Merge pull request #88 from iovisor/parser

support shift left and right

src/ast/ast.cpp

@@ -87,6 +87,8 @@ std::string opstr(Binop &binop)
     case bpftrace::Parser::token::GT:    return ">";
     case bpftrace::Parser::token::LAND:  return "&&";
     case bpftrace::Parser::token::LOR:   return "||";
+    case bpftrace::Parser::token::LEFT:  return "<<";
+    case bpftrace::Parser::token::RIGHT: return ">>";
     case bpftrace::Parser::token::PLUS:  return "+";
     case bpftrace::Parser::token::MINUS: return "-";
     case bpftrace::Parser::token::MUL:   return "*";

src/ast/codegen_llvm.cpp

@@ -596,6 +596,8 @@ void CodegenLLVM::visit(Binop &binop)
       case bpftrace::Parser::token::GE:    expr_ = b_.CreateICmpSGE(lhs, rhs); break;
       case bpftrace::Parser::token::LT:    expr_ = b_.CreateICmpSLT(lhs, rhs); break;
       case bpftrace::Parser::token::GT:    expr_ = b_.CreateICmpSGT(lhs, rhs); break;
+      case bpftrace::Parser::token::LEFT:  expr_ = b_.CreateShl    (lhs, rhs); break;
+      case bpftrace::Parser::token::RIGHT: expr_ = b_.CreateLShr   (lhs, rhs); break;
       case bpftrace::Parser::token::PLUS:  expr_ = b_.CreateAdd    (lhs, rhs); break;
       case bpftrace::Parser::token::MINUS: expr_ = b_.CreateSub    (lhs, rhs); break;
       case bpftrace::Parser::token::MUL:   expr_ = b_.CreateMul    (lhs, rhs); break;

src/lexer.l

@@ -67,6 +67,8 @@ pid|tid|uid|gid|nsecs|cpu|comm|stack|ustack|arg[0-9]|retval|func|name|curtask|ra
 "!="                    { return Parser::make_NE(loc); }
 "<="                    { return Parser::make_LE(loc); }
 ">="                    { return Parser::make_GE(loc); }
+"<<"                    { return Parser::make_LEFT(loc); }
+">>"                    { return Parser::make_RIGHT(loc); }
 "<"                     { return Parser::make_LT(loc); }
 ">"                     { return Parser::make_GT(loc); }
 "&&"                    { return Parser::make_LAND(loc); }

src/parser.yy

@@ -52,6 +52,8 @@ void yyerror(bpftrace::Driver &driver, const char *s);
   NE       "!="
   LE       "<="
   GE       ">="
+  LEFT     "<<"
+  RIGHT    ">>"
   LT       "<"
   GT       ">"
   LAND     "&&"
@@ -106,6 +108,7 @@ void yyerror(bpftrace::Driver &driver, const char *s);
 %left BAND
 %left EQ NE
 %left LE GE LT GT
+%left LEFT RIGHT
 %left PLUS MINUS
 %left MUL DIV MOD
 %right LNOT BNOT DEREF CAST
@@ -183,6 +186,8 @@ expr : INT             { $$ = new ast::Integer($1); }
      | expr GT expr    { $$ = new ast::Binop($1, token::GT, $3); }
      | expr LAND expr  { $$ = new ast::Binop($1, token::LAND,  $3); }
      | expr LOR expr   { $$ = new ast::Binop($1, token::LOR,   $3); }
+     | expr LEFT expr  { $$ = new ast::Binop($1, token::LEFT,  $3); }
+     | expr RIGHT expr { $$ = new ast::Binop($1, token::RIGHT, $3); }
      | expr PLUS expr  { $$ = new ast::Binop($1, token::PLUS,  $3); }
      | expr MINUS expr { $$ = new ast::Binop($1, token::MINUS, $3); }
      | expr MUL expr   { $$ = new ast::Binop($1, token::MUL,   $3); }

