code cleanup: use statics and consts when possible (#1544)

Contribute to #68

src/libespeak-ng/dictionary.c

@@ -424,7 +424,7 @@ void DecodePhonemes(const char *inptr, char *outptr)
 }
 
 // using Kirschenbaum to IPA translation, ascii 0x20 to 0x7f
-unsigned short ipa1[96] = {
+static const unsigned short ipa1[96] = {
 	0x20,  0x21,  0x22,  0x2b0, 0x24,  0x25,  0x0e6, 0x2c8, 0x28,  0x29,  0x27e, 0x2b,  0x2cc, 0x2d,  0x2e,  0x2f,
 	0x252, 0x31,  0x32,  0x25c, 0x34,  0x35,  0x36,  0x37,  0x275, 0x39,  0x2d0, 0x2b2, 0x3c,  0x3d,  0x3e,  0x294,
 	0x259, 0x251, 0x3b2, 0xe7,  0xf0,  0x25b, 0x46,  0x262, 0x127, 0x26a, 0x25f, 0x4b,  0x26b, 0x271, 0x14b, 0x254,

src/libespeak-ng/intonation.c

@@ -62,7 +62,7 @@ static int tone_pitch_env; // used to return pitch envelope
 #define PITCHfrise    4 // and 3 must be for the variant preceded by 'r'
 #define PITCHfrise2   6 // and 5 must be the 'r' variant
 
-unsigned char env_fall[128] = {
+const unsigned char env_fall[128] = {
 	0xff, 0xfd, 0xfa, 0xf8, 0xf6, 0xf4, 0xf2, 0xf0, 0xee, 0xec, 0xea, 0xe8, 0xe6, 0xe4, 0xe2, 0xe0,
 	0xde, 0xdc, 0xda, 0xd8, 0xd6, 0xd4, 0xd2, 0xd0, 0xce, 0xcc, 0xca, 0xc8, 0xc6, 0xc4, 0xc2, 0xc0,
 	0xbe, 0xbc, 0xba, 0xb8, 0xb6, 0xb4, 0xb2, 0xb0, 0xae, 0xac, 0xaa, 0xa8, 0xa6, 0xa4, 0xa2, 0xa0,
@@ -73,7 +73,7 @@ unsigned char env_fall[128] = {
 	0x1e, 0x1c, 0x1a, 0x18, 0x16, 0x14, 0x12, 0x10, 0x0e, 0x0c, 0x0a, 0x08, 0x06, 0x04, 0x02, 0x00
 };
 
-unsigned char env_rise[128] = {
+static const unsigned char env_rise[128] = {
 	0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a, 0x1c, 0x1e,
 	0x20, 0x22, 0x24, 0x26, 0x28, 0x2a, 0x2c, 0x2e, 0x30, 0x32, 0x34, 0x36, 0x38, 0x3a, 0x3c, 0x3e,
 	0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e, 0x50, 0x52, 0x54, 0x56, 0x58, 0x5a, 0x5c, 0x5e,
@@ -84,7 +84,7 @@ unsigned char env_rise[128] = {
 	0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xee, 0xf0, 0xf2, 0xf4, 0xf6, 0xf8, 0xfa, 0xfd, 0xff
 };
 
-unsigned char env_frise[128] = {
+static const unsigned char env_frise[128] = {
 	0xff, 0xf4, 0xea, 0xe0, 0xd6, 0xcc, 0xc3, 0xba, 0xb1, 0xa8, 0x9f, 0x97, 0x8f, 0x87, 0x7f, 0x78,
 	0x71, 0x6a, 0x63, 0x5c, 0x56, 0x50, 0x4a, 0x44, 0x3f, 0x39, 0x34, 0x2f, 0x2b, 0x26, 0x22, 0x1e,
 	0x1a, 0x17, 0x13, 0x10, 0x0d, 0x0b, 0x08, 0x06, 0x04, 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -95,7 +95,7 @@ unsigned char env_frise[128] = {
 	0xa4, 0xa8, 0xac, 0xaf, 0xb3, 0xb7, 0xbb, 0xbf, 0xc3, 0xc7, 0xcb, 0xcf, 0xd3, 0xd7, 0xdb, 0xe0
 };
 
