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Message-Id: <20201110100346.2527031-8-irogers@google.com>
Date: Tue, 10 Nov 2020 02:03:41 -0800
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...hat.com>,
Namhyung Kim <namhyung@...nel.org>,
linux-kernel@...r.kernel.org, Andi Kleen <ak@...ux.intel.com>,
Jin Yao <yao.jin@...ux.intel.com>,
John Garry <john.garry@...wei.com>,
Paul Clarke <pc@...ibm.com>, kajoljain <kjain@...ux.ibm.com>
Cc: Stephane Eranian <eranian@...gle.com>,
Sandeep Dasgupta <sdasgup@...gle.com>,
linux-perf-users@...r.kernel.org, Ian Rogers <irogers@...gle.com>
Subject: [RFC PATCH 07/12] perf topdown-parser: Metric expression parser.
From: Sandeep Dasgupta <sdasgup@...gle.com>
A parser capable of processing metrics found in TMA_Metrics.csv.
Co-authored-by: Ian Rogers <irogers@...gle.com>
Signed-off-by: Ian Rogers <irogers@...gle.com>
Signed-off-by: Sandeep Dasgupta <sdasgup@...gle.com>
---
.../pmu-events/topdown-parser/expr_parser.y | 224 ++++++++++++++++++
1 file changed, 224 insertions(+)
create mode 100644 tools/perf/pmu-events/topdown-parser/expr_parser.y
diff --git a/tools/perf/pmu-events/topdown-parser/expr_parser.y b/tools/perf/pmu-events/topdown-parser/expr_parser.y
new file mode 100644
index 000000000000..ddf635a6470c
--- /dev/null
+++ b/tools/perf/pmu-events/topdown-parser/expr_parser.y
@@ -0,0 +1,224 @@
+/*
+ * Copyright 2020 Google LLC.
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+/* Topdown expression parser */
+%language "c++"
+%define api.value.type variant
+
+%code requires {
+#include <string>
+}
+
+/* Increase error verbosity. */
+%define parse.trace
+%define parse.error verbose
+/* Semantic value printer. */
+%printer { yyo << $$; } <*>;
+
+
+/* Inputs for the parser and yylex. */
+%param { const std::string &input }
+%param { size_t *cursor }
+/* Inputs/output for the parser. */
+%parse-param { bool convert_if_stmt }
+%parse-param { bool remove_false_branch }
+%parse-param { bool wrap_div_in_function }
+%parse-param { std::string *final_val }
+
+/* Tokens returned by yylex. */
+%define api.token.prefix {TOK_}
+%token
+ MIN
+ MAX
+ IF
+ ELSE
+ MODEL
+ IN
+ NEG
+ EOF 0
+%token <std::string> ID_OR_NUM
+
+/* Type of non-terminal expressions. */
+%type <std::string> expr if_expr IDS
+
+/* Presidence and associativity. */
+%left MIN MAX MODEL IN
+%right ELSE
+%right IF
+%left '='
+%left '<' '>'
+%left '-' '+'
+%left '*' '/' '%'
+%left NEG
+
+%code {
+static int yylex(yy::parser::semantic_type *res,
+ const std::string &input,
+ size_t *cursor);
+
+void yy::parser::error (const std::string& m)
+{
+// ERROR(m << '\n' << "Input:\n" << input << "\nCursor: " << *cursor);
+}
+
+}
+
+%%
+%start all_expr;
+all_expr: expr EOF { *final_val = $1; } ;
+
+IDS:
+'\'' ID_OR_NUM '\'' { $$ = std::string(" ") + $2 + " "; }
+|
+IDS '\'' ID_OR_NUM '\'' { $$ = $1 + " " + $3 + " "; }
+;
+
+if_expr:
+expr IF expr ELSE expr
+{
+ if (convert_if_stmt)
+ $$ = $3 + " ? " + $1 + " : " + $5;
+ else
+ $$ = $1 + " if " + $3 + " else " + $5;
+
+ if (remove_false_branch) {
