = FILTER_OP_CAST_TO_S64;
                } else {
                        cast_insn.op = FILTER_OP_CAST_DOUBLE_TO_S64;

diff --git a/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c b/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
index e3dc1aab9481467ec4140341255b099b4d71ff76..85aadcae6fe7baedec1b30d8d34960c65c5b43fd 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
+++ b/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
@@ -140,7 +140,8 @@ struct ir_op *make_op_load_float(double v, enum ir_side side)
 }
 
 static
-struct ir_op *make_op_load_field_ref(char *string, enum ir_side side)
+struct ir_op *make_op_load_field_ref(char *string,
+               enum ir_side side)
 {
        struct ir_op *op;
 
@@ -153,14 +154,61 @@ struct ir_op *make_op_load_field_ref(char *string, enum ir_side side)
        op->side = side;
        op->u.load.u.ref = strdup(string);
        if (!op->u.load.u.ref) {
-               free(op);
+               goto error;
+       }
+       return op;
+
+error:
+       free(op);
+       return NULL;
+}
+
+static
+struct ir_op *make_op_load_field_ref_index(char *string,
+               struct filter_node *next,
+               enum ir_side side)
+{
+       struct ir_op *op;
+
+       op = calloc(sizeof(struct ir_op), 1);
+       if (!op)
                return NULL;
+       op->op = IR_OP_LOAD;
+       op->data_type = IR_DATA_FIELD_REF_INDEX;
+       op->signedness = IR_SIGN_DYN;
+       op->side = side;
+       op->u.load.u.ref_index.symbol = strdup(string);
+       if (!op->u.load.u.ref_index.symbol) {
+               goto error;
+       }
+       /* Only positive integer literals accepted as index. */
+       if (next->type == NODE_UNARY_OP) {
+               fprintf(stderr, "[error] Unexpected unary operator as index\n");
+               goto error;
+       }
+       if (next->type != NODE_EXPRESSION) {
+               fprintf(stderr, "[error] Expecting expression as index\n");
+               goto error;
+       }
+       if (next->u.expression.type != AST_EXP_CONSTANT) {
+               fprintf(stderr, "[error] Expecting constant index\n");
+               goto error;
+       }
+       if (next->u.expression.u.constant < 0) {
+               fprintf(stderr, "[error] Expecting positive constant index\n");
+               goto error;
        }
+       op->u.load.u.ref_index.index = next->u.expression.u.constant;
        return op;
+
+error:
+       free(op);
+       return NULL;
 }
 
 static
-struct ir_op *make_op_load_get_context_ref(char *string, enum ir_side side)
+struct ir_op *make_op_load_get_context_ref(char *string,
+               enum ir_side side)
 {
        struct ir_op *op;
 
@@ -173,10 +221,56 @@ struct ir_op *make_op_load_get_context_ref(char *string, enum ir_side side)
        op->side = side;
        op->u.load.u.ref = strdup(string);
        if (!op->u.load.u.ref) {
-               free(op);
+               goto error;
+       }
+       return op;
+
+error:
+       free(op);
+       return NULL;
+}
+
+static
+struct ir_op *make_op_load_get_context_ref_index(char *string,
+               struct filter_node *next,
+               enum ir_side side)
+{
+       struct ir_op *op;
+
+       op = calloc(sizeof(struct ir_op), 1);
+       if (!op)
                return NULL;
+       op->op = IR_OP_LOAD;
+       op->data_type = IR_DATA_GET_CONTEXT_REF_INDEX;
+       op->signedness = IR_SIGN_DYN;
+       op->side = side;
+       op->u.load.u.ref_index.symbol = strdup(string);
+       if (!op->u.load.u.ref_index.symbol) {
+               goto error;
+       }
+       /* Only positive integer literals accepted as offset. */
+       if (next->type == NODE_UNARY_OP) {
+               fprintf(stderr, "[error] Unexpected unary operator as index\n");
+               goto error;
+       }
+       if (next->type != NODE_EXPRESSION) {
+               fprintf(stderr, "[error] Expecting expression as index\n");
+               goto error;
        }
+       if (next->u.expression.type != AST_EXP_CONSTANT) {
+               fprintf(stderr, "[error] Expecting constant index\n");
+               goto error;
+       }
+       if (next->u.expression.u.constant < 0) {
+               fprintf(stderr, "[error] Expecting positive constant index\n");
+               goto error;
+       }
+       op->u.load.u.ref_index.index = next->u.expression.u.constant;
        return op;
+
+error:
+       free(op);
+       return NULL;
 }
 
