Do not reuse temp registers originally allocated to a subroutine within

the main body of the program logic, since if the subroutine is called
while the reused temp registers are in use, their values will get clobbered.
Candidate fix for ticket [3a77c9714e63330]

FossilOrigin-Name: 092d53315e50be42b51ef7b3069c82c32a129b6a

diff --git a/manifest b/manifest
index ef618fe69b2be6bbb47675a2bce05865d45e5622..5fc0d1a87757a9902033e9b3e2113a09bcb155aa 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\sthe\swinGetLastError\sfixes\sinto\strunk.
-D 2011-12-06T00:47:51.936
+C Do\snot\sreuse\stemp\sregisters\soriginally\sallocated\sto\sa\ssubroutine\swithin\nthe\smain\sbody\sof\sthe\sprogram\slogic,\ssince\sif\sthe\ssubroutine\sis\scalled\nwhile\sthe\sreused\stemp\sregisters\sare\sin\suse,\stheir\svalues\swill\sget\sclobbered.\nCandidate\sfix\sfor\sticket\s[3a77c9714e63330]
+D 2011-12-06T13:24:59.067
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5b4a3e12a850b021547e43daf886b25133b44c07
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -134,7 +134,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c a9c26822515f81ec21588cbb482ca6724be02e33
 F src/date.c 067a81c9942c497aafd2c260e13add8a7d0c7dd4
 F src/delete.c 51d32f0a9c880663e54ce309f52e40c325d5e112
-F src/expr.c fbf116f90cabc917ae50bba24a73a0b55519a0c8
+F src/expr.c 319db0ad9f3c5d039d54bf5a65c98c08c7233924
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 657212460bf5cfd3ae607d12ea62092844c227b5
 F src/func.c 6261ce00aad9c63cd5b4219249b05683979060e9
@@ -180,11 +180,11 @@ F src/printf.c 03104cbff6959ff45df69dc9060ba6212f60a869
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
 F src/resolve.c 365ab1c870e38596d6869e76fb544fe6e4ffc809
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
-F src/select.c 80f3ac44a8514b1d107b80f5df4a424ae059d2b6
+F src/select.c 538b5f096f6aacedf717bf982f9ad9a901008514
 F src/shell.c 29812a900a780eb0f835c4bc65e216272689def8
 F src/sqlite.h.in 57081d8e6b53ce29541d7437c93bce6087ac53b5
 F src/sqlite3ext.h 6904f4aadf976f95241311fbffb00823075d9477
-F src/sqliteInt.h 6f28b69d77356b1e45c024a6c103a1e0f0ec9f62
+F src/sqliteInt.h 142ef5ed3fe0e6c662e99dbf92f38715b29a53b6
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 4568e72dfd36b6a5911f93457364deb072e0b03a
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -976,7 +976,7 @@ F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings-clang.sh 9f406d66e750e8ac031c63a9ef3248aaa347ef2a
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
-P 431556cac0b2c86d7f6a60412ff1023feeaafedf 7e657bbb800107c992a6ee7a3b35bc0a073bf3e4
-R 543654dfa3532b18db5b62d6f330a3c2
+P 5b03ba9db0d23a8597b45e00ad5892c8065ce1cd
+R 9fd2e18e31f5993e2a2417d0bd31fbb8
 U drh
-Z d9a349b5feef66c92d693305f283c870
+Z 6b588a9e7cf08c9f198f7cca1fb8c358

diff --git a/manifest.uuid b/manifest.uuid
index fb1da873595aef24e257af3ecb6c9e09312f7438..0f043b6cf3c2cf008a8e0606a8891451bd3f6216 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5b03ba9db0d23a8597b45e00ad5892c8065ce1cd
\ No newline at end of file
+092d53315e50be42b51ef7b3069c82c32a129b6a
\ No newline at end of file

diff --git a/src/expr.c b/src/expr.c
index d5061737718d4ad66475cb841910c4db5c6a161c..e8a9d641080eabb9456f7a1a6807179336518dd6 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -3762,3 +3762,11 @@ void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
     pParse->iRangeReg = iReg;
   }
 }
+
+/*
+** Mark all temporary registers as being unavailable for reuse.
+*/
+void sqlite3ClearTempRegCache(Parse *pParse){
+  pParse->nTempReg = 0;
+  pParse->nRangeReg = 0;
+}

diff --git a/src/select.c b/src/select.c
index 571a77822b66984d12f765fec9e3a38c90cb6c9b..da75a51cd9add885ab747f5e10f9a673e5f87120 100644 (file)
--- a/src/select.c
+++ b/src/select.c
@@ -3860,7 +3860,7 @@ int sqlite3Select(
       retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
       VdbeComment((v, "end %s", pItem->pTab->zName));
       sqlite3VdbeChangeP1(v, topAddr, retAddr);
-
+      sqlite3ClearTempRegCache(pParse);
     }
     if( /*pParse->nErr ||*/ db->mallocFailed ){
       goto select_end;

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 4e00ad03c1bf6b557917173aaacf1fa35b871c76..890f44f5e10118c2189baf3fe932d4a09c7a3f08 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2660,6 +2660,7 @@ int sqlite3GetTempReg(Parse*);
 void sqlite3ReleaseTempReg(Parse*,int);
 int sqlite3GetTempRange(Parse*,int);
 void sqlite3ReleaseTempRange(Parse*,int,int);
+void sqlite3ClearTempRegCache(Parse*);
 Expr *sqlite3ExprAlloc(sqlite3*,int,const Token*,int);
 Expr *sqlite3Expr(sqlite3*,int,const char*);
 void sqlite3ExprAttachSubtrees(sqlite3*,Expr*,Expr*,Expr*);