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Merged
JohnAmadis merged 3 commits into from
Feb 11, 2026
Merged

Add missing standard printf format specifiers (l, h, hh, z, o) #208

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2fd513b
Initial plan
Copilot Feb 11, 2026
5a04df4
Add support for standard printf format specifiers (l, h, hh, z, o)
Copilot Feb 11, 2026
4148e32
Remove unused IsLongLong variable to fix compiler warning
Copilot Feb 11, 2026
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7 changes: 6 additions & 1 deletion inc/private/dmod_prf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -62,13 +62,18 @@ extern "C" {
* - %u: unsigned integer
* - %x: hexadecimal (lowercase)
* - %X: hexadecimal (uppercase)
* - %o: octal
* - %p: pointer
* - %%: literal %
*
* Supported format modifiers:
* - Width: Minimum field width (e.g., %30s for 30 characters)
* - Left-align: '-' flag for left-justification (e.g., %-30s)
* - Length modifier 'll': long long (64-bit) for d, i, u, x, X (e.g., %lld, %llu, %llx, %llX)
* - Length modifier 'hh': char (8-bit) for d, i, u, x, X, o (e.g., %hhd, %hhu)
* - Length modifier 'h': short (16-bit) for d, i, u, x, X, o (e.g., %hd, %hu)
* - Length modifier 'l': long for d, i, u, x, X, o (e.g., %ld, %lu, %lx)
* - Length modifier 'll': long long (64-bit) for d, i, u, x, X, o (e.g., %lld, %llu, %llx, %llX)
* - Length modifier 'z': size_t for d, i, u, x, X, o (e.g., %zu, %zd, %zx)
*/
extern int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list Args );

Expand Down
3 changes: 2 additions & 1 deletion src/system/Makefile
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Expand Up @@ -39,7 +39,8 @@ DMOD_SOURCES=private/dmod_vars.c\
if/dmod_if_str.c\
if/dmod_if_input.c\
if/dmod_if_proc.c\
Dmod.cpp
Dmod.cpp\
if/dmod_prf.c
DMOD_INC_DIRS = $(DMOD_DIR)/src/system\
$(DMOD_DIR)/inc\
$(DMOD_BUILD_DIR)\
Expand Down
225 changes: 216 additions & 9 deletions src/system/if/dmod_prf.c
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Expand Up @@ -36,6 +36,7 @@
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <limits.h>

//==============================================================================
// HELPER FUNCTIONS
Expand Down Expand Up @@ -308,6 +309,44 @@ static void Dmod_Print_Hex64( char** Buffer, size_t* Pos, size_t Size, uint64_t
}
}

static void Dmod_Print_Octal( char** Buffer, size_t* Pos, size_t Size, uint32_t Value, int* Count )
{
char Temp[12]; // Enough for 11 octal digits (32-bit)
int i = 0;

// Convert to octal string (reversed)
do
{
Temp[i++] = '0' + (Value & 0x7);
Value >>= 3;
} while( Value > 0 );

// Print in correct order
while( i > 0 )
{
Dmod_Print_Char( Buffer, Pos, Size, Temp[--i], Count );
}
}

static void Dmod_Print_Octal64( char** Buffer, size_t* Pos, size_t Size, uint64_t Value, int* Count )
{
char Temp[23]; // Enough for 22 octal digits (64-bit)
int i = 0;

// Convert to octal string (reversed)
do
{
Temp[i++] = '0' + (Value & 0x7);
Value >>= 3;
} while( Value > 0 );

// Print in correct order
while( i > 0 )
{
Dmod_Print_Char( Buffer, Pos, Size, Temp[--i], Count );
}
}

//==============================================================================
// PUBLIC FUNCTIONS
//==============================================================================
Expand Down Expand Up @@ -356,11 +395,47 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
}

// Parse length modifier
bool IsLongLong = false;
if( *Format == 'l' && *(Format + 1) == 'l' )
typedef enum {
LEN_NONE, // default (int/unsigned int)
LEN_HH, // char
LEN_H, // short
LEN_L, // long
LEN_LL, // long long
LEN_Z // size_t
} LengthModifier;

LengthModifier LenMod = LEN_NONE;

if( *Format == 'h' )
{
IsLongLong = true;
Format += 2;
if( *(Format + 1) == 'h' )
{
LenMod = LEN_HH;
Format += 2;
}
else
{
LenMod = LEN_H;
Format++;
}
}
else if( *Format == 'l' )
{
if( *(Format + 1) == 'l' )
{
LenMod = LEN_LL;
Format += 2;
}
else
{
LenMod = LEN_L;
Format++;
}
}
else if( *Format == 'z' )
{
LenMod = LEN_Z;
Format++;
}

// Handle format specifiers
Expand Down Expand Up @@ -389,11 +464,33 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list

case 'd':
case 'i': {
if( IsLongLong )
if( LenMod == LEN_LL )
{
int64_t Value = va_arg( Args, int64_t );
Dmod_Print_LongLong( BufPtr, &Pos, Size, Value, &Count );
}
else if( LenMod == LEN_L || LenMod == LEN_Z )
{
// long and size_t/ssize_t are typically same size
long Value = va_arg( Args, long );
#if LONG_MAX == INT64_MAX
Dmod_Print_LongLong( BufPtr, &Pos, Size, (int64_t)Value, &Count );
#else
Dmod_Print_Int( BufPtr, &Pos, Size, (int32_t)Value, &Count );
#endif
}
else if( LenMod == LEN_HH )
{
// char is promoted to int in varargs
int Value = va_arg( Args, int );
Dmod_Print_Int( BufPtr, &Pos, Size, (int32_t)(signed char)Value, &Count );
}
else if( LenMod == LEN_H )
{
// short is promoted to int in varargs
int Value = va_arg( Args, int );
Dmod_Print_Int( BufPtr, &Pos, Size, (int32_t)(short)Value, &Count );
}
else
{
int32_t Value = va_arg( Args, int32_t );
Expand All @@ -403,11 +500,33 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
}

