Fix some warnings found by clang.

8 files changed, 163 insertions, 47 deletions

diff --git a/libdimension/compiler-internal.h b/libdimension/compiler-internal.h
index ffe8de3..8b35b4a 100644
--- a/libdimension/compiler-internal.h
+++ b/libdimension/compiler-internal.h
@@ -23,14 +23,26 @@
  * Internally-used compiler abstractions.
  */
 
-#include <stdbool.h>
+#include <stdalign.h>
 
+/**
+ * @def dmnsn_likely
+ * Indicate that a test is likely to succeed.
+ * @param test  The test to perform.
+ * @return The truth value of \p test.
+ */
+/**
+ * @def dmnsn_unlikely
+ * Indicate that a test is unlikely to succeed.
+ * @param test  The test to perform.
+ * @return The truth value of \p test.
+ */
 #ifdef DMNSN_PROFILE
   #define dmnsn_likely(test)                                      \
     dmnsn_expect(!!(test), true, DMNSN_FUNC, __FILE__, __LINE__)
   #define dmnsn_unlikely(test)                                    \
     dmnsn_expect(!!(test), false, DMNSN_FUNC, __FILE__, __LINE__)
-#elif defined(__GNUC__)
+#elif DMNSN_GNUC
   #define dmnsn_likely(test)   __builtin_expect(!!(test), true)
   #define dmnsn_unlikely(test) __builtin_expect(!!(test), false)
 #else
@@ -38,7 +50,24 @@
   #define dmnsn_unlikely(test) (!!(test))
 #endif
 
-#ifdef __GNUC__
+/**
+ * @def DMNSN_HOT
+ * Mark a function as a hot path.
+ */
+/**
+ * @def DMNSN_INTERNAL
+ * Mark a function as internal linkage.
+ */
+/**
+ * @def DMNSN_DESTRUCTOR
+ * Queue a function to run at program termination.
+ */
+/**
+ * @def DMNSN_LATE_DESTRUCTOR
+ * Queue a function to run at program termination, after those labeled
+ * DMNSN_DESTRUCTOR.
+ */
+#if DMNSN_GNUC
   #define DMNSN_HOT             __attribute__((hot))
   #define DMNSN_INTERNAL        __attribute__((visibility("hidden")))
   #define DMNSN_DESTRUCTOR      __attribute__((destructor(102)))
@@ -50,4 +79,14 @@
   #define DMNSN_LATE_DESTRUCTOR
 #endif
 
+/// Synonym for _Atomic that stdatomic.h doesn't define for some reason
 #define atomic _Atomic
+
+/// C11-compliant alloca variant
+#define DMNSN_ALLOCA(var, size) DMNSN_ALLOCA_IMPL(var, size, __LINE__)
+
+#define DMNSN_ALLOCA_IMPL(var, size, ctr) DMNSN_ALLOCA_IMPL2(var, size, ctr)
+
+#define DMNSN_ALLOCA_IMPL2(var, size, ctr)      \
+  alignas(max_align_t) char dmnsn_alloca##ctr[size];    \
+  var = (void *)dmnsn_alloca##ctr
diff --git a/libdimension/dimension.h b/libdimension/dimension.h
index b6c1559..71c68fa 100644
--- a/libdimension/dimension.h
+++ b/libdimension/dimension.h
@@ -39,7 +39,9 @@
 #ifndef DIMENSION_H
 #define DIMENSION_H
 
-#ifdef __cplusplus
+#include <dimension/compiler.h>
+
+#if DMNSN_CXX
 /* We've been included from a C++ file; mark everything here as extern "C" */
 extern "C" {
 #endif
@@ -53,7 +55,6 @@ extern "C" {
 typedef void dmnsn_callback_fn(void *ptr);
 
 /* Include all the libdimension headers */
-#include <dimension/compiler.h>
 #include <dimension/error.h>
 #include <dimension/malloc.h>
 #include <dimension/pool.h>
@@ -87,7 +88,7 @@ typedef void dmnsn_callback_fn(void *ptr);
 #include <dimension/scene.h>
 #include <dimension/ray_trace.h>
 
