10 files changed, 77 insertions, 26 deletions
diff --git a/tools/syz-declextract/declextract.go b/tools/syz-declextract/declextract.go
index 0853756bf..7d85adaf8 100644
--- a/tools/syz-declextract/declextract.go
+++ b/tools/syz-declextract/declextract.go
@@ -62,7 +62,7 @@ func run(autoFile string, loadProbeInfo func() (*ifaceprobe.Info, error), cfg *c
 	if err != nil {
 		return err
 	}
-	descriptions, interfaces, err := declextract.Run(out, probeInfo, syscallRename, cfg.DebugTrace)
+	descriptions, interfaces, includeUse, err := declextract.Run(out, probeInfo, syscallRename, cfg.DebugTrace)
 	if err != nil {
 		return err
 	}
@@ -94,6 +94,20 @@ func run(autoFile string, loadProbeInfo func() (*ifaceprobe.Info, error), cfg *c
 	if err := osutil.WriteFile(autoFile+".info", serialize(interfaces)); err != nil {
 		return err
 	}
+	removeUnused(desc, "", unusedNodes)
+	// Second pass to remove unused defines/includes. This needs to be done after removing
+	// other garbage b/c they may be used by other garbage.
+	unusedConsts, err := compiler.CollectUnusedConsts(desc.Clone(), target, includeUse, eh)
+	if err != nil {
+		return fmt.Errorf("failed to typecheck descriptions: %w\n%s", err, errors.Bytes())
+	}
+	removeUnused(desc, autoFile, unusedConsts)
+	// We need re-parse them again b/c new lines are fixed up during parsing.
+	formatted := ast.Format(ast.Parse(ast.Format(desc), autoFile, nil))
+	return osutil.WriteFile(autoFile, formatted)
+}
+
+func removeUnused(desc *ast.Description, autoFile string, unusedNodes []ast.Node) {
 	unused := make(map[string]bool)
 	for _, n := range unusedNodes {
 		_, typ, name := n.Info()
@@ -101,11 +115,8 @@ func run(autoFile string, loadProbeInfo func() (*ifaceprobe.Info, error), cfg *c
 	}
 	desc.Nodes = slices.DeleteFunc(desc.Nodes, func(n ast.Node) bool {
 		pos, typ, name := n.Info()
-		return pos.File != autoFile || unused[typ+name]
+		return autoFile != "" && pos.File != autoFile || unused[typ+name]
 	})
-	// We need re-parse them again b/c new lines are fixed up during parsing.
-	formatted := ast.Format(ast.Parse(ast.Format(desc), autoFile, nil))
-	return osutil.WriteFile(autoFile, formatted)
 }
 
 func prepare(loadProbeInfo func() (*ifaceprobe.Info, error), cfg *clangtool.Config) (
diff --git a/tools/syz-declextract/testdata/file_operations.c b/tools/syz-declextract/testdata/file_operations.c
index 04d548f98..0dd8b9b21 100644
--- a/tools/syz-declextract/testdata/file_operations.c
+++ b/tools/syz-declextract/testdata/file_operations.c
@@ -3,6 +3,7 @@
 
 #include "include/fs.h"
 #include "include/uapi/file_operations.h"
+#include "include/uapi/unused_ioctl.h"
 
 static void foo_open() {}
 static void foo_read() {}
@@ -43,3 +44,16 @@ const struct file_operations proc_ops[] = {
 		.unlocked_ioctl = proc_ioctl,
 	},
 };
+
+#define UNUSED_IOCTL2		_IO('c', 2)
+
+static void unused_ioctl(unsigned int cmd) {
+	switch (cmd) {
+	case UNUSED_IOCTL1:
+	case UNUSED_IOCTL2:
+	}
+}
+
+const struct file_operations unused = {
+	.unlocked_ioctl = unused_ioctl,
+};
diff --git a/tools/syz-declextract/testdata/file_operations.c.json b/tools/syz-declextract/testdata/file_operations.c.json
index df1c9a20f..716dbec38 100644
--- a/tools/syz-declextract/testdata/file_operations.c.json
+++ b/tools/syz-declextract/testdata/file_operations.c.json
@@ -45,6 +45,12 @@
 			"name": "proc_write",
 			"file": "file_operations.c",
 			"is_static": true
+		},
+		{
+			"name": "unused_ioctl",
+			"file": "file_operations.c",
+			"is_static": true,
+			"loc": 4
 		}
 	],
 	"consts": [
@@ -72,6 +78,16 @@
 			"name": "FOO_IOCTL5",
 			"filename": "include/uapi/file_operations.h",
 			"value": 3221775109
+		},
+		{
+			"name": "UNUSED_IOCTL1",
+			"filename": "include/uapi/unused_ioctl.h",
+			"value": 25345
+		},
+		{
+			"name": "UNUSED_IOCTL2",
+			"filename": "file_operations.c",
+			"value": 25346
 		}
 	],
 	"structs": [
@@ -185,6 +201,31 @@
 			"mmap": "proc_open",
 			"ioctl": "proc_ioctl",
 			"source_file": "file_operations.c"
+		},
+		{
+			"name": "unused_file_operations",
+			"ioctl": "unused_ioctl",
+			"ioctl_cmds": [
+				{
+					"name": "UNUSED_IOCTL2",
+					"type": {
+						"int": {
+							"byte_size": 1,
+							"is_const": true
+						}
+					}
+				},
+				{
+					"name": "UNUSED_IOCTL1",
+					"type": {
+						"int": {
+							"byte_size": 1,
+							"is_const": true
+						}
+					}
+				}
+			],
+			"source_file": "file_operations.c"
 		}
 	]
 }
 \ No newline at end of file
diff --git a/tools/syz-declextract/testdata/file_operations.c.txt b/tools/syz-declextract/testdata/file_operations.c.txt
index f2a0455bc..e94856980 100644
--- a/tools/syz-declextract/testdata/file_operations.c.txt
+++ b/tools/syz-declextract/testdata/file_operations.c.txt
@@ -6,7 +6,6 @@ type auto_todo int8
 
