Support attaching probes to multiple functions

e.g.: kprobe:sys_read,sys_write { @[func] = count() }

src/ast.cpp

@@ -93,5 +93,18 @@ std::string opstr(Unop &unop)
   }
 }
 
+std::string Probe::name() const
+{
+  std::string n = type;
+  if (path != "")
+    n += ":" + path;
+  n += ":";
+  for (std::string attach_point : *attach_points)
+  {
+    n += attach_point + ",";
+  }
+  return n.substr(0, n.size()-1);
+}
+
 } // namespace ast
 } // namespace bpftrace

src/ast.h

@@ -135,27 +135,26 @@ public:
   void accept(Visitor &v) override;
 };
 
+using AttachPointList = std::vector<std::string>;
 class Probe : public Node {
 public:
   Probe(const std::string &type, Predicate *pred, StatementList *stmts)
-    : type(type), name(type), pred(pred), stmts(stmts) { }
-  Probe(const std::string &type, const std::string &attach_point,
+    : type(type), attach_points(new AttachPointList), pred(pred), stmts(stmts) { }
+  Probe(const std::string &type, AttachPointList *attach_points,
       Predicate *pred, StatementList *stmts)
-    : type(type), attach_point(attach_point), name(type+":"+attach_point),
-      pred(pred), stmts(stmts) { }
+    : type(type), attach_points(attach_points), pred(pred), stmts(stmts) { }
   Probe(const std::string &type, const std::string &path,
-      const std::string &attach_point, Predicate *pred, StatementList *stmts)
-    : type(type), path(path), attach_point(attach_point),
-      name(type+":"+path+":"+attach_point), pred(pred), stmts(stmts) { }
+      AttachPointList *attach_points, Predicate *pred, StatementList *stmts)
+    : type(type), path(path), attach_points(attach_points), pred(pred), stmts(stmts) { }
 
   std::string type;
   std::string path;
-  std::string attach_point;
-  std::string name;
+  AttachPointList *attach_points;
   Predicate *pred;
   StatementList *stmts;
 
   void accept(Visitor &v) override;
+  std::string name() const;
 };
 using ProbeList = std::vector<Probe *>;
 

src/bpftrace.cpp

@@ -15,28 +15,36 @@ namespace bpftrace {
 
 int BPFtrace::add_probe(ast::Probe &p)
 {
-  Probe probe;
-  probe.path = p.path;
-  probe.attach_point = p.attach_point;
-  probe.name = p.name;
-  probe.type = probetype(p.type);
-
   if (p.type == "BEGIN")
   {
+    Probe probe;
     probe.path = bpftrace_path_;
     probe.attach_point = "BEGIN_trigger";
+    probe.type = probetype(p.type);
+    probe.name = p.name();
     special_probes_.push_back(probe);
     return 0;
   }
   else if (p.type == "END")
   {
+    Probe probe;
     probe.path = bpftrace_path_;
     probe.attach_point = "END_trigger";
+    probe.type = probetype(p.type);
+    probe.name = p.name();
     special_probes_.push_back(probe);
     return 0;
   }
 
-  probes_.push_back(probe);
+  for (std::string attach_point : *p.attach_points)
+  {
+    Probe probe;
+    probe.path = p.path;
+    probe.attach_point = attach_point;
+    probe.type = probetype(p.type);
+    probe.name = p.name();
+    probes_.push_back(probe);
+  }
   return 0;
 }
 

src/codegen_llvm.cpp

@@ -334,8 +334,8 @@ void CodegenLLVM::visit(Probe &probe)
       b_.getInt64Ty(),
       {b_.getInt8PtrTy()}, // struct pt_regs *ctx
       false);
-  Function *func = Function::Create(func_type, Function::ExternalLinkage, probe.name, module_.get());
-  func->setSection(probe.name);
+  Function *func = Function::Create(func_type, Function::ExternalLinkage, probe.name(), module_.get());
+  func->setSection(probe.name());
   BasicBlock *entry = BasicBlock::Create(module_->getContext(), "entry", func);
   b_.SetInsertPoint(entry);
 

src/parser.yy

@@ -84,6 +84,7 @@ void yyerror(bpftrace::Driver &driver, const char *s);
 %type <ast::Map *> map
 %type <ast::Variable *> var
 %type <ast::ExpressionList *> vargs
+%type <ast::AttachPointList *> attach_points
 
 %right ASSIGN
 %left LOR
@@ -108,11 +109,15 @@ probes : probes probe { $$ = $1; $1->push_back($2); }
        | probe        { $$ = new ast::ProbeList; $$->push_back($1); }
        ;
 
-probe : IDENT pred block            { $$ = new ast::Probe($1, $2, $3); }
-      | IDENT ":" IDENT pred block  { $$ = new ast::Probe($1, $3, $4, $5); }
-      | IDENT PATH IDENT pred block { $$ = new ast::Probe($1, $2.substr(1, $2.size()-2), $3, $4, $5); }
+probe : IDENT pred block                    { $$ = new ast::Probe($1, $2, $3); }
+      | IDENT ":" attach_points pred block  { $$ = new ast::Probe($1, $3, $4, $5); }
+      | IDENT PATH attach_points pred block { $$ = new ast::Probe($1, $2.substr(1, $2.size()-2), $3, $4, $5); }
       ;
 
+attach_points : attach_points "," IDENT { $$ = $1; $1->push_back($3); }
+              | IDENT                   { $$ = new ast::AttachPointList; $$->push_back($1); }
+              ;
+
 pred : DIV expr ENDPRED { $$ = new ast::Predicate($2); }
      |                  { $$ = nullptr; }
 

src/printer.cpp

@@ -126,7 +126,7 @@ void Printer::visit(Predicate &pred)
 void Printer::visit(Probe &probe)
 {
   std::string indent(depth_, ' ');
-  out_ << indent << probe.name << std::endl;
+  out_ << indent << probe.name() << std::endl;
 
   ++depth_;
   if (probe.pred) {

src/semantic_analyser.cpp

@@ -322,19 +322,19 @@ void SemanticAnalyser::visit(Probe &probe)
   probe_ = &probe;
 
   if (probe.type == "kprobe" || probe.type == "kretprobe") {
-    if (probe.attach_point == "")
+    if (probe.attach_points->size() == 0)
       err_ << "kprobes must have an attachment point" << std::endl;
     if (probe.path != "")
       err_ << "kprobes should not have a path" << std::endl;
   }
   else if (probe.type == "uprobe" || probe.type == "uretprobe") {
-    if (probe.attach_point == "")
+    if (probe.attach_points->size() == 0)
       err_ << "uprobes must have an attachment point" << std::endl;
     if (probe.path == "")
       err_ << "uprobes must have a path" << std::endl;
   }
   else if (probe.type == "BEGIN" || probe.type == "END") {
-    if (probe.attach_point != "")
+    if (probe.attach_points->size() != 0)
       err_ << "BEGIN/END probes should not have an attachment point" << std::endl;
     if (probe.path != "")
       err_ << "BEGIN/END probes should not have a path" << std::endl;

tests/parser.cpp

@@ -220,6 +220,14 @@ TEST(Parser, begin_probe)
       "  int: 1\n");
 }
 
+TEST(Parser, multiple_attach_points)
+{
+  test("kprobe:sys_open,sys_close { 1 }",
+      "Program\n"
+      " kprobe:sys_open,sys_close\n"
+      "  int: 1\n");
+}
+
 } // namespace parser
 } // namespace test
 } // namespace bpftrace