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[PATCH v2 19/19] config.mak.dev: enable `-Wwrite-strings` warning

From
Patrick Steinhardt <ps@pks.im>
Date
May 30, 2024, 12:52 UTC
Message-ID
<9b9d57ae8432bc0f638bc784b23526d5a26627a5.1717073347.git.ps@pks.im>
In-Reply-To
<cover.1717073346.git.ps@pks.im>

Writing to string constants is undefined behaviour and must be avoided in C. Even so, the compiler does not help us with this by default because those constants are not in fact marked as `const`. This makes it rather easy to accidentally assign a constant to a non-const variable or field and then later on try to either free it or write to it.

Enable `-Wwrite-strings` to catch such mistakes. With this warning enabled, the type of string constants is changed to `const char[]` and will thus cause compiler warnings when being assigned to non-const fields and variables.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 config.mak.dev | 1 +
 1 file changed, 1 insertion(+)
diff --git a/config.mak.dev b/config.mak.dev
index 981304727c..1ce4c70613 100644
--- a/config.mak.dev
+++ b/config.mak.dev
@@ -37,6 +37,7 @@ DEVELOPER_CFLAGS += -Wpointer-arith
 DEVELOPER_CFLAGS += -Wstrict-prototypes
 DEVELOPER_CFLAGS += -Wunused
 DEVELOPER_CFLAGS += -Wvla
+DEVELOPER_CFLAGS += -Wwrite-strings
 DEVELOPER_CFLAGS += -fno-common
 
 ifneq ($(filter clang4,$(COMPILER_FEATURES)),)
-- 
2.45.1.313.g3a57aa566a.dirty
Previous: Patrick SteinhardtNext: Junio C Hamano
Message 72 of 205 in “Compile with `-Wwrite-strings`”
  1. 00/19 Compile with `-Wwrite-strings`Patrick Steinhardt, May 29, 2024
  2. 01/19 global: improve const correctness when assigning string constantsPatrick Steinhardt, May 29, 2024
  3. Junio C HamanoMay 29, 2024
  4. Patrick SteinhardtMay 30, 2024
  5. 02/19 global: assign non-const strings as requiredPatrick Steinhardt, May 29, 2024
  6. Junio C HamanoMay 29, 2024
  7. Patrick SteinhardtMay 30, 2024
  8. Junio C HamanoMay 30, 2024
  9. Patrick SteinhardtMay 31, 2024
  10. Patrick SteinhardtMay 31, 2024
  11. Junio C HamanoMay 31, 2024
  12. Junio C HamanoMay 31, 2024
  13. Jeff KingJun 5, 2024
  14. Junio C HamanoJun 5, 2024
  15. Jeff KingJun 8, 2024
  16. Patrick SteinhardtJun 6, 2024
  17. 03/19 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, May 29, 2024
  18. Junio C HamanoMay 29, 2024
  19. Patrick SteinhardtMay 30, 2024
  20. Junio C HamanoMay 30, 2024
  21. 04/19 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, May 29, 2024
  22. 05/19 reftable: improve const correctness when assigning string constantsPatrick Steinhardt, May 29, 2024
  23. Junio C HamanoMay 29, 2024
  24. Patrick SteinhardtMay 30, 2024
  25. Junio C HamanoMay 30, 2024
  26. 06/19 refspec: remove global tag refspec structurePatrick Steinhardt, May 29, 2024
  27. Junio C HamanoMay 29, 2024
  28. 07/19 http: do not assign string constant to non-const fieldPatrick Steinhardt, May 29, 2024
  29. Junio C HamanoMay 29, 2024
  30. 08/19 line-log: always allocate the output prefixPatrick Steinhardt, May 29, 2024
  31. Junio C HamanoMay 29, 2024
  32. 09/19 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, May 29, 2024
  33. Junio C HamanoMay 29, 2024
  34. 10/19 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, May 29, 2024
  35. 11/19 send-pack: always allocate receive statusPatrick Steinhardt, May 29, 2024
  36. 12/19 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, May 29, 2024
  37. Junio C HamanoMay 29, 2024
  38. Patrick SteinhardtMay 30, 2024
  39. 13/19 revision: always store allocated strings in output encodingPatrick Steinhardt, May 29, 2024
  40. Junio C HamanoMay 29, 2024
  41. 14/19 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, May 29, 2024
  42. 15/19 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, May 29, 2024
  43. 16/19 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, May 29, 2024
  44. Junio C HamanoMay 29, 2024
  45. Patrick SteinhardtMay 30, 2024
  46. Junio C HamanoMay 30, 2024
  47. 17/19 builtin/rebase: adapt code to not assign string constants to non-constPatrick Steinhardt, May 29, 2024
  48. Junio C HamanoMay 29, 2024
  49. Patrick SteinhardtMay 30, 2024
  50. 18/19 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, May 29, 2024
  51. 19/19 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, May 29, 2024
