move VP8GetCPUInfo declaration to cpu.c

This avoids defining a version in each translation unit when using
__declspec(dllexport) which causes failures due to multiply defined
symbols with clang-cl:

lld-link: error: duplicate symbol: VP8GetCPUInfo
>>> defined at CMakeFiles\webpdecode.dir\Debug\src\dec\alpha_dec.c.obj
>>> defined at CMakeFiles\webpdsp.dir\Debug\src\dsp\dec_sse41.c.obj
...

Bug: webp:607
Change-Id: I6cd1ee75b3db984aa513263a05516e867a64925d

sharpyuv/sharpyuv.c

@@ -440,6 +440,7 @@ static int DoSharpArgbToYuv(const uint8_t* r_ptr, const uint8_t* g_ptr,
 // By default SharpYuvConvert calls it with SharpYuvGetCPUInfo. If needed,
 // users can declare it as extern and call it with an alternate VP8CPUInfo
 // function.
+extern VP8CPUInfo SharpYuvGetCPUInfo;
 SHARPYUV_EXTERN void SharpYuvInit(VP8CPUInfo cpu_info_func);
 void SharpYuvInit(VP8CPUInfo cpu_info_func) {
   static volatile VP8CPUInfo sharpyuv_last_cpuinfo_used =

sharpyuv/sharpyuv_dsp.c

@@ -72,6 +72,7 @@ void (*SharpYuvFilterRow)(const int16_t* A, const int16_t* B, int len,
                           const uint16_t* best_y, uint16_t* out,
                           int bit_depth);
 
+extern VP8CPUInfo SharpYuvGetCPUInfo;
 extern void InitSharpYuvSSE2(void);
 extern void InitSharpYuvNEON(void);
 

src/dec/vp8_dec.c

@@ -494,6 +494,8 @@ static int GetCoeffsAlt(VP8BitReader* const br,
   return 16;
 }
 
+extern VP8CPUInfo VP8GetCPUInfo;
+
 WEBP_DSP_INIT_FUNC(InitGetCoeffs) {
   if (VP8GetCPUInfo != NULL && VP8GetCPUInfo(kSlowSSSE3)) {
     GetCoeffs = GetCoeffsAlt;

src/dsp/alpha_processing.c

@@ -425,6 +425,7 @@ void (*WebPAlphaReplace)(uint32_t* src, int length, uint32_t color);
 //------------------------------------------------------------------------------
 // Init function
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void WebPInitAlphaProcessingMIPSdspR2(void);
 extern void WebPInitAlphaProcessingSSE2(void);
 extern void WebPInitAlphaProcessingSSE41(void);

src/dsp/cost.c

@@ -374,6 +374,7 @@ static void SetResidualCoeffs_C(const int16_t* const coeffs,
 VP8GetResidualCostFunc VP8GetResidualCost;
 VP8SetResidualCoeffsFunc VP8SetResidualCoeffs;
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8EncDspCostInitMIPS32(void);
 extern void VP8EncDspCostInitMIPSdspR2(void);
 extern void VP8EncDspCostInitSSE2(void);

src/dsp/cpu.c

@@ -173,6 +173,7 @@ static int x86CPUInfo(CPUFeature feature) {
   }
   return 0;
 }
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = x86CPUInfo;
 #elif defined(WEBP_ANDROID_NEON)  // NB: needs to be before generic NEON test.
 static int AndroidCPUInfo(CPUFeature feature) {
@@ -184,6 +185,7 @@ static int AndroidCPUInfo(CPUFeature feature) {
   }
   return 0;
 }
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = AndroidCPUInfo;
 #elif defined(EMSCRIPTEN) // also needs to be before generic NEON test
 // Use compile flags as an indicator of SIMD support instead of a runtime check.
@@ -208,6 +210,7 @@ static int wasmCPUInfo(CPUFeature feature) {
   }
   return 0;
 }
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = wasmCPUInfo;
 #elif defined(WEBP_HAVE_NEON)
 // In most cases this function doesn't check for NEON support (it's assumed by
@@ -236,6 +239,7 @@ static int armCPUInfo(CPUFeature feature) {
   return 1;
 #endif
 }
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = armCPUInfo;
 #elif defined(WEBP_USE_MIPS32) || defined(WEBP_USE_MIPS_DSP_R2) || \
       defined(WEBP_USE_MSA)
@@ -247,7 +251,9 @@ static int mipsCPUInfo(CPUFeature feature) {
   }
 
 }
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = mipsCPUInfo;
 #else
+WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
 VP8CPUInfo VP8GetCPUInfo = NULL;
 #endif

src/dsp/cpu.h

@@ -242,16 +242,7 @@ typedef enum {
   kMSA
 } CPUFeature;
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 // returns true if the CPU supports the feature.
 typedef int (*VP8CPUInfo)(CPUFeature feature);
-WEBP_EXTERN VP8CPUInfo VP8GetCPUInfo;
-
-#ifdef __cplusplus
-}    // extern "C"
-#endif
 