+ if (std::string::npos != $3.find("0.000", 0))
+ $$ = $5;
+ else if (std::string::npos != $3.find("1.000", 0))
+ $$ = $1;
+ }
+}
+|
+expr IF MODEL IN '[' IDS ']' ELSE expr
+{
+ $$ = std::string("#Model in [ ") + $6 + " ] ? " + $1 + " : " + $9;
+}
+;
+
+expr:
+ID_OR_NUM { $$ = $1; }
+|
+expr '+' expr { $$ = $1 + " + " + $3; }
+|
+expr '-' expr { $$ = $1 + " - " + $3; }
+|
+expr '*' expr { $$ = $1 + " * " + $3; }
+|
+expr '>' expr { $$ = $1 + " > " + $3; }
+|
+expr '<' expr { $$ = $1 + " < " + $3; }
+|
+expr '%' expr { $$ = $1 + " % " + $3; }
+|
+'(' expr ')' { $$ = std::string("( ") + $2 + " )"; }
+|
+expr '=' '=' expr { $$ = $1 + " == " + $4; }
+|
+'-' expr %prec NEG { $$ = std::string(" - ") + $2; }
+|
+expr '/' expr
+{
+ if (wrap_div_in_function)
+ $$ = std::string("d_ratio ( ") + $1 + " , " + $3 + " )";
+ else
+ $$ = $1 + " / " + $3;
+}
+|
+MIN '(' expr ',' expr ')'
+{
+ $$ = std::string("min ( ") + $3 + " , " + $5 + " )";
+}
+|
+MAX '(' expr ',' expr ')'
+{
+ $$ = std::string("max ( ") + $3 + " , " + $5 + " )";
+}
+|
+if_expr
+{
+ if (convert_if_stmt)
+ $$ = std::string("( ") + $1 + " )";
+ else
+ $$ = $1;
+}
+;
+
+%%
+static int expr__symbol(yy::parser::semantic_type *res,
+ size_t p,
+ const std::string &input,
+ size_t *cursor)
+{
+ std::string dst;
+
+ if (input[p] == '#')
+ dst += input[p++];
+
+ while (p < input.size() &&
+ (isalnum(input[p]) ||
+ input[p] == '_' ||
+ input[p] == '.' ||
+ input[p] == ':' ||
+ input[p] == '@' ||
+ input[p] == '\\' ||
+ input[p] == '=')
+ ) {
+ if(input[p] == '\\') {
+ // Consume 2 consequitive '\\' and the escaped char.
+ dst += input[p++];
+ if (p >= input.size())
+ break;
+ dst += input[p++];
+ if (p >= input.size())
+ break;
+ }
+ dst += input[p++];
+ }
+ *cursor = p;
+ if (p >= input.size() && dst.empty())
+ return yy::parser::token::TOK_EOF;
+ if (dst == "min") return yy::parser::token::TOK_MIN;
+ if (dst == "max") return yy::parser::token::TOK_MAX;
+ if (dst == "if") return yy::parser::token::TOK_IF;
+ if (dst == "in") return yy::parser::token::TOK_IN;
+ if (dst == "else") return yy::parser::token::TOK_ELSE;
+ if (dst == "#Model") return yy::parser::token::TOK_MODEL;
+ res->emplace<std::string>(dst);
+ return yy::parser::token::TOK_ID_OR_NUM;
+}
+
+static int yylex(yy::parser::semantic_type *res,
+ const std::string &input,
+ size_t *cursor)
+{
+ size_t p = *cursor;
+
+ // Skip spaces.
+ while (p < input.size() && isspace(input[p]))
+ p++;
+
+ if (p >= input.size()) {
+ *cursor = p;
+ return yy::parser::token::TOK_EOF;
+ }
+ switch (input[p]) {
+ case '#':
+ case 'a' ... 'z':
+ case 'A' ... 'Z':
+ return expr__symbol(res, p, input, cursor);
+ case '0' ... '9': case '.': {
+ // Read the number and regularize numbers starting
+ // with '.' adjusting the cursor to after the number.
+ const size_t s = p;
+ res->emplace<std::string>(
+ std::to_string(std::stod(input.substr(p), &p)));
+ *cursor = p + s;
+ return yy::parser::token::TOK_ID_OR_NUM;
+ }
+ default:
+ *cursor = p + 1;
+ return input[p];
+ }
+}
--
2.29.2.222.g5d2a92d10f8-goog
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