case 'u': {
if( IsLongLong )
if( LenMod == LEN_LL )
{
uint64_t Value = va_arg( Args, uint64_t );
Dmod_Print_ULongLong( BufPtr, &Pos, Size, Value, &Count );
}
else if( LenMod == LEN_L || LenMod == LEN_Z )
{
// unsigned long and size_t are typically same size
unsigned long Value = va_arg( Args, unsigned long );
#if ULONG_MAX == UINT64_MAX
Dmod_Print_ULongLong( BufPtr, &Pos, Size, (uint64_t)Value, &Count );
#else
Dmod_Print_UInt( BufPtr, &Pos, Size, (uint32_t)Value, &Count );
#endif
}
else if( LenMod == LEN_HH )
{
// unsigned char is promoted to int in varargs
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_UInt( BufPtr, &Pos, Size, (uint32_t)(unsigned char)Value, &Count );
}
else if( LenMod == LEN_H )
{
// unsigned short is promoted to int in varargs
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_UInt( BufPtr, &Pos, Size, (uint32_t)(unsigned short)Value, &Count );
}
else
{
uint32_t Value = va_arg( Args, uint32_t );
Expand All @@ -417,11 +536,30 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
}

case 'x': {
if( IsLongLong )
if( LenMod == LEN_LL )
{
uint64_t Value = va_arg( Args, uint64_t );
Dmod_Print_Hex64( BufPtr, &Pos, Size, Value, false, &Count );
}
else if( LenMod == LEN_L || LenMod == LEN_Z )
{
unsigned long Value = va_arg( Args, unsigned long );
#if ULONG_MAX == UINT64_MAX
Dmod_Print_Hex64( BufPtr, &Pos, Size, (uint64_t)Value, false, &Count );
#else
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)Value, false, &Count );
#endif
}
else if( LenMod == LEN_HH )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)(unsigned char)Value, false, &Count );
}
else if( LenMod == LEN_H )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)(unsigned short)Value, false, &Count );
}
else
{
uint32_t Value = va_arg( Args, uint32_t );
Expand All @@ -431,11 +569,30 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
}

case 'X': {
if( IsLongLong )
if( LenMod == LEN_LL )
{
uint64_t Value = va_arg( Args, uint64_t );
Dmod_Print_Hex64( BufPtr, &Pos, Size, Value, true, &Count );
}
else if( LenMod == LEN_L || LenMod == LEN_Z )
{
unsigned long Value = va_arg( Args, unsigned long );
#if ULONG_MAX == UINT64_MAX
Dmod_Print_Hex64( BufPtr, &Pos, Size, (uint64_t)Value, true, &Count );
#else
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)Value, true, &Count );
#endif
}
else if( LenMod == LEN_HH )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)(unsigned char)Value, true, &Count );
}
else if( LenMod == LEN_H )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Hex( BufPtr, &Pos, Size, (uint32_t)(unsigned short)Value, true, &Count );
}
else
{
uint32_t Value = va_arg( Args, uint32_t );
Expand All @@ -444,6 +601,39 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
break;
}

case 'o': {
if( LenMod == LEN_LL )
{
uint64_t Value = va_arg( Args, uint64_t );
Dmod_Print_Octal64( BufPtr, &Pos, Size, Value, &Count );
}
else if( LenMod == LEN_L || LenMod == LEN_Z )
{
unsigned long Value = va_arg( Args, unsigned long );
#if ULONG_MAX == UINT64_MAX
Dmod_Print_Octal64( BufPtr, &Pos, Size, (uint64_t)Value, &Count );
#else
Dmod_Print_Octal( BufPtr, &Pos, Size, (uint32_t)Value, &Count );
#endif
}
else if( LenMod == LEN_HH )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Octal( BufPtr, &Pos, Size, (uint32_t)(unsigned char)Value, &Count );
}
else if( LenMod == LEN_H )
{
unsigned int Value = va_arg( Args, unsigned int );
Dmod_Print_Octal( BufPtr, &Pos, Size, (uint32_t)(unsigned short)Value, &Count );
}
else
{
uint32_t Value = va_arg( Args, uint32_t );
Dmod_Print_Octal( BufPtr, &Pos, Size, Value, &Count );
}
break;
}

case 'p': {
void* Ptr = va_arg( Args, void* );
Dmod_Print_Pointer( BufPtr, &Pos, Size, Ptr, &Count );
Expand Down Expand Up @@ -471,11 +661,28 @@ int Dmod_VSnPrintf_Impl( char* Buffer, size_t Size, const char* Format, va_list
}
}
// Print length modifier if present
if( IsLongLong )
if( LenMod == LEN_HH )
{
Dmod_Print_Char( BufPtr, &Pos, Size, 'h', &Count );
Dmod_Print_Char( BufPtr, &Pos, Size, 'h', &Count );
}
else if( LenMod == LEN_H )
{
Dmod_Print_Char( BufPtr, &Pos, Size, 'h', &Count );
}
else if( LenMod == LEN_L )
{
Dmod_Print_Char( BufPtr, &Pos, Size, 'l', &Count );
}
else if( LenMod == LEN_LL )
{
Dmod_Print_Char( BufPtr, &Pos, Size, 'l', &Count );
Dmod_Print_Char( BufPtr, &Pos, Size, 'l', &Count );
}
else if( LenMod == LEN_Z )
{
Dmod_Print_Char( BufPtr, &Pos, Size, 'z', &Count );
}
Dmod_Print_Char( BufPtr, &Pos, Size, *Format, &Count );
break;
}
Expand Down
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