attr: flag test methods (#177)

Adds a method to the Attribute type to test for each flag in the textflag.h header.

attr/attr_test.go

@@ -42,3 +42,34 @@ func TestAttributeContainsTextFlags(t *testing.T) {
 		}
 	}
 }
+
+func TestAttributeTestMethods(t *testing.T) {
+	cases := []struct {
+		Attribute Attribute
+		Predicate func(Attribute) bool
+		Expect    bool
+	}{
+		// Confirm logic works as expected.
+		{DUPOK | NOSPLIT, Attribute.DUPOK, true},
+		{DUPOK | NOSPLIT, Attribute.NOSPLIT, true},
+		{DUPOK | NOSPLIT, Attribute.NOFRAME, false},
+
+		// Basic test for every method.
+		{NOPROF, Attribute.NOPROF, true},
+		{DUPOK, Attribute.DUPOK, true},
+		{NOSPLIT, Attribute.NOSPLIT, true},
+		{RODATA, Attribute.RODATA, true},
+		{NOPTR, Attribute.NOPTR, true},
+		{WRAPPER, Attribute.WRAPPER, true},
+		{NEEDCTXT, Attribute.NEEDCTXT, true},
+		{TLSBSS, Attribute.TLSBSS, true},
+		{NOFRAME, Attribute.NOFRAME, true},
+		{REFLECTMETHOD, Attribute.REFLECTMETHOD, true},
+		{TOPFRAME, Attribute.TOPFRAME, true},
+	}
+	for _, c := range cases {
+		if c.Predicate(c.Attribute) != c.Expect {
+			t.Errorf("%s: expected %#v", c.Attribute.Asm(), c.Expect)
+		}
+	}
+}

attr/make_textflag.go

@@ -197,4 +197,10 @@ func PrintFlagAttributes(w io.Writer, fs []Flag) {
 		fmt.Fprintf(w, "\t%s: %q,\n", f.Name, f.Name)
 	}
 	fmt.Fprintf(w, "}\n")
+
+	// Flag test methods.
+	for _, f := range fs {
+		fmt.Fprintf(w, "\n// %s reports whether the %s flag is set.\n", f.Name, f.Name)
+		fmt.Fprintf(w, "func (a Attribute) %s() bool { return (a & %s) != 0 }\n", f.Name, f.Name)
+	}
 }

attr/ztextflag.go

@@ -55,3 +55,36 @@ var attrname = map[Attribute]string{
 	REFLECTMETHOD: "REFLECTMETHOD",
 	TOPFRAME:      "TOPFRAME",
 }
+
+// NOPROF reports whether the NOPROF flag is set.
+func (a Attribute) NOPROF() bool { return (a & NOPROF) != 0 }
+
+// DUPOK reports whether the DUPOK flag is set.
+func (a Attribute) DUPOK() bool { return (a & DUPOK) != 0 }
+
+// NOSPLIT reports whether the NOSPLIT flag is set.
+func (a Attribute) NOSPLIT() bool { return (a & NOSPLIT) != 0 }
+
+// RODATA reports whether the RODATA flag is set.
+func (a Attribute) RODATA() bool { return (a & RODATA) != 0 }
+
+// NOPTR reports whether the NOPTR flag is set.
+func (a Attribute) NOPTR() bool { return (a & NOPTR) != 0 }
+
+// WRAPPER reports whether the WRAPPER flag is set.
+func (a Attribute) WRAPPER() bool { return (a & WRAPPER) != 0 }
+
+// NEEDCTXT reports whether the NEEDCTXT flag is set.
+func (a Attribute) NEEDCTXT() bool { return (a & NEEDCTXT) != 0 }
+
+// TLSBSS reports whether the TLSBSS flag is set.
+func (a Attribute) TLSBSS() bool { return (a & TLSBSS) != 0 }
+
+// NOFRAME reports whether the NOFRAME flag is set.
+func (a Attribute) NOFRAME() bool { return (a & NOFRAME) != 0 }
+
+// REFLECTMETHOD reports whether the REFLECTMETHOD flag is set.
+func (a Attribute) REFLECTMETHOD() bool { return (a & REFLECTMETHOD) != 0 }
+
+// TOPFRAME reports whether the TOPFRAME flag is set.
+func (a Attribute) TOPFRAME() bool { return (a & TOPFRAME) != 0 }