  52. Patrick SteinhardtMay 29, 2024
  53. 00/19 Compile with `-Wwrite-strings`Patrick Steinhardt, May 30, 2024
  54. 01/19 global: improve const correctness when assigning string constantsPatrick Steinhardt, May 30, 2024
  55. 02/19 global: assign non-const strings as requiredPatrick Steinhardt, May 30, 2024
  56. 03/19 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, May 30, 2024
  57. 04/19 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, May 30, 2024
  58. 05/19 refspec: remove global tag refspec structurePatrick Steinhardt, May 30, 2024
  59. 06/19 http: do not assign string constant to non-const fieldPatrick Steinhardt, May 30, 2024
  60. 07/19 line-log: always allocate the output prefixPatrick Steinhardt, May 30, 2024
  61. 08/19 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, May 30, 2024
  62. 09/19 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, May 30, 2024
  63. 10/19 send-pack: always allocate receive statusPatrick Steinhardt, May 30, 2024
  64. 11/19 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, May 30, 2024
  65. 12/19 revision: always store allocated strings in output encodingPatrick Steinhardt, May 30, 2024
  66. 13/19 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, May 30, 2024
  67. 14/19 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, May 30, 2024
  68. 15/19 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, May 30, 2024
  69. 16/19 builtin/rebase: do not assign default backend to non-constant fieldPatrick Steinhardt, May 30, 2024
  70. 17/19 builtin/rebase: always store allocated string in `options.strategy`Patrick Steinhardt, May 30, 2024
  71. 18/19 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, May 30, 2024
  72. 19/19 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, May 30, 2024
  73. Junio C HamanoMay 31, 2024
  74. Patrick SteinhardtMay 31, 2024
  75. 00/27 Compile with `-Wwrite-strings`Patrick Steinhardt, Jun 3, 2024
  76. 01/27 global: improve const correctness when assigning string constantsPatrick Steinhardt, Jun 3, 2024
  77. 02/27 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, Jun 3, 2024
  78. 03/27 refs/reftable: stop micro-optimizing refname allocations on copyPatrick Steinhardt, Jun 3, 2024
  79. Junio C HamanoJun 3, 2024
  80. 04/27 reftable: cast away constness when assigning constants to recordsPatrick Steinhardt, Jun 3, 2024
  81. 05/27 refspec: remove global tag refspec structurePatrick Steinhardt, Jun 3, 2024
  82. Junio C HamanoJun 3, 2024
  83. 06/27 builtin/remote: cast away constness in `get_head_names()`Patrick Steinhardt, Jun 3, 2024
  84. 07/27 diff: cast string constant in `fill_textconv()`Patrick Steinhardt, Jun 3, 2024
  85. 08/27 line-log: stop assigning string constant to file parent bufferPatrick Steinhardt, Jun 3, 2024
  86. 09/27 line-log: always allocate the output prefixPatrick Steinhardt, Jun 3, 2024
  87. 10/27 entry: refactor how we remove items for delayed checkoutsPatrick Steinhardt, Jun 3, 2024
  88. 11/27 ident: add casts for fallback name and GECOSPatrick Steinhardt, Jun 3, 2024
  89. 12/27 object-file: mark cached object buffers as constPatrick Steinhardt, Jun 3, 2024
  90. 13/27 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, Jun 3, 2024
  91. 14/27 pretty: add casts for decoration option pointersPatrick Steinhardt, Jun 3, 2024
  92. 15/27 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, Jun 3, 2024
  93. Eric SunshineJun 3, 2024
  94. Junio C HamanoJun 3, 2024
  95. Patrick SteinhardtJun 4, 2024
  96. 16/27 http: do not assign string constant to non-const fieldPatrick Steinhardt, Jun 3, 2024
  97. 17/27 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, Jun 3, 2024
  98. 18/27 send-pack: always allocate receive statusPatrick Steinhardt, Jun 3, 2024
  99. 19/27 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, Jun 3, 2024
  100. 20/27 revision: always store allocated strings in output encodingPatrick Steinhardt, Jun 3, 2024
  101. 21/27 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, Jun 3, 2024
  102. 22/27 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, Jun 3, 2024
  103. 23/27 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, Jun 3, 2024
  104. 24/27 builtin/rebase: do not assign default backend to non-constant fieldPatrick Steinhardt, Jun 3, 2024