-static unsigned char env_r_frise[128] = {
+static const unsigned char env_r_frise[128] = {
 	0xcf, 0xcc, 0xc9, 0xc6, 0xc3, 0xc0, 0xbd, 0xb9, 0xb4, 0xb0, 0xab, 0xa7, 0xa2, 0x9c, 0x97, 0x92,
 	0x8c, 0x86, 0x81, 0x7b, 0x75, 0x6f, 0x69, 0x63, 0x5d, 0x57, 0x50, 0x4a, 0x44, 0x3e, 0x38, 0x33,
 	0x2d, 0x27, 0x22, 0x1c, 0x17, 0x12, 0x0d, 0x08, 0x04, 0x02, 0x02, 0x01, 0x00, 0x00, 0x00, 0x00,
@@ -106,7 +106,7 @@ static unsigned char env_r_frise[128] = {
 	0xa4, 0xa8, 0xac, 0xaf, 0xb3, 0xb7, 0xbb, 0xbf, 0xc3, 0xc7, 0xcb, 0xcf, 0xd3, 0xd7, 0xdb, 0xe0
 };
 
-static unsigned char env_frise2[128] = {
+static const unsigned char env_frise2[128] = {
 	0xff, 0xf9, 0xf4, 0xee, 0xe9, 0xe4, 0xdf, 0xda, 0xd5, 0xd0, 0xcb, 0xc6, 0xc1, 0xbd, 0xb8, 0xb3,
 	0xaf, 0xaa, 0xa6, 0xa1, 0x9d, 0x99, 0x95, 0x90, 0x8c, 0x88, 0x84, 0x80, 0x7d, 0x79, 0x75, 0x71,
 	0x6e, 0x6a, 0x67, 0x63, 0x60, 0x5d, 0x59, 0x56, 0x53, 0x50, 0x4d, 0x4a, 0x47, 0x44, 0x41, 0x3e,
@@ -117,7 +117,7 @@ static unsigned char env_frise2[128] = {
 	0x09, 0x0a, 0x0b, 0x0c, 0x0e, 0x0f, 0x10, 0x12, 0x13, 0x15, 0x17, 0x18, 0x1a, 0x1c, 0x1e, 0x20
 };
 
-static unsigned char env_r_frise2[128] = {
+static const unsigned char env_r_frise2[128] = {
 	0xd0, 0xce, 0xcd, 0xcc, 0xca, 0xc8, 0xc7, 0xc5, 0xc3, 0xc1, 0xc0, 0xbd, 0xbb, 0xb8, 0xb5, 0xb3,
 	0xb0, 0xad, 0xaa, 0xa7, 0xa3, 0xa0, 0x9d, 0x99, 0x96, 0x92, 0x8f, 0x8b, 0x87, 0x84, 0x80, 0x7c,
 	0x78, 0x74, 0x70, 0x6d, 0x69, 0x65, 0x61, 0x5d, 0x59, 0x55, 0x51, 0x4d, 0x4a, 0x46, 0x42, 0x3e,
@@ -128,7 +128,7 @@ static unsigned char env_r_frise2[128] = {
 	0x09, 0x0a, 0x0b, 0x0c, 0x0e, 0x0f, 0x10, 0x12, 0x13, 0x15, 0x17, 0x18, 0x1a, 0x1c, 0x1e, 0x20
 };
 
-static unsigned char env_risefall[128] = {
+static const unsigned char env_risefall[128] = {
 	0x98, 0x99, 0x99, 0x9a, 0x9c, 0x9d, 0x9f, 0xa1, 0xa4, 0xa7, 0xa9, 0xac, 0xb0, 0xb3, 0xb6, 0xba,
 	0xbe, 0xc1, 0xc5, 0xc9, 0xcd, 0xd1, 0xd4, 0xd8, 0xdc, 0xdf, 0xe3, 0xe6, 0xea, 0xed, 0xf0, 0xf2,
 	0xf5, 0xf7, 0xf9, 0xfb, 0xfc, 0xfd, 0xfe, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfd,
@@ -139,7 +139,7 @@ static unsigned char env_risefall[128] = {
 	0x15, 0x12, 0x0f, 0x0d, 0x0a, 0x08, 0x07, 0x05, 0x03, 0x02, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 
-static unsigned char env_rise2[128] = {
+static const unsigned char env_rise2[128] = {
 	0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01, 0x02, 0x02, 0x03, 0x03, 0x04, 0x04, 0x05, 0x06, 0x06,
 	0x07, 0x08, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14,
 	0x16, 0x17, 0x18, 0x19, 0x1b, 0x1c, 0x1d, 0x1f, 0x20, 0x22, 0x23, 0x25, 0x26, 0x28, 0x29, 0x2b,
@@ -150,7 +150,7 @@ static unsigned char env_rise2[128] = {
 	0xdc, 0xdf, 0xe2, 0xe4, 0xe7, 0xe9, 0xec, 0xee, 0xf0, 0xf2, 0xf4, 0xf6, 0xf8, 0xfa, 0xfb, 0xfd
 };
 
