Re: "error: ‘t.data.character.ptr’ may be used uninitialized " when building hubbub with gcc 11

From 69d81a8a4d4c223aad67cde0fdf64d64351b9802 Mon Sep 17 00:00:00 2001
From: Andy Tai <atai@atai.org>
Date: Sat, 27 May 2023 00:01:34 -0700
Subject: [PATCH] prevent -Werror=maybe-uninitialized build failure with gcc 11
when building tests tokeniser2 and tokeniser3

---
test/tokeniser2.c | 2 +-
test/tokeniser3.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/tokeniser2.c b/test/tokeniser2.c
index c8ab9c0..4caae38 100644
--- a/test/tokeniser2.c
+++ b/test/tokeniser2.c
@@ -438,7 +438,7 @@ hubbub_error token_handler(const hubbub_token *token, void *pw)
/* Expected token only contained part of the data
* Calculate how much is left, then try again with
* the next expected token */
- hubbub_token t;
+ hubbub_token t = { 0 };

t.type = HUBBUB_TOKEN_CHARACTER;
t.data.character.ptr += len;
diff --git a/test/tokeniser3.c b/test/tokeniser3.c
index e33d018..b3be901 100644
--- a/test/tokeniser3.c
+++ b/test/tokeniser3.c
@@ -447,7 +447,7 @@ hubbub_error token_handler(const hubbub_token *token, void *pw)
/* Expected token only contained part of the data
* Calculate how much is left, then try again with
* the next expected token */
- hubbub_token t;
+ hubbub_token t = { 0 };

t.type = HUBBUB_TOKEN_CHARACTER;
t.data.character.ptr += len;
--
2.40.1

patch to get rid of the warning:


On Thu, May 25, 2023 at 12:16 PM Andy Tai <atai@atai.org> wrote:
>
> Hi, I found from GNU Guix's build check that when building with gcc 11,
>
> building hubbub would fail when building tests with errors like
>
> COMPILE: test/tokeniser2.c
> COMPILE: test/tokeniser3.c
> COMPILE: test/tree.c
> COMPILE: test/tree2.c
> COMPILE: test/tree-buf.c
> test/tokeniser2.c: In function 'token_handler':
> test/tokeniser2.c:444:46: error: 't.data.character.ptr' may be used
> uninitialized [-Werror=maybe-uninitialized]
> 444 | t.data.character.ptr += len;
> | ^~
> test/tokeniser2.c:441:38: note: 't' declared here
> 441 | hubbub_token t;
> | ^
> test/tokeniser2.c:445:46: error: 't.data.character.len' may be used
> uninitialized [-Werror=maybe-uninitialized]
> 445 | t.data.character.len -= len;
> | ^~
>
> ...
>
> I briefly took a look of the test source code in question and the
> hubbub_token structs seem not explicitly initialized. Is this a real
> warning from gcc of possibly uninitialized variable which can cause
> the build to fail if allow warnings are treated as errors by gcc
> during build (a common practice)? Thanks if maintainer can take a
> look.
>
> relevant bug entry and complete bug logs:
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=63526



--
Andy Tai, atai@atai.org, Skype: licheng.tai, Line: andy_tai, WeChat: andytai1010
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