 #endif  // WEBP_DSP_CPU_H_

src/dsp/dec.c

@@ -734,6 +734,7 @@ VP8SimpleFilterFunc VP8SimpleHFilter16i;
 void (*VP8DitherCombine8x8)(const uint8_t* dither, uint8_t* dst,
                             int dst_stride);
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8DspInitSSE2(void);
 extern void VP8DspInitSSE41(void);
 extern void VP8DspInitNEON(void);

src/dsp/enc.c

@@ -732,6 +732,7 @@ VP8QuantizeBlockWHT VP8EncQuantizeBlockWHT;
 VP8BlockCopy VP8Copy4x4;
 VP8BlockCopy VP8Copy16x8;
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8EncDspInitSSE2(void);
 extern void VP8EncDspInitSSE41(void);
 extern void VP8EncDspInitNEON(void);

src/dsp/filters.c

@@ -233,6 +233,7 @@ static void GradientUnfilter_C(const uint8_t* prev, const uint8_t* in,
 WebPFilterFunc WebPFilters[WEBP_FILTER_LAST];
 WebPUnfilterFunc WebPUnfilters[WEBP_FILTER_LAST];
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8FiltersInitMIPSdspR2(void);
 extern void VP8FiltersInitMSA(void);
 extern void VP8FiltersInitNEON(void);

src/dsp/lossless.c

@@ -588,6 +588,7 @@ VP8LConvertFunc VP8LConvertBGRAToBGR;
 VP8LMapARGBFunc VP8LMapColor32b;
 VP8LMapAlphaFunc VP8LMapColor8b;
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8LDspInitSSE2(void);
 extern void VP8LDspInitSSE41(void);
 extern void VP8LDspInitNEON(void);

src/dsp/lossless_enc.c

@@ -791,6 +791,7 @@ VP8LBundleColorMapFunc VP8LBundleColorMap;
 VP8LPredictorAddSubFunc VP8LPredictorsSub[16];
 VP8LPredictorAddSubFunc VP8LPredictorsSub_C[16];
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8LEncDspInitSSE2(void);
 extern void VP8LEncDspInitSSE41(void);
 extern void VP8LEncDspInitNEON(void);

src/dsp/rescaler.c

@@ -197,6 +197,7 @@ WebPRescalerImportRowFunc WebPRescalerImportRowShrink;
 WebPRescalerExportRowFunc WebPRescalerExportRowExpand;
 WebPRescalerExportRowFunc WebPRescalerExportRowShrink;
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void WebPRescalerDspInitSSE2(void);
 extern void WebPRescalerDspInitMIPS32(void);
 extern void WebPRescalerDspInitMIPSdspR2(void);

src/dsp/ssim.c

@@ -137,6 +137,7 @@ VP8SSIMGetClippedFunc VP8SSIMGetClipped;
 VP8AccumulateSSEFunc VP8AccumulateSSE;
 #endif
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void VP8SSIMDspInitSSE2(void);
 
 WEBP_DSP_INIT_FUNC(VP8SSIMDspInit) {

src/dsp/upsampling.c

@@ -215,6 +215,7 @@ static void EmptyYuv444Func(const uint8_t* y,
 
 WebPYUV444Converter WebPYUV444Converters[MODE_LAST];
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void WebPInitYUV444ConvertersMIPSdspR2(void);
 extern void WebPInitYUV444ConvertersSSE2(void);
 extern void WebPInitYUV444ConvertersSSE41(void);

src/dsp/yuv.c

@@ -70,6 +70,7 @@ void WebPSamplerProcessPlane(const uint8_t* y, int y_stride,
 
 WebPSamplerRowFunc WebPSamplers[MODE_LAST];
 
+extern VP8CPUInfo VP8GetCPUInfo;
 extern void WebPInitSamplersSSE2(void);
 extern void WebPInitSamplersSSE41(void);
 extern void WebPInitSamplersMIPS32(void);

src/enc/picture_csp_enc.c

@@ -98,6 +98,7 @@ static int kLinearToGammaTab[GAMMA_TAB_SIZE + 1];
 static uint16_t kGammaToLinearTab[256];
 static volatile int kGammaTablesOk = 0;
 static void InitGammaTables(void);
+extern VP8CPUInfo VP8GetCPUInfo;
 
 WEBP_DSP_INIT_FUNC(InitGammaTables) {
   if (!kGammaTablesOk) {

tests/fuzzer/fuzz_utils.h

@@ -74,6 +74,11 @@ static WEBP_INLINE uint32_t Extract(uint32_t max_value,
 //------------------------------------------------------------------------------
 // Some functions to override VP8GetCPUInfo and disable some optimizations.
 
+#ifdef __cplusplus
+extern "C" VP8CPUInfo VP8GetCPUInfo;
+#else
+extern VP8CPUInfo VP8GetCPUInfo;
+#endif
 static VP8CPUInfo GetCPUInfo;
 
 static WEBP_INLINE int GetCPUInfoNoSSE41(CPUFeature feature) {