check for /proc/<pid>/exe and /proc/<pid>/cmdline during build

NetBSD also support them in current version

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>

CMakeLists.txt

@@ -424,6 +424,9 @@ katie_check_function64(mmap64 "sys/mman.h")
 katie_check_function64(readdir64 "dirent.h")
 katie_check_function64(readdir64_r "dirent.h")
 
+katie_check_proc(exe)
+katie_check_proc(cmdline)
+
 configure_file(
     ${CMAKE_SOURCE_DIR}/src/core/global/qconfig.h.cmake
     ${CMAKE_BINARY_DIR}/include/QtCore/qconfig.h

cmake/modules/KatieBuildMacros.cmake

@@ -7,8 +7,9 @@ set(KATIE_MOC "bootstrap_moc")
 
 include(CMakePushCheckState)
 include(CheckStructHasMember)
+include(CheckCXXSourceRuns)
 
-# a function to check for C function/definition, works for external functions.
+# a function to check for C function/definition, works for external functions
 function(KATIE_CHECK_DEFINED FORDEFINITION FROMHEADER)
     # see comment in top-level CMake file
     set(CMAKE_REQUIRED_INCLUDES /usr/X11R7/include /usr/pkg/include /usr/local/include /usr/include)
@@ -36,7 +37,7 @@ int main() {
 endfunction()
 
 # a macro to check for C function presence in header, if function is found a
-# definition is added.
+# definition is added
 macro(KATIE_CHECK_FUNCTION FORFUNCTION FROMHEADER)
     katie_check_defined("${FORFUNCTION}" "${FROMHEADER}")
 
@@ -62,8 +63,8 @@ function(KATIE_CHECK_FUNCTION64 FORFUNCTION FROMHEADER)
     endif()
 endfunction()
 
-# a macro to check for C struct member presence in header, if member is found a
+# a function to check for C struct member presence in header, if member is found a
-# definition is added.
+# definition is added
 function(KATIE_CHECK_STRUCT FORSTRUCT FORMEMBER FROMHEADER)
     check_struct_has_member("struct ${FORSTRUCT}" "${FORMEMBER}" "${FROMHEADER}" HAVE_${FORSTRUCT}_${FORMEMBER})
 
@@ -73,6 +74,34 @@ function(KATIE_CHECK_STRUCT FORSTRUCT FORMEMBER FROMHEADER)
     endif()
 endfunction()
 
+# a function to check for file existence in /proc, if file exists a definition
+# is added
+function(KATIE_CHECK_PROC FORFILE)
+    check_cxx_source_runs(
+        "
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+int main() {
+    char snprintfbuf[1024];
+    snprintf(snprintfbuf, sizeof(snprintfbuf), \"/proc/%d/${FORFILE}\", getpid());
+
+    struct stat statbuf;
+    if (lstat(snprintfbuf, &statbuf) == -1) {
+        return 1;
+    }
+    return 0;
+}
+"
+        HAVE_proc_${FORFILE}
+    )
+    if(HAVE_proc_${FORFILE})
+        string(TOUPPER "${FORFILE}" upperfile)
+        add_definitions(-DQT_HAVE_PROC_${upperfile})
+    endif()
+endfunction()
+
 # a macro to write data to file, does nothing if the file exists and its
 # content is the same as the data to be written
 macro(KATIE_WRITE_FILE OUTFILE DATA)

src/core/kernel/qcoreapplication.cpp

@@ -1489,7 +1489,7 @@ QString QCoreApplication::applicationFilePath()
     if (!d->cachedApplicationFilePath.isNull())
         return d->cachedApplicationFilePath;
 
-#ifdef Q_OS_LINUX
+#if defined(QT_HAVE_PROC_EXE)
     // Try looking for a /proc/<pid>/exe symlink first which points to
     // the absolute path of the executable
     QFileInfo pfi(QString::fromLatin1("/proc/%1/exe").arg(::getpid()));

src/gui/kernel/qapplication_x11.cpp

@@ -957,12 +957,12 @@ static void getXDefault(const char *group, const char *key, bool *val)
 }
 #endif
 
-#if !defined(QT_NO_DEBUG) && defined(Q_OS_LINUX)
+#if !defined(QT_NO_DEBUG) && defined(QT_HAVE_PROC_CMDLINE) && defined(QT_HAVE_PROC_EXE)
 // Find out if our parent process is gdb by looking at the 'exe' symlink under /proc,.
 // or, for older Linuxes, read out 'cmdline'.
 bool runningUnderDebugger()
 {
-    const QString parentProc = QLatin1String("/proc/") + QString::number(getppid());
+    const QString parentProc = QString::fromLatin1("/proc/%1").arg(::getppid());
     const QFileInfo parentProcExe(parentProc + QLatin1String("/exe"));
     if (parentProcExe.isSymLink())
         return parentProcExe.readLink().endsWith(QLatin1String("/gdb"));
@@ -1157,7 +1157,7 @@ void qt_init(QApplicationPrivate *priv, int,
 
     priv->argc = j;
 
-#if !defined(QT_NO_DEBUG) && defined(Q_OS_LINUX)
+#if !defined(QT_NO_DEBUG) && defined(QT_HAVE_PROC_CMDLINE) && defined(QT_HAVE_PROC_EXE)
     if (!appNoGrab && !appDoGrab && runningUnderDebugger()) {
         appNoGrab = true;
         qDebug("Qt: gdb: -nograb added to command-line options.\n"