Merge pull request #490 from centricular/has_function_link

Use the linker to check if a specific function is provided by the toolchain or runtime

2 files changed, 42 insertions, 0 deletions

diff --git a/test cases/common/111 has header symbol/meson.build b/test cases/common/111 has header symbol/meson.build
new file mode 100644
index 0000000..e0afb42
--- /dev/null
+++ b/test cases/common/111 has header symbol/meson.build
@@ -0,0 +1,18 @@
+project('has header symbol', 'c')
+
+cc = meson.get_compiler('c')
+
+assert (cc.has_header_symbol('stdio.h', 'int'), 'base types should always be available')
+assert (cc.has_header_symbol('stdio.h', 'printf'), 'printf function not found')
+assert (cc.has_header_symbol('stdio.h', 'FILE'), 'FILE structure not found')
+assert (cc.has_header_symbol('limits.h', 'INT_MAX'), 'INT_MAX define not found')
+assert (not cc.has_header_symbol('limits.h', 'guint64'), 'guint64 is not defined in limits.h')
+assert (not cc.has_header_symbol('stdlib.h', 'FILE'), 'FILE structure is defined in stdio.h, not stdlib.h')
+assert (not cc.has_header_symbol('stdlol.h', 'printf'), 'stdlol.h shouldn\'t exist')
+assert (not cc.has_header_symbol('stdlol.h', 'int'), 'shouldn\'t be able to find "int" with invalid header')
+
+# This is likely only available on Glibc, so just test for it
+if cc.has_function('ppoll')
+  assert (not cc.has_header_symbol('poll.h', 'ppoll'), 'ppoll should not be accessible without _GNU_SOURCE')
+  assert (cc.has_header_symbol('poll.h', 'ppoll', prefix : '#define _GNU_SOURCE'), 'ppoll should be accessible with _GNU_SOURCE')
+endif
diff --git a/test cases/common/43 has function/meson.build b/test cases/common/43 has function/meson.build
index 8fccaef..3736a3d 100644
--- a/test cases/common/43 has function/meson.build
+++ b/test cases/common/43 has function/meson.build
@@ -6,6 +6,30 @@ if not cc.has_function('printf', prefix : '#include<stdio.h>')
   error('Existing function not found.')
 endif
 
+# Should also be able to detect it without specifying the header
+# We check for a different function here to make sure the result is
+# not taken from a cache (ie. the check above)
+assert(cc.has_function('fprintf'), 'Existing function not found without include')
+
 if cc.has_function('hfkerhisadf', prefix : '#include<stdio.h>')
   error('Found non-existant function.')
 endif
+
+# With glibc on Linux lchmod is a stub that will always return an error,
+# we want to detect that and declare that the function is not available.
+# We can't check for the C library used here of course, but if it's not
+# implemented in glibc it's probably not implemented in any other 'slimmer'
+# C library variants either, so the check should be safe either way hopefully.
+if host_machine.system() == 'linux' and cc.get_id() == 'gcc'
+  assert (cc.has_function('poll', prefix : '#include <poll.h>'), 'couldn\'t detect poll when defined by a header')
+  assert (not cc.has_function('lchmod', prefix : '''#include <sys/stat.h>
+                                                    #include <unistd.h>'''), 'lchmod check should have failed')
+endif
+
+# For some functions one needs to define _GNU_SOURCE before including the
+# right headers to get them picked up. Make sure we can detect these functions
+# as well without any prefix
+if cc.has_header_symbol('sys/socket.h', 'recvmmsg', prefix : '#define _GNU_SOURCE')
+  # We assume that if recvmmsg exists sendmmsg does too
+  assert (cc.has_function('sendmmsg'), 'Failed to detect existing function')
+endif