From b00f7b41ffdee03f9982287d61c2fa21ebee5e6b Mon Sep 17 00:00:00 2001 From: Arnout Vandecappelle Date: Sat, 17 May 2025 22:09:32 +0200 Subject: [PATCH] configure.pri: remove some of the thumb detection logic The hasThumbFlag test has a roundabout way of discovering whether thumb is available. It looks at the -mthumb and -marm flag (which does make some sense), but then it tries to look at -march to determine which ARM architecture version is used. That test doesn't work if GCC is configured for a default target architecture and no -march is passed on the command line. In Buildroot, we don't pass any -mthumb, -marm or -march in CFLAGS because all of that is included in the toolchain wrapper. Therefore, the logic has nothing to determine the target ARM ISA version and returns false. As a result, nothing is passed down to gn, and gn adds -marm to the build. There is in fact a warning about this: WARNING: Thumb instruction set is required to build ffmpeg for QtWebEngine. but since it's just a warning, it gets ignored. Indeed, the build does fail (when ffmpeg is built, i.e. when BR2_PACKAGE_QT5WEBENGINE_PROPRIETARY_CODECS is enabled) with: FAILED: obj/third_party/ffmpeg/ffmpeg_internal/vp8.o [...] {standard input}: Assembler messages: {standard input}:1119: Error: bad instruction `ldrhcs r0,[ip],#2' {standard input}:1156: Error: bad instruction `ldrhcs r9,[ip],#2' In practice, the architecture version doesn't really matter, because all the architectures supported by JSCore have thumb. Therefore, remove the logic for detecting if the CPU architecture supports thumb. Do keep the -marm and -mthumb logic, even though in Buildroot it doesn't do anything, and the warning gets ignored. Signed-off-by: Arnout Vandecappelle Upstream: It's not clear if the same logic about JSCore applies in upstream, so not sent. --- configure.pri | 8 -------- 1 file changed, 8 deletions(-) diff --git a/configure.pri b/configure.pri index 8da334c83..3ff298e9f 100644 --- a/configure.pri +++ b/configure.pri @@ -370,14 +370,6 @@ defineTest(qtConfTest_hasThumbFlag) { !isEmpty(FLAG): return(true) FLAG = $$qtwebengine_extractCFlag("-marm") !isEmpty(FLAG): return(false) - - MARCH = $$qtwebengine_extractCFlag("-march=.*") - MARMV = $$replace(MARCH, "armv",) - !isEmpty(MARMV) { - MARMV = $$split(MARMV,) - MARMV = $$member(MARMV, 0) - } - if (isEmpty(MARMV) | lessThan(MARMV, 7)): return(false) # no flag assume mthumb return(true) } -- 2.49.0