diff --git a/test/helloworld.go b/test/helloworld.go
index 16c95f00686..9c33cab3bea 100644
--- a/test/helloworld.go
+++ b/test/helloworld.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test that we can do page 1 of the C book.
+
 package main
 
 func main() {
diff --git a/test/if.go b/test/if.go
index 13955781f90..25cc141648b 100644
--- a/test/if.go
+++ b/test/if.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test if statements in various forms.
+
 package main
 
 func assertequal(is, shouldbe int, msg string) {
diff --git a/test/import.go b/test/import.go
index a02a4ad8a49..d135cd28451 100644
--- a/test/import.go
+++ b/test/import.go
@@ -4,8 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// check that when import gives multiple names
-// to a type, they're still all the same type
+// Test that when import gives multiple names
+// to a single type, they still all refer to the same type.
 
 package main
 
diff --git a/test/import1.go b/test/import1.go
index f5b8926a70a..56b29d58c06 100644
--- a/test/import1.go
+++ b/test/import1.go
@@ -4,7 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// check for import conflicts
+// Verify that import conflicts are detected by the compiler.
+// Does not compile.
 
 package main
 
diff --git a/test/import2.go b/test/import2.go
index 0efc285fac8..0acfabcc182 100644
--- a/test/import2.go
+++ b/test/import2.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Various declarations of exported variables and functions.
+// Imported by import3.go.
+
 package p
 
 var C1 chan <- chan int = (chan<- (chan int))(nil)
diff --git a/test/import3.go b/test/import3.go
index e4900b93ddc..274fcfe42ab 100644
--- a/test/import3.go
+++ b/test/import3.go
@@ -4,7 +4,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Check that all the types from import2.go made it
+// Test that all the types from import2.go made it
 // intact and with the same meaning, by assigning to or using them.
 
 package main
diff --git a/test/import4.go b/test/import4.go
index 1ae1d0e4ad3..cbfebf7e184 100644
--- a/test/import4.go
+++ b/test/import4.go
@@ -4,9 +4,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package main
+// Verify that various kinds of "imported and not used"
+// errors are caught by the compiler.
+// Does not compile.
 
-// various kinds of imported and not used
+package main
 
 // standard
 import "fmt"	// ERROR "imported and not used.*fmt"
diff --git a/test/import5.go b/test/import5.go
index acd03c9ce9f..54d22fd9e18 100644
--- a/test/import5.go
+++ b/test/import5.go
@@ -4,7 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// import paths are slash-separated; reject backslash
+// Verify that imports with backslashes are rejected by the compiler.
+// Does not compile.
+// TODO: make more thorough.
 
 package main
 
diff --git a/test/index.go b/test/index.go
index 38aa33dd305..eb0c45495dc 100644
--- a/test/index.go
+++ b/test/index.go
@@ -9,6 +9,7 @@
 // license that can be found in the LICENSE file.
 
 // Generate test of index and slice bounds checks.
+// The output is compiled and run.
 
 package main
 
diff --git a/test/indirect.go b/test/indirect.go
index df8d3c73661..bb20f3009bf 100644
--- a/test/indirect.go
+++ b/test/indirect.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test various safe uses of indirection.
+
 package main
 
 var m0 map[string]int
diff --git a/test/indirect1.go b/test/indirect1.go
index e49eeb06508..51da4cc7c45 100644
--- a/test/indirect1.go
+++ b/test/indirect1.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Verify that illegal uses of indirection are caught by the compiler.
+// Does not compile.
+
 package main
 
 var m0 map[string]int
diff --git a/test/init.go b/test/init.go
index 0146f4b3ee6..f4689443cf1 100644
--- a/test/init.go
+++ b/test/init.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Verify that erroneous use of init is detected.
+// Does not compile.
+
 package main
 
 import "runtime"
diff --git a/test/initialize.go b/test/initialize.go
index 5bab5a708d6..1307e020961 100644
--- a/test/initialize.go
+++ b/test/initialize.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test initialization of package-level variables.
+
 package main
 