  105. 25/27 builtin/rebase: always store allocated string in `options.strategy`Patrick Steinhardt, Jun 3, 2024
  106. 26/27 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, Jun 3, 2024
  107. 27/27 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, Jun 3, 2024
  108. Junio C HamanoJun 3, 2024
  109. 00/27 Compile with `-Wwrite-strings`Patrick Steinhardt, Jun 4, 2024
  110. 01/27 global: improve const correctness when assigning string constantsPatrick Steinhardt, Jun 4, 2024
  111. 02/27 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, Jun 4, 2024
  112. 03/27 refs/reftable: stop micro-optimizing refname allocations on copyPatrick Steinhardt, Jun 4, 2024
  113. 04/27 reftable: cast away constness when assigning constants to recordsPatrick Steinhardt, Jun 4, 2024
  114. 05/27 refspec: remove global tag refspec structurePatrick Steinhardt, Jun 4, 2024
  115. 06/27 builtin/remote: cast away constness in `get_head_names()`Patrick Steinhardt, Jun 4, 2024
  116. 07/27 diff: cast string constant in `fill_textconv()`Patrick Steinhardt, Jun 4, 2024
  117. 08/27 line-log: stop assigning string constant to file parent bufferPatrick Steinhardt, Jun 4, 2024
  118. 09/27 line-log: always allocate the output prefixPatrick Steinhardt, Jun 4, 2024
  119. 10/27 entry: refactor how we remove items for delayed checkoutsPatrick Steinhardt, Jun 4, 2024
  120. 11/27 ident: add casts for fallback name and GECOSPatrick Steinhardt, Jun 4, 2024
  121. 12/27 object-file: mark cached object buffers as constPatrick Steinhardt, Jun 4, 2024
  122. Junio C HamanoJun 6, 2024
  123. Junio C HamanoJun 6, 2024
  124. Patrick SteinhardtJun 6, 2024
  125. Junio C HamanoJun 6, 2024
  126. Patrick SteinhardtJun 7, 2024
  127. 13/27 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, Jun 4, 2024
  128. 14/27 pretty: add casts for decoration option pointersPatrick Steinhardt, Jun 4, 2024
  129. 15/27 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, Jun 4, 2024
  130. 16/27 http: do not assign string constant to non-const fieldPatrick Steinhardt, Jun 4, 2024
  131. 17/27 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, Jun 4, 2024
  132. 18/27 send-pack: always allocate receive statusPatrick Steinhardt, Jun 4, 2024
  133. 19/27 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, Jun 4, 2024
  134. 20/27 revision: always store allocated strings in output encodingPatrick Steinhardt, Jun 4, 2024
  135. 21/27 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, Jun 4, 2024
  136. 22/27 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, Jun 4, 2024
  137. 23/27 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, Jun 4, 2024
  138. 24/27 builtin/rebase: do not assign default backend to non-constant fieldPatrick Steinhardt, Jun 4, 2024
  139. Phillip WoodJun 4, 2024
  140. Patrick SteinhardtJun 5, 2024
  141. Phillip WoodJun 5, 2024
  142. Patrick SteinhardtJun 6, 2024
  143. Junio C HamanoJun 5, 2024
  144. 25/27 builtin/rebase: always store allocated string in `options.strategy`Patrick Steinhardt, Jun 4, 2024
  145. Phillip WoodJun 4, 2024
  146. 26/27 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, Jun 4, 2024
  147. 27/27 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, Jun 4, 2024
  148. 00/27 Compile with `-Wwrite-strings`Patrick Steinhardt, Jun 6, 2024
  149. 01/27 global: improve const correctness when assigning string constantsPatrick Steinhardt, Jun 6, 2024
  150. 02/27 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, Jun 6, 2024
  151. 03/27 refs/reftable: stop micro-optimizing refname allocations on copyPatrick Steinhardt, Jun 6, 2024
  152. 04/27 reftable: cast away constness when assigning constants to recordsPatrick Steinhardt, Jun 6, 2024
  153. 05/27 refspec: remove global tag refspec structurePatrick Steinhardt, Jun 6, 2024
  154. 06/27 builtin/remote: cast away constness in `get_head_names()`Patrick Steinhardt, Jun 6, 2024
  155. 07/27 diff: cast string constant in `fill_textconv()`Patrick Steinhardt, Jun 6, 2024
  156. 08/27 line-log: stop assigning string constant to file parent bufferPatrick Steinhardt, Jun 6, 2024
  157. 09/27 line-log: always allocate the output prefixPatrick Steinhardt, Jun 6, 2024
  158. 10/27 entry: refactor how we remove items for delayed checkoutsPatrick Steinhardt, Jun 6, 2024
  159. 11/27 ident: add casts for fallback name and GECOSPatrick Steinhardt, Jun 6, 2024