tests/codegen.cpp

@@ -2249,6 +2249,76 @@ attributes #1 = { argmemonly nounwind }
 )EXPECTED");
 }
 
+TEST(codegen, bitshift_left)
+{
+  test("kprobe:f { @x = 1 << 10; }",
+
+R"EXPECTED(; Function Attrs: nounwind
+declare i64 @llvm.bpf.pseudo(i64, i64) #0
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #1
+
+define i64 @"kprobe:f"(i8* nocapture readnone) local_unnamed_addr section "s_kprobe:f" {
+entry:
+  %"@x_val" = alloca i64, align 8
+  %"@x_key" = alloca i64, align 8
+  %1 = bitcast i64* %"@x_key" to i8*
+  call void @llvm.lifetime.start.p0i8(i64 -1, i8* nonnull %1)
+  store i64 0, i64* %"@x_key", align 8
+  %2 = bitcast i64* %"@x_val" to i8*
+  call void @llvm.lifetime.start.p0i8(i64 -1, i8* nonnull %2)
+  store i64 1024, i64* %"@x_val", align 8
+  %pseudo = tail call i64 @llvm.bpf.pseudo(i64 1, i64 1)
+  %update_elem = call i64 inttoptr (i64 2 to i64 (i8*, i8*, i8*, i64)*)(i64 %pseudo, i64* nonnull %"@x_key", i64* nonnull %"@x_val", i64 0)
+  call void @llvm.lifetime.end.p0i8(i64 -1, i8* nonnull %1)
+  call void @llvm.lifetime.end.p0i8(i64 -1, i8* nonnull %2)
+  ret i64 0
+}
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #1
+
+attributes #0 = { nounwind }
+attributes #1 = { argmemonly nounwind }
+)EXPECTED");
+}
+
+TEST(codegen, bitshift_right)
+{
+  test("kprobe:f { @x = 1024 >> 9; }",
+
+R"EXPECTED(; Function Attrs: nounwind
+declare i64 @llvm.bpf.pseudo(i64, i64) #0
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) #1
+
+define i64 @"kprobe:f"(i8* nocapture readnone) local_unnamed_addr section "s_kprobe:f" {
+entry:
+  %"@x_val" = alloca i64, align 8
+  %"@x_key" = alloca i64, align 8
+  %1 = bitcast i64* %"@x_key" to i8*
+  call void @llvm.lifetime.start.p0i8(i64 -1, i8* nonnull %1)
+  store i64 0, i64* %"@x_key", align 8
+  %2 = bitcast i64* %"@x_val" to i8*
+  call void @llvm.lifetime.start.p0i8(i64 -1, i8* nonnull %2)
+  store i64 2, i64* %"@x_val", align 8
+  %pseudo = tail call i64 @llvm.bpf.pseudo(i64 1, i64 1)
+  %update_elem = call i64 inttoptr (i64 2 to i64 (i8*, i8*, i8*, i64)*)(i64 %pseudo, i64* nonnull %"@x_key", i64* nonnull %"@x_val", i64 0)
+  call void @llvm.lifetime.end.p0i8(i64 -1, i8* nonnull %1)
+  call void @llvm.lifetime.end.p0i8(i64 -1, i8* nonnull %2)
+  ret i64 0
+}
+
+; Function Attrs: argmemonly nounwind
+declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture) #1
+
+attributes #0 = { nounwind }
+attributes #1 = { argmemonly nounwind }
+)EXPECTED");
+}
+
 TEST(codegen, ternary_int)
 {
   test("kprobe:f { @x = pid < 10000 ? 1 : 2; }",

tests/parser.cpp

@@ -239,6 +239,39 @@ TEST(Parser, expressions)
       "  int: 1\n");
 }
 
+TEST(Parser, bit_shifting)
+{
+  test("kprobe:do_nanosleep { @x = 1 << 10 }",
+       "Program\n"
+       " kprobe:do_nanosleep\n"
+       "  =\n"
+       "   map: @x\n"
+       "   <<\n"
+       "    int: 1\n"
+       "    int: 10\n");
+  test("kprobe:do_nanosleep { @x = 1024 >> 9 }",
+       "Program\n"
+       " kprobe:do_nanosleep\n"
+       "  =\n"
+       "   map: @x\n"
+       "   >>\n"
+       "    int: 1024\n"
+       "    int: 9\n");
+  test("kprobe:do_nanosleep / 2 < 1 >> 8 / { $x = 1 }",
+       "Program\n"
+       " kprobe:do_nanosleep\n"
+       "  pred\n"
+       "   <\n"
+       "    int: 2\n"
+       "    >>\n"
+       "     int: 1\n"
+       "     int: 8\n"
+       "  =\n"
+       "   variable: $x\n"
+       "   int: 1\n");
+}
+
+
 TEST(Parser, ternary_int)
 {
   test("kprobe:sys_open { @x = pid < 10000 ? 1 : 2 }",

tools/loads.bt

@@ -34,8 +34,8 @@ interval:s:1
 	$load15 = *($avenrun + 16);
 	time("%H:%M:%S ");
 	printf("load averages: %d.%03d %d.%03d %d.%03d\n",
-	    ($load1 / 2048), (($load1 & 2047) * 1000) / 2048,
-	    ($load5 / 2048), (($load5 & 2047) * 1000) / 2048,
-	    ($load15 / 2048), (($load15 & 2047) * 1000) / 2048
+	    ($load1 >> 11), (($load1 & ((1 << 11) - 1)) * 1000) >> 11,
+	    ($load5 >> 11), (($load5 & ((1 << 11) - 1)) * 1000) >> 11,
+	    ($load15 >> 11), (($load15 & ((1 << 11) - 1)) * 1000) >> 11
 	);
 }