Fixes #54: Fixed the mess I created in the not-really-a-fix for issue #14. Added a test for whether aliasing works, in which the standard library function names are used, without including the <stdio.h> or any other standard library headers.

Author: eyalroz

CMakeLists.txt

@@ -29,7 +29,6 @@ foreach(opt
 		set("PRINTF_${opt}" 1)
 	else()
 		set("PRINTF_${opt}" 0)
-		message(STATUS "PRINTF_${opt} 0")
 	endif()
 endforeach()
 

printf.c

@@ -39,15 +39,26 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include "printf.h"
-
-
 // Define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H ...) to include the
 // printf_config.h header file
-// default: undefined
 #ifdef PRINTF_INCLUDE_CONFIG_H
+#if PRINTF_INCLUDE_CONFIG_H
 #include "printf_config.h"
 #endif
+#endif
+
+#include "printf.h"
+
+#ifdef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+# define printf_    printf
+# define sprintf_   sprintf
+# define vsprintf_  vsprintf
+# define snprintf_  snprintf
+# define vsnprintf_ vsnprintf
+# define vprintf_   vprintf
+#endif
+#endif
 
 
 // 'ntoa' conversion buffer size, this must be big enough to hold one converted
@@ -1148,3 +1159,4 @@ int vfctprintf(void (*out)(char character, void* arg), void* arg, const char* fo
   const out_fct_wrap_type out_fct_wrap = { out, arg };
   return _vsnprintf(_out_fct, (char*)(uintptr_t)&out_fct_wrap, (size_t)-1, format, va);
 }
+

printf.h

@@ -57,14 +57,15 @@ __attribute__((format(__printf__, (one_based_format_index), (first_arg))))
 #endif
 
 #ifdef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
-# define printf_    printf_
-# define sprintf_   sprintf_
-# define vsprintf_  vsprintf_
-# define snprintf_  snprintf_
-# define vsnprintf_ vsnprintf_
-# define vprintf_   vprintf_
+#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+# define printf_    printf
+# define sprintf_   sprintf
+# define vsprintf_  vsprintf
+# define snprintf_  snprintf
+# define vsnprintf_ vsnprintf
+# define vprintf_   vprintf
+#endif
 #endif
-
 
 /**
  * Output a character to a custom device like UART, used by the printf() function
@@ -137,12 +138,14 @@ int vfctprintf(void (*out)(char character, void* arg), void* arg, const char* fo
 #endif
 
 #ifdef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
 # undef printf_
 # undef sprintf_
 # undef vsprintf_
 # undef snprintf_
 # undef vsnprintf_
 # undef vprintf_
 #endif
+#endif
 
 #endif  // PRINTF_H_

test/CMakeLists.txt

@@ -20,8 +20,19 @@ foreach(tgt ${test_targets})
 	if (TEST_WITH_NON_STANDARD_FORMAT_STRINGS)
 		target_compile_definitions(${tgt} PRIVATE TEST_WITH_NON_STANDARD_FORMAT_STRINGS)
 	endif()
+endforeach()
 
+add_executable(aliasing "aliasing.c")
+set_target_properties(
+	${tgt}
+	PROPERTIES
+	C_STANDARD 11
+	C_STANDARD_REQUIRED YES
+	C_EXTENSIONS NO
+)
+list(APPEND test_targets aliasing)
 
+foreach(tgt ${test_targets})
 	if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
 		target_compile_options(test_suite PRIVATE /W4)
 	elseif (CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR
@@ -70,5 +81,15 @@ add_test(
 target_link_libraries(autotest PRIVATE printf)
 target_include_directories(autotest PRIVATE "$<BUILD_INTERFACE:${GENERATED_INCLUDE_DIR}>")
 
+add_test(
+	NAME "${PROJECT_NAME}.aliasing"
+	COMMAND "aliasing"
+)
+target_link_libraries(aliasing PRIVATE printf)
+target_include_directories(aliasing PRIVATE "$<BUILD_INTERFACE:${GENERATED_INCLUDE_DIR}>")
+
+
+
+
 # Not running autotest by default - it's randomized after all.
 

test/aliasing.c

@@ -0,0 +1,55 @@
+#include <printf_config.h>
+
+// Note: If we include <printf.h>, that will likely get us the
+// the file /usr/include/printf.h on Linux systems
+#include "../printf.h"
+
+int strcmp_(const char* lhs, const char* rhs)
+{
+	while (1) {
+		char lhs_c = *lhs++;
+		char rhs_c = *rhs++;
+		if (lhs_c != rhs_c) { return lhs_c - rhs_c; }
+		if (lhs_c == '\0') { return 0; }
+	}
+}
+
+enum { BufferSize = 100 };
+char buffer[BufferSize];
+
+void _putchar(char c)
+{
+	for(char* ptr = buffer; ptr - buffer < BufferSize; ptr++) {
+		if (*ptr == '\0') {
+			*ptr++ = c;
+			*ptr++ = '\0';
+			return;
+		}
+	}
+}
+
+void clear_buffer()
+{
+	for(int i = 0; i < BufferSize; i++) {
+		buffer[i] = '\0';
+	}
+}
+
+int main()
+{
+#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+	clear_buffer();
+	printf("printf'ing an integer: %d and a string: %s\n", 12, "Hello world");
+	const char* expected = "sprintf'ing an integer: 12 and a string: Hello world\n";
+	if (strcmp_(buffer, expected) != 0) {
+		return(-1);
+	}
+	clear_buffer();
+	sprintf(buffer, "sprintf'ing an integer: %d and a string: %s\n", 34, "quick brown fox");
+	expected = "sprintf'ing an integer: 34 and a string: quick brown fox\n";
+	if (strcmp_(buffer, expected) != 0) {
+		return(-1);
+	}
+#endif
+	return 0;
+}

test/autotest.cpp

@@ -11,9 +11,22 @@
 #endif
 #include <assert.h>
 
-#undef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
-#include "../printf.h"
 #include "printf_config.h"
+#include "../printf.h"
+
+#ifndef PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+#define PRINTF_ALIAS_STANDARD_FUNCTION_NAMES 0
+#endif
+
+#if PRINTF_ALIAS_STANDARD_FUNCTION_NAMES
+# define printf_    printf
+# define sprintf_   sprintf
+# define vsprintf_  vsprintf
+# define snprintf_  snprintf
+# define vsnprintf_ vsnprintf
+# define vprintf_   vprintf
+#endif
+
 
 //*******************************************************
 // Defines