threads / patch / 56247

v3userdiff: improve java regex for array, qualified, and generic return types

Subject: [PATCH v3] userdiff: improve java regex for array, qualified, and generic return types

## tl;dr

2 messages between Aug 10, 2021 and Aug 10, 2021. Diffs are folded; open one to read it.

replies: 1people: 1as markdown or json

Tassilo Horn· Aug 10, 2021, 14:43 UTC · lore

Currently, the git diff hunk headers show the wrong method signature if the method has a qualified return type, an array return type, or a generic return type because the regex doesn't allow dots (.), [], or < and > in the return type. Also, type parameter declarations couldn't be matched.

Add several t4018 tests asserting the right hunk headers for increasingly complex method signatures:

  public String[] secondMethod(String[] RIGHT)
  public List<String> secondMethod(String[] RIGHT)
  public <T> List<T> secondMethod(T[] RIGHT)
  public <AType, B> Map<AType, B> secondMethod(String[] RIGHT)
  public <AType, B> java.util.Map<AType, Map<B, B[]>> secondMethod(String[] RIGHT)
Signed-off-by: Tassilo Horn <tsdh@gnu.org>
---
 t/t4018/java-return-array    | 10 ++++++++++
 t/t4018/java-return-generic  | 10 ++++++++++
 t/t4018/java-return-generic2 | 10 ++++++++++
 t/t4018/java-return-generic3 | 10 ++++++++++
 t/t4018/java-return-generic4 | 10 ++++++++++
 userdiff.c                   | 10 +++++++++-
 6 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 t/t4018/java-return-array
 create mode 100644 t/t4018/java-return-generic
 create mode 100644 t/t4018/java-return-generic2
 create mode 100644 t/t4018/java-return-generic3
 create mode 100644 t/t4018/java-return-generic4
Show changes to 6 files +59 −1

t/t4018/java-return-array, t/t4018/java-return-generic, t/t4018/java-return-generic2, t/t4018/java-return-generic3, t/t4018/java-return-generic4, userdiff.c

diff --git a/t/t4018/java-return-array b/t/t4018/java-return-array
new file mode 100644
index 0000000000..fc8882a5a9
--- /dev/null
+++ b/t/t4018/java-return-array
@@ -0,0 +1,10 @@
+class MyExample {
+    public void firstMethod() {
+        // Whatever...
+    }
+
+ public String[] secondMethod(String[] RIGHT) {
+        // Whatever...
+        return new; // ChangeMe
+    }
+}
diff --git a/t/t4018/java-return-generic b/t/t4018/java-return-generic
new file mode 100644
index 0000000000..7ea7bf8f07
--- /dev/null
+++ b/t/t4018/java-return-generic
@@ -0,0 +1,10 @@
+class MyExample {
+    public void firstMethod() {
+        // Whatever...
+    }
+
+    public List<String> secondMethod(String[] RIGHT) {
+        // Whatever...
+        return Arrays.asList("ChangeMe");
+    }
+}
diff --git a/t/t4018/java-return-generic2 b/t/t4018/java-return-generic2
new file mode 100644
index 0000000000..d2d2ab7f37
--- /dev/null
+++ b/t/t4018/java-return-generic2
@@ -0,0 +1,10 @@
+class MyExample {
+    public void firstMethod() {
+        // Whatever...
+    }
+
+    public <T> List<T> secondMethod(T[] RIGHT) {
+        // Whatever...
+        return (List<T>) Arrays.asList("ChangeMe");
+    }
+}
diff --git a/t/t4018/java-return-generic3 b/t/t4018/java-return-generic3
new file mode 100644
index 0000000000..3db1a1ddba
--- /dev/null
+++ b/t/t4018/java-return-generic3
@@ -0,0 +1,10 @@
+class MyExample {
+    public void firstMethod() {
+        // Whatever...
+    }
+
+    public <AType, B> Map<AType, B> secondMethod(String[] RIGHT) {
+        // Whatever...
+        return new java.util.HashMap<>(); // ChangeMe
+    }
+}
diff --git a/t/t4018/java-return-generic4 b/t/t4018/java-return-generic4
new file mode 100644
index 0000000000..59f2a50dd2
--- /dev/null
+++ b/t/t4018/java-return-generic4
@@ -0,0 +1,10 @@
+class MyExample {
+    public void firstMethod() {
+        // Whatever...
+    }
+
+ public <AType, B> java.util.Map<AType, Map<B, B[]>> secondMethod(String[] RIGHT) {
+        // Whatever...
+        return new java.util.HashMap<>(); // ChangeMe
+    }
+}
diff --git a/userdiff.c b/userdiff.c
index 3c3bbe38b0..ded42945c3 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -142,7 +142,15 @@ PATTERNS("html",
 	 "[^<>= \t]+"),
 PATTERNS("java",
 	 "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
-	 "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
+         /* Method signatures contain: */
+         /*   modifiers: public static */
+         "^[ \t]*(([A-Za-z_][A-Za-z]*[ \t]+)*"
+         /*   optionally type parameters: <A, B, C> */
+         "(<[A-Za-z0-9_, \t]+>[ \t]+)?"
+         /*   a return type: java.util.Map<A, B[]> */
+         "([A-Za-z_]([A-Za-z_0-9<>,.]|\\[[ \t]*\\])*[ \t]+)+"
+         /*   the method name followed by the parameter list: myMethod(...) */
+         "[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
 	 /* -- */
 	 "[a-zA-Z_][a-zA-Z0-9_]*"
 	 "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
-- 
2.32.0
Tassilo Horn· Aug 10, 2021, 15:22 UTC · re: Tassilo Horn · lore

Re: [PATCH v3] userdiff: improve java regex for array, qualified, and generic return types

Gosh, I'm sorry. I've just discovered yet another corner case that has to be catered for (generic return types with wildcards). Stay tuned for patch version v4...

Bye, Tassilo

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