compiler: Add compute_int functionality.

Fixes #435

6 files changed, 102 insertions, 0 deletions

diff --git a/mesonbuild/compilers.py b/mesonbuild/compilers.py
index 8c2bb92..d1a564b 100644
--- a/mesonbuild/compilers.py
+++ b/mesonbuild/compilers.py
@@ -1010,6 +1010,34 @@ class CCompiler(Compiler):
                 return i
         raise EnvironmentException('Cross-compile check overflowed')
 
+    def cross_compute_int(self, fragment, prefix, env, extra_args=None, dependencies=None):
+        if extra_args is None:
+            extra_args = []
+        fargs = {'prefix': prefix, 'fragment': fragment}
+        t = '''#include <stdio.h>
+        {prefix}
+        int temparray[{size}-({fragment})];'''
+        return self._bisect_compiles(t, fargs, env, extra_args, dependencies)
+
+    def compute_int(self, fragment, prefix, env, extra_args=None, dependencies=None):
+        if extra_args is None:
+            extra_args = []
+        fargs = {'prefix': prefix, 'fragment': fragment}
+        if self.is_cross:
+            return self.cross_compute_int(fragment, prefix, env, extra_args, dependencies)
+        t = '''#include<stdio.h>
+        {prefix}
+        int main(int argc, char **argv) {{
+            printf("%ld\\n", (long)({fragment}));
+            return 0;
+        }};'''
+        res = self.run(t.format(**fargs), env, extra_args, dependencies)
+        if not res.compiled:
+            return -1
+        if res.returncode != 0:
+            raise EnvironmentException('Could not run compute_int test binary.')
+        return int(res.stdout)
+
     def cross_sizeof(self, element, prefix, env, extra_args=None, dependencies=None):
         if extra_args is None:
             extra_args = []
diff --git a/mesonbuild/interpreter.py b/mesonbuild/interpreter.py
index 07b5c40..dca7934 100644
--- a/mesonbuild/interpreter.py
+++ b/mesonbuild/interpreter.py
@@ -631,6 +631,7 @@ class CompilerHolder(InterpreterObject):
         self.methods.update({'compiles': self.compiles_method,
                              'links': self.links_method,
                              'get_id': self.get_id_method,
+                             'compute_int': self.compute_int_method,
                              'sizeof': self.sizeof_method,
                              'has_header': self.has_header_method,
                              'has_header_symbol': self.has_header_symbol_method,
@@ -822,6 +823,20 @@ class CompilerHolder(InterpreterObject):
         mlog.log('Checking for type "', mlog.bold(typename), '": ', hadtxt, sep='')
         return had
 
+    def compute_int_method(self, args, kwargs):
+        if len(args) != 1:
+            raise InterpreterException('Compute_int takes exactly one argument.')
+        check_stringlist(args)
+        fragment = args[0]
+        prefix = kwargs.get('prefix', '')
+        if not isinstance(prefix, str):
+            raise InterpreterException('Prefix argument of compute_int must be a string.')
+        extra_args = self.determine_args(kwargs)
+        deps = self.determine_dependencies(kwargs)
+        res = self.compiler.compute_int(fragment, prefix, self.environment, extra_args, deps)
+        mlog.log('Computing int of "%s": %d' % (fragment, res))
+        return res
+
     def sizeof_method(self, args, kwargs):
         if len(args) != 1:
             raise InterpreterException('Sizeof takes exactly one argument.')
diff --git a/test cases/common/139 compute int/config.h.in b/test cases/common/139 compute int/config.h.in
new file mode 100644
index 0000000..ad8d077
--- /dev/null
+++ b/test cases/common/139 compute int/config.h.in
@@ -0,0 +1,2 @@
+#define INTSIZE @INTSIZE@
+#define FOOBAR_IN_CONFIG_H @FOOBAR@
diff --git a/test cases/common/139 compute int/foobar.h b/test cases/common/139 compute int/foobar.h
new file mode 100644
index 0000000..fd3cb5e
--- /dev/null
+++ b/test cases/common/139 compute int/foobar.h
@@ -0,0 +1,6 @@
+#ifndef __FOOBAR_H__
+#define __FOOBAR_H__
+
+#define FOOBAR_IN_FOOBAR_H    10
+
+#endif /*__FOOBAR_H__*/
diff --git a/test cases/common/139 compute int/meson.build b/test cases/common/139 compute int/meson.build
new file mode 100644
index 0000000..6f813c5
--- /dev/null
+++ b/test cases/common/139 compute int/meson.build
@@ -0,0 +1,35 @@
+project('compute int', 'c', 'cpp')
+
+inc = include_directories('.')
+
+# Test with C
+cc = meson.get_compiler('c')
+
+intsize = cc.compute_int('sizeof(int)')
+foobar = cc.compute_int('FOOBAR_IN_FOOBAR_H', prefix : '#include "foobar.h"', include_directories : inc)
+
+cd = configuration_data()
+cd.set('INTSIZE', intsize)
+cd.set('FOOBAR', foobar)
+cd.set('CONFIG', 'config.h')
+configure_file(input : 'config.h.in', output : 'config.h', configuration : cd)
+s = configure_file(input : 'prog.c.in', output : 'prog.c', configuration : cd)
+
+e = executable('prog', s)
+test('compute int test', e)
+
+# Test with C++
+cpp = meson.get_compiler('cpp')
+
+intsize = cpp.compute_int('sizeof(int)')
+foobar = cpp.compute_int('FOOBAR_IN_FOOBAR_H', prefix : '#include "foobar.h"', include_directories : inc)
+
+cdpp = configuration_data()
+cdpp.set('INTSIZE', intsize)
+cdpp.set('FOOBAR', foobar)
+cdpp.set('CONFIG', 'config.hpp')
+configure_file(input : 'config.h.in', output : 'config.hpp', configuration : cdpp)
+spp = configure_file(input : 'prog.c.in', output : 'prog.cc', configuration : cdpp)
+
+epp = executable('progpp', spp)
+test('compute int test c++', epp)
diff --git a/test cases/common/139 compute int/prog.c.in b/test cases/common/139 compute int/prog.c.in
new file mode 100644
index 0000000..3ff1463
--- /dev/null
+++ b/test cases/common/139 compute int/prog.c.in
@@ -0,0 +1,16 @@
+#include "@CONFIG@"
+#include <stdio.h>
+#include <wchar.h>
+#include "foobar.h"
+
+int main(int argc, char **argv) {
+    if(INTSIZE != sizeof(int)) {
+        fprintf(stderr, "Mismatch: computed int size %d, actual size %d.\n", INTSIZE, (int)sizeof(int));
+        return 1;
+    }
+    if(FOOBAR_IN_CONFIG_H != FOOBAR_IN_FOOBAR_H) {
+        fprintf(stderr, "Mismatch: computed int %d, should be %d.\n", FOOBAR_IN_CONFIG_H, FOOBAR_IN_FOOBAR_H);
+        return 1;
+    }
+    return 0;
+}