-#ifdef __cplusplus
+#if DMNSN_CXX
 }
 #endif
 
diff --git a/libdimension/dimension/compiler.h b/libdimension/dimension/compiler.h
index 3d392b5..af3f4c8 100644
--- a/libdimension/dimension/compiler.h
+++ b/libdimension/dimension/compiler.h
@@ -1,5 +1,5 @@
 /*************************************************************************
- * Copyright (C) 2009-2010 Tavian Barnes <tavianator@tavianator.com>     *
+ * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com>     *
  *                                                                       *
  * This file is part of The Dimension Library.                           *
  *                                                                       *
@@ -24,18 +24,70 @@
  */
 
 /**
+ * @internal
+ * @def DMNSN_C_VERSION
+ * The C version according to \p __STDC_VERSION__ if available, otherwise 0.
+ */
+#ifdef __STDC_VERSION__
+  #define DMNSN_C_VERSION __STDC_VERSION__
+#else
+  #define DMNSN_C_VERSION 0L
+#endif
+
+/**
+ * @internal
+ * @def DMNSN_CXX_VERSION
+ * The C++ version according to \p __cplusplus if available, otherwise 0.
+ */
+#ifdef __cplusplus
+  #define DMNSN_CXX_VERSION __cplusplus
+#else
+  #define DMNSN_CXX_VERSION 0L
+#endif
+
+/**
+ * @internal
+ * Whether we're being compiled as C++.
+ */
+#define DMNSN_CXX (DMNSN_CXX_VERSION > 0)
+
+/**
+ * @internal
+ * Whether C++11 features are supported.
+ */
+#define DMNSN_CXX11 (DMNSN_CXX_VERSION >= 201103L)
+
+/**
+ * @internal
+ * Whether C99 features are supported.
+ */
+#define DMNSN_C99 (DMNSN_C_VERSION >= 199901L || DMNSN_CXX11)
+
+/**
+ * @internal
+ * Whether C11 features are supported.
+ */
+#define DMNSN_C11 (DMNSN_C_VERSION >= 201112L)
+
+/**
+ * @internal
+ * Whether GNU C features are supported.
+ */
+#define DMNSN_GNUC defined(__GNUC__)
+
+/**
  * @def DMNSN_INLINE
  * A portable inline specifier. Expands to the correct method of declaring
  * inline functions for the version of C you are using.
  */
 #ifndef DMNSN_INLINE
-  #ifdef __cplusplus
+  #if DMNSN_CXX
     /* C++ inline semantics */
     #define DMNSN_INLINE inline
-  #elif __STDC_VERSION__ >= 199901L
+  #elif DMNSN_C99
     /* C99 inline semantics */
     #define DMNSN_INLINE inline
-  #elif defined(__GNUC__)
+  #elif DMNSN_GNUC
     /* GCC inline semantics */
     #define DMNSN_INLINE __extension__ extern __inline__
   #else
@@ -46,13 +98,27 @@
 #endif
 