-static unsigned char env_fall2[128] = {
+static const unsigned char env_fall2[128] = {
 	0xfe, 0xfe, 0xfd, 0xfd, 0xfc, 0xfb, 0xfb, 0xfa, 0xfa, 0xf9, 0xf8, 0xf8, 0xf7, 0xf7, 0xf6, 0xf6,
 	0xf5, 0xf4, 0xf4, 0xf3, 0xf3, 0xf2, 0xf2, 0xf1, 0xf0, 0xf0, 0xef, 0xee, 0xee, 0xed, 0xec, 0xeb,
 	0xea, 0xea, 0xe9, 0xe8, 0xe7, 0xe6, 0xe5, 0xe4, 0xe3, 0xe2, 0xe1, 0xe0, 0xde, 0xdd, 0xdc, 0xdb,
@@ -161,7 +161,7 @@ static unsigned char env_fall2[128] = {
 	0x18, 0x14, 0x11, 0x0d, 0x0b, 0x09, 0x07, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00, 0x00, 0x00, 0x00
 };
 
-static unsigned char env_fallrise3[128] = {
+static const unsigned char env_fallrise3[128] = {
 	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfd, 0xfc, 0xfa, 0xf8, 0xf6, 0xf4, 0xf1, 0xee, 0xeb,
 	0xe8, 0xe5, 0xe1, 0xde, 0xda, 0xd6, 0xd2, 0xcd, 0xc9, 0xc4, 0xbf, 0xba, 0xb6, 0xb0, 0xab, 0xa6,
 	0xa1, 0x9c, 0x96, 0x91, 0x8b, 0x86, 0x80, 0x7b, 0x75, 0x6f, 0x6a, 0x64, 0x5f, 0x59, 0x54, 0x4f,
@@ -172,7 +172,7 @@ static unsigned char env_fallrise3[128] = {
 	0x76, 0x78, 0x7b, 0x7c, 0x7e, 0x80, 0x81, 0x82, 0x83, 0x83, 0x84, 0x84, 0x83, 0x83, 0x82, 0x81
 };
 
-static unsigned char env_fallrise4[128] = {
+static const unsigned char env_fallrise4[128] = {
 	0x72, 0x72, 0x71, 0x71, 0x70, 0x6f, 0x6d, 0x6c, 0x6a, 0x68, 0x66, 0x64, 0x61, 0x5f, 0x5c, 0x5a,
 	0x57, 0x54, 0x51, 0x4e, 0x4b, 0x48, 0x45, 0x42, 0x3f, 0x3b, 0x38, 0x35, 0x32, 0x2f, 0x2c, 0x29,
 	0x26, 0x23, 0x20, 0x1d, 0x1b, 0x18, 0x16, 0x14, 0x12, 0x10, 0x0e, 0x0c, 0x0b, 0x0a, 0x09, 0x08,
@@ -183,7 +183,7 @@ static unsigned char env_fallrise4[128] = {
 	0xc0, 0xc7, 0xce, 0xd5, 0xdc, 0xe3, 0xea, 0xf1, 0xf5, 0xf7, 0xfa, 0xfc, 0xfd, 0xfe, 0xff, 0xff
 };
 
-static unsigned char env_risefallrise[128] = {
+static const unsigned char env_risefallrise[128] = {
 	0x7f, 0x7f, 0x7f, 0x80, 0x81, 0x83, 0x84, 0x87, 0x89, 0x8c, 0x8f, 0x92, 0x96, 0x99, 0x9d, 0xa1,
 	0xa5, 0xaa, 0xae, 0xb2, 0xb7, 0xbb, 0xc0, 0xc5, 0xc9, 0xcd, 0xd2, 0xd6, 0xda, 0xde, 0xe2, 0xe6,
 	0xea, 0xed, 0xf0, 0xf3, 0xf5, 0xf8, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xfe, 0xfd, 0xfc, 0xfb, 0xf9,
@@ -194,7 +194,7 @@ static unsigned char env_risefallrise[128] = {
 	0x50, 0x5a, 0x64, 0x70, 0x7c, 0x83, 0x85, 0x88, 0x8a, 0x8c, 0x8e, 0x8f, 0x91, 0x92, 0x93, 0x93
 };
 
-unsigned char *envelope_data[N_ENVELOPE_DATA] = {
+const unsigned char *envelope_data[N_ENVELOPE_DATA] = {
 	env_fall,  env_fall,
 	env_rise,  env_rise,
 	env_frise,  env_r_frise,
@@ -209,15 +209,15 @@ unsigned char *envelope_data[N_ENVELOPE_DATA] = {
 };
 
