Estádio da Luz do not host music concerts or events like this, it wasn't conceived with that purpose. On the other hand, Estádio de Alvalade XXI (like its predecessor) was (U2 played there in 2005).
In Barcelona, if performing in a stadium, it would certainly be Camp Nou, not a Estadi Olimpic...
There have been many concerts at the Olympic Stadium in Barcelona, including U2 in 1997. Camp Nou is bigger, so it would probably be U2's choice in the future. Wikipedia says;
Concerts[edit]
1990 (June 13 and 14): Concerts by The Rolling Stones in the framework of their Urban Jungle Tour
1990 (July 25): Concert by Prince in the framework of his Nude Tour, before some 30,000 spectators
1990 (August 1): Concert by Madonna in the framework of her Blond Ambition Tour before more than 60,000
1990 (September 16): Concert by David Bowie, as part of his Sound + Vision Tour before some 30,000 spectators
1990 (October 6 and 7): Concert by Tina Turner, performed on two nights as part of her Foreign Affair Tour
1991 (September 24): Concerts by AC/DC, Metallica, Tesla and Legion in the framework of the Monsters of Rock festival, before some 45,000 spectators
1992 (September 18): Concert by Michael Jackson in the framework of his Dangerous Tour in front of 65,000 spectators
1993 (May 11): Concert by Bruce Springsteen as part of the Human Touch World Tour
1993 (July 5): Concert by Guns N' Roses
1993 (October 6): Concert by Jean Michel Jarre
1995 (June 13): Concert by Bon Jovi with The Pretenders and Van Halen in front of 30,000 people
1997 (September 13): Concert U2 during their Pop Mart tour
1998 (July 20): Concert by The Rolling Stones during their Bridges to Babylon Tour
2003 (May 17): Concert by Bruce Springsteen as part of the The Rising Tour
2003 (June 29): Concert by The Rolling Stones as part of the Licks Tour. The Pretenders acted as openers, 50,000 people attended
2007 (June 21): Concert by The Rolling Stones during their A Bigger Bang Tour" (after cancelling a show the previous year) to 50,000
2007 (June 30): Concert by Mexican pop group RBD during their Tour Celestial to more than 57,000 people
2007 (September 27): Concert by The Police during their Police Reunion Tour before 55,000 spectators
2008 (June 1): Concert by Bon Jovi as part of their Lost Highway Tour to more than 45,000 people
2009 (June 7): Concert by AC/DC, during their Black Ice Tour before some 62,000 spectators[5]
2009 (July 21): Concert by Madonna during the second leg of her Sticky & Sweet Tour to more than 45,000 spectators[6]
2009 (September 4): Concert by Coldplay on their Viva la Vida Tour to more than 63,000 spectators
2009 (December 3): Concert by The Prodigy, promoting their latest studio album Invaders Must Die
2009 (December 4): Concert by Marilyn Manson, presenting his album The High End of Low
2011 (May 29): Concert by Shakira during her The Sun Comes Out World Tour
2011 (July 27): Concert by Bon Jovi as part of their Greatest Hits Tour in front of a crowd of 40000
2012 (May 17 and May 18): Concert by Bruce Springsteen as part of his "WRECKING BALL" World Tour.
2013 (June 7) : Concert by Muse as part of their The 2nd Law World Tour
2014 (July 8) : Concert by One Direction as part of their Where We Are Stadium Tour