  160. 12/27 object-file: mark cached object buffers as constPatrick Steinhardt, Jun 6, 2024
  161. Junio C HamanoJun 6, 2024
  162. 13/27 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, Jun 6, 2024
  163. 14/27 pretty: add casts for decoration option pointersPatrick Steinhardt, Jun 6, 2024
  164. 15/27 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, Jun 6, 2024
  165. 16/27 http: do not assign string constant to non-const fieldPatrick Steinhardt, Jun 6, 2024
  166. 17/27 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, Jun 6, 2024
  167. 18/27 send-pack: always allocate receive statusPatrick Steinhardt, Jun 6, 2024
  168. 19/27 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, Jun 6, 2024
  169. 20/27 revision: always store allocated strings in output encodingPatrick Steinhardt, Jun 6, 2024
  170. 21/27 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, Jun 6, 2024
  171. 22/27 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, Jun 6, 2024
  172. 23/27 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, Jun 6, 2024
  173. 24/27 builtin/rebase: do not assign default backend to non-constant fieldPatrick Steinhardt, Jun 6, 2024
  174. 25/27 builtin/rebase: always store allocated string in `options.strategy`Patrick Steinhardt, Jun 6, 2024
  175. 26/27 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, Jun 6, 2024
  176. 27/27 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, Jun 6, 2024
  177. 00/27 Compile with `-Wwrite-strings`Patrick Steinhardt, Jun 7, 2024
  178. 01/27 global: improve const correctness when assigning string constantsPatrick Steinhardt, Jun 7, 2024
  179. 02/27 global: convert intentionally-leaking config strings to constsPatrick Steinhardt, Jun 7, 2024
  180. 03/27 refs/reftable: stop micro-optimizing refname allocations on copyPatrick Steinhardt, Jun 7, 2024
  181. 04/27 reftable: cast away constness when assigning constants to recordsPatrick Steinhardt, Jun 7, 2024
  182. 05/27 refspec: remove global tag refspec structurePatrick Steinhardt, Jun 7, 2024
  183. 06/27 builtin/remote: cast away constness in `get_head_names()`Patrick Steinhardt, Jun 7, 2024
  184. 07/27 diff: cast string constant in `fill_textconv()`Patrick Steinhardt, Jun 7, 2024
  185. 08/27 line-log: stop assigning string constant to file parent bufferPatrick Steinhardt, Jun 7, 2024
  186. 09/27 line-log: always allocate the output prefixPatrick Steinhardt, Jun 7, 2024
  187. 10/27 entry: refactor how we remove items for delayed checkoutsPatrick Steinhardt, Jun 7, 2024
  188. 11/27 ident: add casts for fallback name and GECOSPatrick Steinhardt, Jun 7, 2024
  189. 12/27 object-file: mark cached object buffers as constPatrick Steinhardt, Jun 7, 2024
  190. 13/27 object-file: make `buf` parameter of `index_mem()` a constantPatrick Steinhardt, Jun 7, 2024
  191. 14/27 pretty: add casts for decoration option pointersPatrick Steinhardt, Jun 7, 2024
  192. 15/27 compat/win32: fix const-correctness with string constantsPatrick Steinhardt, Jun 7, 2024
  193. 16/27 http: do not assign string constant to non-const fieldPatrick Steinhardt, Jun 7, 2024
  194. 17/27 parse-options: cast long name for OPTION_ALIASPatrick Steinhardt, Jun 7, 2024
  195. 18/27 send-pack: always allocate receive statusPatrick Steinhardt, Jun 7, 2024
  196. 19/27 remote-curl: avoid assigning string constant to non-const variablePatrick Steinhardt, Jun 7, 2024
  197. 20/27 revision: always store allocated strings in output encodingPatrick Steinhardt, Jun 7, 2024
  198. 21/27 mailmap: always store allocated strings in mailmap blobPatrick Steinhardt, Jun 7, 2024
  199. 22/27 imap-send: drop global `imap_server_conf` variablePatrick Steinhardt, Jun 7, 2024
  200. 23/27 imap-send: fix leaking memory in `imap_server_conf`Patrick Steinhardt, Jun 7, 2024
  201. 24/27 builtin/rebase: do not assign default backend to non-constant fieldPatrick Steinhardt, Jun 7, 2024
  202. 25/27 builtin/rebase: always store allocated string in `options.strategy`Patrick Steinhardt, Jun 7, 2024
  203. 26/27 builtin/merge: always store allocated strings in `pull_twohead`Patrick Steinhardt, Jun 7, 2024
  204. 27/27 config.mak.dev: enable `-Wwrite-strings` warningPatrick Steinhardt, Jun 7, 2024
  205. Junio C HamanoJun 7, 2024

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