 // indexed by stress
-static int min_drop[] =  { 6, 7, 9, 9, 20, 20, 20, 25 };
+static const int min_drop[] =  { 6, 7, 9, 9, 20, 20, 20, 25 };
 
 // pitch change during the main part of the clause
-static int drops_0[8] = { 9, 9, 16, 16, 16, 23, 55, 32 };
+static const int drops_0[8] = { 9, 9, 16, 16, 16, 23, 55, 32 };
 
 // overflow table values are 64ths of the body pitch range (between body_start and body_end)
-static signed char oflow[] = { 0, 40, 24, 8, 0 };
-static signed char oflow_emf[] = { 10, 52, 32, 20, 10 };
-static signed char oflow_less[] = { 6, 38, 24, 14, 4 };
+static const signed char oflow[] = { 0, 40, 24, 8, 0 };
+static const signed char oflow_emf[] = { 10, 52, 32, 20, 10 };
+static const signed char oflow_less[] = { 6, 38, 24, 14, 4 };
 
 #define N_TONE_HEAD_TABLE    13
 #define N_TONE_NUCLEUS_TABLE 13
@@ -229,12 +229,12 @@ typedef struct {
 	unsigned char body_start;
 	unsigned char body_end;
 
-	int  *body_drops;
+	const int  *body_drops;
 	unsigned char body_max_steps;
 	char body_lower_u;
 
 	unsigned char n_overflow;
-	signed char *overflow;
+	const signed char *overflow;
 } TONE_HEAD;
 
 typedef struct {
@@ -255,7 +255,7 @@ typedef struct {
 
 #define T_EMPH  1
 
-static TONE_HEAD tone_head_table[N_TONE_HEAD_TABLE] = {
+static const TONE_HEAD tone_head_table[N_TONE_HEAD_TABLE] = {
 	{ 46, 57,   78, 50,  drops_0, 3, 7,   5, oflow },      // 0 statement
 	{ 46, 57,   78, 46,  drops_0, 3, 7,   5, oflow },      // 1 comma
 	{ 46, 57,   78, 46,  drops_0, 3, 7,   5, oflow },      // 2 question
@@ -271,7 +271,7 @@ static TONE_HEAD tone_head_table[N_TONE_HEAD_TABLE] = {
 	{ 46, 57,   55, 50,  drops_0, 3, 7,   5, oflow_less }, // 12 test
 };
 
-static TONE_NUCLEUS tone_nucleus_table[N_TONE_NUCLEUS_TABLE] = {
+static const TONE_NUCLEUS tone_nucleus_table[N_TONE_NUCLEUS_TABLE] = {
 	{ PITCHfall,   64,  8, PITCHfall,   70, 18, NULL, 24, 12, 0 },      //  0 statement
 	{ PITCHfrise,  80, 18, PITCHfrise2, 78, 22, NULL, 34, 52, 0 },      //  1 comma
 	{ PITCHfrise,  88, 22, PITCHfrise2, 82, 22, NULL, 34, 64, 0 },      //  2 question
@@ -418,7 +418,7 @@ static int SetHeadIntonation(SYLLABLE *syllable_tab, TUNE *tune, int syl_ix, int
 	int overflow_ix = 0;
 	int pitch_range;
 	int pitch_range_abs;
-	int *drops;
+	const int *drops;
 	int n_unstressed = 0;
 	int unstressed_ix = 0;
 	int unstressed_inc;
@@ -523,7 +523,7 @@ static int SetHeadIntonation(SYLLABLE *syllable_tab, TUNE *tune, int syl_ix, int
 /* Calculate pitches until next RESET or tonic syllable, or end.
     Increment pitch if stress is >= min_stress.
     Used for tonic segment */
-static int calc_pitch_segment(SYLLABLE *syllable_tab, int ix, int end_ix, TONE_HEAD *th, TONE_NUCLEUS *tn, int min_stress, bool continuing)
+static int calc_pitch_segment(SYLLABLE *syllable_tab, int ix, int end_ix, const TONE_HEAD *th, const TONE_NUCLEUS *tn, int min_stress, bool continuing)
 {
 	int stress;
 	int pitch = 0;
@@ -535,7 +535,7 @@ static int calc_pitch_segment(SYLLABLE *syllable_tab, int ix, int end_ix, TONE_H
 	int n_overflow;
 	int pitch_range;
 	int pitch_range_abs;
-	int *drops;
+	const int *drops;
 	const signed char *overflow_tab;
 	SYLLABLE *syl;
 
@@ -711,8 +711,8 @@ static int calc_pitches2(SYLLABLE *syllable_tab, int start, int end,  int tune_n
 static int calc_pitches(SYLLABLE *syllable_tab, int control, int start, int end,  int tune_number)
 {
 	int ix;
-	TONE_HEAD *th;
-	TONE_NUCLEUS *tn;
+	const TONE_HEAD *th;
+	const TONE_NUCLEUS *tn;
 	int drop;
 	bool continuing = false;
 

src/libespeak-ng/klatt.c

@@ -71,7 +71,7 @@ static klatt_global_t kt_globals;
 static int scale_wav_tab[] = { 45, 38, 45, 45, 55, 45 }; // scale output from different voicing sources
 
 // For testing, this can be overwritten in KlattInit()
-static short natural_samples2[256] = {
+static const short natural_samples2[256] = {
 	 2583,  2516,  2450,  2384,  2319,  2254,  2191,  2127,
 	 2067,  2005,  1946,  1890,  1832,  1779,  1726,  1675,
 	 1626,  1579,  1533,  1491,  1449,  1409,  1372,  1336,
@@ -105,7 +105,7 @@ static short natural_samples2[256] = {
 	-1680, -1732, -1783, -1839, -1894, -1952, -2010, -2072,
 	-2133, -2196, -2260, -2325, -2390, -2456, -2522, -2589,
 };
-static short natural_samples[100] = {
+static const short natural_samples[100] = {
 	 -310,  -400,   530,   356,   224,    89,   23,  -10, -58, -16, 461,  599,  536,   701,   770,
 	  605,   497,   461,   560,   404,   110,  224,  131, 104, -97, 155,  278, -154, -1165,
 	 -598,   737,   125,  -592,    41,    11, -247,  -10,  65,  92,  80, -304,   71,   167,    -1, 122,
@@ -194,7 +194,7 @@ static double sampled_source(int source_num)
 	int current_value;
 	int next_value;
 	double temp_diff;
-	short *samples;
+	const short *samples;
 
 	if (source_num == 0) {
 		samples = natural_samples;

src/libespeak-ng/klatt.h

@@ -89,7 +89,7 @@ typedef struct {
 	double amp_gain0; /* G0 converted to linear gain              */
 	int num_samples; /* number of glottal samples */
 	double sample_factor; /* multiplication factor for glottal samples */
-	short *natural_samples; /* pointer to an array of glottal samples */
+	const short *natural_samples; /* pointer to an array of glottal samples */
 	long original_f0; /* original value of f0 not modified by flutter */
 
 	int fadein;

src/libespeak-ng/numbers.c

@@ -83,7 +83,7 @@ typedef struct {
 } ACCENTS;
 
 // these are tokens to look up in the *_list file.
-static ACCENTS accents_tab[] = {
+static const ACCENTS accents_tab[] = {
 	{ "_lig", 1 },
 	{ "_smc", 0 },  // smallcap
 	{ "_tur", 0 },  // turned

src/libespeak-ng/phonemelist.c

@@ -40,7 +40,7 @@
 #include "translate.h"
 #include "speech.h"
 
-const unsigned char pause_phonemes[8] = {
+static const unsigned char pause_phonemes[8] = {
 	0, phonPAUSE_VSHORT, phonPAUSE_SHORT, phonPAUSE, phonPAUSE_LONG, phonGLOTTALSTOP, phonPAUSE_LONG, phonPAUSE_LONG
 };
 

src/libespeak-ng/setlengths.c

@@ -388,7 +388,7 @@ void CalcLengths(Translator *tr)
 	int pitch1;
 
 	int tone_mod;
-	unsigned char *pitch_env = NULL;
+	const unsigned char *pitch_env = NULL;
 	PHONEME_DATA phdata_tone;
 
 
@@ -743,7 +743,7 @@ void CalcLengths(Translator *tr)
 // indexes are the "length_mod" value for the following phonemes
 
 // use this table if vowel is not the last in the word
-static unsigned char length_mods_en[100] = {
+static const unsigned char length_mods_en[100] = {
 //	a    ,    t    s    n    d    z    r    N    <- next
 	100, 120, 100, 105, 100, 110, 110, 100,  95, 100, // a  <- next2
 	105, 120, 105, 110, 125, 130, 135, 115, 125, 100, // ,
@@ -758,7 +758,7 @@ static unsigned char length_mods_en[100] = {
 };
 
 // as above, but for the last syllable in a word
-static unsigned char length_mods_en0[100] = {
+static const unsigned char length_mods_en0[100] = {
 //	a    ,    t    s    n    d    z    r    N    <- next
 	100, 150, 100, 105, 110, 115, 110, 110, 110, 100, // a  <- next2
 	105, 150, 105, 110, 125, 135, 140, 115, 135, 100, // ,
@@ -773,7 +773,7 @@ static unsigned char length_mods_en0[100] = {
 };
 
 
-static unsigned char length_mods_equal[100] = {
+static const unsigned char length_mods_equal[100] = {
 //	a    ,    t    s    n    d    z    r    N    <- next
 	110, 120, 100, 110, 110, 110, 110, 110, 110, 110, // a  <- next2
 	110, 120, 100, 110, 110, 110, 110, 110, 110, 110, // ,
@@ -787,7 +787,7 @@ static unsigned char length_mods_equal[100] = {
 	110, 120, 100, 110, 110, 110, 110, 110, 110, 110
 };
 
-static unsigned char *length_mod_tabs[6] = {
+static const unsigned char *const length_mod_tabs[6] = {
 	length_mods_en,
 	length_mods_en,    // 1
 	length_mods_en0,   // 2

src/libespeak-ng/sintab.h

@@ -25,7 +25,7 @@ extern "C"
 {
 #endif
 
-const short int sin_tab[2048] = {
+static const short int sin_tab[2048] = {
 	0, -25, -50, -75, -100, -125, -150, -175,
 	-201, -226, -251, -276, -301, -326, -351, -376,
 	-401, -427, -452, -477, -502, -527, -552, -577,

src/libespeak-ng/speech.c

@@ -959,7 +959,7 @@ ESPEAK_NG_API espeak_ng_STATUS espeak_ng_Terminate(void)
 	return ENS_OK;
 }
 
-const char *version_string = PACKAGE_VERSION;
+static const char version_string[] = PACKAGE_VERSION;
 ESPEAK_API const char *espeak_Info(const char **ptr)
 {
 	if (ptr != NULL)

src/libespeak-ng/synth_mbrola.c

@@ -241,7 +241,7 @@ static char *WritePitch(int env, int pitch1, int pitch2, int split, int final)
 	int pitch_base;
 	int pitch_range;
 	int p1, p2, p_end;
-	unsigned char *pitch_env;
+	const unsigned char *pitch_env;
 	int max = -1;
 	int min = 999;
 	int y_max = 0;

src/libespeak-ng/synthdata.c

@@ -319,7 +319,7 @@ frameref_t *LookupSpect(PHONEME_TAB *this_ph, int which, FMT_PARAMS *fmt_params,
 	return frames;
 }
 
-unsigned char *GetEnvelope(int index)
+const unsigned char *GetEnvelope(int index)
 {
 	if (index == 0) {
 		fprintf(stderr, "espeak: No envelope\n");

src/libespeak-ng/synthdata.h

@@ -41,7 +41,7 @@ void InterpretPhoneme2(int phcode,
 		PHONEME_DATA *phdata);
 
 void FreePhData(void);
-unsigned char *GetEnvelope(int index);
+const unsigned char *GetEnvelope(int index);
 espeak_ng_STATUS LoadPhData(int *srate, espeak_ng_ERROR_CONTEXT *context);
 int LookupPhonemeString(const char *string);
 int LookupPhonemeTable(const char *name);

src/libespeak-ng/synthesize.c

@@ -121,7 +121,7 @@ static void EndPitch(int voice_break)
 	}
 }
 
-static void DoAmplitude(int amp, unsigned char *amp_env)
+static void DoAmplitude(int amp, const unsigned char *amp_env)
 {
 	intptr_t *q;
 
@@ -144,7 +144,7 @@ static void DoPhonemeAlignment(char* pho, int type)
 	WcmdqInc();
 }
 
-static void DoPitch(unsigned char *env, int pitch1, int pitch2)
+static void DoPitch(const unsigned char *env, int pitch1, int pitch2)
 {
 	intptr_t *q;
 
@@ -1131,8 +1131,8 @@ int Generate(PHONEME_LIST *phoneme_list, int *n_ph, bool resume)
 	bool  pre_voiced;
 	int free_min;
 	int value;
-	unsigned char *pitch_env = NULL;
-	unsigned char *amp_env;
+	const unsigned char *pitch_env = NULL;
+	const unsigned char *amp_env;
 	PHONEME_TAB *ph;
 	int use_ipa = 0;
 	int vowelstart_prev;

src/libespeak-ng/synthesize.h

@@ -122,7 +122,7 @@ typedef struct { // 44 bytes
 } frame_t2; // without the extra Klatt parameters
 
 typedef struct {
-	unsigned char *pitch_env;
+	const unsigned char *pitch_env;
 	int pitch;      // pitch Hz*256
 	int pitch_ix;   // index into pitch envelope (*256)
 	int pitch_inc;  // increment to pitch_ix
@@ -392,12 +392,7 @@ extern int n_phoneme_list;
 extern PHONEME_LIST phoneme_list[N_PHONEME_LIST+1];
 extern unsigned int embedded_list[];
 
-extern unsigned char env_fall[128];
-extern unsigned char env_rise[128];
-extern unsigned char env_frise[128];
-
-#define MAX_PITCH_VALUE  101
-extern unsigned char pitch_adjust_tab[MAX_PITCH_VALUE+1];
+extern const unsigned char env_fall[128];
 
 // queue of commands for wavegen
 #define WCMD_KLATT  1
@@ -453,7 +448,7 @@ void DoSonicSpeed(int value);
 #define PITCHfall   0  // standard pitch envelopes
 #define PITCHrise   2
 #define N_ENVELOPE_DATA   20
-extern unsigned char *envelope_data[N_ENVELOPE_DATA];
+extern const unsigned char *envelope_data[N_ENVELOPE_DATA];
 
 extern int formant_rate[];         // max rate of change of each formant
 extern SPEED_FACTORS speed;

src/libespeak-ng/tr_languages.c

@@ -61,7 +61,7 @@
 #define OFFSET_ETHIOPIC 0x1200
 
 // character ranges must be listed in ascending unicode order
-const ALPHABET alphabets[] = {
+static const ALPHABET alphabets[] = {
 	{ "_el",    OFFSET_GREEK,    0x380, 0x3ff,  L('e', 'l'), AL_DONT_NAME | AL_NOT_LETTERS | AL_WORDS },
 	{ "_cyr",   OFFSET_CYRILLIC, 0x400, 0x52f,  0, 0 },
 	{ "_hy",    OFFSET_ARMENIAN, 0x530, 0x58f,  L('h', 'y'), AL_WORDS },
@@ -203,8 +203,8 @@ static const unsigned short chars_ignore_zwnj_hyphen[] = {
 	0,      0
 };
 
-const unsigned char utf8_ordinal[] = { 0xc2, 0xba, 0 }; // masculine ordinal character, UTF-8
-const unsigned char utf8_null[] = { 0 }; // null string, UTF-8
+static const unsigned char utf8_ordinal[] = { 0xc2, 0xba, 0 }; // masculine ordinal character, UTF-8
+static const unsigned char utf8_null[] = { 0 }; // null string, UTF-8
 
 static Translator *NewTranslator(void)
 {

src/libespeak-ng/translate.c

@@ -896,7 +896,7 @@ static int TranslateChar(Translator *tr, char *ptr, int prev_in, unsigned int c,
 	return SubstituteChar(tr, c, next_in, ptr, insert, wordflags);
 }
 
-static const char *UCase_ga[] = { "bp", "bhf", "dt", "gc", "hA", "mb", "nd", "ng", "ts", "tA", "nA", NULL };
+static const char *const UCase_ga[] = { "bp", "bhf", "dt", "gc", "hA", "mb", "nd", "ng", "ts", "tA", "nA", NULL };
 
 static int UpperCaseInWord(Translator *tr, char *word, int c)
 {
@@ -1791,4 +1791,4 @@ void InitText(int control)
 
 	if ((control & espeakKEEP_NAMEDATA) == 0)
 		InitNamedata();
-}
+}

src/libespeak-ng/translate.h

@@ -431,8 +431,8 @@ typedef struct {
 	int unstressed_wd1; // stress for $u word of 1 syllable
 	int unstressed_wd2; // stress for $u word of >1 syllable
 	int param[N_LOPTS];
-	unsigned char *length_mods;
-	unsigned char *length_mods0;
+	const unsigned char *length_mods;
+	const unsigned char *length_mods0;
 
 #define NUM_DEFAULT           0x00000001 // enable number processing; use if no other NUM_ option is specified
 #define NUM_THOUS_SPACE       0x00000004 // thousands separator must be space

src/libespeak-ng/translateword.c

@@ -772,8 +772,8 @@ static char *SpeakIndividualLetters(Translator *tr, char *word, char *phonemes,
 }
 
 
-static const char *hex_letters[] = {"'e:j",	"b'i:",	"s'i:",	"d'i:",	"'i:",	"'ef"};
-static const char *modifiers[] = { NULL, "_sub", "_sup", NULL };
+static const char *const hex_letters[] = {"'e:j",	"b'i:",	"s'i:",	"d'i:",	"'i:",	"'ef"};
+static const char *const modifiers[] = { NULL, "_sub", "_sup", NULL };
 // unicode ranges for non-ascii digits 0-9 (these must be in ascending order)
 static const int number_ranges[] = {
 	0x660, 0x6f0, // arabic
@@ -1197,4 +1197,4 @@ static int Unpronouncable2(Translator *tr, char *word)
 	if ((end_flags == 0) || (end_flags & SUFX_UNPRON))
 		return 1;
 	return 0;
-}
+}

src/libespeak-ng/voices.c

@@ -75,10 +75,10 @@ static espeak_VOICE *voices_list[N_VOICES_LIST];
 espeak_VOICE current_voice_selected;
 
 #define N_VOICE_VARIANTS   12
-const char variants_either[N_VOICE_VARIANTS] = { 1, 2, 12, 3, 13, 4, 14, 5, 11, 0 };
-const char variants_male[N_VOICE_VARIANTS] = { 1, 2, 3, 4, 5, 6, 0 };
-const char variants_female[N_VOICE_VARIANTS] = { 11, 12, 13, 14, 0 };
-const char *variant_lists[3] = { variants_either, variants_male, variants_female };
+static const char variants_either[N_VOICE_VARIANTS] = { 1, 2, 12, 3, 13, 4, 14, 5, 11, 0 };
+static const char variants_male[N_VOICE_VARIANTS] = { 1, 2, 3, 4, 5, 6, 0 };
+static const char variants_female[N_VOICE_VARIANTS] = { 11, 12, 13, 14, 0 };
+static const char *const variant_lists[3] = { variants_either, variants_male, variants_female };
 
 static voice_t voicedata;
 voice_t *voice = &voicedata;
@@ -1422,4 +1422,4 @@ static int AddToVoicesList(const char *fname, int len_path_voices, int is_langua
 			return 0;
 	}
 	return 0;
-}
+}

src/libespeak-ng/wavegen.c

@@ -124,7 +124,7 @@ static int embedded_max[N_EMBEDDED_VALUES] = { 0, 0x7fff, 750, 300, 99, 99, 99,
 
 #if HAVE_SONIC_H
 static sonicStream sonicSpeedupStream = NULL;
-double sonicSpeed = 1.0;
+static double sonicSpeed = 1.0;
 #endif
 
 // 1st index=roughness
@@ -218,7 +218,8 @@ static unsigned char wavemult[N_WAVEMULT] = {
 };
 
 // set from y = pow(2,x) * 128,  x=-1 to 1
-unsigned char pitch_adjust_tab[MAX_PITCH_VALUE+1] = {
+#define MAX_PITCH_VALUE  101
+static const unsigned char pitch_adjust_tab[MAX_PITCH_VALUE+1] = {
 	 64,  65,  66,  67,  68,  69,  70,  71,
 	 72,  73,  74,  75,  76,  77,  78,  79,
 	 80,  81,  82,  83,  84,  86,  87,  88,
@@ -278,7 +279,7 @@ static void WcmdqIncHead()
 
 #define PEAKSHAPEW 256
 
-unsigned char pk_shape1[PEAKSHAPEW+1] = {
+static const unsigned char pk_shape1[PEAKSHAPEW+1] = {
 	255, 254, 254, 254, 254, 254, 253, 253, 252, 251, 251, 250, 249, 248, 247, 246,
 	245, 244, 242, 241, 239, 238, 236, 234, 233, 231, 229, 227, 225, 223, 220, 218,
 	216, 213, 211, 209, 207, 205, 203, 201, 199, 197, 195, 193, 191, 189, 187, 185,
@@ -298,7 +299,7 @@ unsigned char pk_shape1[PEAKSHAPEW+1] = {
 	  0
 };
 
-static unsigned char pk_shape2[PEAKSHAPEW+1] = {
+static const unsigned char pk_shape2[PEAKSHAPEW+1] = {
 	255, 254, 254, 254, 254, 254, 254, 254, 254, 254, 253, 253, 253, 253, 252, 252,
 	252, 251, 251, 251, 250, 250, 249, 249, 248, 248, 247, 247, 246, 245, 245, 244,
 	243, 243, 242, 241, 239, 237, 235, 233, 231, 229, 227, 225, 223, 221, 218, 216,
@@ -318,7 +319,7 @@ static unsigned char pk_shape2[PEAKSHAPEW+1] = {
 	  0
 };
 
-static unsigned char *pk_shape;
+static const unsigned char *pk_shape;
 
 void WavegenInit(int rate, int wavemult_fact)
 {