 /**
+ * @def DMNSN_NORETURN
+ * A portable noreturn attribute.
+ */
+#if DMNSN_CXX11
+  #define DMNSN_NORETURN [[noreturn]] void
+#elif DMNSN_C11
+  #define DMNSN_NORETURN _Noreturn void
+#elif DMNSN_GNUC
+  #define DMNSN_NORETURN __attribute__((noreturn)) void
+#else
+  #define DMNSN_NORETURN void
+#endif
+
+/**
  * @internal
  * @def DMNSN_FUNC
  * @brief Expands to the name of the current function
  */
-#ifdef __GNUC__
+#if DMNSN_GNUC
   #define DMNSN_FUNC __PRETTY_FUNCTION__
-#elif __STDC_VERSION__ >= 199901L
+#elif DMNSN_C99
   #define DMNSN_FUNC __func__
 #else
   #define DMNSN_FUNC "<unknown function>"
@@ -62,14 +128,8 @@
  * @internal
  * An unreachable statement.
  */
-#ifdef __GNUC__
+#if DMNSN_GNUC
   #define DMNSN_UNREACHABLE() __builtin_unreachable()
 #else
   #define DMNSN_UNREACHABLE() ((void)0)
 #endif
-
-/**
- * @internal
- * Whether C99 features are supported.
- */
-#define DMNSN_C99 (__STDC_VERSION__ >= 199901L || __cplusplus >= 201103L)
diff --git a/libdimension/dimension/error.h b/libdimension/dimension/error.h
index f07261e..0561b8a 100644
--- a/libdimension/dimension/error.h
+++ b/libdimension/dimension/error.h
@@ -32,18 +32,15 @@
  * Report a warning.
  * @param[in] str  A string to print explaining the warning.
  */
-#define dmnsn_warning(str)                                              \
-  dmnsn_report_error(false, DMNSN_FUNC, __FILE__, __LINE__, str)
+#define dmnsn_warning(str)                                      \
+  dmnsn_report_warning(DMNSN_FUNC, __FILE__, __LINE__, str)
 
 /**
  * Report an error.
  * @param[in] str  A string to print explaining the error.
  */
-#define dmnsn_error(str)                                                \
-  do {                                                                  \
-    dmnsn_report_error(true, DMNSN_FUNC, __FILE__, __LINE__, str);      \
-    DMNSN_UNREACHABLE();                                                \
-  } while (0)
+#define dmnsn_error(str)                                        \
+  dmnsn_report_error(DMNSN_FUNC, __FILE__, __LINE__, str)
 
 /**
  * @def dmnsn_assert
@@ -75,15 +72,23 @@
 
 /**
  * @internal
- * Called by dmnsn_warning() and dmnsn_error(); don't call directly.
- * @param[in] die   Whether the error is fatal.
+ * Called by dmnsn_warning(); don't call directly.
  * @param[in] func  The name of the function where the error originated.
  * @param[in] file  The file where the error originated.
  * @param[in] line  The line number where the error originated.
  * @param[in] str   A string describing the error.
  */
-void dmnsn_report_error(bool die, const char *func, const char *file,
-                        unsigned int line, const char *str);
+void dmnsn_report_warning(const char *func, const char *file, unsigned int line, const char *str);
+
+/**
+ * @internal
+ * Called by dmnsn_error(); don't call directly.
+ * @param[in] func  The name of the function where the error originated.
+ * @param[in] file  The file where the error originated.
+ * @param[in] line  The line number where the error originated.
+ * @param[in] str   A string describing the error.
+ */
+DMNSN_NORETURN dmnsn_report_error(const char *func, const char *file, unsigned int line, const char *str);
 
 /**
  * Treat warnings as errors.
diff --git a/libdimension/error.c b/libdimension/error.c
index 1366c4c..e9e7cf1 100644
--- a/libdimension/error.c
+++ b/libdimension/error.c
@@ -49,10 +49,8 @@ static atomic(dmnsn_fatal_error_fn *) dmnsn_fatal = ATOMIC_VAR_INIT(dmnsn_defaul
 /// The current resilience.
 static atomic_bool dmnsn_always_die = ATOMIC_VAR_INIT(false);
 
-// Called by dmnsn_error macro (don't call directly)
 void
-dmnsn_report_error(bool die, const char *func, const char *file,
-                   unsigned int line, const char *str)
+dmnsn_report_impl(bool die, const char *func, const char *file, unsigned int line, const char *str)
 {
   // Save the value of errno
   int err = errno;
@@ -89,7 +87,7 @@ dmnsn_report_error(bool die, const char *func, const char *file,
     if (thread_exiting) {
       if (die) {
         // Prevent infinite recursion if the fatal error function itself calls
-        // dmnsn_error() (not dmnsn_warning()) */
+        // dmnsn_error() (not dmnsn_warning())
         DMNSN_LOCAL_ERROR("Error raised while in error handler, aborting.");
       }
     } else {
@@ -103,6 +101,19 @@ dmnsn_report_error(bool die, const char *func, const char *file,
 }
 
 void
+dmnsn_report_warning(const char *func, const char *file, unsigned int line, const char *str)
+{
+  dmnsn_report_impl(false, func, file, line, str);
+}
+
+DMNSN_NORETURN
+dmnsn_report_error(const char *func, const char *file, unsigned int line, const char *str)
+{
+  dmnsn_report_impl(true, func, file, line, str);
+  DMNSN_UNREACHABLE();
+}
+
+void
 dmnsn_die_on_warnings(bool always_die)
 {
   atomic_store(&dmnsn_always_die, always_die);
diff --git a/libdimension/map.c b/libdimension/map.c
index 1ae2a10..f5454b1 100644
--- a/libdimension/map.c
+++ b/libdimension/map.c
@@ -23,7 +23,7 @@
  * Generic maps.
  */
 
-#include "dimension.h"
+#include "dimension-internal.h"
 
 /// dmnsn_map definition.
 struct dmnsn_map {
@@ -49,8 +49,9 @@ dmnsn_new_map(dmnsn_pool *pool, size_t size)
 void
 dmnsn_map_add_entry(dmnsn_map *map, double n, const void *obj)
 {
-  char mem[sizeof(dmnsn_map_entry) + map->obj_size];
-  dmnsn_map_entry *entry = (dmnsn_map_entry *)mem;
+  dmnsn_map_entry *entry;
+  DMNSN_ALLOCA(entry, sizeof(dmnsn_map_entry) + map->obj_size);
+
   entry->n = n;
   memcpy(entry->object, obj, map->obj_size);
 
@@ -91,11 +92,10 @@ dmnsn_map_evaluate(const dmnsn_map *map, double n,
     return;
   }
 
-  const dmnsn_map_entry *last = dmnsn_array_last(map->array);
   ptrdiff_t skip = sizeof(dmnsn_map_entry) + map->obj_size;
-  for (; entry <= last;
-       entry = (const dmnsn_map_entry *)((const char *)entry + skip))
-  {
+  for (const dmnsn_map_entry *last = dmnsn_array_last(map->array);
+       entry <= last;
+       entry = (const dmnsn_map_entry *)((const char *)entry + skip)) {
     n1 = n2;
     o1 = o2;
 
diff --git a/libdimension/platform.c b/libdimension/platform.c
index e0de578..b5d23cc 100644
--- a/libdimension/platform.c
+++ b/libdimension/platform.c
@@ -53,10 +53,10 @@ void
 dmnsn_backtrace(FILE *file)
 {
 #if DMNSN_BACKTRACE
-  const size_t size = 128;
-  void *buffer[size];
+#define DMNSN_BACKTRACE_SIZE 128
+  void *buffer[DMNSN_BACKTRACE_SIZE];
 
-  int nptrs = backtrace(buffer, size);
+  int nptrs = backtrace(buffer, DMNSN_BACKTRACE_SIZE);
   int fd = fileno(file);
   if (fd != -1) {
     backtrace_symbols_fd(buffer, nptrs, fd);
diff --git a/libdimension/tests/tests.h b/libdimension/tests/tests.h
index afa7c11..2ce2f01 100644
--- a/libdimension/tests/tests.h
+++ b/libdimension/tests/tests.h
@@ -1,5 +1,5 @@
 /*************************************************************************
- * Copyright (C) 2009-2012 Tavian Barnes <tavianator@tavianator.com>     *
+ * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com>     *
  *                                                                       *
  * This file is part of The Dimension Test Suite.                        *
  *                                                                       *
@@ -23,7 +23,7 @@
 #include "dimension.h"
 #include <check.h>
 
-#ifdef __cplusplus
+#if DMNSN_CXX
 // We've been included from a C++ file; mark everything here as extern "C"
 extern "C" {
 #endif
@@ -122,7 +122,7 @@ void dmnsn_delete_display(dmnsn_display *display);
 // Flush the GL buffers
 void dmnsn_display_flush(dmnsn_display *display);
 
-#ifdef __cplusplus
+#if DMNSN_CXX
 }
 #endif