From 395ef5e6f4dc696f8b43551b89396f03df91d30d Mon Sep 17 00:00:00 2001
From: Pieter Duchi <pieterduchi@telenet.be>
Date: Wed, 21 Oct 2026 21:41:52 +0200
Subject: [PATCH 1/3] gtk.cfg: fix the g_ascii_formatd() configuration

g_ascii_formatd(buffer, buf_len, format, d) formats exactly one double
into buffer, but every call was reported as
  g_ascii_formatd format string requires 1 parameter but only 0 are given.
  Uninitialized variable: buffer
- The double is a fixed argument: with it configured as arg 4 the format
  check did not count it. Leave it to the format string check, which now
  also checks its type.
- buffer is written, not read: it need not be initialized or a string.
  Its size must be at least buf_len.
---
 cfg/gtk.cfg    |  7 +------
 test/cfg/gtk.c | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/cfg/gtk.cfg b/cfg/gtk.cfg
index 3aee2e2b1a2..8fc40969855 100644
--- a/cfg/gtk.cfg
+++ b/cfg/gtk.cfg
@@ -3285,8 +3285,7 @@
     <returnValue type="gchar*"/>
     <arg nr="1" direction="out">
       <not-null/>
-      <not-uninit/>
-      <strz/>
+      <minsize type="argvalue" arg="2"/>
     </arg>
     <arg nr="2" direction="in">
       <not-bool/>
@@ -3299,10 +3298,6 @@
       <strz/>
       <formatstr/>
     </arg>
-    <arg nr="4" direction="in">
-      <not-bool/>
-      <not-uninit/>
-    </arg>
   </function>
   <!-- gboolean g_ascii_isalnum(gchar c); -->
   <function name="g_ascii_isalnum">
diff --git a/test/cfg/gtk.c b/test/cfg/gtk.c
index b923135e2d9..0858a6b3554 100644
--- a/test/cfg/gtk.c
+++ b/test/cfg/gtk.c
@@ -655,3 +655,20 @@ int g_return_val_if_reached_test(const char *s) {
 
     return 0;
 }
+
+void g_ascii_formatd_test(double d)
+{
+    // g_ascii_formatd() writes the buffer and formats exactly one double
+    gchar buf[39];
+    g_ascii_formatd(buf, sizeof(buf), "%.2f", d);
+    g_print("%s", buf);
+
+    // cppcheck-suppress invalidPrintfArgType_sint
+    g_ascii_formatd(buf, sizeof(buf), "%d", d);
+    g_print("%s", buf);
+
+    gchar small[4];
+    // cppcheck-suppress bufferAccessOutOfBounds
+    g_ascii_formatd(small, sizeof(buf), "%.2f", d);
+    g_print("%s", small);
+}

From 65c0efeb53dfe83083cdc97a3c2993bd61e5a0b1 Mon Sep 17 00:00:00 2001
From: Pieter Duchi <pieterduchi@telenet.be>
Date: Thu, 22 Oct 2026 08:27:29 +0200
Subject: [PATCH 2/3] gtk.cfg: keep reporting a bool as the g_ascii_formatd()
 value

Review of the previous commit: dropping <arg nr="4"> also dropped its
<not-bool/>, so with a format string that is not a literal a bool passed as
the value was no longer reported (invalidFunctionArgBool). Describing arg 4
again makes the format check count it as a fixed argument and report
"requires 1 parameter but only 0 are given" again, so describe it as the
variadic argument instead, as gnu.cfg does.
---
 cfg/gtk.cfg    | 3 +++
 test/cfg/gtk.c | 8 ++++++++
 2 files changed, 11 insertions(+)

diff --git a/cfg/gtk.cfg b/cfg/gtk.cfg
index 8fc40969855..e8e86043b4f 100644
--- a/cfg/gtk.cfg
+++ b/cfg/gtk.cfg
@@ -3298,6 +3298,9 @@
       <strz/>
       <formatstr/>
     </arg>
+    <arg nr="variadic" direction="in">
+      <not-bool/>
+    </arg>
   </function>
   <!-- gboolean g_ascii_isalnum(gchar c); -->
   <function name="g_ascii_isalnum">
diff --git a/test/cfg/gtk.c b/test/cfg/gtk.c
index 0858a6b3554..f3e0f032b5e 100644
--- a/test/cfg/gtk.c
+++ b/test/cfg/gtk.c
@@ -672,3 +672,11 @@ void g_ascii_formatd_test(double d)
     g_ascii_formatd(small, sizeof(buf), "%.2f", d);
     g_print("%s", small);
 }
+
+void g_ascii_formatd_format_test(const gchar *format, int i)
+{
+    gchar buf[39];
+    // cppcheck-suppress invalidFunctionArgBool
+    g_ascii_formatd(buf, sizeof(buf), format, i == 1);
+    g_print("%s", buf);
+}

From d9593a06954c4a932cf8b6c01f1a47792761dd70 Mon Sep 17 00:00:00 2001
From: Pieter Duchi <pieterduchi@telenet.be>
Date: Thu, 22 Oct 2026 12:56:24 +0200
Subject: [PATCH 3/3] gtk.cfg: the g_ascii_formatd() value must be initialized

Review of the previous commit: the variadic argument lacked the
<not-uninit/> that gnu.cfg gives its variadic arguments, so an
uninitialized struct member passed as the value was only reported as
uninitvar, without uninitStructMember.
---
 cfg/gtk.cfg    | 1 +
 test/cfg/gtk.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/cfg/gtk.cfg b/cfg/gtk.cfg
index e8e86043b4f..e7119755b3e 100644
--- a/cfg/gtk.cfg
+++ b/cfg/gtk.cfg
@@ -3300,6 +3300,7 @@
     </arg>
     <arg nr="variadic" direction="in">
       <not-bool/>
+      <not-uninit/>
     </arg>
   </function>
   <!-- gboolean g_ascii_isalnum(gchar c); -->
diff --git a/test/cfg/gtk.c b/test/cfg/gtk.c
index f3e0f032b5e..015aa6a6a3d 100644
--- a/test/cfg/gtk.c
+++ b/test/cfg/gtk.c
@@ -679,4 +679,11 @@ void g_ascii_formatd_format_test(const gchar *format, int i)
     // cppcheck-suppress invalidFunctionArgBool
     g_ascii_formatd(buf, sizeof(buf), format, i == 1);
     g_print("%s", buf);
+
+    struct {
+        double x;
+    } s;
+    // cppcheck-suppress [uninitvar, uninitStructMember]
+    g_ascii_formatd(buf, sizeof(buf), format, s.x);
+    g_print("%s", buf);
 }