 static
@@ -390,6 +484,10 @@ void filter_free_ir_recursive(struct ir_op *op)
                case IR_DATA_GET_CONTEXT_REF:
                        free(op->u.load.u.ref);
                        break;
+               case IR_DATA_FIELD_REF_INDEX:   /* fall-through */
+               case IR_DATA_GET_CONTEXT_REF_INDEX:
+                       free(op->u.load.u.ref_index.symbol);
+                       break;
                default:
                        break;
                }
@@ -428,12 +526,18 @@ struct ir_op *make_expression(struct filter_parser_ctx *ctx,
                return make_op_load_float(node->u.expression.u.float_constant,
                                        side);
        case AST_EXP_IDENTIFIER:
-               if (node->u.expression.pre_op != AST_LINK_UNKNOWN) {
+               switch (node->u.expression.pre_op) {
+               case AST_LINK_UNKNOWN:
+                       return make_op_load_field_ref(node->u.expression.u.identifier,
+                                       side);
+               case AST_LINK_BRACKET:
+                       return make_op_load_field_ref_index(node->u.expression.u.identifier,
+                                       node->u.expression.next,
+                                       side);
+               default:
                        fprintf(stderr, "[error] %s: dotted and dereferenced identifiers not supported\n", __func__);
                        return NULL;
                }
-               return make_op_load_field_ref(node->u.expression.u.identifier,
-                                       side);
        case AST_EXP_GLOBAL_IDENTIFIER:
        {
                const char *name;
@@ -459,8 +563,19 @@ struct ir_op *make_expression(struct filter_parser_ctx *ctx,
                        fprintf(stderr, "[error] %s: Expecting a context name, e.g. \'$ctx.name\'.\n", __func__);
                        return NULL;
                }
-               return make_op_load_get_context_ref(node->u.expression.u.identifier,
+               switch (node->u.expression.pre_op) {
+               case AST_LINK_UNKNOWN:
+                       return make_op_load_get_context_ref(node->u.expression.u.identifier,
                                        side);
+               case AST_LINK_BRACKET:
+                       return make_op_load_get_context_ref_index(node->u.expression.u.identifier,
+                                       node->u.expression.next,
+                                       side);
+               default:
+                       fprintf(stderr, "[error] %s: dotted and dereferenced identifiers not supported\n", __func__);
+                       return NULL;
+               }
+
        }
        case AST_EXP_NESTED:
                return generate_ir_recursive(ctx, node->u.expression.u.child,

diff --git a/src/lib/lttng-ctl/filter/filter-visitor-xml.c b/src/lib/lttng-ctl/filter/filter-visitor-xml.c
index 24d618ac9b45920cdb02393d26ae87f4bd45aaab..c293ad15ef59617933dc9adb698d2937773d47b3 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-visitor-xml.c
+++ b/src/lib/lttng-ctl/filter/filter-visitor-xml.c
@@ -49,6 +49,8 @@ static
 int recursive_visit_print_expression(struct filter_node *node,
                FILE *stream, int indent)
 {
+       struct filter_node *iter_node;
+
        if (!node) {
                fprintf(stderr, "[error] %s: NULL child\n", __func__);
                return -EINVAL;
@@ -80,33 +82,18 @@ int recursive_visit_print_expression(struct filter_node *node,
                        node->u.expression.type == AST_EXP_IDENTIFIER ?
                                "identifier" : "global_identifier",
                        node->u.expression.u.identifier);
-               while (node->u.expression.next) {
+               iter_node = node->u.expression.next;
+               while (iter_node) {
                        print_tabs(stream, indent);
-                       fprintf(stream, "<link type=\"");
-                       switch (node->u.expression.pre_op) {
-                       case AST_LINK_UNKNOWN:
-                       default:
-                               fprintf(stderr, "[error] %s: unknown link\n", __func__);
-                               return -EINVAL;
-                       case AST_LINK_DOT:
-                               fprintf(stream, ".");
-                               break;
-                       case AST_LINK_RARROW:
-                               fprintf(stream, "->");
-                               break;
-                       }
-                       fprintf(stream, "\"/>\n");
-
-                       node = node->u.expression.next;
-                       if (node->type != NODE_EXPRESSION ||
-                               node->u.expression.type != AST_EXP_IDENTIFIER) {
-                               fprintf(stderr, "[error] %s: expecting identifier before link\n", __func__);
+                       fprintf(stream, "<bracket>\n");
+                       if (recursive_visit_print_expression(iter_node,
+                                       stream, indent + 1)) {
                                return -EINVAL;
                        }
-
                        print_tabs(stream, indent);
-                       fprintf(stream, "<identifier value=\"%s\"/>\n",
-                               node->u.expression.u.identifier);
+                       fprintf(stream, "</bracket>\n");
+                       iter_node = iter_node->u.expression.next;
+
                }
                break;
        case AST_EXP_NESTED: