[PATCH] tests: pacify gcc -fanalyzer on zerosize_ptr

[PATCH] tests: pacify gcc -fanalyzer on zerosize_ptr

[Paul Eggert]

* tests/test-memcasecmp.c (main):
* tests/test-memchr.c (main):
* tests/test-memchr2.c (main):
* tests/test-memcmp.c (main):
* tests/test-memmem.c (main):
* tests/test-memrchr.c (main):
* tests/unistr/test-chr.h (main):
* tests/unistr/test-cmp.h (test_cmp):
Check whether zerosize_ptr returns NULL before using it.
This pacifies GCC 10.1’s new fanalyzer option, and matches
other uses of zerosize_ptr.
---
 ChangeLog               | 15 +++++++++++++++
 tests/test-memcasecmp.c |  5 ++++-
 tests/test-memchr.c     |  4 +++-
 tests/test-memchr2.c    |  4 +++-
 tests/test-memcmp.c     |  5 ++++-
 tests/test-memmem.c     | 22 +++++++++++++---------
 tests/test-memrchr.c    |  4 +++-
 tests/unistr/test-chr.h |  4 +++-
 tests/unistr/test-cmp.h |  5 ++++-
 9 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3cde29456..edb63b348 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2020-07-01  Paul Eggert  <eggert@cs.ucla.edu>
+
+	tests: pacify gcc -fanalyzer on zerosize_ptr
+	* tests/test-memcasecmp.c (main):
+	* tests/test-memchr.c (main):
+	* tests/test-memchr2.c (main):
+	* tests/test-memcmp.c (main):
+	* tests/test-memmem.c (main):
+	* tests/test-memrchr.c (main):
+	* tests/unistr/test-chr.h (main):
+	* tests/unistr/test-cmp.h (test_cmp):
+	Check whether zerosize_ptr returns NULL before using it.
+	This pacifies GCC 10.1’s new fanalyzer option, and matches
+	other uses of zerosize_ptr.
+
 2020-07-01  Bruno Haible  <bruno@clisp.org>
 
 	asyncsafe-spin: Add tests.
diff --git a/tests/test-memcasecmp.c b/tests/test-memcasecmp.c
index 00df2f7cf..33507dc23 100644
--- a/tests/test-memcasecmp.c
+++ b/tests/test-memcasecmp.c
@@ -28,7 +28,10 @@ int
 main (void)
 {
   /* Test equal / not equal distinction.  */
-  ASSERT (memcasecmp (zerosize_ptr (), zerosize_ptr (), 0) == 0);
+  void *page_boundary1 = zerosize_ptr ();
+  void *page_boundary2 = zerosize_ptr ();
+  if (page_boundary1 && page_boundary2)
+    ASSERT (memcasecmp (page_boundary1, page_boundary2, 0) == 0);
   ASSERT (memcasecmp ("foo", "foobar", 2) == 0);
   ASSERT (memcasecmp ("foo", "foobar", 3) == 0);
   ASSERT (memcasecmp ("foo", "foobar", 4) != 0);
diff --git a/tests/test-memchr.c b/tests/test-memchr.c
index ab8d2c0da..d81bf3baf 100644
--- a/tests/test-memchr.c
+++ b/tests/test-memchr.c
@@ -49,7 +49,9 @@ main (void)
   ASSERT (MEMCHR (input, 'a', n) == input);
 
   ASSERT (MEMCHR (input, 'a', 0) == NULL);
-  ASSERT (MEMCHR (zerosize_ptr (), 'a', 0) == NULL);
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    ASSERT (MEMCHR (page_boundary, 'a', 0) == NULL);
 
   ASSERT (MEMCHR (input, 'b', n) == input + 1);
   ASSERT (MEMCHR (input, 'c', n) == input + 2);
diff --git a/tests/test-memchr2.c b/tests/test-memchr2.c
index 47428f215..8d5478919 100644
--- a/tests/test-memchr2.c
+++ b/tests/test-memchr2.c
@@ -48,7 +48,9 @@ main (void)
   ASSERT (MEMCHR2 (input, 'b', 'a', n) == input);
 
   ASSERT (MEMCHR2 (input, 'a', 'b', 0) == NULL);
-  ASSERT (MEMCHR2 (zerosize_ptr (), 'a', 'b', 0) == NULL);
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    ASSERT (MEMCHR2 (page_boundary, 'a', 'b', 0) == NULL);
 
   ASSERT (MEMCHR2 (input, 'b', 'd', n) == input + 1);
   ASSERT (MEMCHR2 (input + 2, 'b', 'd', n - 2) == input + 1026);
diff --git a/tests/test-memcmp.c b/tests/test-memcmp.c
index eaaac4531..5b262aae7 100644
--- a/tests/test-memcmp.c
+++ b/tests/test-memcmp.c
@@ -31,7 +31,10 @@ main (void)
   int (* volatile memcmp_ptr) (const void *, const void *, size_t) = memcmp;
 
   /* Test equal / not equal distinction.  */
-  ASSERT (memcmp (zerosize_ptr (), zerosize_ptr (), 0) == 0);
+  void *page_boundary1 = zerosize_ptr ();
+  void *page_boundary2 = zerosize_ptr ();
+  if (page_boundary1 && page_boundary2)
+    ASSERT (memcmp (page_boundary1, page_boundary2, 0) == 0);
   ASSERT (memcmp ("foo", "foobar", 2) == 0);
   ASSERT (memcmp ("foo", "foobar", 3) == 0);
   ASSERT (memcmp ("foo", "foobar", 4) != 0);
diff --git a/tests/test-memmem.c b/tests/test-memmem.c
index 1c1e0ad39..132265f12 100644
--- a/tests/test-memmem.c
+++ b/tests/test-memmem.c
@@ -73,16 +73,20 @@ main (int argc, char *argv[])
   }
 
   /* Check that length 0 does not dereference the pointer.  */
-  {
-    const char *result = memmem (zerosize_ptr (), 0, "foo", 3);
-    ASSERT (result == NULL);
-  }
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    {
+      {
+        const char *result = memmem (page_boundary, 0, "foo", 3);
+        ASSERT (result == NULL);
+      }
 
-  {
-    const char input[] = "foo";
-    const char *result = memmem (input, strlen (input), zerosize_ptr (), 0);
-    ASSERT (result == input);
-  }
+      {
+        const char input[] = "foo";
+        const char *result = memmem (input, strlen (input), page_boundary, 0);
+        ASSERT (result == input);
+      }
+    }
 
   /* Check that a long periodic needle does not cause false positives.  */
   {
diff --git a/tests/test-memrchr.c b/tests/test-memrchr.c
index 001134bb2..235fb6948 100644
--- a/tests/test-memrchr.c
+++ b/tests/test-memrchr.c
@@ -49,7 +49,9 @@ main (void)
   ASSERT (MEMRCHR (input, 'a', n) == input + n - 1);
 
   ASSERT (MEMRCHR (input, 'a', 0) == NULL);
-  ASSERT (MEMRCHR (zerosize_ptr (), 'a', 0) == NULL);
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    ASSERT (MEMRCHR (page_boundary, 'a', 0) == NULL);
 
   ASSERT (MEMRCHR (input, 'b', n) == input + n - 2);
   ASSERT (MEMRCHR (input, 'c', n) == input + n - 3);
diff --git a/tests/unistr/test-chr.h b/tests/unistr/test-chr.h
index b67be4886..f60610f22 100644
--- a/tests/unistr/test-chr.h
+++ b/tests/unistr/test-chr.h
@@ -48,7 +48,9 @@ main (void)
   ASSERT (U_CHR (input, length, 'a') == input);
 
   ASSERT (U_CHR (input, 0, 'a') == NULL);
-  ASSERT (U_CHR (zerosize_ptr (), 0, 'a') == NULL);
+  void *page_boundary = zerosize_ptr ();
+  if (page_boundary)
+    ASSERT (U_CHR (page_boundary, 0, 'a') == NULL);
 
   ASSERT (U_CHR (input, length, 'b') == input + 1);
   ASSERT (U_CHR (input, length, 'c') == input + 2);
diff --git a/tests/unistr/test-cmp.h b/tests/unistr/test-cmp.h
index 38a5223f7..207c59a77 100644
--- a/tests/unistr/test-cmp.h
+++ b/tests/unistr/test-cmp.h
@@ -20,7 +20,10 @@ static void
 test_cmp (void)
 {
   /* Test equal / not equal distinction.  */
-  ASSERT (U_CMP (zerosize_ptr (), zerosize_ptr (), 0) == 0);
+  void *page_boundary1 = zerosize_ptr ();
+  void *page_boundary2 = zerosize_ptr ();
+  if (page_boundary1 && page_boundary2)
+    ASSERT (U_CMP (page_boundary1, page_boundary2, 0) == 0);
   {
     static const UNIT input1[] = { 'f', 'o', 'o', 0 };
     static const UNIT input2[] = { 'f', 'o', 'o', 'b', 'a', 'r', 0 };
-- 
2.26.1

