luo980/miniz
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Update miniz_tdef.c to enable compiling in forced-C++ mode

Browse Source 
Summary:
Merged definition of static const mz_uint s_tdefl_num_probes[11] with its declaration to avoid compilation error when compiling in forced-C++mode

Details:
When miniz_tdef.c is compiled in C++ mode (either by forcing the compiler to treat the input as C++ or by renaming the file into miniz.cpp), MSVC17 produces the following error:
```
miniz_tdef.cpp(2113,22): error C2086: 'const mz_uint s_tdefl_num_probes[11]': redefinition
miniz_tdef.cpp(1254,22): message : see declaration of 's_tdefl_num_probes'
```
This happens because in miniz_tdef.c we have the following:

```
/*Line 606:*/ static const mz_uint s_tdefl_num_probes[11];
/*Line 1465:*/ static const mz_uint s_tdefl_num_probes[11] = { 0, 1, 6, 32, 16, 32, 128, 256, 512, 768, 1500 };
```
While miniz_tdef.c is a C source file and not C++, sometimes it is used in C++ projects where settings are such that mixed C/C++ compilation is not allowed and all input source files are treated as forced C++. So there would be no harm to make a small adjustment so that the source code is conformant with both C and C++ requirements.

There are two ways it can be done:
Option 1: change line 606 from `static const mz_uint s_tdefl_num_probes[11];` to `extern const mz_uint s_tdefl_num_probes[11];`
Option2: eliminate line 1465 entirely and move line 2113 into line 1254 so that the code looks like this:
```
/*Line 606:*/ static const mz_uint s_tdefl_num_probes[11] = { 0, 1, 6, 32, 16, 32, 128, 256, 512, 768, 1500 };
/*Line 1465:*/ //Nothing here
```
Either option works for both C and C++ and really there is no harm in simply moving the full definition up like in option B and avoid duplication.

This change implements option B.
This commit is contained in:
Nyq 2023-08-15 04:50:07 -04:00 committed by GitHub
parent 9ae305f6e1
commit b0af33a61b
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 1 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
miniz_tdef.c
View File

@ -603,7 +603,7 @@ static mz_bool tdefl_compress_block(tdefl_compressor *d, mz_bool static_block)
return tdefl_compress_lz_codes(d);
}
static const mz_uint s_tdefl_num_probes[11];
static const mz_uint s_tdefl_num_probes[11] = { 0, 1, 6, 32, 16, 32, 128, 256, 512, 768, 1500 };
static int tdefl_flush_block(tdefl_compressor *d, int flush)
{
@ -1462,8 +1462,6 @@ size_t tdefl_compress_mem_to_mem(void *pOut_buf, size_t out_buf_len, const void
return out_buf.m_size;
}
static const mz_uint s_tdefl_num_probes[11] = { 0, 1, 6, 32, 16, 32, 128, 256, 512, 768, 1500 };
/* level may actually range from [0,10] (10 is a "hidden" max level, where we want a bit more compression and it's fine if throughput to fall off a cliff on some files). */
mz_uint tdefl_create_comp_flags_from_zip_params(int level, int window_bits, int strategy)
{