 import "fmt"
diff --git a/test/initializerr.go b/test/initializerr.go
index c2703e3eb4b..48908c34786 100644
--- a/test/initializerr.go
+++ b/test/initializerr.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Verify that erroneous initialization expressions are caught by the compiler
+// Does not compile.
+
 package main
 
 type S struct {
diff --git a/test/int_lit.go b/test/int_lit.go
index a109fa9574a..78deaea1302 100644
--- a/test/int_lit.go
+++ b/test/int_lit.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test integer literal syntax.
+
 package main
 
 import "os"
diff --git a/test/intcvt.go b/test/intcvt.go
index 81b04effdc6..3920528a403 100644
--- a/test/intcvt.go
+++ b/test/intcvt.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test implicit and explicit conversions of constants.
+
 package main
 
 const (
diff --git a/test/iota.go b/test/iota.go
index 7e9e3527978..7187dbe335e 100644
--- a/test/iota.go
+++ b/test/iota.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test iota.
+
 package main
 
 func assert(cond bool, msg string) {
diff --git a/test/label.go b/test/label.go
index 8f2df4ccbca..b30c27ec44b 100644
--- a/test/label.go
+++ b/test/label.go
@@ -4,7 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Pass 1 label errors.
+// Verify that erroneous labels are caught by the compiler.
+// This set is caught by pass 1.
+// Does not compile.
 
 package main
 
diff --git a/test/label1.go b/test/label1.go
index 8a192c2910a..f923a18820e 100644
--- a/test/label1.go
+++ b/test/label1.go
@@ -4,7 +4,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Pass 2 label errors.
+
+// Verify that erroneous labels are caught by the compiler.
+// This set is caught by pass 2. That's why this file is label1.go.
+// Does not compile.
 
 package main
 
diff --git a/test/linkx.go b/test/linkx.go
index caa815a391f..d2c9545679b 100644
--- a/test/linkx.go
+++ b/test/linkx.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test the -X facility of the gc linker (6l etc.).
+
 package main
 
 var tbd string
diff --git a/test/literal.go b/test/literal.go
index 396d75c01f6..ba185fc9ace 100644
--- a/test/literal.go
+++ b/test/literal.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test literal syntax for basic types.
+
 package main
 
 var nbad int
diff --git a/test/mallocfin.go b/test/mallocfin.go
index 2f9f8386da1..be6d79b2b8e 100644
--- a/test/mallocfin.go
+++ b/test/mallocfin.go
@@ -4,7 +4,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// trivial finalizer test
+// Test basic operation of finalizers.
 
 package main
 
diff --git a/test/map.go b/test/map.go
index c7f1d05a981..6dec0dfd719 100644
--- a/test/map.go
+++ b/test/map.go
@@ -4,6 +4,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test maps, almost exhaustively.
+
 package main
 
 import (
diff --git a/test/map1.go b/test/map1.go
index 44708c11bb2..369e49da5d0 100644
--- a/test/map1.go
+++ b/test/map1.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test map declarations of many types, including erroneous ones.
+// Does not compile.
+
 package main
 
 func main() {}
diff --git a/test/method.go b/test/method.go
index 40b42ac7aa6..6080ce5a770 100644
--- a/test/method.go
+++ b/test/method.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Test simple methods of various types, with pointer and
+// value receivers.
+
 package main
 
 type S string
diff --git a/test/method1.go b/test/method1.go
index bbbdbfa1c19..365b8ca553d 100644
--- a/test/method1.go
+++ b/test/method1.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Verify that method redeclarations are caught by the compiler.
+// Does not compile.
+
 package main
 
 type T struct { }
diff --git a/test/method2.go b/test/method2.go
index 7db1c3abb5d..b63da10dc69 100644
--- a/test/method2.go
+++ b/test/method2.go
@@ -4,6 +4,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// Verify that pointers and interface types cannot be method receivers.
+// Does not compile.
+
 package main
 
 type T struct {
diff --git a/test/method3.go b/test/method3.go
index 5711ffd94ca..fd64771527e 100644
--- a/test/method3.go
+++ b/test/method3.go
@@ -4,7 +4,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// test that methods on slices work
+// Test methods on slices.
 
 package main