Re: [PATCH] tests: pacify gcc -fanalyzer on zerosize_ptr

[Bernhard Voelker]

[-- Attachment #1: Type: text/plain, Size: 833 bytes --]

On 2020-07-02 01:48, Paul Eggert wrote:
> diff --git a/tests/test-memchr.c b/tests/test-memchr.c

> -  ASSERT (MEMCHR (zerosize_ptr (), 'a', 0) == NULL);
> +  void *page_boundary = zerosize_ptr ();
> +  if (page_boundary)
> +    ASSERT (MEMCHR (page_boundary, 'a', 0) == NULL);

This triggers a new shadowing warning (here with -Werror, gcc 10.1.1):

  test-memchr.c: In function 'main':
  test-memchr.c:98:11: error: declaration of 'page_boundary' shadows a previous local [-Werror=shadow]
     98 |     char *page_boundary = (char *) zerosize_ptr ();
        |           ^~~~~~~~~~~~~
  test-memchr.c:52:9: note: shadowed declaration is here
     52 |   void *page_boundary = zerosize_ptr ();
        |         ^~~~~~~~~~~~~
  cc1: all warnings being treated as errors

The attached fixes it.
Okay to push?

Have a nice day,
Berny

[-- Attachment #2: 0001-tests-avoid-shadowing-warning.patch --]
[-- Type: text/x-patch, Size: 1408 bytes --]

From c24438ea3d142267f9e5e14440ffe4fa6052f075 Mon Sep 17 00:00:00 2001
From: Bernhard Voelker <mail@bernhard-voelker.de>
Date: Thu, 2 Jul 2020 23:11:52 +0200
Subject: [PATCH] tests: avoid shadowing warning

* tests/test-memchr.c (main): Give page_boundary variable a tight scope.
---
 ChangeLog           | 5 +++++
 tests/test-memchr.c | 9 ++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6115ab946..047a3bbd5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2020-07-02  Bernhard Voelker  <mail@bernhard-voelker.de>
+
+	tests: avoid shadowing warning
+	* tests/test-memchr.c (main): Give page_boundary variable a tight scope.
+
 2020-07-01  Paul Eggert  <eggert@cs.ucla.edu>
 
 	manywarnings: improve port to GCC 10.1
diff --git a/tests/test-memchr.c b/tests/test-memchr.c
index d81bf3baf..5ea4c03b0 100644
--- a/tests/test-memchr.c
+++ b/tests/test-memchr.c
@@ -49,9 +49,12 @@ main (void)
   ASSERT (MEMCHR (input, 'a', n) == input);
 
   ASSERT (MEMCHR (input, 'a', 0) == NULL);
-  void *page_boundary = zerosize_ptr ();
-  if (page_boundary)
-    ASSERT (MEMCHR (page_boundary, 'a', 0) == NULL);
+
+  {
+    void *page_boundary = zerosize_ptr ();
+    if (page_boundary)
+      ASSERT (MEMCHR (page_boundary, 'a', 0) == NULL);
+  }
 
   ASSERT (MEMCHR (input, 'b', n) == input + 1);
   ASSERT (MEMCHR (input, 'c', n) == input + 2);
-- 
2.27.0

Re: [PATCH] tests: pacify gcc -fanalyzer on zerosize_ptr

[Paul Eggert]

On 7/2/20 2:37 PM, Bernhard Voelker wrote:
> The attached fixes it.
> Okay to push?

Thanks, looks good.

Re: [PATCH] tests: pacify gcc -fanalyzer on zerosize_ptr

[Bernhard Voelker]

On 2020-07-05 11:14, Paul Eggert wrote:
> On 7/2/20 2:37 PM, Bernhard Voelker wrote:
>> The attached fixes it.
>> Okay to push?
> 
> Thanks, looks good.

Thanks, pushed.

Have a nice day,
Berny