 include <vdso/bits.h>
 include <linux/types.h>
-include <net/netlink.h>
 include <include/uapi/file_operations.h>
 
 resource fd_foo_file_operations[fd]
diff --git a/tools/syz-declextract/testdata/functions.c.txt b/tools/syz-declextract/testdata/functions.c.txt
index 6dc51303b..8bd11c8fc 100644
--- a/tools/syz-declextract/testdata/functions.c.txt
+++ b/tools/syz-declextract/testdata/functions.c.txt
@@ -4,8 +4,4 @@ meta automatic
 
 type auto_todo int8
 
-include <vdso/bits.h>
-include <linux/types.h>
-include <net/netlink.h>
-
 functions$auto(x fd) fd
diff --git a/tools/syz-declextract/testdata/include/uapi/unused_ioctl.h b/tools/syz-declextract/testdata/include/uapi/unused_ioctl.h
new file mode 100644
index 000000000..6c3dbb036
--- /dev/null
+++ b/tools/syz-declextract/testdata/include/uapi/unused_ioctl.h
@@ -0,0 +1,6 @@
+// Copyright 2024 syzkaller project authors. All rights reserved.
+// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
+
+#include "ioctl.h"
+
+#define UNUSED_IOCTL1		_IO('c', 1)
diff --git a/tools/syz-declextract/testdata/io_uring.c.txt b/tools/syz-declextract/testdata/io_uring.c.txt
index 77183198f..2829bcbf1 100644
--- a/tools/syz-declextract/testdata/io_uring.c.txt
+++ b/tools/syz-declextract/testdata/io_uring.c.txt
@@ -3,8 +3,3 @@
 meta automatic
 
 type auto_todo int8
-
-include <vdso/bits.h>
-include <linux/types.h>
-include <net/netlink.h>
-include <include/uapi/io_uring.h>
diff --git a/tools/syz-declextract/testdata/netlink.c.txt b/tools/syz-declextract/testdata/netlink.c.txt
index e61244406..6ceb9111e 100644
--- a/tools/syz-declextract/testdata/netlink.c.txt
+++ b/tools/syz-declextract/testdata/netlink.c.txt
@@ -4,9 +4,6 @@ meta automatic
 
 type auto_todo int8
 
-include <vdso/bits.h>
-include <linux/types.h>
-include <net/netlink.h>
 include <include/uapi/netlink_family.h>
 
 resource genl_bar_family_id$auto[int16]
diff --git a/tools/syz-declextract/testdata/syscall.c.txt b/tools/syz-declextract/testdata/syscall.c.txt
index de87f1866..bb0cad8c4 100644
--- a/tools/syz-declextract/testdata/syscall.c.txt
+++ b/tools/syz-declextract/testdata/syscall.c.txt
@@ -4,9 +4,5 @@ meta automatic
 
 type auto_todo int8
 
-include <vdso/bits.h>
-include <linux/types.h>
-include <net/netlink.h>
-
 chmod$auto(filename ptr[in, filename], mode int32)
 open$auto(filename ptr[in, filename], flags int32, mode int32)
diff --git a/tools/syz-declextract/testdata/types.c.txt b/tools/syz-declextract/testdata/types.c.txt
index 45d451d8a..04a160771 100644
--- a/tools/syz-declextract/testdata/types.c.txt
+++ b/tools/syz-declextract/testdata/types.c.txt
@@ -4,10 +4,6 @@ meta automatic
 
 type auto_todo int8
 
-include <vdso/bits.h>
-include <linux/types.h>
-include <net/netlink.h>
-
 bitfield_enum$auto = a, b, c
 
 types_syscall$auto(p ptr[inout, anon_struct$auto], y ptr[inout, void], b ptr[inout, bitfields$auto], pid pid, f int32, v ptr[inout, various$auto])